Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated b...Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1%glucose used as a base for primary screening.Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level.Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.Results:Among the 210 actinomyeetes,64.3%exhibited activity against Gram positive bacteria,48.5%showed activity towards Cram negative bacteria,38.8%exhibited both Cram positive and negative bacteria and 80.85%isolates revealed significant antifungal activity.However,five isolates AP-5,AP-18,AP-41 and AP-70 showed significant antimicrobial activity.The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates.Sequencing analysis indicated that the isolates shared 98.5%-99.8%sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons.The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30X for five days.The antimicrobial activity was assessed using broth micro dilution technique.Each of the culture extracts from these five strains showed a typical polyenelike property.The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Cumularia lunula were 67.5 and 125.0μg/mL,respectively.Conclusions:It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.展开更多
Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on...Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.展开更多
Objective: To evaluate the effects of methanol root extract of Mahonia leschenaultii and berberine of Mahonia leschenaultii on Dalton’s ascitic lymphoma in Swiss Albino mice. Methods: The methanol root extracts of Ma...Objective: To evaluate the effects of methanol root extract of Mahonia leschenaultii and berberine of Mahonia leschenaultii on Dalton’s ascitic lymphoma in Swiss Albino mice. Methods: The methanol root extracts of Mahonia leschenaultii(200 and 400 mg/kg) were given orally, and berberines(10 and 20 mg/kg) were injected intra-peritoneally for 14 successive days in tumor bearing mice. Hematological parameters(white and red blood cells, haemoglobin level, granulocytes, and agranulocytes), lipid parameters(total cholesterol and triglycerides), serum enzymes(serum glutamate pyruvate transaminases, serum glutamate oxaloacetate transaminases, and alkaline phosphatise) and mean survival and solid tumor growth were determined and compared with untreated mice. 5-fluorouracil(20 mg/kg) was used as a reference standard drug. Results: Mahonia leschenaultii and berberine reduced the hematocrit significantly. Furthermore, Mahonia leschenaultii and berberine improved the survival of mice significantly and restored the affected hematological and lipid parameters similar to the normal levels. Conclusions: These observations show a strong anticancer effect of methanol root extract of Mahonia leschenaultii and berberine in suppressing Dalton’s ascitic lymphoma cancer cell growth in a mouse model by controlling haematological, lipid, serum enzymes, and other derived parameters effectively.展开更多
Objective: To study the phytochemistry, anti-asthmatic and antioxidant activities of the aqueous leaf extract of Anchomanes difformis(Blume) Engl.(A. difformis) and to verify claims of use in folk medicine.Methods: Fo...Objective: To study the phytochemistry, anti-asthmatic and antioxidant activities of the aqueous leaf extract of Anchomanes difformis(Blume) Engl.(A. difformis) and to verify claims of use in folk medicine.Methods: For anti-asthmatic activity, male and female guinea pigs with average body weight of(451.4 ± 118.1) g were divided into six groups of six animals each. Group 1served as control(distilled water); Group 2 was administered with salbutamol(reference drug) only; Group 3 served as ovalbumin sensitized group, Group 4, 5 and 6 were treated with A. difformis extract at doses of 100, 200 and 400 mg/kg, respectively. Described methods were used to test fluid viscosity, fluid volume and quantitative phytochemistry analysis. Absorbance was read using a UV–Vis spectrophotometer and results computed in percentage. Total antioxidant assays [2, 2-diphenyl-1-picrylhydrazyl(DPPH) and lipid peroxidation assay], were carried out using reported procedures.Results: The anti-asthmatic evaluation showed that protection from asthma of the animals in Group 6(400 mg/kg, 32.7%) were similar to that in Group 2(salbutamol, 33.0%).Excised trachea was free of mucus secretion in Group 5(200 mg/kg) as was observed in the control group. Fluid volume increase in Groups 3 and 6 indicated mucus secretion.DPPH radical scavenging activity of extract was effective as ascorbic acid which served as standard at 20 mg/m L. But, the extract elicited low lipid peroxidation activity compared with the reference(tocopherol) at concentrations tested.Conclusions: A. difformis aqueous leaf extract is safe and possesses positive antiasthmatic and antioxidant activities as claimed by traditional herbal practitioners in Delta State.展开更多
Objective: To outline the antibacterial, antioxidant, a-glucosidase inhibition and anticancer properties of Michelia nilagirica(M. nilagirica) bark extract.Methods: The antibacterial activity of bark extracts against ...Objective: To outline the antibacterial, antioxidant, a-glucosidase inhibition and anticancer properties of Michelia nilagirica(M. nilagirica) bark extract.Methods: The antibacterial activity of bark extracts against human pathogens was assessed by disc diffusion assay. Phytochemical screening, total phenols, flavonoids content, antioxidant and a-glucosidase inhibition properties of bark extracts were investigated by standard methods. In vitro anticancer activity of ethyl acetate extract at various concentrations was observed against Hep G2 cells using MTT [3-(4, 5-dimethyl thiazol-2 yl)-2,5-diphenyl tetrazolium bromide] assay. The presence of diverse bioactive constituents in the ethyl acetate extract was identified using FT-IR and GC–MS analysis.Results: Ethyl acetate extract was found to be the promising agent against human pathogens tested. The ethyl acetate extracts showed the presence of various phytochemicals and comprised the substantial content of phenolics and flavonoids. The ethyl acetate extract showed better antioxidant activities and also revealed remarkable reducing power ability and a-glucosidase inhibition property. The dose dependent assay of extract showed remarkable cancer cell death with IC_(50) value of(303.26 ± 2.30) mg/m L. FTIR and GC–MS results indicated the presence of major bioactive constituents in the ethyl acetate extract of M. nilagirica bark.Conclusions: Revealing the first report on in vitro biological properties and chemical composition analysis of M. nilagirica bark extract, our study implied that this plant could be of great importance in food and pharmaceutical industries.展开更多
