Microbial biomass and species in the rhizosphere soil of Mirabilis jalapa（Linn.）（the saline-alkali soil contaminated by total petroleum hydrocarbon（TPH））were studied with the technology of phospholipid fatty ac...Microbial biomass and species in the rhizosphere soil of Mirabilis jalapa（Linn.）（the saline-alkali soil contaminated by total petroleum hydrocarbon（TPH））were studied with the technology of phospholipid fatty acids（PLFAs） analysis,to explore the effects of Mirabilis jalapa（Linn.） growth on the structure characteristics of microbial communities and degradation of TPH in the petroleum-contaminated salinealkali soil.The result showed that compared with the CK soil without Mirabilis jalapa（Linn.）,the kind change rates of PLFAs were 71.4%,69.2% and 33.3% in spring,summer and autumn,respectively,and the degradation of TPH increased by 47.6%,28.3%,and 18.9% in the rhizosphere soil in spring,summer and autumn,respectively.Correlation analysis was used to determine the correlation between the degradation of TPH and the soil microbial communities：77.8% of the microbial PLFAs showed positive correlation（the correlation coefficient r﹥0） with the degradation of TPH,and 55.6% of the PLFAs had high positive correlation with the degradation of TPH with a correlation coefficient r ≥0.8.In addition,the relative contents of SAT and MONO had high correlation with the degradation of TPH in the CK soil,and the correlation coefficients were 0.92 and 0.60,respectively;but in the rhizosphere soil,42.1% of the PLFAs had positive correlation with it,and only21.1% had high positive correlation with the degradation of TPH,the relative contents of TBSAT,MONO and CYCLO had moderate or low positive correlation with the degradation of TPH,and the correlation coefficients were 0.56,0.50 and 0.07 respectively.It was shown that the growth of mirabilis jalapa（Linn.） highly affected the microbial community structure and TPH degradation speed in the rhizosphere soil,providing a theoretical basis for the research on phytoremediation of petroleumcontaminated saline-alkali soil.展开更多
The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight ...The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight biomass is up to 2.78 g/L and 2.70g/L respectively on medium containing 0.34 g/L nitrogen. Peptone is a favorable nitrogen source for DHA accumulation, DHA yield increases up to 338.56 mg/L. Using peptone and KNO3 as a multiple nitrogen source, the highest biomass and DHA yield are obtained from media containing 0.34 g/L nitrogen in which the ratio of peptone-N:NO3--N is 1:2,and the biomass and DHA yield are 2.98 g/L(DW) and 527.97mg/L respectively.展开更多
The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and ...The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.展开更多
The objectives of this study were to isolate a bensulfuron-methyl （BSM）-degrading strain of Bacillus spp. and to evaluate its effectiveness in remediation of a BSM-contaminated soil. A BSM-degrading bacterium, strai...The objectives of this study were to isolate a bensulfuron-methyl （BSM）-degrading strain of Bacillus spp. and to evaluate its effectiveness in remediation of a BSM-contaminated soil. A BSM-degrading bacterium, strain L1, was successfully isolated in this study. Strain L1 was identified as Bacillus megaterium based on its morphological, physiological, and biochemical properties, G＋C content, phylogenetie similarity of 16S rDNA, and fatty acid composition. Two experiments were used to examine BSM degradation by strain L1. When BSM was used as a sole carbon source in a mineral salt medium, the average degradation rate of BSM by strain L1 was 12.8%, which suggested that the strain was able to utilize BSM as a sole carbon and energy source. Supplement of yeast extract （200 mg L^-1） significantly （P ≤ 0.01） accelerated the degradation of BSM by strain L1. Ahnost complete degradation （97.7%） of BSM could be achieved in 84 h with addition of yeast extract. In addition, in a sterile soil with 50 mg L^-1 BSM, BSM degradation rate by strain L1 was 94.3% in 42 d, indicating the potential of using microbes for the remediation of BSM-contaminated soils in fields.展开更多
Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in South...Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in Southeast China, and that two representative tree species （Castanopisi carlesii and Cunninghamia lanceolata） may have different soil microbial community composition. Phospholipids fatty acid analysis （PLFA） of seasonal shifts and was used to assess the effect vegetation types on soil microbial community structure. A total of 22 different PLFAs were identified from all the soil samples. The bacterial PLFAs accounted for 62.37% of the total PLFAs, followed by fungi （28.94%）, and the minimum was actinomycetes （6.41%）. Overall, the level of PLFAs in C. carlesii soil was greater than those in C. lanceolata soil, and significant differences were observed in some seasons. The amounts of total, bacteria, actinomycic and fungal PLFAs significantly changed with the seasons and followed a sequence order （summer 〉 autumn 〉 spring 〉 winter）. The bacteria/fungi PLFAs and G （＋）/G （-） PLFAs of two vegetation types also changed with the seasons and the ratios in summer and autumn were higher than those in spring and winter. The correlation analysis of microbial PLFAs and soil physicochemical properties showed that the total, bacteria, fungal, actinomycic, G （＋） and G （-） PLFAs were significantly positive correlation with TOC, TN, TP, TK and moisture content. We concluded that the seasonal shifts and vegetation types affect soil microbial community composition by changing the soil physicochemical properties.展开更多
The study evaluated impact of psychrophilic anaerobic digestion on levels of viable populations of fecal indicator bacteria using various inoculum-to-substrate ratios （I：S）. Laboratory-scale batch reactors were mai...The study evaluated impact of psychrophilic anaerobic digestion on levels of viable populations of fecal indicator bacteria using various inoculum-to-substrate ratios （I：S）. Laboratory-scale batch reactors were maintained at 10 ℃ and 20 ℃ for 25 days with dairy manure substrate. Five treatments included inoculum （control inoculum; inoculum only [CI]）, manure （control manure; substrate only [CM]）, and 3I：1S, II：IS, and 1I：3S. E. coli decreased in all treatments, while Enterococci decreased in only a few treatments. Treatment 1 I： 1S achieved highest E. coli decrease at 20 ℃ （3.11 log）; CM showed highest E. coli decrease at 10 ℃ （2.33 log）. The 1I：3 Streatment showed highest decrease of Enterococci at 20 ℃ （1.82 log）, whereas CM had highest, but less substantial, decrease at 10 ℃ （0.49 log）. These decreases may be the result of environmental conditions, namely substrate limitation for E. coli, and, increased VFA （volatile fatty acid） levels for Enterococci. Lower I：S showed higher levels of indicator organisms; less stable conditions with more acidic pH, higher VFAs, and lower biogas production. Results suggest II：IS is ideal for starting a digester at 20 ℃, whereas 3I：1S appears optimal for 10 ℃, Overall, I：S influenced chemical parameters and fecal indicators during batch psychrophilic anaerobic digestion of manure.展开更多
A greenhouse pot experiment was conducted to evaluate pyrene degradation, microbial biomass, basal soil respiration, metabolic quotient （qCO2）, soil enzyme activities, and the FAME patterns of rhizospheric soil and ...A greenhouse pot experiment was conducted to evaluate pyrene degradation, microbial biomass, basal soil respiration, metabolic quotient （qCO2）, soil enzyme activities, and the FAME patterns of rhizospheric soil and nonrhizospheric soil. The results showed that the pyrene concentrations in soil decreased with time extending and were very significant less in rhizospheric soil grown with maize plants （p〈0.01）. At the end of the 45-day experiment, the ratios of pyrene degradation were 61.25% and 35.58% in rhizospheric and nonrhizospheric soil, respectively. Maize enhanced the decrease of pyrene concentration and increased the degradation rate of pyrene in soil. During the experimental period, a relatively large amount of microbial biomass biomass （Craig）, basal soil respiration, the Cmic/Corg ratio, enzyme （urease, dehydrogenase, polyphenol oxidase, and catalase） activities were detected in rbizospheric soil. Metabolic quotient was lower in rhizospheric soil than in nonrhizospheric soil at the whole experimental period. Soil microbial communities in rhizospheric soil and nonrhizospheric soil were characterized using fatty acid methyl ester （FAME） analysis. Fatty acid profiles demonstrated that soil microbial community structure was significantly altered in pyrene contaminated soil with maize. Fatty acid indicators for fungi and the ratio of fungi to bacteria significant increased, and fatty acid indicators for bacteria and Gram-negative bacteria significantly decreased. The effect gradually increased and got very significant （p〈0.01） with the time extending. The differences of fatty acid indicators for arbuscular mycorrhizal fungi （AMF）, Gram-positive bacteria and actinomycetes gradually increased, and the differences reached significant level （p〈0.05） at the end of the experiment （45 d）.展开更多
Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughte...Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughtered, therefore it is necessary to preserved meat, using simple techniques. One of such method of preservation is drying method to produced Intermediate Moisture Meat （IMM）. The quality attributes and microbiological status of Kundi, a West African dried meat product （IMM） were studied over three months of storage period by comparing commercial products and laboratory Kundi products. Chemical and minerals composition and microbiological counts were reported. Moisture and water activity results indicated that the experimental Kundi was sufficiently dried to minimize microbial growth. Fat oxidation levels measured by free fatty acids （FFA, %） on extracted fats were unacceptably high for the commercial Kundi （2.64%）, which may be a reflection of the oil used in spraying the products. Processing of Kundi, appears to have relative higher amounts of minerals than fresh meat but their relative solubility were lower. Aflatoxin levels far exceeded established safe limits for commercial samples while laboratory samples fell under the safe limits, resulting from the mould growth in each product, with laboratory samples having lower growth than commercial samples.展开更多
In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average mois...In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average moisture content of Karinyagi samples was found to be 17.64%. The average peroxide values of the samples was found 2.33 meq O2/kg fat. Free fatty acid values of samples ranged at 2.2-5.2 mg NaOH/g fat and the average acidity value was found to be 3.43 mg NaOH/g fat. Total aerobic mesophilic bacteria, yeast/mould, coliform group and Micrococcus/Staphylococcus counts of Karinyagi samples were 5.59, 5.54, 2.56, 1.24 log CFU/g fat, respectively.展开更多
Water and nitrogen （N） are considered the most important factors affecting rice production and play vital roles in regulating soil microbial biomass, activity, and community. The effects of irrigation patterns and N...Water and nitrogen （N） are considered the most important factors affecting rice production and play vital roles in regulating soil microbial biomass, activity, and community. The effects of irrigation patterns and N fertilizer levels on the soil microbial community structure and yield of paddy rice were investigated in a pot experiment. The experiment was designed with four N levels of 0 （NO）, 126 （N1）, 157.5 （N2）, and 210 kg N ha^（-1） （N3） under two irrigation patterns of continuous water-logging irrigation （WLI） and water- controlled irrigation （WCI）. Phospholipid fatty acid （PLFA） analysis was conducted to track the dynamics of soil microbial communities at tillering, grain-filling, and maturity stages. The results showed that the maximums of grain yield, above-ground biomass, and total N uptake were all obtained in the N2 treatment under WCI. Similar variations in total PLFAs, as well as bacterial and fungM PLFAs, were found, with an increase from the tillering to the grain-filling stage and a decrease at the maturity stage except for actinomycetic PLFAs, which decreased continuously from the tillering to the maturity stage. A shift in composition of the microbial community at different stages of the plant growth was indicated by principal component analysis （PCA）, in which the samples at the vegetative stage （tillering stage） were separated from those at the reproductive stage （grain-filling and maturity stages）. Soil microbial biomass, measured as total PLFAs, was significantly higher under WCI than that under WLI mainly at the grain-filling stage, whereas the fungal PLFAs detected under WCI were significantly higher than those under WLI at the tillering, grain-filling, and maturity stages. The application of N fertilizer also significantly increased soil microbial biomass and the main microbial groups both under WLI and WCI conditions. The proper combination of irrigation management and N fertilizer level in this study was the N2 （157.5 kg N ha^（-1）） treatment under the water-controlled irrigation pattern.展开更多
Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent ...Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent vegetative state were randomized into a control group and an observation group,with 33 cases in each group.The control group was given conventional treatment plus enteral nutrition support.The observation group was treated with additional Tiao Shen Jian Pi acupuncture therapy(acupuncture for spirit-regulating and spleen-invigorating)based on the same interventions in the control group.Both groups were treated for 8 weeks.The levels of total protein(TP),prealbumin(PA),albumin(Alb),and hemoglobin(Hb)were measured before and after treatment.The upper arm circumference and skinfold thickness of triceps brachii were measured.And the intestinal flora and fecal short-chain fatty acids contents were determined.Results After treatment,the levels of TP,PA,Alb,and Hb in the control group were decreased(P<0.05),while in the observation group,compared with those before treatment,the levels of TP,PA,Alb,and Hb