Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contam...Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in Egypt.The aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these compounds.Surface seven sediment samples were collected from various drains in the southern part of Burullus Lake.Soxhlet extraction method was employed to extract PAHs(16PAHs)from the sediment sample.Analytically,target compounds were located using HPLC.The results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the European standard for PAHs pollution.Additionally,there was no apparent source of PAHs in the ElKhashah drain or the Brinbal Canal,as HPLC found none of the compounds.The most prevalent compound in sediment samples along the study area was fluoranthene.The diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus Lake.The principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface sediments.The non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was calculated.HI values under 1,therefore,demonstrated that they had no carcinogenic effects on human health.TEQs and MEQs in the sediments of Burullus Lake do not have a cancer-causing impact on people.For the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and controlled.According to the ecological risk assessment,there is little chance that PAHs will be found in the sediments of Burullus Lake.This study underscores the urgent need for effective pollution control measures and regular monitoring of PAHs levels in Burullus Lake sediments to protect the aquatic ecosystem and public health.It also highlights the importance of considering eco-toxicity and human health risks in integrated risk assessments of PAHs-contaminated environments.展开更多
Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of...Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of Cd stress in sustainable and environmentally friendly way,a pot study was designed by using exogenous application of various biostimulants,i.e.,Nigella sativa and Ocimum sanctum extracts:0%,10%,and 20%in combination with the chelating agent ethylenediaminetetraacetic acid(EDTA)using 0 and 5 mg kg^(-1) under various levels of Cd stress(i.e.,0,5,10,and 15 mg kg^(-1) soil).Results revealed that Cd stress significantly reduced the seed emergence,growth,root,and allometric characters and yield-related parameters of wheat crops.The most observable reduc-tion was documented in wheat plants exposed to a higher Cd concentration(15 mg kg^(-1)),followed by the lower Cd level(control).The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress.The highest increase in seedling emergence(5.44%),leaf area(50.60%),number of tillers(31.02%),grain yield per plant(24.28%),biological yield(13.97%),and decrease in Cd levels in grains(40%)was noticed where 20%foliar application of N.sativa and 10%of O.sanctum biostimulants were done using 5 mg kg^(-1) of soil-applied EDTA.This intervention demonstrated a notable reduction in Cd-induced negative effects,highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments.Moreover,it is an eco-friendly and approachable method at thefield level able to ensure food safety.展开更多
Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipme...Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipment and accessories used increase the risk of transmission of nosocomial bacteria. Objective: This study aims to reveal the extent and nature of microbiological contamination in four hospital diagnostic imaging departments to determine their potential role in the spread of nosocomial bacteria and to evaluate the effectiveness of routine daily disinfection practices in controlling microorganisms in diagnostic imaging departments. Methods & Results: In each department, swabs were taken from the surfaces of selected parts of the equipment and accessories three times a day (early morning, noon, and evening) for five consecutive days. Bacteria were isolated from 65 swabs (36.1% of all samples). The bacteria were isolated 3 times (4.6%) in the morning, 16 times (24.6%) at midday, and 46 times (70.7%) in the evening. The bacteria isolated were Escherichia coli (isolated 34 times;52.3%), Staphylococcus aureus (20 times;30.8%), Staphylococcus epidermidis (6 times;9.3%), and Klebsiella species (5 times;7.7%). Discussion & Conclusion: Findings demonstrated that radiology equipment and accessories are not free of bacteria and further improvements in the sterilization and disinfection of radiology equipment and accessories are needed to protect staff and patients from nosocomial infections.展开更多
Background:The role of human papillomavirus(HPV)in the development of vulvar cancer(VC)has been widely studied,but findings have been inconsistent.Despite numerous meta-analyses exploring the potential link between HP...Background:The role of human papillomavirus(HPV)in the development of vulvar cancer(VC)has been widely studied,but findings have been inconsistent.Despite numerous meta-analyses exploring the potential link between HPV and VC,the association remains controversial due to inherent limitations in meta-analytic methods.Objectives:To address this controversy,the study aims to investigate the potential link between HPV and VC using the Bradford Hill criteria,which offer a more comprehensive framework for establishing causation.Methodology:The study began by extracting all relevant studies on the association between HPV and VC from the PubMed database.The potential links were then assessed by examining the data using the major postulates of the Bradford Hill criteria.To ensure the reliability of the findings,the methodologies of the identified studies were critically evaluated to account for possible false-negative and false-positive results.Results:The assessment of previous studies against the Bradford Hill criteria revealed that the major postulates were not fulfilled.Conclusion:Based on the findings,it can concluded that there is no causal association between HPV and VC.展开更多
Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emira...Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert(the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone(SS1) distributes all the 126 endemic species, Arabian regional subzone(SS2) owns 79 taxa, and Nubo-Sindian subzone(SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis(TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., Ⅰ Asphodelus refractus group, Ⅱ Agathophora alopecuroides var. papillosa group, Ⅲ Anvillea garcinii group, Ⅳ Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, Ⅵ Scrophularia deserti group, and Ⅶ Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region.展开更多
Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Differe...Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.展开更多