The development of transgenic cotton varieties resistant to bollworms has been a major success of applying plant genetic engineering technology to agriculture,evidenced by phenomenal increase in
In the face of a global scarcity of water resources,drought has already become a primary factor in limiting crop production worldwide.In cotton,fiber productivity and quality is strongly influenced
The magnitude of rice grain losses during storage is huge and warrants critical attention. We investigated the diversity of fungi and insect contamination related to losses of domestic and imported rice from local mil...The magnitude of rice grain losses during storage is huge and warrants critical attention. We investigated the diversity of fungi and insect contamination related to losses of domestic and imported rice from local mills and markets, stored under room conditions for 10 weeks in Cameroon. The highest percentage discolored grain was on imported milled white rice (3.5%), 10 weeks after storage. In general, imported rice samples contained the highest fungal load with a proportion of 65.90% compared to 34.3% for domestic samples. Weight loss due to insect damage was up to 19.9% in white milled domestic rice. Among the 67 isolated fungi strains, the genus Aspergillus had the highest prevalence (63.8%). From all the samples, 877 insects were collected with 719 (81.9%) of Sitophilus. It is urgent to develop sustainable and affordable storage methods to limit insect and fungi infestation on rice in Cameroon.展开更多
Tuberculosis(TB) is a symbolic menace to mankind,infecting almost one third of the world's populace and causing over a million mortalities annually.Mycobacterium tuberculosis(M.tuberculosis) is the key pathogen of...Tuberculosis(TB) is a symbolic menace to mankind,infecting almost one third of the world's populace and causing over a million mortalities annually.Mycobacterium tuberculosis(M.tuberculosis) is the key pathogen of TB that invades and replicates inside the host's macrophage.With the emerging dilemma of multi-drug resistant tuberculosis(MDR-TB) and extensivelydrug resistant tuberculosis(XDR-TB),the exigency for developing new TB drugs is an obligation now for worldwide researchers.Among the propitious antimycobacterial agents examined in last few decades,anti-tubercular peptides have been substantiated to be persuasive with multiple advantages such as low immunogenicity,selective affinity to bacterial negatively charged cell envelopes and most importantly divergent mechanisms of action.In this review,we epitomized the current advances in the anti-tubercular peptides,focusing the sources and highlighting the mycobactericidal mechanisms of promising peptides.The review investigates the current anti-tubercular peptides exploited not only from human immune cells,human non-immune cells,bacteria and fungi but also from venoms,cyanobacteria,bacteriophages and several other unplumbed sources.The anti-tubercular peptides of those origins are also known to have unique second non-membrane targets within M.tuberculosis.The present context also describes the several cases that manifested the severe side effects of extant antiTB drugs.The downfall,failure to reach clinical trial phases,inept to MDR- or XDR-TB and severe complications of the currently available anti-tubercular drugs accentuate the imperative necessity to develop efficacious drugs from adequate anti-tubercular peptides.Keeping in view of the emerging trends of drug resistant M.tuberculosis globally and unexampled mycobactericidal characteristics of peptides,the anti-tubercular peptides of varied origins can be used as a potential weapon to eradicatc TB in future by developing new therapeutic drugs.展开更多
In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both...In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both the physical and social health of all people. Water samples were obtained during the dry and wet seasons from a borehole and a man-made lake constructed through self-help effort in Obazuwa community in Ovia North East Local Government Area of Edo State, Nigeria. They were analyzed for physicochemical parameters and subjected to cyto-genotoxic evaluation using the Allium cepa assay. Results of the physicochemical analysis showed that most of the parameters (pH, chromium, copper, chlorides, nickel, iron, zinc, cadmium, lead and manganese) of the lake water in both seasons exceeded World Health Organisation (WHO) permissible limits. Total heterotrophic bacteria and E. coli were present with dry season water samples having higher amounts. Compared to the control, the mitotic index decreased significantly (p < 0.05) in the water samples and were characterized by a number of chromosomal aberrations notably bridges, fragments, sticky chromosomes, disoriented chromosomes, and micronuclei in significant amounts and these were more pronounced in water samples obtained during the dry season. The findings in this study are of public health relevance as access to safe water is a fundamental human need and therefore, a basic human right.展开更多
The ethnological knowledge of mushrooms despite its millennial existence and its empirical documentation are more recent phenomena. In Africa, the knowledge of their historical uses as food, medicine, source of income...The ethnological knowledge of mushrooms despite its millennial existence and its empirical documentation are more recent phenomena. In Africa, the knowledge of their historical uses as food, medicine, source of income and small scale businesses, and the sociological impacts (myth, culture and spirituality) are apparently threatened due to slow ethnomycology research drive. The poor identification and documentation of edible and medicinal species of mushrooms in many developing nations have created some degrees of inconsistencies in their usages relative to folk medicine practice, food and mythological beliefs. Their relevance in modern day pharmaceutics and nutraceuticals is a product of human experimentation over time.Factors that may be anthropogenic, ethnographic, ethnoecological/environmental have been implicated in mushrooms underutilization and under-exploration of mushrooms in West Africa. Ethnomycological literatures on West Africa are scant, random, are limited in scope and fraught with taxonomic inconsistencies. This paper is based on extant ethnomycology treatise and aims at representing an integrative knowledge of useful mushrooms of West Africa and their uses vis-a-vis indigent cultures.展开更多