had no statistical differences(P>0.05),and the levels were all higher than those in the control group(P<0.05).The upper arm circumference and skinfold thickness of triceps brachii in both groups decreased(P<0.05),and the values of these two items in the observation group were higher than those in the control group(P<0.05).In the control group,the contents of Bifidobacterium and Lactobacillus in feces decreased(P<0.05),and the content of Enterococcus increased(P<0.05).In the observation group,the contents of Bifidobacterium and Lactobacillus in feces increased(P<0.05),and the content of Enterococcus decreased(P<0.05).The differences between the two groups were statistically significant(P<0.05).In the control group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces decreased(P<0.05).In the observation group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces increased(P<0.05)and were all higher than those in the control group(P<0.05).Conclusion Acupuncture can improve nutrition-related blood indicators in patients in a persistent vegetative state and delay the decrease of upper arm circumference and skinfold thickness of triceps brachii,which may be related to the regulation of intestinal flora and fecal short-chain fatty acids contents.展开更多
The temperature gradient along the altitude transect of Mt. Jianfengling provides a good opportunity to establish and evaluate the microbial lipid-based environmental proxies. The soils collected from 14 different alt...The temperature gradient along the altitude transect of Mt. Jianfengling provides a good opportunity to establish and evaluate the microbial lipid-based environmental proxies. The soils collected from 14 different altitudes of Mt. Jianfengling contain abundant microbial fatty acids and fatty alcohols, including iso/anteiso fatty acids （i/aC12：0-i[aCl9：0）, 10-Me-C16：0 fatty acid, iso/anteiso fatty alcohols （i/aC13-iC26）, 10-Me-C16：0 fatty alcohol and unsaturated fatty alcohols, which can indicate a strong microbial activity in the Jianfengling soils. The branched and unsaturated fatty alcohols can be only detected when saponifica- tion is performed, implying that these lipids are present as the constituents of bacterial wax esters in the soils. The ratio of aC15/iC15 fatty acids is positively correlated with altitude, suggesting that the decrease in temperature can induce the increase in the relative abundance of anteiso C^5 fatty acid. In contrast, the ratio of aCJiC15 fatty alcohols and of aCjs/nC15 fatty alco- hols both decrease with increased altitude or decreased temperature. Similarly, the ratio of nC18：l/nCi8：0 fatty alcohols also de- creases with decreased temperature, which is opposite to the previous observation that unsaturation of fatty acids in microor- ganism increases in response to decreased temperature. Besides, the average chain length （ACL） of long chain fatty alcohols （C22-C30） from leaf waxes and carbon preference index （CPI） of all n-fatty alcohols are also significantly correlated with alti- tude or mean annual temperature, demonstrating their potential for paleoclimate reconstruction. The correlation of microbial fatty acids and alcohols as well as ACL and CPI of plant wax-derived fatty alcohols with altitude may provide novel ways to reconstruct paleotemperature and paleoaltimetry.展开更多
The purpose of this study was to clarify effects of selected oligosaccharides on concentrations of cecal short-chain fatty acids （SCFAs）, total large bowel wet weight and wall weight, and cecal microbiota levels in ...The purpose of this study was to clarify effects of selected oligosaccharides on concentrations of cecal short-chain fatty acids （SCFAs）, total large bowel wet weight and wall weight, and cecal microbiota levels in mice. Mice were respectively given gavage of selected fructooligosaccharides （FOS）, galactooligosaccharides （GOS）, mannanoligosaccharides （MOS）, and ehitooligosaccharides （COS） [1000 mg/（kg body weightd）]. Control group was given physiological saline solution. After 14 d treatment, SCFAs and lactate in mice cecum were significantly increased （P〈0.05） by intake of oligosaccharides, especially FOS and GOS. Thus, providing these oligosaccharides as ingredients in nutritional formulas may benefit the gastrointestinal tract.展开更多