Climate change and human activities can influence vegetation net primary productivity(NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural v...Climate change and human activities can influence vegetation net primary productivity(NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index(NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach(redundancy analysis) was used to determine which climatic variables or human-related factors mostly influenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area(TRH zone) in the south and the non-conservation area(NTRH zone) in the north. The results indicated an overall(73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long-and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI(with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI.展开更多
Studying the population ecology of endangered plants provides important baseline information for its monitoring and conservation.Juniperus phoenicea L.is an endangered species in arid ecosystems in Africa and the Midd...Studying the population ecology of endangered plants provides important baseline information for its monitoring and conservation.Juniperus phoenicea L.is an endangered species in arid ecosystems in Africa and the Middle East.The static life tables,survival curve and age structure of J.phoenicea populations from two mountains in North Sinai,Egypt(Gabal(G.)El-Halal and G.El-Maghara)were investigated.In each mountain,fifteen plots were selected,and field measurements such as stand density,tree height,and crown diameter were conducted.Moreover,44 trees were cored and crossdated according to standard dendrochronological procedures.The results showed that the tree ages ranged from 50 to 262 years at G.El-Halal and 96 to431 years at G.El-Maghara.Mature J.phoenicea individuals dominated the study area,with only a few individuals being younger than 100 years.Moreover,seedling recruitment was extremely limited.Since the studied J.phoenicea populations showed high mortality rates among both old and young individuals,there is an imminent need for establishing a conservation program to prevent its extinction in the future.Therefore,management and conservation efforts should be made to minimize human disturbance and protect the relic habitats of this endangered species at its southern distribution limits in Africa.展开更多
Gibberellins(GAs)are an important hormone in regulating plant growth and development,and DELLA protein is an essential negative regulator of GA signal transduction.The aim of the study was to clone a GAinhibiting prot...Gibberellins(GAs)are an important hormone in regulating plant growth and development,and DELLA protein is an essential negative regulator of GA signal transduction.The aim of the study was to clone a GAinhibiting protein DELLA from trifoliate orange(Poncirus trifoliata L.Raf.)and to analyze the bioinformations and expression patterns of the protein gene in tissues and in response to drought stress.A DELLA protein was isolated from trifoliate orange and named as PtGai(Genebank number:MZ170959).The PtGai protein had 1731 bp open reading frames,along with 576 amino acid codes,and also grouped with sweet orange(XM_006430552.4).The PtGai protein sequence was 65%homology with the sequences of DELLA proteins in other plant families.PtGai protein existed in the nucleus based on the prediction of subcellular localization.PtGai protein could be expressed in roots,stems,and leaves,along with the highest expression in stems.PtGai was upregulated by drought stress in leaves and roots,along with the decrease of root total GA concentration and the inhibition of shoot and root biomass production.It indicated the characteristics of PtGai protein and the roles of PtGai in GA synthesis and plant growth.展开更多
South Sinai includes Egypt’s highest mountains that resemble an ecological island surrounded by desert.The present study aims to analyse the vegetation physiognomy along the altitudinal and environmental gradients in...South Sinai includes Egypt’s highest mountains that resemble an ecological island surrounded by desert.The present study aims to analyse the vegetation physiognomy along the altitudinal and environmental gradients in the main wadi beds in South Sinai mountainous region.This includes determining the natural,native-weed and alien vegetation in representative stands in this region,analysing their vegetation in terms of species composition,abundance and life forms and determining the national and global distribution of the associated species.This investigation also aims to describe the prevailing plant communities and assess the role of environmental conditions that affect the vegetation in this region.Thus,thirty-two stands were chosen during March-June 2018 to reflect the prevailing altitude and environmental gradients.Total species was 316(229 genera and 61 families):186 species were perennials(58.9%),while 130 were annuals(41.1%).In addition,152 species were native weeds(48.1%of total species),31 were aliens(9.8%),along with 133 natural species(42.1%).Eight species were recorded as endemic to Egypt:Anarrhinum pubescens,Euphorbia sanctae-catharinae,Hypericum sinaicum,Origanum syriacum subsp.sinaicum,Phlomis aurea,Primula boveana,Rosa arabica and Solanum sinaicum.In addition,10 species were recorded as near-endemics to Egypt and other adjacent countries:Allium desertorum,Asclepias sinaica,Centaurea scoparia,Fagonia mollis var.hispida,Hyoscyamus boveanus,Iphiona mucronata,Micromeria sinaica,Pterocephalus sanctus,Salvia deserti and Stachys aegyptiaca.In the present study,33 species are threatened and categorized as follows:8 endangered,8 vulnerable and one indeterminate,while the rest were evaluated by the authors as rares.The rich plant diversity of this region is due to its extensive mountainous massif,which supports many microhabitats.The high elevations in this region hinder the dispersal process of propagules,a situation which often tends to increase endemic and near-endemic species.The current results were discussed and compared with some related previous studies.展开更多
After wheat,rice,maize,and barley,sorghum is the fifth most widely grown cereal on the planet.Due to its high production,drought resistance,and heat tolerance,this crop is replacing maize in some areas.Sorghum is avai...After wheat,rice,maize,and barley,sorghum is the fifth most widely grown cereal on the planet.Due to its high production,drought resistance,and heat tolerance,this crop is replacing maize in some areas.Sorghum is available in a variety of colors,including cream,lemon-yellow,red,and even black.The principal grain anatomical components are pericarp,germ or embryo and endosperm.This review provides an overview of key sorghum grain components,including starches,fiber,proteins,lipids,and vitamins.Also,we summarized phenolic compounds,flavonoids,tannins,carotenoids,vitamin E,amines,Policosanols and Phytosterols in sorghum grains.Sorghum is used to manufacture bread and porridge,and it provides a significant source of energy and nutrition for humans;sorghum is extensively farmed for animal feed.However,because the natural components in sorghum are useful in the development of healthy and functional foods,sorghum farming for both biofuel production and human consumption is gaining popularity.Pigmented sorghum grain is high in antioxidants such as polyphenols,primarily tannins,which have a variety of health benefits,including antiproliferative properties linked to the prevention of certain cancers,antioxidant activities linked to the prevention of diseases linked to oxidative stress,and anti-inflammatory effects,as well as improving glucose metabolism.Because these chemicals cannot be assimilated,their application in the food business has been limited,as sorghum is regarded as a lownutritional grain due to the presence of anti-nutritional components such as strong tannins,which form complexes with proteins and iron,limiting their digestibility.This review aims to show the utilization of sorghum as a source of bioactive chemicals and the value they bestow on human health due to the general biological potential it possesses.展开更多