A screening of human phycotoxin poisoning symptoms was done in the coastal communities of Nigeria, every quarter for one year, using structured questionnaires. A multi-stage sampling technique consisting of cluster, s...A screening of human phycotoxin poisoning symptoms was done in the coastal communities of Nigeria, every quarter for one year, using structured questionnaires. A multi-stage sampling technique consisting of cluster, snowballing, convenience purposive and random sampling was applied in the study. Based on the responses, a total of 17 Harmful algal toxin-related poisoning symptoms were recorded from respondents, who experienced these symptoms from seafood consumption. The symptoms were Balance difficulty, Breathing difficulty, Burning sensation, Chills, Confusion, Diarrhea, Dizziness, Body itching, Headache, Memory loss, Mouth tingling, Muscle pain, Nausea, Rashes, Abdominal pain, Tiredness and Vomiting. These could be grouped into five categories of diseases namely, Respiratory, Gastrointestinal, Neurological, Dermatological, and Musculo-Skeletal symptoms. The most commonly experienced symptoms were vomiting (24%), mouth tingling (21%), Nausea (14%), diarrhea (11%), headache (10%), tiredness (9%) and body itching (8%) and the least were muscle pain, rashes, confusion, chills, dizziness, balance difficulty burning sensation, breathing difficulty and abdominal pain. Statistical analyses revealed a nexus and significant relationship between visible symptoms and: seafood;season;water colour;habitats/environment of dead seafood and age of respondents. Symptoms enlisted are reminiscent of harmful algal blooms, with grave consequences for public health, commercial fisheries, recreation, tourism, monitoring/management. Therefore, preventive measures, requiring routine monitoring of water bodies, coupled with greater public awareness is suggested for early detection of occurrence of toxin-producing symptoms.展开更多
Metabolic adjustments are a significant, but poorly understood, part of the response of plants to oxidative stress. In a previous study (Baxter et al., 2007), the metabolic response of Arabidopsis cells in culture t...Metabolic adjustments are a significant, but poorly understood, part of the response of plants to oxidative stress. In a previous study (Baxter et al., 2007), the metabolic response of Arabidopsis cells in culture to induction of oxidative stress by menadione was characterized. An emergency survival strategy was uncovered in which anabolic primary metabolism was largely down-regulated in favour of catabolic and antioxidant metabolism. The response in whole plant tissues may be different and we have therefore investigated the response of Arabidopsis roots to menadione treatment, analyzing the transcriptome, metabolome and key metabolic fluxes with focus on primary as well as secondary metabolism. Using a redox-sensitive GFP, it was also shown that menadione causes redox perturbation, not just in the mitochondrion, but also in the cytosol and plastids of roots. In the first 30 min of treatment, the response was similar to the cell culture: there was a decrease in metabolites of the TCA cycle and amino acid biosynthesis and the transcriptomic response was dominated by up-regulation of DNA regulatory proteins. After 2 and 6 h of treatment, the response of the roots was different to the cell culture. Metabolite levels did not remain depressed, but instead recovered and, in the case of pyruvate, some amino acids and aliphatic glucosinolates showed a steady increase above control levels. However, no major changes in fluxes of central carbon metabolism were observed and metabolic transcripts changed largely independently of the corresponding metabolites. Together, the results suggest that root tissues can recover metabolic activity after oxidative inhibition and highlight potentially important roles for glycolysis and the oxidative pentose phosphate pathway.展开更多
Phenolic compounds constitute one of the major pollutants in the modern world. Although many physical and chemical treatment technologies for their removal exist, most of them are economically not feasible. The presen...Phenolic compounds constitute one of the major pollutants in the modern world. Although many physical and chemical treatment technologies for their removal exist, most of them are economically not feasible. The present study was aimed at using silk cotton hull, a potent agricultural waste as an adsobent for removal of 2,4-dichlorophenol (2,4-DCP), which was used as a model phenolic compound. The process parameters were investigated and optimized conditions were determined. The equilibrium time was found to ...展开更多
Glycosyltransferases of the Cellulose Synthase Like D (CS/D) subfamily have been reported to be involved in tip growth and stem development in Arabidopsis. The csld2 and csld3 mutants are root hair defective and the...Glycosyltransferases of the Cellulose Synthase Like D (CS/D) subfamily have been reported to be involved in tip growth and stem development in Arabidopsis. The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth. In this study, we produced double and triple knockout mutants of CSLD2, CSLD3, and CSLD5. Unlike the single mutants and the csld2/csld3 double mutant, the csld2/csld5, csld3/csld5, and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability. This demonstrates that the cooperative activities of CSLD2, CSLD3, and CSLD5 are required for normal Arabidopsis development, and that they are involved in important processes besides the specialized role in tip growth. The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development, whereas the CSLD2 and CSLD3 proteins are non-redundant. To determine the biochemical function of CSLD proteins, we used transient expression in tobacco leaves. Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors. The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately. With monosaccharides as exogenous acceptors, microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose. These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.展开更多
