Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing prob...Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.展开更多
[Objective] This study aimed to investigate the effect of different short-term preservation conditions on mycelial growth of Morchella conica, and search for opti- mum preservation conditions. [Method] M. conica strai...[Objective] This study aimed to investigate the effect of different short-term preservation conditions on mycelial growth of Morchella conica, and search for opti- mum preservation conditions. [Method] M. conica strains in tubes were preserved at two temperature treatments 10 ℃/5 ℃ (day/night) and 15℃/10 ℃(day/night) in scat- tered light or dark for 30 or 60 d. The strain preserved at 4 ℃ dark for 90 d was the control (CK). So, a total of nine treatments were prepared in this study. [Result] Mycelial growth of M. conica preserved at 10 ℃/5 ℃ was better than that at 15 ℃/10 ℃ and control. The colony color and aerial hyphae of strains preserved in scattered light was also better than that in dark. Additionally, the preservation time showed no distinct effect on mycelial growth at 10 ℃/5 ℃. So the time could be lengthened. But the maximal preservation time was 60 d at 15 ℃/10 ℃. Therefore, preserved under the appropriate conditions of 10 ℃/5 ℃, scattered light for 30 d, the strain had the neat colony edge, moderate aerial mycelia, dense mycelia, lower sectoral variation, uniform mycelial growth rate and high dry weight of mycelia.展开更多
Currently in China,no technically and economically viable methods exist to handle large quantities of Camptotheca acuminata Decne residue(CA residue) after camptothecin extract while there is a great demand for low co...Currently in China,no technically and economically viable methods exist to handle large quantities of Camptotheca acuminata Decne residue(CA residue) after camptothecin extract while there is a great demand for low cost alternatives to replace the cottonseed hull-based materials used in commercial mushroom culture.Hence,it is of importance for camptothecin extract factories and mushroom producers to explore the utilization of CA residue in mushroom industry.We conducted a research to study how partially or completely substituting traditional mushroom substrate by CA residue would influence the mycelial growth in mushroom spawn production.5 mushroom strains from 4 species were used in the test,i.e.,oyster mushroom(Pleurotus ostreatu) strains,Zayou No.1 and Xide 33,needle mushroom(Flammulina velutipes) strain Chuanjin No.3,hairy wood ear(Auricularia polytricha) strain Huang Er No.10,and shiitake(Lentinula edodes) strain Wuxiang.The nutrient element composition and heavy metal contents of CA residue were determined to ensure its safety and to determine its appropriate component in the substrate formulation for mushroom spawn production.The four substrate formulations(one control-CK,and three treatments,named,T1,T2,T3,) contained 0%,40%,79%,and 100% CA residue,respectively,to allow comparison of the fungal mycelial growth.The control(CK) was the popularly used formulation in Chinese commercial mushroom production,comprising of 73% cottonseed hulls,10% sawdust,15% wheat bran,1% lime,1% white sugar(percentage by weight).All mushroom spawns of the five strains in the four treatments were incubated under the same conditions.The results showed that mycelia of the five mushroom strains grew significantly faster on the substrates containing CA residue than on the substrate with no CA residue(CK).There were no significant differences in the mycelial growth rate among treatments containing CA residue for the two oyster mushrooms and the needle mushroom,but mycelial growth rate in treatments T2 and T3 was significantly higher than in treatment T1 for hairy wood ear and shiitake.The results suggest that CA residue can be used to culture oyster mushroom,needle mushroom,hairy wood ear,and shiitake spawn,and the medium containing CA residue can stimulate their mycelial growth.The commercial production of mushroom spawn using CA residue not only brings better economical benefits including lower cost to mushroom producers,but also reduces environmental pollution by providing a means to reduce dumping and piling of CA residue.展开更多
The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology (RSM). Central composite design (CCD) was used to study the interactive effect of culture conditi...The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology (RSM). Central composite design (CCD) was used to study the interactive effect of culture conditions (temperature, pH, and inoculum) on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% (v/v) in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.展开更多
[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Pr...[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.展开更多
Production of polysaccharides by lactic acid bacteria is vital and its technology is very important, too in dairy study. The selection ofexpolysaccharides producing encapsulated Lactobacillus bulgaricus in alginate ge...Production of polysaccharides by lactic acid bacteria is vital and its technology is very important, too in dairy study. The selection ofexpolysaccharides producing encapsulated Lactobacillus bulgaricus in alginate gel and the factors affecting the production of polysaccharides such as time, temperature, pH and the growth with Streptococcus thermophilus were studied, pH 5.5 and temperature 35℃/18hr were found to be optimal for exopolysaccharides production by encapsulated L. bulgaricus and free culture yielding 600 mg/L and 380 mg/L respectively. Co-culturing L. bulgaricus with S. thermophilus increased exopolysaccharides production at 35 ℃/18hr to 660 mg/L by encapsulated cells and 400 mg/L by free culture. Results of this study were applied in the manufacture of Labneh cheese vitally containing probiotic species ofL. acidophilus, L. gasseri, L. johnsonii and protection of these bacteria by polysaeeharide produced encapsulated L. bulgaricus. The use of exopolysaccharides producing encapsulated L. bulgaricus and probiotic bacteria can provide acceptable quality to functional Labneh. This product can be used as therapeutic and diabetic milk product with highly acceptable qualities. It is noted that all of the results are the means of triplicate experiments.展开更多