No studies have examined the effect of experimental warming on the microbial biomass and community composition of soil in agricultural ecosystem on the Qinghai-Tibet Plateau. Thus it is unclear whether the influences ...No studies have examined the effect of experimental warming on the microbial biomass and community composition of soil in agricultural ecosystem on the Qinghai-Tibet Plateau. Thus it is unclear whether the influences of experimental warming on microbial communities in soil are related to warming magnitude in croplands on this Plateau. This study performed warming experiment(control, low-and high-level) in a highland barley system of the Lhasa River in May 2014 to examine the correlation between the response of microbial communities in soil to warming and warming magnitude. Topsoil samples(0–10 and 10–20 cm) were collected on September 14, 2014. Experimental warming at both low and high levels significantly increased soil temperature by 1.02 ℃ and 1.59 ℃, respectively at the depth of 15 cm. Phospho lipid fatty acid(PLFA) method was used to determine the microbial community in soil. The low-level experimental warming did not significantly affect the soil’s total PLFA, fungi, bacteria, arbuscular mycorrhizal fungi(AMF), actinomycetes, gram-positive bacteria(G+), gram-negative bacteria(G–), protozoa, the ratio of fungi to bacteria(F/B ratio), and ratio of G+ to G–(G+/G– ratio) at the 0–10 and 10–20 cm depth. The low-level experimental warming also did not significantly alter the composition of microbial community in soil at the 0–10 and 10–20 cm depth. The high-level experimental warming significantly increased total PLFA by 74.4%, fungi by 78.0%, bacteria by 74.0%, AMF by 66.9%, actinomycetes by 81.4%, G+ by 67.0% and G– by 74.4% at the 0–10 cm depth rather than at 10–20 cm depth. The high-level experimental warming significantly altered microbial community composition in soil at the 0–10 cm depth rather than at 10-20 cm depth. Our findings suggest that the response of microbial communities in soil to warming varied with warming magnitudes in the highland barley system of the Lhasa River.展开更多
An incubation experiment was designed in order to determine the further microbiological response to an addition （500 m3 ha-1） of fresh olive mill wastewater （FOMWW） in a soil that has been frequently amended with ...An incubation experiment was designed in order to determine the further microbiological response to an addition （500 m3 ha-1） of fresh olive mill wastewater （FOMWW） in a soil that has been frequently amended with uncontrolled doses of OMWW since the 1990s in an active disposal site （ADS soil）. To achieve this aim, the phospholipid fatty acid （PLFA） profiles, microbial biomass C （Cmic）, and dehydrogenase （DHA） and urease activities （URA） were monitored at the beginning （To）, 3 h （T1） and 97 d （Tf, i.e., the end） of incubation after FOMWW addition. After the FOMWW addition, an increase in the ratio of fungal to bacterial PLFAs was observed in ADS soil. Moreover, a relative increase of monounsaturated fatty acids （MUFAs） with respect to saturated fatty acids （SATFA） was found in the ADS soil. An increase of the Gram-positive to Gram-negative ratio was observed in this soil at the end of the incubation. While DHA and Cmic increased in the ADS soil after FOMWW addition, URA showed a decrease. Fungi and Gram-positive bacterial biomass experienced an increase after addition of a high dose of FOMWW in laboratory conditions.展开更多
文摘Microbial biomass and species in the rhizosphere soil of Mirabilis jalapa（Linn.）（the saline-alkali soil contaminated by total petroleum hydrocarbon（TPH））were studied with the technology of phospholipid fatty acids（PLFAs） analysis,to explore the effects of Mirabilis jalapa（Linn.） growth on the structure characteristics of microbial communities and degradation of TPH in the petroleum-contaminated salinealkali soil.The result showed that compared with the CK soil without Mirabilis jalapa（Linn.）,the kind change rates of PLFAs were 71.4%,69.2% and 33.3% in spring,summer and autumn,respectively,and the degradation of TPH increased by 47.6%,28.3%,and 18.9% in the rhizosphere soil in spring,summer and autumn,respectively.Correlation analysis was used to determine the correlation between the degradation of TPH and the soil microbial communities：77.8% of the microbial PLFAs showed positive correlation（the correlation coefficient r﹥0） with the degradation of TPH,and 55.6% of the PLFAs had high positive correlation with the degradation of TPH with a correlation coefficient r ≥0.8.In addition,the relative contents of SAT and MONO had high correlation with the degradation of TPH in the CK soil,and the correlation coefficients were 0.92 and 0.60,respectively;but in the rhizosphere soil,42.1% of the PLFAs had positive correlation with it,and only21.1% had high positive correlation with the degradation of TPH,the relative contents of TBSAT,MONO and CYCLO had moderate or low positive correlation with the degradation of TPH,and the correlation coefficients were 0.56,0.50 and 0.07 respectively.It was shown that the growth of mirabilis jalapa（Linn.） highly affected the microbial community structure and TPH degradation speed in the rhizosphere soil,providing a theoretical basis for the research on phytoremediation of petroleumcontaminated saline-alkali soil.