OBJECTIVE: To explore the total phenolic and flavonoid content, enzymatic, non-enzymatic antioxidant properties, anti-inflammation and anticancer activities of hexane, ethyl acetate and methanol extracts of Floscopa s...OBJECTIVE: To explore the total phenolic and flavonoid content, enzymatic, non-enzymatic antioxidant properties, anti-inflammation and anticancer activities of hexane, ethyl acetate and methanol extracts of Floscopa scandens(F. scandens).METHODS: Non-enzymatic antioxidant activity was examined by 2, 2-diphenyl-1-picrylhydrazyl assay, nitric oxide scavenging assay, hydroxyl radical scavenging assay, reducing power assay, hydrogen peroxide scavenging assay, superoxide scavenging assay and metal chelating assay. Enzymatic antioxidant ability was screened for the antioxidant enzymes such as ascorbate oxidase, peroxidase, catalase and polyphenol oxidase. The anti-inflammatory property was proved with the inhibition of protein denaturation and protease inhibitory assays. In vitro anticancer activity was assessed by cell viability assay.RESULTS: Methanol extract contained high amount of phenols(198.41 mg catechol equivalent/gram extract) and flavonoids(101.70 mg quercetin equivalent/gram extract) showed higher activity than hexane and ethyl acetate extracts in all experiments. Fresh plant showed considerable enzymatic antioxidant activity.CONCLUSION: The results revealed that the methanol extracts of F. scandens could be used as a potential source of antioxidant, anti-inflammatory and anticancer bioactive compounds.展开更多
VAR2 is an integral thylakoid membrane protein and a member of the versatile FtsH class of metalloproteases in prokaryotes and eukaryotes. Recessive mutations in the VAR2 locus give rise to variegated plants (var2) ...VAR2 is an integral thylakoid membrane protein and a member of the versatile FtsH class of metalloproteases in prokaryotes and eukaryotes. Recessive mutations in the VAR2 locus give rise to variegated plants (var2) that contain white sectors with abnormal plastids and green sectors with normal-appearing chloroplasts. In a continuing effort to isolate second-site suppressors of var2 variegation, we characterize in this report ems2505, a suppressor strain that has a virescent phenotype due to a missense mutation in At4g28590, the gene for a pioneer protein. We designated this gene SVR4 (for SUPPRESSOR OF VARIEGATION4) and the mutant allele in ems2505 as svr4-1. We demonstrate that SVR4 is located in chloroplasts and that svr4-1 single mutants are normal with respect to chloroplast anatomy and thylakoid membrane protein accumulation. However, they are modestly impaired in several aspects of photochemistry and have enhanced non-photochemical quenching (NPQ) capacity. A T-DNA insertion allele of SVR4, svr4-2, is seedling-lethal due to an early blockage of chloroplast development. We conclude that SVR4 is essential for chloroplast biogenesis, and hypothesize that SVR4 mediates some aspect of thylakoid structure or function that controls NPQ. We propose that in the suppressor strain, photoinhibitory pressure caused by a lack of VAR2 is ameliorated early in chloroplast development by enhanced NPQ capacity caused by reduced SVR4 activity. This would result in an increase in the number of chloroplasts that are able to surmount a threshold necessary to avoid photo-damage and thereby develop into functional chloroplasts.展开更多
Auxin homeostasis is pivotal for normal plant growth and development. The superroot2 (sur2) mutant was initially isolated in a forward genetic screen for auxin overproducers, and SUR2 was suggested to control auxin ...Auxin homeostasis is pivotal for normal plant growth and development. The superroot2 (sur2) mutant was initially isolated in a forward genetic screen for auxin overproducers, and SUR2 was suggested to control auxin conju- gation and thereby regulate auxin homeostasis. However, the phenotype was not uniform and could not be described as a pure high auxin phenotype, indicating that knockout of CYP83B1 has multiple effects. Subsequently, SUR2 was identified as CYP83B1, a cytochrome P450 positioned at the metabolic branch point between auxin and indole glucosinolate metabolism. To investigate concomitant global alterations triggered by knockout of CYP83B1 and the countermeasures chosen by the mutant to cope with hormonal and metabolic imbalances, 10-day-old mutant seedlings were characterized with respect to their transcriptome and metabolome profiles. Here, we report a global analysis of the sur2 mutant by the use of a combined transcriptomic and metabolomic approach revealing pronounced effects on several metabolic grids including the intersection between secondary metabolism, cell wall turnover, hormone metabolism, and stress responses. Metabolic and transcriptional cross-talks in sur2 were found to be regulated by complex interactions between both positively and negatively acting transcription factors. The complex phenotype of sur2 may thus not only be assigned to elevated levels of auxin, but also to ethylene and abscisic acid responses as well as drought responses in the absence of a water deficiency. The delicate balance between these signals explains why minute changes in growth conditions may result in the non-uniform phenotype. The large phenotypic variation observed between and within the different surveys may be reconciled by the complex and intricate hormonal balances in sur2 seedlings decoded in this study.展开更多
文摘Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1%glucose used as a base for primary screening.Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level.Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.Results:Among the 210 actinomyeetes,64.3%exhibited activity against Gram positive bacteria,48.5%showed activity towards Cram negative bacteria,38.8%exhibited both Cram positive and negative bacteria and 80.85%isolates revealed significant antifungal activity.However,five isolates AP-5,AP-18,AP-41 and AP-70 showed significant antimicrobial activity.The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates.Sequencing analysis indicated that the isolates shared 98.5%-99.8%sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons.The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30X for five days.The antimicrobial activity was assessed using broth micro dilution technique.Each of the culture extracts from these five strains showed a typical polyenelike property.The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Cumularia lunula were 67.5 and 125.0μg/mL,respectively.Conclusions:It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.