A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorr...A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorrhizal inoculation on plant growth and degradation of DEHP in two contaminated soils, a yellow-brown soil and a red soil. The air-dried soils were uniformly sprayed with different concentrations of DEHP, inoculated or left uninoculated with an arbuscular mycorrhizal (AM) fungus, and planted with…展开更多
In order to determine the level of resistance of sugar beet varieties against Rhizoctonia solani AG 2-21IIB and AG 4, a methodology was implemented under greenhouse conditions that contemplated the most important crit...In order to determine the level of resistance of sugar beet varieties against Rhizoctonia solani AG 2-21IIB and AG 4, a methodology was implemented under greenhouse conditions that contemplated the most important criteria regarding to plant-pathogen interaction. The effect of plant growth stage on the development of the disease was evaluated. Seven sugar beet varieties were tested for resistance to R. solani AG 2-2IIIB and AG 4. To detect differences in leaf temperature between/L solani inoculated plants and non-infected plants, an infrared (IR) camera was tested. High incidence of R. solani AG 2-2IIIB and AG 4 in sugar beet plants was evident when the fungal inoculum was applied to two and four weeks old plants. At four weeks after sowing, it was the optimum time to inoculate sugar beet plants in order to generate R. solani infection, since at this time all plants were infected. Significant differences were detected regarding disease incidence between sugar beet varieties inoculated with different anastomosis groups. Leaf temperature was significant different between inoculated and non-inoculated plants, demonstrated that this technique could be a new tool for breeders to screen for resistance of new varieties.展开更多
A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode ...A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp. stimulated the growth of wheat (Triticum aestivum) and the uptake of N. By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.) increased by 6.5% and 5.9%, respectively, compared with bacteria alone treatment. The presence of nematode mainly accelerated the growth of aboveground of wheat, while it slightly inhibited the root development. There was little difference in plant tissue N concentration between treatments. P concentration and uptake of wheat, however, were generally reduced by nematode. It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineralization induced by nematode feeding on bacteria, and the reduction of phosphorous uptake is the result of weak root status and competition by bacteria immobilization.展开更多
Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. ...Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. Inoculation resulted in nodule number increases of 28.6, 29.02 and 23.9 times in sterilized soiland 3.4, 3.6 and 3.27 times in non-sterilized soil for A. parocera A. lebbeck and L. leucocephala seedlingsrespectively. Total dry mass increased by 127.6%, 66.7% and 60.7% in sterilized soil and 100%, 95.5%and 52.65% in non-sterilized soil for these three legume trees, respectively, after a period of two months.Significalltly high inoculation responses of root length, root diameter, collar diameter, shoot length, and drymass of root, shoot, leaves and nodules were also observed in both sterilized and non-sterilized soil media ascompared to respective control treatments. The response to inoculation was strong in sterilized and modestin non-sterilized soils. The significantly higher response to Rhizobium inoculation over control in all thespecies tested suggested that application of Rhizobium greatly enhanced plant growth, nodulation, biomassproduction and nitrogen-fixing activity of the nodules.展开更多
Black aspergilli, the potential ochratoxin A (OTA) producers, were predominant fungi in fermented cocoa bean, coffee bean and dried cassava in Yogyakarta. Identification of black aspergilli at species level will be ...Black aspergilli, the potential ochratoxin A (OTA) producers, were predominant fungi in fermented cocoa bean, coffee bean and dried cassava in Yogyakarta. Identification of black aspergilli at species level will be useful to make clear link between OTA contamination on food product and the toxin producer. The objective of this study was to identify the species of the black aspergilli producing OTA which contaminated dried agriculture products. In this study, 16 isolates were obtained, and four isolates among of them (YAC-9, YAK-6, YAK-12 and YAG-2) were found as OTA producing-strains, with the highest OTA found on Yeast Extract Sucrose (YES) solid medium of 57.68 ppb. Based on morphological characters, 16 isolates can be grouped into four species, after confirmation by molecular data based on PCR method, the groups were identified as A. carbonarius, A. niger, A. tubingensis and A. aculeatus. OTA producing-strains were identified as A. carbonarius and A. niger, meanwhile, A. tubingensis and A. aculeatus were found as non-OTA producing-strains.展开更多
Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed...Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.展开更多