Fruit, seed morphology and seed coat sculpturing were recorded for 10 species belongs to 9 genera and five tribes of Brassicaceae in eastern region of Saudi Arabia by using light microscope (LM) and scanning electron ...Fruit, seed morphology and seed coat sculpturing were recorded for 10 species belongs to 9 genera and five tribes of Brassicaceae in eastern region of Saudi Arabia by using light microscope (LM) and scanning electron microscope (SEM). Four seed patterns were recognized based on surface sculpturing pattern;Reticulate, with four subtypes, undulate, verrucate and ocellate. The results of numerical analysis showed that species were grouped into two major clusters and each cluster divided into two groups. The cluster analysis indicates that the characters of fruit and seed are very important characters for identification and taxonomical classification of the tribes. The results indicate that the most tribes of Brassicaceae are polyphyletic, and some are related to each other’s as Lepidieae, Alyssieae and Sisymbrieae.展开更多
This investigation was conducting to explain that four barley genotypes varied in their drought tolerance according to their genotype and their tested organs. It can be recorded that growth parameters (fresh, dry matt...This investigation was conducting to explain that four barley genotypes varied in their drought tolerance according to their genotype and their tested organs. It can be recorded that growth parameters (fresh, dry matter and length, water content, leaf area and pigment contents) were decreased as decreasing M. C. in the soil. This indicated that Giza 123 was the superior in its drought tolerance and Giza 129 was the interior and both cv. Giza 2000 and cv. Giza 124 were the intermediated between them. This concomitant with increase in soluble sugar and soluble protein content of both organs in Giza 123 and shoot Ca++, this related with lower value of OP other than genotypes, in Giza 2000 this was related with a huge accumulation in soluble protein of shoot and root, shoot amino acids and root proline reach 3-folds than control plants as decreasing M. C. Whereas drought stress increased soluble protein only in Giza 124 while in Giza 129 decreasing M. C. increased soluble protein, amino acids and proline contents in shoot and root and shoot Ca++. The values of OP increased as decreasing M. C. in four barley cultivars concomitant with their drought tolerance. Also, SA application was markedly enhanced the production of growth parameters in shoot and root with varied degree according to each tested barley genotypes. SA application was significantly increased OP in shoot, root and spike of barley pants. Spraying vegetative parts with 0.5 mM SA was markedly increased the soluble sugar, soluble protein and amino acids in shoot, root and spike of four barley cultivars. On the other side, SA application lowered the accumulation of proline in shoot and root of barley genotypes. SA treatment induced no significant change in K+, Ca++, and Mg++ in shoot, root and spike of Giza 123, it significantly increased K+, Ca++, and Mg++ in shoot and root of Giza 2000. SA application enhanced accumulation of K+, Ca++ in shoot and root of Giza 124 and K+, Ca++ and Mg++in three organs of Giza 129.展开更多
Microorganisms are a huge mine of bioactive metabolites,and actinomycetes are one of the very active groups in this area.In this article,we are concerned about the full taxonomical characterization of Streptomyces liv...Microorganisms are a huge mine of bioactive metabolites,and actinomycetes are one of the very active groups in this area.In this article,we are concerned about the full taxonomical characterization of Streptomyces lividans AM,isolated from Egyptian soil.This isolate produced three new bioactive metabolites,namely:1-Nona-decanoyl,4-oleyl disuccinate(1),filoboletic acid;(9Z,11E)-8,13-dihydroxy octadeca-9,11-dienoic acid(2),and sitosteryl-3β-D-glucoside(3).Extensive 1D and 2D NMR and HR-mass spectrometry were used to elucidate the structures of the three compounds.Moreover,ten known compounds were also identified.The antimicrobial activity of the producing organism and newly reported compounds(1–3)was investigated against a selected group of pathogenic microorganisms.A full taxonomical characterization of the strain was described as well.展开更多
Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated...Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated from tomato plant rhizosphere, have high phosphate solubilization index (SI from 2.8 to 3.2) on Pikovskaya agar medium (which contains calcium phosphate). Moreover, phosphate release from calcium in Pikovskaya broth over 5 days is increasing with cell growth for the different isolates. The most efficient phosphate solubilization case is the mixed culture of the 3 strains (OD475 is almost 1). On the other hand, pH values decreased dramatically with time due to organic acids secretion and the maximum acidification level is recoded for Serratia marcescens PH2 (pH = 1.94). Interestingly, the isolates are resistance to important pesticides (oxamyl, thiophanate methyl, and captan) that are commonly used in the sampling area. This resistance is very favorable and increases the persistence of the phosphate solubilizing bacteria in contaminated soils. The isolates are therefore plant symbionts and growth promoting agents.展开更多
Surfaces submerged in seawater are colonized by various microorganisms,resulting in the formation of heterogenic marine biofilms.This work aims to evaluate the biofilm formation by Cobetia marina alex and doing a comp...Surfaces submerged in seawater are colonized by various microorganisms,resulting in the formation of heterogenic marine biofilms.This work aims to evaluate the biofilm formation by Cobetia marina alex and doing a comparative study between this promising strain with the two bacterial strains isolated previously from the Mediterranean seawater,Alexandria,Egypt.Three strains;Cobetia marina alex,Pseudoalteromonas sp.alex,and Pseudoalteromonas prydzensis alex were screened for biofilm formation using the crystal violet(CV)quantification method in a single culture.The values of biofilm formed were OD600=3.0,2.7,and 2.6,respectively leading to their selection for further evaluation.However,factors affecting biofilm formation by C.marina alex were investigated.Biofilm formation was evaluated in single and multispecies consortia.Synergistic and antagonistic interactions proved in this work lead to the belief that these bacteria have the capability to produce some interesting signal molecules N-acyl Homoserine Lactones(AHLs).展开更多