文摘Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.
文摘Objective: To evaluate the effects of methanol root extract of Mahonia leschenaultii and berberine of Mahonia leschenaultii on Dalton’s ascitic lymphoma in Swiss Albino mice. Methods: The methanol root extracts of Mahonia leschenaultii(200 and 400 mg/kg) were given orally, and berberines(10 and 20 mg/kg) were injected intra-peritoneally for 14 successive days in tumor bearing mice. Hematological parameters(white and red blood cells, haemoglobin level, granulocytes, and agranulocytes), lipid parameters(total cholesterol and triglycerides), serum enzymes(serum glutamate pyruvate transaminases, serum glutamate oxaloacetate transaminases, and alkaline phosphatise) and mean survival and solid tumor growth were determined and compared with untreated mice. 5-fluorouracil(20 mg/kg) was used as a reference standard drug. Results: Mahonia leschenaultii and berberine reduced the hematocrit significantly. Furthermore, Mahonia leschenaultii and berberine improved the survival of mice significantly and restored the affected hematological and lipid parameters similar to the normal levels. Conclusions: These observations show a strong anticancer effect of methanol root extract of Mahonia leschenaultii and berberine in suppressing Dalton’s ascitic lymphoma cancer cell growth in a mouse model by controlling haematological, lipid, serum enzymes, and other derived parameters effectively.
文摘Objective: To study the phytochemistry, anti-asthmatic and antioxidant activities of the aqueous leaf extract of Anchomanes difformis(Blume) Engl.(A. difformis) and to verify claims of use in folk medicine.Methods: For anti-asthmatic activity, male and female guinea pigs with average body weight of(451.4 ± 118.1) g were divided into six groups of six animals each. Group 1served as control(distilled water); Group 2 was administered with salbutamol(reference drug) only; Group 3 served as ovalbumin sensitized group, Group 4, 5 and 6 were treated with A. difformis extract at doses of 100, 200 and 400 mg/kg, respectively. Described methods were used to test fluid viscosity, fluid volume and quantitative phytochemistry analysis. Absorbance was read using a UV–Vis spectrophotometer and results computed in percentage. Total antioxidant assays [2, 2-diphenyl-1-picrylhydrazyl(DPPH) and lipid peroxidation assay], were carried out using reported procedures.Results: The anti-asthmatic evaluation showed that protection from asthma of the animals in Group 6(400 mg/kg, 32.7%) were similar to that in Group 2(salbutamol, 33.0%).Excised trachea was free of mucus secretion in Group 5(200 mg/kg) as was observed in the control group. Fluid volume increase in Groups 3 and 6 indicated mucus secretion.DPPH radical scavenging activity of extract was effective as ascorbic acid which served as standard at 20 mg/m L. But, the extract elicited low lipid peroxidation activity compared with the reference(tocopherol) at concentrations tested.Conclusions: A. difformis aqueous leaf extract is safe and possesses positive antiasthmatic and antioxidant activities as claimed by traditional herbal practitioners in Delta State.
基金supported by Rajiv Gandhi National Fellowship (RGNF-2013-14-ST-TAM-48307),University Grants Commission,Delhi,India
文摘Objective: To outline the antibacterial, antioxidant, a-glucosidase inhibition and anticancer properties of Michelia nilagirica(M. nilagirica) bark extract.Methods: The antibacterial activity of bark extracts against human pathogens was assessed by disc diffusion assay. Phytochemical screening, total phenols, flavonoids content, antioxidant and a-glucosidase inhibition properties of bark extracts were investigated by standard methods. In vitro anticancer activity of ethyl acetate extract at various concentrations was observed against Hep G2 cells using MTT [3-(4, 5-dimethyl thiazol-2 yl)-2,5-diphenyl tetrazolium bromide] assay. The presence of diverse bioactive constituents in the ethyl acetate extract was identified using FT-IR and GC–MS analysis.Results: Ethyl acetate extract was found to be the promising agent against human pathogens tested. The ethyl acetate extracts showed the presence of various phytochemicals and comprised the substantial content of phenolics and flavonoids. The ethyl acetate extract showed better antioxidant activities and also revealed remarkable reducing power ability and a-glucosidase inhibition property. The dose dependent assay of extract showed remarkable cancer cell death with IC_(50) value of(303.26 ± 2.30) mg/m L. FTIR and GC–MS results indicated the presence of major bioactive constituents in the ethyl acetate extract of M. nilagirica bark.Conclusions: Revealing the first report on in vitro biological properties and chemical composition analysis of M. nilagirica bark extract, our study implied that this plant could be of great importance in food and pharmaceutical industries.