Aerobic, heterotrophic bacteria, recovered from two sites located on the west coast of Scotland, were compared to cultures obtained in a similar way from industrial, aquacultural and clean sites in the vicinity of Qin...Aerobic, heterotrophic bacteria, recovered from two sites located on the west coast of Scotland, were compared to cultures obtained in a similar way from industrial, aquacultural and clean sites in the vicinity of Qingdao, Shandong, P.R. China. Gram-negative bacterial cultures were examined by BIOLOG-GN, and the data analysed by the simple matching (S SM) and Jaccard coefficients (S J) and unweighted average linkage clustering using NTSys. The output revealed that 20% of the bacteria, namely, Acinetobacter johnsonii, Aquaspirillum dispar, Pseudomonas spp. (two groups), Sphingobacterium sp., Vibrio sp., V. campbellii, V. mimicus and V. hollisae, were common between the two geographical locations. However, the study revealed shortcomings with the BIOLOG-GN system for the study of coastal Gram-negative bacteria.展开更多
Twenty isolates of Fusarium oxysporum f. sp. ciceris were isolated from wilted chickpea plants obtained from different districts of north part of Iraq to assess variability in pathogenicity of the populations. Each is...Twenty isolates of Fusarium oxysporum f. sp. ciceris were isolated from wilted chickpea plants obtained from different districts of north part of Iraq to assess variability in pathogenicity of the populations. Each isolate was tested on 12 differential chickpea varieties. Isolates showed highly significant variation in wilt severity on the differential varieties. Based on the reaction types that induced on differential varieties, isolates were grouped into four groups, First group included isolates FocSl, FocQ7, FocQ 10, FocFI3, FocH 17 and FocHl8; the second group included isolates FocS2, FocS3, FocS4, FocQ5, FocQ8, FocQ9, FocF11, FocF12, FocFl4 and FocH19; the third group included isolates FocF15, FocHl6, FocH20; where the isolate FocQ6 was placed in the fourth group. Results showed that the percentage of genetic similarity was ranged 42% to 100% and was 42% between the first group and other groups and 72% between the three groups the rest and thus this indicate the presence of four races of the fungus which are O, 4, 5 and 1B/C, this represent the first record of these races in lraq.展开更多
AIM:To study whether selected bacterial 16S ribosomal RNA(rRNA)gene phylotypes are capable of disting- uishing irritable bowel syndrome(IBS). METHODS:The faecal microbiota of twenty volunteers with IBS,subdivided into...AIM:To study whether selected bacterial 16S ribosomal RNA(rRNA)gene phylotypes are capable of disting- uishing irritable bowel syndrome(IBS). METHODS:The faecal microbiota of twenty volunteers with IBS,subdivided into eight diarrhoea-predominant (IBS-D),eight constipation-predominant(IBS-C)and four mixed symptom-subtype(IBS-M)IBS patients,and fifteen control subjects,were analysed at three time-points with a set of fourteen quantitative real-timepolymerase chain reaction assays.All assays targeted 16S rRNA gene phylotypes putatively associated with IBS,based on 16S rRNA gene library sequence analysis. The target phylotypes were affiliated with Actinobac-teria,Bacteroidetes and Firmicutes.Eight of the target phylotypes had less than 95%similarity to cultured bacterial species according to their 16S rRNA gene sequence.The data analyses were made with repeated-measures ANCOVA-type modelling of the data and principle component analysis(PCA)with linear mixed-effects models applied to the principal component scores. RESULTS:Bacterial phylotypes Clostridium cocleatum 88%,Clostridium thermosuccinogenes 85%,Coprobacillus catenaformis 91%,Ruminococcus bromii-like, Ruminococcus torques 91%,and R.torques 93%were detected from all samples analysed.A multivariate analysis of the relative quantities of all 14 bacterial 16S rRNA gene phylotypes suggested that the intestinal microbiota of the IBS-D patients differed from other sample groups.The PCA on the first principal component(PC1),explaining 30.36%of the observed variation in the IBS-D patient group,was significantly altered from all other sample groups(IBS-D vs control, P=0.01;IBS-D vs IBS-M,P=0.00;IBS-D vs IBS-C, P=0.05).Significant differences were also observed in the levels of distinct phylotypes using relative values in proportion to the total amount of bacteria.A phy- lotype with 85%similarity to C.thermosuccinogenes was quantified in significantly different quantities among the IBS-D and control subjects(-4.08±0.90 vs -3.33±1.16,P=0.04)and IBS-D and IBS-M subjects (-4.08±0.90 vs-3.08±1.38,P=0.05).Furthermore,a phylotype with 94%similarity to R.torques was more prevalent in IBS-D patients'intestinal micro- biota than in that of control subjects(-2.43±1.49 vs -4.02±1.63,P=0.01).A phylotype with 93%simi- larity to R.torques was associated with control sam- ples when compared with IBS-M(-2.41±0.53 vs -2.92±0.56,P=0.00).Additionally,a R.bromii-like phylotype was associated with IBS-C patients in com- parison to control subjects(-1.61±1.83 vs-3.69± 2.42,P=0.01).All of the above mentioned phylotype specific alterations were independent of the effect of time. CONCLUSION:Significant phylotype level alterationsin the intestinal microbiotas of IBS patients were observed,further emphasizing the possible contribution of the gastrointestinal microbiota in IBS.展开更多