The polar and nonpolar extracts of Colpomenia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum vulgare collected during spring, summer and autumn were evaluated for their antifungal activities. The phytochem...The polar and nonpolar extracts of Colpomenia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum vulgare collected during spring, summer and autumn were evaluated for their antifungal activities. The phytochemicals of unexplored seaweeds were analyzed by gas chromatography and mass spectrometric (GC/MS). The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium parasiticus, Candida utilis and Fusarium solani. Phytochemicals were extracted from the four seaweeds with various solvents including methanol, ethanol, acetone, chloroform and dimethyl ether. Among the various extracts, methanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while methanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the most effective seaweed, having anatifungal activity throughout the whole year. The UV-Vis phytochemical procedure and GC-MS analysis of the methanol extracts from tested species indicated the existence of different constituents. In conclusions, the compounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.展开更多
Rice straw(RS)collected from Egyptian agricultural environment(Al-Masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed cultu...Rice straw(RS)collected from Egyptian agricultural environment(Al-Masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed culture of(4b,1Asp).Isolates number 4b and 1Asp were identified using the molecular technique(18S rRNA).Isolate 4b and 1Asp,were identified as Trichoderma saturnisporum MN1-EGY and Aspergillus niger MN2-EGY,respectively.Trichoderma saturnisporum MN1-EGY extract exhibited the highest antimicrobial activity compared to the other fungal extracts.Total phenolic,antimicrobial and antioxidant activities were also determined from the ethyl acetate extract of rice straw inoculated by these fungi.The antioxidant scavenging concentration(SC50)values of the tested samples were 88.84,91.45,94.65 and 100.0μg/ml,respectively for Pleurotus sp.,Aspergiluus niger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.,after 15 days incubation,compared to ascorbic acid as positive control with SC50 value equal to 8.0μg/ml.Total phenolic contents(TPCs)were maximum in Pleurotus sp.extract and found to be the most polyphenolic enriched sample(380.64 mg GAE/g dry extract)compared to extracts of Aspergiluusniger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.(261.89,198.52,and 119.80 mg GAE/g dry extract),respectively.The GC-MS analysis has been also performed for the promising extracts.展开更多
Moringa leaf extract(MLE)has been shown to promote beneficial outcomes in animals and plants.It is rich in amino acids,antioxidants,phytohormones,minerals,and many other bioactive compounds with nutritional and growth...Moringa leaf extract(MLE)has been shown to promote beneficial outcomes in animals and plants.It is rich in amino acids,antioxidants,phytohormones,minerals,and many other bioactive compounds with nutritional and growth-promoting potential.Recent reports indicated that MLE improved abiotic stress tolerance in plants.Our understanding of the mechanisms underlying MLE-mediated abiotic stress tolerance remains limited.This review summarizes the existing literature on the role of MLE in promoting plant abiotic stress acclimation processes.MLE is applied to plants in a variety of ways,including foliar spray,rooting media,and seed priming.Exogenous application of MLE promoted crop plant growth,photosynthesis,and yield under both nonstress and abiotic stress conditions.MLE treatment reduced the severity of osmotic and oxidative stress in plants by regulating osmolyte accumulation,antioxidant synthesis,and secondary metabolites.MLE also improves mineral homeostasis in the presence of abiotic stress.Overall,this review describes the potential mechanisms underpinning MLEmediated stress tolerance.展开更多
Genus Heliotropium L. (Heliotropiaceae) in south west of Saudi Arabia has been studied;seven species of H. arbainense Fresen, H. longiflorum (D.C.) Jauber & Spach, H. petrocarpum Hockst & Steud, H. strigosium ...Genus Heliotropium L. (Heliotropiaceae) in south west of Saudi Arabia has been studied;seven species of H. arbainense Fresen, H. longiflorum (D.C.) Jauber & Spach, H. petrocarpum Hockst & Steud, H. strigosium Willd, H. zeylanicum Lam., H. jizanense Al-Turki and H. lasiocarpum Fisch were collected, recognized, typed and nomenclatured. The most valuable characters were those of macro and distinct micromorphological data such as stomata, hairs, pollen grains and stem anatomy. Light microscopy has been used in these studies. From the obtained results, trichomes and pollen grains data in addition to stem anatomy indicated good taxonomic tools to differentiate between species of this genus. Different traditional measurements were strikingly also helpful for the discrimination of species. H. longiflorum was characterized by distinctive data such as prominent anatomical information, P/E (1.8 μm) in addition to presence of spindle hair which in turn can be separated as a taxonomic level. Also, the results revealed a complete affinity between the two species of H. jizanense and H. lasiocarpum. An artificial key is provided for the differentiation between the studied species.展开更多
文摘Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in Egypt.The aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these compounds.Surface seven sediment samples were collected from various drains in the southern part of Burullus Lake.Soxhlet extraction method was employed to extract PAHs(16PAHs)from the sediment sample.Analytically,target compounds were located using HPLC.The results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the European standard for PAHs pollution.Additionally,there was no apparent source of PAHs in the ElKhashah drain or the Brinbal Canal,as HPLC found none of the compounds.The most prevalent compound in sediment samples along the study area was fluoranthene.The diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus Lake.The principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface sediments.The non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was calculated.HI values under 1,therefore,demonstrated that they had no carcinogenic effects on human health.TEQs and MEQs in the sediments of Burullus Lake do not have a cancer-causing impact on people.For the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and controlled.According to the ecological risk assessment,there is little chance that PAHs will be found in the sediments of Burullus Lake.This study underscores the urgent need for effective pollution control measures and regular monitoring of PAHs levels in Burullus Lake sediments to protect the aquatic ecosystem and public health.It also highlights the importance of considering eco-toxicity and human health risks in integrated risk assessments of PAHs-contaminated environments.