文摘The development of transgenic cotton varieties resistant to bollworms has been a major success of applying plant genetic engineering technology to agriculture,evidenced by phenomenal increase in
文摘In the face of a global scarcity of water resources,drought has already become a primary factor in limiting crop production worldwide.In cotton,fiber productivity and quality is strongly influenced
文摘The magnitude of rice grain losses during storage is huge and warrants critical attention. We investigated the diversity of fungi and insect contamination related to losses of domestic and imported rice from local mills and markets, stored under room conditions for 10 weeks in Cameroon. The highest percentage discolored grain was on imported milled white rice (3.5%), 10 weeks after storage. In general, imported rice samples contained the highest fungal load with a proportion of 65.90% compared to 34.3% for domestic samples. Weight loss due to insect damage was up to 19.9% in white milled domestic rice. Among the 67 isolated fungi strains, the genus Aspergillus had the highest prevalence (63.8%). From all the samples, 877 insects were collected with 719 (81.9%) of Sitophilus. It is urgent to develop sustainable and affordable storage methods to limit insect and fungi infestation on rice in Cameroon.
基金supported by Maulana Azad National Fellowship(Fl17.1/2015-16/MANF-2015-17-BIH-60730),University Grants Commission,Delhi,India
文摘Tuberculosis(TB) is a symbolic menace to mankind,infecting almost one third of the world's populace and causing over a million mortalities annually.Mycobacterium tuberculosis(M.tuberculosis) is the key pathogen of TB that invades and replicates inside the host's macrophage.With the emerging dilemma of multi-drug resistant tuberculosis(MDR-TB) and extensivelydrug resistant tuberculosis(XDR-TB),the exigency for developing new TB drugs is an obligation now for worldwide researchers.Among the propitious antimycobacterial agents examined in last few decades,anti-tubercular peptides have been substantiated to be persuasive with multiple advantages such as low immunogenicity,selective affinity to bacterial negatively charged cell envelopes and most importantly divergent mechanisms of action.In this review,we epitomized the current advances in the anti-tubercular peptides,focusing the sources and highlighting the mycobactericidal mechanisms of promising peptides.The review investigates the current anti-tubercular peptides exploited not only from human immune cells,human non-immune cells,bacteria and fungi but also from venoms,cyanobacteria,bacteriophages and several other unplumbed sources.The anti-tubercular peptides of those origins are also known to have unique second non-membrane targets within M.tuberculosis.The present context also describes the several cases that manifested the severe side effects of extant antiTB drugs.The downfall,failure to reach clinical trial phases,inept to MDR- or XDR-TB and severe complications of the currently available anti-tubercular drugs accentuate the imperative necessity to develop efficacious drugs from adequate anti-tubercular peptides.Keeping in view of the emerging trends of drug resistant M.tuberculosis globally and unexampled mycobactericidal characteristics of peptides,the anti-tubercular peptides of varied origins can be used as a potential weapon to eradicatc TB in future by developing new therapeutic drugs.
文摘In most rural settlements in Nigeria, provision of potable water for drinking and domestic purposes is a big challenge;therefore analysis of drinking water is of great importance as contaminated water jeopardizes both the physical and social health of all people. Water samples were obtained during the dry and wet seasons from a borehole and a man-made lake constructed through self-help effort in Obazuwa community in Ovia North East Local Government Area of Edo State, Nigeria. They were analyzed for physicochemical parameters and subjected to cyto-genotoxic evaluation using the Allium cepa assay. Results of the physicochemical analysis showed that most of the parameters (pH, chromium, copper, chlorides, nickel, iron, zinc, cadmium, lead and manganese) of the lake water in both seasons exceeded World Health Organisation (WHO) permissible limits. Total heterotrophic bacteria and E. coli were present with dry season water samples having higher amounts. Compared to the control, the mitotic index decreased significantly (p < 0.05) in the water samples and were characterized by a number of chromosomal aberrations notably bridges, fragments, sticky chromosomes, disoriented chromosomes, and micronuclei in significant amounts and these were more pronounced in water samples obtained during the dry season. The findings in this study are of public health relevance as access to safe water is a fundamental human need and therefore, a basic human right.