To reveal the effects of Fe2+ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage (AMD) samples were collected at Dabaoshan Mine and Shenbu Mine. Community success...To reveal the effects of Fe2+ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage (AMD) samples were collected at Dabaoshan Mine and Shenbu Mine. Community successions of AMD niches were analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA), sequencing, and phylogenetic analysis in original AMD samples and their subculture under Fe2+ concentrations. Although geochemical properties and community structures were greatly different between the two original AMD samples, bacterial community successions were still very similar under high Fe2+ concentrations. The results showed that Acidithiobacillus ferrooxidans have competitive relationship with other bacterial species living in the AMD, including species that were also capable of oxidizing ferrous ion. A competitive relationship among different At. ferrooxidans strains likewise existed. Some of At. ferrooxidans can grow first under conditions of high ferrous ion concentration, and other At. ferrooxidans species decreased gradually and disappeared. This suggested that these species of At. ferrooxidans are most acidophilic bacteria and afford Fe3+ to leach other metallic ion in the early stages of minerals dissolution.展开更多
Ten seed borne fungi (Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.) were isolated and identifie...Ten seed borne fungi (Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.) were isolated and identified from two wheat varieties, the highest frequency of seed borne fungi was observed on wheat cultivar site Moll4 Alternaria sp.. Their mean and standard deviation was (5.5 ~ 1.69) while the lowest frequency fungal isolated was Dreschslera sp. and Rhizopus sp.. Their mean and standard deviation was (0.1 ~ 0.64). The aflatoxin-producing isolates appeared as gray or black colonies in the UV photographs, whereas nonproducing isolates appeared as white colonies, the plate five colony four (P5CO4) showed the positive results which means the presence of aflatoxin as compaired to the control which showed the ngative results. Ammonium Hydroxide Vapor-Induced Color Change method used which the dish was inverted and 1 or 2 drops of concentrated ammonium hydroxide solution are placed on the inside of the lid. The undersides of aflatoxin-producing colonies quickly turn plum-red after the bottom of the Petri dish has been inverted over the lid containing the ammonium hydroxide aspositive result in (P5CO4) and (P7CO4) observed. Essentially no color change occurs on the undersides of colonies that are not producing aflatoxinsthis indicate to the negative results (control). The main objective of this study is to isolation, identification and rapid detection of aflatoxin from wheat seed borne fungi.展开更多
Apple/Malus x domestica cv. 'Topaz'/M26 and sour cherry cv. 'Debreceni Botermo'/Prunus mahaleb L. maidens were fertilized with different organic fertilizers and soil amendments in an organic nursery. A mycorrhizal...Apple/Malus x domestica cv. 'Topaz'/M26 and sour cherry cv. 'Debreceni Botermo'/Prunus mahaleb L. maidens were fertilized with different organic fertilizers and soil amendments in an organic nursery. A mycorrhizal inoculant, Micosat, was added to the non-fertilized control and to combinations fertilized with various bioproducts. Under assessment was the effect of nutrient delivery on the growth and development of maiden fruit trees focussing on tree height, thickness of the tree trunk, the number and the length of lateral shoots in each treatment combination. It was found that the introduction of mycorrhizal fungi into the soil without fertilizer application significantly improved the growth and development of apple and sour cherry maidens. Mineral fertilizer application (NPK) combined with mycorrhizal inoculation had a negligible effect on the above features. In the presence of bioproducts such as granular manure, Humus Active + Aktywit PM, BF Amin, Vinassa and Florovit Eko, the mycorrhizal fungi were more biologically active than in the absence of these products.展开更多
A study was conducted at two pair sites of Chittagong Hill Tracts in Bangladesh to find out the effects of shifting cultivation on soil fungi and bacterial population. The first pair of sites with shifting culti-vatio...A study was conducted at two pair sites of Chittagong Hill Tracts in Bangladesh to find out the effects of shifting cultivation on soil fungi and bacterial population. The first pair of sites with shifting culti-vation and village common forest-managed by indigenous community was at Madhya Para in Rangamati district and the second pair of sites with the shifting cultivated land and village common forest at Ampu Para in Bandarban district of Chittagong Hill Tracts. At both the locations with two different land uses, soil textures in surface (0?10 cm) and sub-surface (10?20 cm) soils varied from sandy loam to sandy clay loam. Soil pH and moisture content were lower in shifting cultivated land com-pared to village common forest. The results also showed that both fungal and bacterial population in surface and subsurface soils was significantly (p ≤ 0.05) lower, in most cases, in shifting cultivated land compared to village common forest at both Madhya Para and Ampu Para. At Ranga-mati and Bandarban in shifting cultivated lands, Colletrotrichum and Fusarium fungi were absent and all the bacterial genus viz. Coccus, Bacillus and Streptococcus common in two different locations with dif-ferent land uses. Common identified fungi at both the land uses and locations were Aspergillus, Rhizopus, Trichoderma and Penicillium. Further study can be done on the other soil biota to understand the extent of environmental deterioration due to shifting cultivation.展开更多
基金Supported by the National Science and Technology Program of the Ministry of Science and Technology of China(2010BAD01B04)Research Fund of Department of Science and Technology of Sichuan Province(2008NG0003)the Genetic Engineering Fund of Department of Finance of Sichuan Province(2011JYGC06)~~
文摘Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.