基金The authors would like to extend their sincere appreciation to the Researchers Supporting Project Number(RSP2024R356),King Saud University,Riyadh,Saudi Arabia.
文摘Wheat(Triticum aestivum L.)exhibits a greater capacity for cadmium(Cd)absorption compared to other cereal crops,leading to elevated daily Cd intake,and posing a significant threat to public health.For the mitigation of Cd stress in sustainable and environmentally friendly way,a pot study was designed by using exogenous application of various biostimulants,i.e.,Nigella sativa and Ocimum sanctum extracts:0%,10%,and 20%in combination with the chelating agent ethylenediaminetetraacetic acid(EDTA)using 0 and 5 mg kg^(-1) under various levels of Cd stress(i.e.,0,5,10,and 15 mg kg^(-1) soil).Results revealed that Cd stress significantly reduced the seed emergence,growth,root,and allometric characters and yield-related parameters of wheat crops.The most observable reduc-tion was documented in wheat plants exposed to a higher Cd concentration(15 mg kg^(-1)),followed by the lower Cd level(control).The combined application of bio-stimulants and EDTA minimized the negative impacts of Cd stress.The highest increase in seedling emergence(5.44%),leaf area(50.60%),number of tillers(31.02%),grain yield per plant(24.28%),biological yield(13.97%),and decrease in Cd levels in grains(40%)was noticed where 20%foliar application of N.sativa and 10%of O.sanctum biostimulants were done using 5 mg kg^(-1) of soil-applied EDTA.This intervention demonstrated a notable reduction in Cd-induced negative effects,highlighting the potential of these substances in promoting sustainable wheat cultivation in contaminated environments.Moreover,it is an eco-friendly and approachable method at thefield level able to ensure food safety.
文摘Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipment and accessories used increase the risk of transmission of nosocomial bacteria. Objective: This study aims to reveal the extent and nature of microbiological contamination in four hospital diagnostic imaging departments to determine their potential role in the spread of nosocomial bacteria and to evaluate the effectiveness of routine daily disinfection practices in controlling microorganisms in diagnostic imaging departments. Methods & Results: In each department, swabs were taken from the surfaces of selected parts of the equipment and accessories three times a day (early morning, noon, and evening) for five consecutive days. Bacteria were isolated from 65 swabs (36.1% of all samples). The bacteria were isolated 3 times (4.6%) in the morning, 16 times (24.6%) at midday, and 46 times (70.7%) in the evening. The bacteria isolated were Escherichia coli (isolated 34 times;52.3%), Staphylococcus aureus (20 times;30.8%), Staphylococcus epidermidis (6 times;9.3%), and Klebsiella species (5 times;7.7%). Discussion & Conclusion: Findings demonstrated that radiology equipment and accessories are not free of bacteria and further improvements in the sterilization and disinfection of radiology equipment and accessories are needed to protect staff and patients from nosocomial infections.
文摘Background:The role of human papillomavirus(HPV)in the development of vulvar cancer(VC)has been widely studied,but findings have been inconsistent.Despite numerous meta-analyses exploring the potential link between HPV and VC,the association remains controversial due to inherent limitations in meta-analytic methods.Objectives:To address this controversy,the study aims to investigate the potential link between HPV and VC using the Bradford Hill criteria,which offer a more comprehensive framework for establishing causation.Methodology:The study began by extracting all relevant studies on the association between HPV and VC from the PubMed database.The potential links were then assessed by examining the data using the major postulates of the Bradford Hill criteria.To ensure the reliability of the findings,the methodologies of the identified studies were critically evaluated to account for possible false-negative and false-positive results.Results:The assessment of previous studies against the Bradford Hill criteria revealed that the major postulates were not fulfilled.Conclusion:Based on the findings,it can concluded that there is no causal association between HPV and VC.