文摘The ethnological knowledge of mushrooms despite its millennial existence and its empirical documentation are more recent phenomena. In Africa, the knowledge of their historical uses as food, medicine, source of income and small scale businesses, and the sociological impacts (myth, culture and spirituality) are apparently threatened due to slow ethnomycology research drive. The poor identification and documentation of edible and medicinal species of mushrooms in many developing nations have created some degrees of inconsistencies in their usages relative to folk medicine practice, food and mythological beliefs. Their relevance in modern day pharmaceutics and nutraceuticals is a product of human experimentation over time.Factors that may be anthropogenic, ethnographic, ethnoecological/environmental have been implicated in mushrooms underutilization and under-exploration of mushrooms in West Africa. Ethnomycological literatures on West Africa are scant, random, are limited in scope and fraught with taxonomic inconsistencies. This paper is based on extant ethnomycology treatise and aims at representing an integrative knowledge of useful mushrooms of West Africa and their uses vis-a-vis indigent cultures.
文摘A screening of human phycotoxin poisoning symptoms was done in the coastal communities of Nigeria, every quarter for one year, using structured questionnaires. A multi-stage sampling technique consisting of cluster, snowballing, convenience purposive and random sampling was applied in the study. Based on the responses, a total of 17 Harmful algal toxin-related poisoning symptoms were recorded from respondents, who experienced these symptoms from seafood consumption. The symptoms were Balance difficulty, Breathing difficulty, Burning sensation, Chills, Confusion, Diarrhea, Dizziness, Body itching, Headache, Memory loss, Mouth tingling, Muscle pain, Nausea, Rashes, Abdominal pain, Tiredness and Vomiting. These could be grouped into five categories of diseases namely, Respiratory, Gastrointestinal, Neurological, Dermatological, and Musculo-Skeletal symptoms. The most commonly experienced symptoms were vomiting (24%), mouth tingling (21%), Nausea (14%), diarrhea (11%), headache (10%), tiredness (9%) and body itching (8%) and the least were muscle pain, rashes, confusion, chills, dizziness, balance difficulty burning sensation, breathing difficulty and abdominal pain. Statistical analyses revealed a nexus and significant relationship between visible symptoms and: seafood;season;water colour;habitats/environment of dead seafood and age of respondents. Symptoms enlisted are reminiscent of harmful algal blooms, with grave consequences for public health, commercial fisheries, recreation, tourism, monitoring/management. Therefore, preventive measures, requiring routine monitoring of water bodies, coupled with greater public awareness is suggested for early detection of occurrence of toxin-producing symptoms.
文摘Metabolic adjustments are a significant, but poorly understood, part of the response of plants to oxidative stress. In a previous study (Baxter et al., 2007), the metabolic response of Arabidopsis cells in culture to induction of oxidative stress by menadione was characterized. An emergency survival strategy was uncovered in which anabolic primary metabolism was largely down-regulated in favour of catabolic and antioxidant metabolism. The response in whole plant tissues may be different and we have therefore investigated the response of Arabidopsis roots to menadione treatment, analyzing the transcriptome, metabolome and key metabolic fluxes with focus on primary as well as secondary metabolism. Using a redox-sensitive GFP, it was also shown that menadione causes redox perturbation, not just in the mitochondrion, but also in the cytosol and plastids of roots. In the first 30 min of treatment, the response was similar to the cell culture: there was a decrease in metabolites of the TCA cycle and amino acid biosynthesis and the transcriptomic response was dominated by up-regulation of DNA regulatory proteins. After 2 and 6 h of treatment, the response of the roots was different to the cell culture. Metabolite levels did not remain depressed, but instead recovered and, in the case of pyruvate, some amino acids and aliphatic glucosinolates showed a steady increase above control levels. However, no major changes in fluxes of central carbon metabolism were observed and metabolic transcripts changed largely independently of the corresponding metabolites. Together, the results suggest that root tissues can recover metabolic activity after oxidative inhibition and highlight potentially important roles for glycolysis and the oxidative pentose phosphate pathway.
基金the Chonbuk National Uni-versity Post-Doctoral Program (2006)Research Centerfor Industrial Development of Biofood Materials in the Chonbuk National University, Chonju, KoreaThe centeris designated as a Regional Research Center appointed by the Korea Science and Engineering Foundation (KOSEF),Jeollabuk-do Provincial Government and Chonbuk Nation-al University
文摘Phenolic compounds constitute one of the major pollutants in the modern world. Although many physical and chemical treatment technologies for their removal exist, most of them are economically not feasible. The present study was aimed at using silk cotton hull, a potent agricultural waste as an adsobent for removal of 2,4-dichlorophenol (2,4-DCP), which was used as a model phenolic compound. The process parameters were investigated and optimized conditions were determined. The equilibrium time was found to ...