文摘[Objective] This study aimed to investigate the effect of different short-term preservation conditions on mycelial growth of Morchella conica, and search for opti- mum preservation conditions. [Method] M. conica strains in tubes were preserved at two temperature treatments 10 ℃/5 ℃ (day/night) and 15℃/10 ℃(day/night) in scat- tered light or dark for 30 or 60 d. The strain preserved at 4 ℃ dark for 90 d was the control (CK). So, a total of nine treatments were prepared in this study. [Result] Mycelial growth of M. conica preserved at 10 ℃/5 ℃ was better than that at 15 ℃/10 ℃ and control. The colony color and aerial hyphae of strains preserved in scattered light was also better than that in dark. Additionally, the preservation time showed no distinct effect on mycelial growth at 10 ℃/5 ℃. So the time could be lengthened. But the maximal preservation time was 60 d at 15 ℃/10 ℃. Therefore, preserved under the appropriate conditions of 10 ℃/5 ℃, scattered light for 30 d, the strain had the neat colony edge, moderate aerial mycelia, dense mycelia, lower sectoral variation, uniform mycelial growth rate and high dry weight of mycelia.
基金funded by theCrop Breeding Key Project of Sichuan Province(Grant No. 2006YZGG 26)
文摘Currently in China,no technically and economically viable methods exist to handle large quantities of Camptotheca acuminata Decne residue(CA residue) after camptothecin extract while there is a great demand for low cost alternatives to replace the cottonseed hull-based materials used in commercial mushroom culture.Hence,it is of importance for camptothecin extract factories and mushroom producers to explore the utilization of CA residue in mushroom industry.We conducted a research to study how partially or completely substituting traditional mushroom substrate by CA residue would influence the mycelial growth in mushroom spawn production.5 mushroom strains from 4 species were used in the test,i.e.,oyster mushroom(Pleurotus ostreatu) strains,Zayou No.1 and Xide 33,needle mushroom(Flammulina velutipes) strain Chuanjin No.3,hairy wood ear(Auricularia polytricha) strain Huang Er No.10,and shiitake(Lentinula edodes) strain Wuxiang.The nutrient element composition and heavy metal contents of CA residue were determined to ensure its safety and to determine its appropriate component in the substrate formulation for mushroom spawn production.The four substrate formulations(one control-CK,and three treatments,named,T1,T2,T3,) contained 0%,40%,79%,and 100% CA residue,respectively,to allow comparison of the fungal mycelial growth.The control(CK) was the popularly used formulation in Chinese commercial mushroom production,comprising of 73% cottonseed hulls,10% sawdust,15% wheat bran,1% lime,1% white sugar(percentage by weight).All mushroom spawns of the five strains in the four treatments were incubated under the same conditions.The results showed that mycelia of the five mushroom strains grew significantly faster on the substrates containing CA residue than on the substrate with no CA residue(CK).There were no significant differences in the mycelial growth rate among treatments containing CA residue for the two oyster mushrooms and the needle mushroom,but mycelial growth rate in treatments T2 and T3 was significantly higher than in treatment T1 for hairy wood ear and shiitake.The results suggest that CA residue can be used to culture oyster mushroom,needle mushroom,hairy wood ear,and shiitake spawn,and the medium containing CA residue can stimulate their mycelial growth.The commercial production of mushroom spawn using CA residue not only brings better economical benefits including lower cost to mushroom producers,but also reduces environmental pollution by providing a means to reduce dumping and piling of CA residue.
文摘The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology (RSM). Central composite design (CCD) was used to study the interactive effect of culture conditions (temperature, pH, and inoculum) on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% (v/v) in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.
基金Supported by the Key Project of the National 11th Five-Year Plan of China (2006BADO8A04-06)
文摘[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.
文摘Production of polysaccharides by lactic acid bacteria is vital and its technology is very important, too in dairy study. The selection ofexpolysaccharides producing encapsulated Lactobacillus bulgaricus in alginate gel and the factors affecting the production of polysaccharides such as time, temperature, pH and the growth with Streptococcus thermophilus were studied, pH 5.5 and temperature 35℃/18hr were found to be optimal for exopolysaccharides production by encapsulated L. bulgaricus and free culture yielding 600 mg/L and 380 mg/L respectively. Co-culturing L. bulgaricus with S. thermophilus increased exopolysaccharides production at 35 ℃/18hr to 660 mg/L by encapsulated cells and 400 mg/L by free culture. Results of this study were applied in the manufacture of Labneh cheese vitally containing probiotic species ofL. acidophilus, L. gasseri, L. johnsonii and protection of these bacteria by polysaeeharide produced encapsulated L. bulgaricus. The use of exopolysaccharides producing encapsulated L. bulgaricus and probiotic bacteria can provide acceptable quality to functional Labneh. This product can be used as therapeutic and diabetic milk product with highly acceptable qualities. It is noted that all of the results are the means of triplicate experiments.