文摘Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert(the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone(SS1) distributes all the 126 endemic species, Arabian regional subzone(SS2) owns 79 taxa, and Nubo-Sindian subzone(SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis(TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., Ⅰ Asphodelus refractus group, Ⅱ Agathophora alopecuroides var. papillosa group, Ⅲ Anvillea garcinii group, Ⅳ Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, Ⅵ Scrophularia deserti group, and Ⅶ Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region.
基金funded by the Deanship of Scientific Research at King Saud University with the research group project No.RGP-VPP-010
文摘Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.
基金funded by the National Key Research and Development Program of China (2016YFC0502101)the National Natural Science Foundation of China (31700544)the Chinese Academy of Sciences (CAS) "Light of West China" Program (2016XBZG-XBQNXZ-B005)
文摘Climate change and human activities can influence vegetation net primary productivity(NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index(NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach(redundancy analysis) was used to determine which climatic variables or human-related factors mostly influenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area(TRH zone) in the south and the non-conservation area(NTRH zone) in the north. The results indicated an overall(73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long-and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI(with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI.
文摘Studying the population ecology of endangered plants provides important baseline information for its monitoring and conservation.Juniperus phoenicea L.is an endangered species in arid ecosystems in Africa and the Middle East.The static life tables,survival curve and age structure of J.phoenicea populations from two mountains in North Sinai,Egypt(Gabal(G.)El-Halal and G.El-Maghara)were investigated.In each mountain,fifteen plots were selected,and field measurements such as stand density,tree height,and crown diameter were conducted.Moreover,44 trees were cored and crossdated according to standard dendrochronological procedures.The results showed that the tree ages ranged from 50 to 262 years at G.El-Halal and 96 to431 years at G.El-Maghara.Mature J.phoenicea individuals dominated the study area,with only a few individuals being younger than 100 years.Moreover,seedling recruitment was extremely limited.Since the studied J.phoenicea populations showed high mortality rates among both old and young individuals,there is an imminent need for establishing a conservation program to prevent its extinction in the future.Therefore,management and conservation efforts should be made to minimize human disturbance and protect the relic habitats of this endangered species at its southern distribution limits in Africa.
基金the 2020 Joint Projects between Chinese and CEECs’Universities(202019)the National Key Research and Development Program of China(2018YFD1000303)+1 种基金the UHK Project VT2019-2021the Researchers Supporting Project No.(RSP-2021/134),King Saud University,Riyadh,Saudi Arabia.
文摘Gibberellins(GAs)are an important hormone in regulating plant growth and development,and DELLA protein is an essential negative regulator of GA signal transduction.The aim of the study was to clone a GAinhibiting protein DELLA from trifoliate orange(Poncirus trifoliata L.Raf.)and to analyze the bioinformations and expression patterns of the protein gene in tissues and in response to drought stress.A DELLA protein was isolated from trifoliate orange and named as PtGai(Genebank number:MZ170959).The PtGai protein had 1731 bp open reading frames,along with 576 amino acid codes,and also grouped with sweet orange(XM_006430552.4).The PtGai protein sequence was 65%homology with the sequences of DELLA proteins in other plant families.PtGai protein existed in the nucleus based on the prediction of subcellular localization.PtGai protein could be expressed in roots,stems,and leaves,along with the highest expression in stems.PtGai was upregulated by drought stress in leaves and roots,along with the decrease of root total GA concentration and the inhibition of shoot and root biomass production.It indicated the characteristics of PtGai protein and the roles of PtGai in GA synthesis and plant growth.
基金supported by the Deanship of Scientific Research at King Khalid University,Saudi Arabia under Grant number R.G.P.1/73/40。
文摘South Sinai includes Egypt’s highest mountains that resemble an ecological island surrounded by desert.The present study aims to analyse the vegetation physiognomy along the altitudinal and environmental gradients in the main wadi beds in South Sinai mountainous region.This includes determining the natural,native-weed and alien vegetation in representative stands in this region,analysing their vegetation in terms of species composition,abundance and life forms and determining the national and global distribution of the associated species.This investigation also aims to describe the prevailing plant communities and assess the role of environmental conditions that affect the vegetation in this region.Thus,thirty-two stands were chosen during March-June 2018 to reflect the prevailing altitude and environmental gradients.Total species was 316(229 genera and 61 families):186 species were perennials(58.9%),while 130 were annuals(41.1%).In addition,152 species were native weeds(48.1%of total species),31 were aliens(9.8%),along with 133 natural species(42.1%).Eight species were recorded as endemic to Egypt:Anarrhinum pubescens,Euphorbia sanctae-catharinae,Hypericum sinaicum,Origanum syriacum subsp.sinaicum,Phlomis aurea,Primula boveana,Rosa arabica and Solanum sinaicum.In addition,10 species were recorded as near-endemics to Egypt and other adjacent countries:Allium desertorum,Asclepias sinaica,Centaurea scoparia,Fagonia mollis var.hispida,Hyoscyamus boveanus,Iphiona mucronata,Micromeria sinaica,Pterocephalus sanctus,Salvia deserti and Stachys aegyptiaca.In the present study,33 species are threatened and categorized as follows:8 endangered,8 vulnerable and one indeterminate,while the rest were evaluated by the authors as rares.The rich plant diversity of this region is due to its extensive mountainous massif,which supports many microhabitats.The high elevations in this region hinder the dispersal process of propagules,a situation which often tends to increase endemic and near-endemic species.The current results were discussed and compared with some related previous studies.