文摘Glycosyltransferases of the Cellulose Synthase Like D (CS/D) subfamily have been reported to be involved in tip growth and stem development in Arabidopsis. The csld2 and csld3 mutants are root hair defective and the csld5 mutant has reduced stem growth. In this study, we produced double and triple knockout mutants of CSLD2, CSLD3, and CSLD5. Unlike the single mutants and the csld2/csld3 double mutant, the csld2/csld5, csld3/csld5, and csld2/csld3/csld5 mutants were dwarfed and showed severely reduced viability. This demonstrates that the cooperative activities of CSLD2, CSLD3, and CSLD5 are required for normal Arabidopsis development, and that they are involved in important processes besides the specialized role in tip growth. The mutant phenotypes indicate that CSLD2 and CSLD3 have overlapping functions with CSLD5 in early plant development, whereas the CSLD2 and CSLD3 proteins are non-redundant. To determine the biochemical function of CSLD proteins, we used transient expression in tobacco leaves. Microsomes containing heterologously expressed CSLD5 transferred mannose from GDP-mannose onto endogenous acceptors. The same activity was detected when CSLD2 and CSLD3 were coexpressed but not when they were expressed separately. With monosaccharides as exogenous acceptors, microsomal preparations from CSLD5-expressing plants mediated the transfer of mannose from GDP-mannose onto mannose. These results were supported by immunodetection studies that showed reduced levels of a mannan epitope in the cell walls of stem interfascicular fibers and xylem vessels of the csld2/csld3/csld5 mutant.
文摘OBJECTIVE: To explore the total phenolic and flavonoid content, enzymatic, non-enzymatic antioxidant properties, anti-inflammation and anticancer activities of hexane, ethyl acetate and methanol extracts of Floscopa scandens(F. scandens).METHODS: Non-enzymatic antioxidant activity was examined by 2, 2-diphenyl-1-picrylhydrazyl assay, nitric oxide scavenging assay, hydroxyl radical scavenging assay, reducing power assay, hydrogen peroxide scavenging assay, superoxide scavenging assay and metal chelating assay. Enzymatic antioxidant ability was screened for the antioxidant enzymes such as ascorbate oxidase, peroxidase, catalase and polyphenol oxidase. The anti-inflammatory property was proved with the inhibition of protein denaturation and protease inhibitory assays. In vitro anticancer activity was assessed by cell viability assay.RESULTS: Methanol extract contained high amount of phenols(198.41 mg catechol equivalent/gram extract) and flavonoids(101.70 mg quercetin equivalent/gram extract) showed higher activity than hexane and ethyl acetate extracts in all experiments. Fresh plant showed considerable enzymatic antioxidant activity.CONCLUSION: The results revealed that the methanol extracts of F. scandens could be used as a potential source of antioxidant, anti-inflammatory and anticancer bioactive compounds.
文摘VAR2 is an integral thylakoid membrane protein and a member of the versatile FtsH class of metalloproteases in prokaryotes and eukaryotes. Recessive mutations in the VAR2 locus give rise to variegated plants (var2) that contain white sectors with abnormal plastids and green sectors with normal-appearing chloroplasts. In a continuing effort to isolate second-site suppressors of var2 variegation, we characterize in this report ems2505, a suppressor strain that has a virescent phenotype due to a missense mutation in At4g28590, the gene for a pioneer protein. We designated this gene SVR4 (for SUPPRESSOR OF VARIEGATION4) and the mutant allele in ems2505 as svr4-1. We demonstrate that SVR4 is located in chloroplasts and that svr4-1 single mutants are normal with respect to chloroplast anatomy and thylakoid membrane protein accumulation. However, they are modestly impaired in several aspects of photochemistry and have enhanced non-photochemical quenching (NPQ) capacity. A T-DNA insertion allele of SVR4, svr4-2, is seedling-lethal due to an early blockage of chloroplast development. We conclude that SVR4 is essential for chloroplast biogenesis, and hypothesize that SVR4 mediates some aspect of thylakoid structure or function that controls NPQ. We propose that in the suppressor strain, photoinhibitory pressure caused by a lack of VAR2 is ameliorated early in chloroplast development by enhanced NPQ capacity caused by reduced SVR4 activity. This would result in an increase in the number of chloroplasts that are able to surmount a threshold necessary to avoid photo-damage and thereby develop into functional chloroplasts.
文摘Auxin homeostasis is pivotal for normal plant growth and development. The superroot2 (sur2) mutant was initially isolated in a forward genetic screen for auxin overproducers, and SUR2 was suggested to control auxin conju- gation and thereby regulate auxin homeostasis. However, the phenotype was not uniform and could not be described as a pure high auxin phenotype, indicating that knockout of CYP83B1 has multiple effects. Subsequently, SUR2 was identified as CYP83B1, a cytochrome P450 positioned at the metabolic branch point between auxin and indole glucosinolate metabolism. To investigate concomitant global alterations triggered by knockout of CYP83B1 and the countermeasures chosen by the mutant to cope with hormonal and metabolic imbalances, 10-day-old mutant seedlings were characterized with respect to their transcriptome and metabolome profiles. Here, we report a global analysis of the sur2 mutant by the use of a combined transcriptomic and metabolomic approach revealing pronounced effects on several metabolic grids including the intersection between secondary metabolism, cell wall turnover, hormone metabolism, and stress responses. Metabolic and transcriptional cross-talks in sur2 were found to be regulated by complex interactions between both positively and negatively acting transcription factors. The complex phenotype of sur2 may thus not only be assigned to elevated levels of auxin, but also to ethylene and abscisic acid responses as well as drought responses in the absence of a water deficiency. The delicate balance between these signals explains why minute changes in growth conditions may result in the non-uniform phenotype. The large phenotypic variation observed between and within the different surveys may be reconciled by the complex and intricate hormonal balances in sur2 seedlings decoded in this study.