基金Project supported by the National Natural Science Foundation of China (No. 40101015) the National Key Basic Research Support foundation of China (No. G1999011806)
文摘A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorrhizal inoculation on plant growth and degradation of DEHP in two contaminated soils, a yellow-brown soil and a red soil. The air-dried soils were uniformly sprayed with different concentrations of DEHP, inoculated or left uninoculated with an arbuscular mycorrhizal (AM) fungus, and planted with…
文摘In order to determine the level of resistance of sugar beet varieties against Rhizoctonia solani AG 2-21IIB and AG 4, a methodology was implemented under greenhouse conditions that contemplated the most important criteria regarding to plant-pathogen interaction. The effect of plant growth stage on the development of the disease was evaluated. Seven sugar beet varieties were tested for resistance to R. solani AG 2-2IIIB and AG 4. To detect differences in leaf temperature between/L solani inoculated plants and non-infected plants, an infrared (IR) camera was tested. High incidence of R. solani AG 2-2IIIB and AG 4 in sugar beet plants was evident when the fungal inoculum was applied to two and four weeks old plants. At four weeks after sowing, it was the optimum time to inoculate sugar beet plants in order to generate R. solani infection, since at this time all plants were infected. Significant differences were detected regarding disease incidence between sugar beet varieties inoculated with different anastomosis groups. Leaf temperature was significant different between inoculated and non-inoculated plants, demonstrated that this technique could be a new tool for breeders to screen for resistance of new varieties.
基金Project (No. 39570134 and 39970419) supported by the National Natural Science Foundation of China.
文摘A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp. stimulated the growth of wheat (Triticum aestivum) and the uptake of N. By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.) increased by 6.5% and 5.9%, respectively, compared with bacteria alone treatment. The presence of nematode mainly accelerated the growth of aboveground of wheat, while it slightly inhibited the root development. There was little difference in plant tissue N concentration between treatments. P concentration and uptake of wheat, however, were generally reduced by nematode. It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineralization induced by nematode feeding on bacteria, and the reduction of phosphorous uptake is the result of weak root status and competition by bacteria immobilization.
文摘Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. Inoculation resulted in nodule number increases of 28.6, 29.02 and 23.9 times in sterilized soiland 3.4, 3.6 and 3.27 times in non-sterilized soil for A. parocera A. lebbeck and L. leucocephala seedlingsrespectively. Total dry mass increased by 127.6%, 66.7% and 60.7% in sterilized soil and 100%, 95.5%and 52.65% in non-sterilized soil for these three legume trees, respectively, after a period of two months.Significalltly high inoculation responses of root length, root diameter, collar diameter, shoot length, and drymass of root, shoot, leaves and nodules were also observed in both sterilized and non-sterilized soil media ascompared to respective control treatments. The response to inoculation was strong in sterilized and modestin non-sterilized soils. The significantly higher response to Rhizobium inoculation over control in all thespecies tested suggested that application of Rhizobium greatly enhanced plant growth, nodulation, biomassproduction and nitrogen-fixing activity of the nodules.
文摘Black aspergilli, the potential ochratoxin A (OTA) producers, were predominant fungi in fermented cocoa bean, coffee bean and dried cassava in Yogyakarta. Identification of black aspergilli at species level will be useful to make clear link between OTA contamination on food product and the toxin producer. The objective of this study was to identify the species of the black aspergilli producing OTA which contaminated dried agriculture products. In this study, 16 isolates were obtained, and four isolates among of them (YAC-9, YAK-6, YAK-12 and YAG-2) were found as OTA producing-strains, with the highest OTA found on Yeast Extract Sucrose (YES) solid medium of 57.68 ppb. Based on morphological characters, 16 isolates can be grouped into four species, after confirmation by molecular data based on PCR method, the groups were identified as A. carbonarius, A. niger, A. tubingensis and A. aculeatus. OTA producing-strains were identified as A. carbonarius and A. niger, meanwhile, A. tubingensis and A. aculeatus were found as non-OTA producing-strains.
基金Financial support of the UGC-DAE, Center for Scientific Research, Kolkata Centre
文摘Water samples from chromite mine quarry of Sukinda and its adjacent areas were analyzed for their heavy metal contamination along with physico-chemical and microbial contents. The chromite mine water samples possessed high concentrations of heavy metals in the order of Cr〉Fe〉Zn〉Ni〉Co〉Mn while ground water did not show any heavy metal contamination except Fe. Physico-chemical parameters of mine water samples showed deviation from those of normal water. Mine water harboured low microbial populations of bacteria, fungi and actinomycetes in comparison with mine adjacent water samples. The correlation of data between metals with physico-chemical parameters showed both positive and negative responses while that of metal and microbial population exhibited negative correlation. Bacterial strains isolated from chromite mine water exhibited high tolerance towards chromium and other heavy metals as well as antibiotics which could be used as an indicator of heavy metal pollution.