文摘After wheat,rice,maize,and barley,sorghum is the fifth most widely grown cereal on the planet.Due to its high production,drought resistance,and heat tolerance,this crop is replacing maize in some areas.Sorghum is available in a variety of colors,including cream,lemon-yellow,red,and even black.The principal grain anatomical components are pericarp,germ or embryo and endosperm.This review provides an overview of key sorghum grain components,including starches,fiber,proteins,lipids,and vitamins.Also,we summarized phenolic compounds,flavonoids,tannins,carotenoids,vitamin E,amines,Policosanols and Phytosterols in sorghum grains.Sorghum is used to manufacture bread and porridge,and it provides a significant source of energy and nutrition for humans;sorghum is extensively farmed for animal feed.However,because the natural components in sorghum are useful in the development of healthy and functional foods,sorghum farming for both biofuel production and human consumption is gaining popularity.Pigmented sorghum grain is high in antioxidants such as polyphenols,primarily tannins,which have a variety of health benefits,including antiproliferative properties linked to the prevention of certain cancers,antioxidant activities linked to the prevention of diseases linked to oxidative stress,and anti-inflammatory effects,as well as improving glucose metabolism.Because these chemicals cannot be assimilated,their application in the food business has been limited,as sorghum is regarded as a lownutritional grain due to the presence of anti-nutritional components such as strong tannins,which form complexes with proteins and iron,limiting their digestibility.This review aims to show the utilization of sorghum as a source of bioactive chemicals and the value they bestow on human health due to the general biological potential it possesses.
文摘Fruit, seed morphology and seed coat sculpturing were recorded for 10 species belongs to 9 genera and five tribes of Brassicaceae in eastern region of Saudi Arabia by using light microscope (LM) and scanning electron microscope (SEM). Four seed patterns were recognized based on surface sculpturing pattern;Reticulate, with four subtypes, undulate, verrucate and ocellate. The results of numerical analysis showed that species were grouped into two major clusters and each cluster divided into two groups. The cluster analysis indicates that the characters of fruit and seed are very important characters for identification and taxonomical classification of the tribes. The results indicate that the most tribes of Brassicaceae are polyphyletic, and some are related to each other’s as Lepidieae, Alyssieae and Sisymbrieae.
文摘This investigation was conducting to explain that four barley genotypes varied in their drought tolerance according to their genotype and their tested organs. It can be recorded that growth parameters (fresh, dry matter and length, water content, leaf area and pigment contents) were decreased as decreasing M. C. in the soil. This indicated that Giza 123 was the superior in its drought tolerance and Giza 129 was the interior and both cv. Giza 2000 and cv. Giza 124 were the intermediated between them. This concomitant with increase in soluble sugar and soluble protein content of both organs in Giza 123 and shoot Ca++, this related with lower value of OP other than genotypes, in Giza 2000 this was related with a huge accumulation in soluble protein of shoot and root, shoot amino acids and root proline reach 3-folds than control plants as decreasing M. C. Whereas drought stress increased soluble protein only in Giza 124 while in Giza 129 decreasing M. C. increased soluble protein, amino acids and proline contents in shoot and root and shoot Ca++. The values of OP increased as decreasing M. C. in four barley cultivars concomitant with their drought tolerance. Also, SA application was markedly enhanced the production of growth parameters in shoot and root with varied degree according to each tested barley genotypes. SA application was significantly increased OP in shoot, root and spike of barley pants. Spraying vegetative parts with 0.5 mM SA was markedly increased the soluble sugar, soluble protein and amino acids in shoot, root and spike of four barley cultivars. On the other side, SA application lowered the accumulation of proline in shoot and root of barley genotypes. SA treatment induced no significant change in K+, Ca++, and Mg++ in shoot, root and spike of Giza 123, it significantly increased K+, Ca++, and Mg++ in shoot and root of Giza 2000. SA application enhanced accumulation of K+, Ca++ in shoot and root of Giza 124 and K+, Ca++ and Mg++in three organs of Giza 129.
基金grant from the Deanship of Scientific Research at King Khalid University for Funding under Grant No.(R.G.P 2/90/41)German Academic Exchange Service(DAAD)Project-ID-57166072.
文摘Microorganisms are a huge mine of bioactive metabolites,and actinomycetes are one of the very active groups in this area.In this article,we are concerned about the full taxonomical characterization of Streptomyces lividans AM,isolated from Egyptian soil.This isolate produced three new bioactive metabolites,namely:1-Nona-decanoyl,4-oleyl disuccinate(1),filoboletic acid;(9Z,11E)-8,13-dihydroxy octadeca-9,11-dienoic acid(2),and sitosteryl-3β-D-glucoside(3).Extensive 1D and 2D NMR and HR-mass spectrometry were used to elucidate the structures of the three compounds.Moreover,ten known compounds were also identified.The antimicrobial activity of the producing organism and newly reported compounds(1–3)was investigated against a selected group of pathogenic microorganisms.A full taxonomical characterization of the strain was described as well.