文摘Aerobic, heterotrophic bacteria, recovered from two sites located on the west coast of Scotland, were compared to cultures obtained in a similar way from industrial, aquacultural and clean sites in the vicinity of Qingdao, Shandong, P.R. China. Gram-negative bacterial cultures were examined by BIOLOG-GN, and the data analysed by the simple matching (S SM) and Jaccard coefficients (S J) and unweighted average linkage clustering using NTSys. The output revealed that 20% of the bacteria, namely, Acinetobacter johnsonii, Aquaspirillum dispar, Pseudomonas spp. (two groups), Sphingobacterium sp., Vibrio sp., V. campbellii, V. mimicus and V. hollisae, were common between the two geographical locations. However, the study revealed shortcomings with the BIOLOG-GN system for the study of coastal Gram-negative bacteria.
文摘Twenty isolates of Fusarium oxysporum f. sp. ciceris were isolated from wilted chickpea plants obtained from different districts of north part of Iraq to assess variability in pathogenicity of the populations. Each isolate was tested on 12 differential chickpea varieties. Isolates showed highly significant variation in wilt severity on the differential varieties. Based on the reaction types that induced on differential varieties, isolates were grouped into four groups, First group included isolates FocSl, FocQ7, FocQ 10, FocFI3, FocH 17 and FocHl8; the second group included isolates FocS2, FocS3, FocS4, FocQ5, FocQ8, FocQ9, FocF11, FocF12, FocFl4 and FocH19; the third group included isolates FocF15, FocHl6, FocH20; where the isolate FocQ6 was placed in the fourth group. Results showed that the percentage of genetic similarity was ranged 42% to 100% and was 42% between the first group and other groups and 72% between the three groups the rest and thus this indicate the presence of four races of the fungus which are O, 4, 5 and 1B/C, this represent the first record of these races in lraq.
基金Supported by The Finnish Funding Agency for Technologyand Innovation,Tekes,grants No.945/401/00 and 40160/05the Finnish Graduate School of Applied Biosciences,the Academy of Finland,Grant No.214 157the Centre of Excellence on Microbial Food Safety Research,Academy of Finland
文摘AIM:To study whether selected bacterial 16S ribosomal RNA(rRNA)gene phylotypes are capable of disting- uishing irritable bowel syndrome(IBS). METHODS:The faecal microbiota of twenty volunteers with IBS,subdivided into eight diarrhoea-predominant (IBS-D),eight constipation-predominant(IBS-C)and four mixed symptom-subtype(IBS-M)IBS patients,and fifteen control subjects,were analysed at three time-points with a set of fourteen quantitative real-timepolymerase chain reaction assays.All assays targeted 16S rRNA gene phylotypes putatively associated with IBS,based on 16S rRNA gene library sequence analysis. The target phylotypes were affiliated with Actinobac-teria,Bacteroidetes and Firmicutes.Eight of the target phylotypes had less than 95%similarity to cultured bacterial species according to their 16S rRNA gene sequence.The data analyses were made with repeated-measures ANCOVA-type modelling of the data and principle component analysis(PCA)with linear mixed-effects models applied to the principal component scores. RESULTS:Bacterial phylotypes Clostridium cocleatum 88%,Clostridium thermosuccinogenes 85%,Coprobacillus catenaformis 91%,Ruminococcus bromii-like, Ruminococcus torques 91%,and R.torques 93%were detected from all samples analysed.A multivariate analysis of the relative quantities of all 14 bacterial 16S rRNA gene phylotypes suggested that the intestinal microbiota of the IBS-D patients differed from other sample groups.The PCA on the first principal component(PC1),explaining 30.36%of the observed variation in the IBS-D patient group,was significantly altered from all other sample groups(IBS-D vs control, P=0.01;IBS-D vs IBS-M,P=0.00;IBS-D vs IBS-C, P=0.05).Significant differences were also observed in the levels of distinct phylotypes using relative values in proportion to the total amount of bacteria.A phy- lotype with 85%similarity to C.thermosuccinogenes was quantified in significantly different quantities among the IBS-D and control subjects(-4.08±0.90 vs -3.33±1.16,P=0.04)and IBS-D and IBS-M subjects (-4.08±0.90 vs-3.08±1.38,P=0.05).Furthermore,a phylotype with 94%similarity to R.torques was more prevalent in IBS-D patients'intestinal micro- biota than in that of control subjects(-2.43±1.49 vs -4.02±1.63,P=0.01).A phylotype with 93%simi- larity to R.torques was associated with control sam- ples when compared with IBS-M(-2.41±0.53 vs -2.92±0.56,P=0.00).Additionally,a R.bromii-like phylotype was associated with IBS-C patients in com- parison to control subjects(-1.61±1.83 vs-3.69± 2.42,P=0.01).All of the above mentioned phylotype specific alterations were independent of the effect of time. CONCLUSION:Significant phylotype level alterationsin the intestinal microbiotas of IBS patients were observed,further emphasizing the possible contribution of the gastrointestinal microbiota in IBS.
文摘To reveal the effects of Fe2+ on bacterial communities in the early stages of minerals dissolution, two different acid mine drainage (AMD) samples were collected at Dabaoshan Mine and Shenbu Mine. Community successions of AMD niches were analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA), sequencing, and phylogenetic analysis in original AMD samples and their subculture under Fe2+ concentrations. Although geochemical properties and community structures were greatly different between the two original AMD samples, bacterial community successions were still very similar under high Fe2+ concentrations. The results showed that Acidithiobacillus ferrooxidans have competitive relationship with other bacterial species living in the AMD, including species that were also capable of oxidizing ferrous ion. A competitive relationship among different At. ferrooxidans strains likewise existed. Some of At. ferrooxidans can grow first under conditions of high ferrous ion concentration, and other At. ferrooxidans species decreased gradually and disappeared. This suggested that these species of At. ferrooxidans are most acidophilic bacteria and afford Fe3+ to leach other metallic ion in the early stages of minerals dissolution.
文摘Ten seed borne fungi (Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.) were isolated and identified from two wheat varieties, the highest frequency of seed borne fungi was observed on wheat cultivar site Moll4 Alternaria sp.. Their mean and standard deviation was (5.5 ~ 1.69) while the lowest frequency fungal isolated was Dreschslera sp. and Rhizopus sp.. Their mean and standard deviation was (0.1 ~ 0.64). The aflatoxin-producing isolates appeared as gray or black colonies in the UV photographs, whereas nonproducing isolates appeared as white colonies, the plate five colony four (P5CO4) showed the positive results which means the presence of aflatoxin as compaired to the control which showed the ngative results. Ammonium Hydroxide Vapor-Induced Color Change method used which the dish was inverted and 1 or 2 drops of concentrated ammonium hydroxide solution are placed on the inside of the lid. The undersides of aflatoxin-producing colonies quickly turn plum-red after the bottom of the Petri dish has been inverted over the lid containing the ammonium hydroxide aspositive result in (P5CO4) and (P7CO4) observed. Essentially no color change occurs on the undersides of colonies that are not producing aflatoxinsthis indicate to the negative results (control). The main objective of this study is to isolation, identification and rapid detection of aflatoxin from wheat seed borne fungi.
文摘Apple/Malus x domestica cv. 'Topaz'/M26 and sour cherry cv. 'Debreceni Botermo'/Prunus mahaleb L. maidens were fertilized with different organic fertilizers and soil amendments in an organic nursery. A mycorrhizal inoculant, Micosat, was added to the non-fertilized control and to combinations fertilized with various bioproducts. Under assessment was the effect of nutrient delivery on the growth and development of maiden fruit trees focussing on tree height, thickness of the tree trunk, the number and the length of lateral shoots in each treatment combination. It was found that the introduction of mycorrhizal fungi into the soil without fertilizer application significantly improved the growth and development of apple and sour cherry maidens. Mineral fertilizer application (NPK) combined with mycorrhizal inoculation had a negligible effect on the above features. In the presence of bioproducts such as granular manure, Humus Active + Aktywit PM, BF Amin, Vinassa and Florovit Eko, the mycorrhizal fungi were more biologically active than in the absence of these products.
基金This study was supported by United States Depart-ment of Agriculture (USDA), Grant No.: BG-ARS-123
文摘A study was conducted at two pair sites of Chittagong Hill Tracts in Bangladesh to find out the effects of shifting cultivation on soil fungi and bacterial population. The first pair of sites with shifting culti-vation and village common forest-managed by indigenous community was at Madhya Para in Rangamati district and the second pair of sites with the shifting cultivated land and village common forest at Ampu Para in Bandarban district of Chittagong Hill Tracts. At both the locations with two different land uses, soil textures in surface (0?10 cm) and sub-surface (10?20 cm) soils varied from sandy loam to sandy clay loam. Soil pH and moisture content were lower in shifting cultivated land com-pared to village common forest. The results also showed that both fungal and bacterial population in surface and subsurface soils was significantly (p ≤ 0.05) lower, in most cases, in shifting cultivated land compared to village common forest at both Madhya Para and Ampu Para. At Ranga-mati and Bandarban in shifting cultivated lands, Colletrotrichum and Fusarium fungi were absent and all the bacterial genus viz. Coccus, Bacillus and Streptococcus common in two different locations with dif-ferent land uses. Common identified fungi at both the land uses and locations were Aspergillus, Rhizopus, Trichoderma and Penicillium. Further study can be done on the other soil biota to understand the extent of environmental deterioration due to shifting cultivation.