文摘Plants need phosphorus for many physiological activities in a form of phosphate anions. Three different bacterial strains (Bacillus subtilis PH, Serratia marcescens PH1, and Serratia marcescens PH2), recently isolated from tomato plant rhizosphere, have high phosphate solubilization index (SI from 2.8 to 3.2) on Pikovskaya agar medium (which contains calcium phosphate). Moreover, phosphate release from calcium in Pikovskaya broth over 5 days is increasing with cell growth for the different isolates. The most efficient phosphate solubilization case is the mixed culture of the 3 strains (OD475 is almost 1). On the other hand, pH values decreased dramatically with time due to organic acids secretion and the maximum acidification level is recoded for Serratia marcescens PH2 (pH = 1.94). Interestingly, the isolates are resistance to important pesticides (oxamyl, thiophanate methyl, and captan) that are commonly used in the sampling area. This resistance is very favorable and increases the persistence of the phosphate solubilizing bacteria in contaminated soils. The isolates are therefore plant symbionts and growth promoting agents.
文摘Surfaces submerged in seawater are colonized by various microorganisms,resulting in the formation of heterogenic marine biofilms.This work aims to evaluate the biofilm formation by Cobetia marina alex and doing a comparative study between this promising strain with the two bacterial strains isolated previously from the Mediterranean seawater,Alexandria,Egypt.Three strains;Cobetia marina alex,Pseudoalteromonas sp.alex,and Pseudoalteromonas prydzensis alex were screened for biofilm formation using the crystal violet(CV)quantification method in a single culture.The values of biofilm formed were OD600=3.0,2.7,and 2.6,respectively leading to their selection for further evaluation.However,factors affecting biofilm formation by C.marina alex were investigated.Biofilm formation was evaluated in single and multispecies consortia.Synergistic and antagonistic interactions proved in this work lead to the belief that these bacteria have the capability to produce some interesting signal molecules N-acyl Homoserine Lactones(AHLs).
文摘The polar and nonpolar extracts of Colpomenia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum vulgare collected during spring, summer and autumn were evaluated for their antifungal activities. The phytochemicals of unexplored seaweeds were analyzed by gas chromatography and mass spectrometric (GC/MS). The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium parasiticus, Candida utilis and Fusarium solani. Phytochemicals were extracted from the four seaweeds with various solvents including methanol, ethanol, acetone, chloroform and dimethyl ether. Among the various extracts, methanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while methanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the most effective seaweed, having anatifungal activity throughout the whole year. The UV-Vis phytochemical procedure and GC-MS analysis of the methanol extracts from tested species indicated the existence of different constituents. In conclusions, the compounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.
文摘Rice straw(RS)collected from Egyptian agricultural environment(Al-Masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed culture of(4b,1Asp).Isolates number 4b and 1Asp were identified using the molecular technique(18S rRNA).Isolate 4b and 1Asp,were identified as Trichoderma saturnisporum MN1-EGY and Aspergillus niger MN2-EGY,respectively.Trichoderma saturnisporum MN1-EGY extract exhibited the highest antimicrobial activity compared to the other fungal extracts.Total phenolic,antimicrobial and antioxidant activities were also determined from the ethyl acetate extract of rice straw inoculated by these fungi.The antioxidant scavenging concentration(SC50)values of the tested samples were 88.84,91.45,94.65 and 100.0μg/ml,respectively for Pleurotus sp.,Aspergiluus niger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.,after 15 days incubation,compared to ascorbic acid as positive control with SC50 value equal to 8.0μg/ml.Total phenolic contents(TPCs)were maximum in Pleurotus sp.extract and found to be the most polyphenolic enriched sample(380.64 mg GAE/g dry extract)compared to extracts of Aspergiluusniger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.(261.89,198.52,and 119.80 mg GAE/g dry extract),respectively.The GC-MS analysis has been also performed for the promising extracts.
文摘Moringa leaf extract(MLE)has been shown to promote beneficial outcomes in animals and plants.It is rich in amino acids,antioxidants,phytohormones,minerals,and many other bioactive compounds with nutritional and growth-promoting potential.Recent reports indicated that MLE improved abiotic stress tolerance in plants.Our understanding of the mechanisms underlying MLE-mediated abiotic stress tolerance remains limited.This review summarizes the existing literature on the role of MLE in promoting plant abiotic stress acclimation processes.MLE is applied to plants in a variety of ways,including foliar spray,rooting media,and seed priming.Exogenous application of MLE promoted crop plant growth,photosynthesis,and yield under both nonstress and abiotic stress conditions.MLE treatment reduced the severity of osmotic and oxidative stress in plants by regulating osmolyte accumulation,antioxidant synthesis,and secondary metabolites.MLE also improves mineral homeostasis in the presence of abiotic stress.Overall,this review describes the potential mechanisms underpinning MLEmediated stress tolerance.
文摘Genus Heliotropium L. (Heliotropiaceae) in south west of Saudi Arabia has been studied;seven species of H. arbainense Fresen, H. longiflorum (D.C.) Jauber & Spach, H. petrocarpum Hockst & Steud, H. strigosium Willd, H. zeylanicum Lam., H. jizanense Al-Turki and H. lasiocarpum Fisch were collected, recognized, typed and nomenclatured. The most valuable characters were those of macro and distinct micromorphological data such as stomata, hairs, pollen grains and stem anatomy. Light microscopy has been used in these studies. From the obtained results, trichomes and pollen grains data in addition to stem anatomy indicated good taxonomic tools to differentiate between species of this genus. Different traditional measurements were strikingly also helpful for the discrimination of species. H. longiflorum was characterized by distinctive data such as prominent anatomical information, P/E (1.8 μm) in addition to presence of spindle hair which in turn can be separated as a taxonomic level. Also, the results revealed a complete affinity between the two species of H. jizanense and H. lasiocarpum. An artificial key is provided for the differentiation between the studied species.