文摘The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight biomass is up to 2.78 g/L and 2.70g/L respectively on medium containing 0.34 g/L nitrogen. Peptone is a favorable nitrogen source for DHA accumulation, DHA yield increases up to 338.56 mg/L. Using peptone and KNO3 as a multiple nitrogen source, the highest biomass and DHA yield are obtained from media containing 0.34 g/L nitrogen in which the ratio of peptone-N:NO3--N is 1:2,and the biomass and DHA yield are 2.98 g/L(DW) and 527.97mg/L respectively.
基金Project(2009QNA6015) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(Y3110055)supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(Y200803219) supported by the Foundation of Zhejiang Educational Committee of China
文摘The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis （PCA） and phospholipid fatty acids （PLFA） profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9：0 to 18：1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18： lco7c, 16： lco7t, 16： lco5c and 18：2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L.
基金Project supported by the National High Technology Research and Development Program of China (863 Program)(No. 2007AA06Z329)the Science and Technology Program of Zhejiang Province (Nos. 2007C23036 and 2008C13014-3)the International Cooperation Program in Science and Technology of Zhejiang Province (No. 2008C14038)
文摘The objectives of this study were to isolate a bensulfuron-methyl （BSM）-degrading strain of Bacillus spp. and to evaluate its effectiveness in remediation of a BSM-contaminated soil. A BSM-degrading bacterium, strain L1, was successfully isolated in this study. Strain L1 was identified as Bacillus megaterium based on its morphological, physiological, and biochemical properties, G＋C content, phylogenetie similarity of 16S rDNA, and fatty acid composition. Two experiments were used to examine BSM degradation by strain L1. When BSM was used as a sole carbon source in a mineral salt medium, the average degradation rate of BSM by strain L1 was 12.8%, which suggested that the strain was able to utilize BSM as a sole carbon and energy source. Supplement of yeast extract （200 mg L^-1） significantly （P ≤ 0.01） accelerated the degradation of BSM by strain L1. Ahnost complete degradation （97.7%） of BSM could be achieved in 84 h with addition of yeast extract. In addition, in a sterile soil with 50 mg L^-1 BSM, BSM degradation rate by strain L1 was 94.3% in 42 d, indicating the potential of using microbes for the remediation of BSM-contaminated soils in fields.
基金supported by the National Natural Science Foundation of China (Grant No.31500443)Fujian Province Department of Education Foundation (Grant No.JA15178)
文摘Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in Southeast China, and that two representative tree species （Castanopisi carlesii and Cunninghamia lanceolata） may have different soil microbial community composition. Phospholipids fatty acid analysis （PLFA） of seasonal shifts and was used to assess the effect vegetation types on soil microbial community structure. A total of 22 different PLFAs were identified from all the soil samples. The bacterial PLFAs accounted for 62.37% of the total PLFAs, followed by fungi （28.94%）, and the minimum was actinomycetes （6.41%）. Overall, the level of PLFAs in C. carlesii soil was greater than those in C. lanceolata soil, and significant differences were observed in some seasons. The amounts of total, bacteria, actinomycic and fungal PLFAs significantly changed with the seasons and followed a sequence order （summer 〉 autumn 〉 spring 〉 winter）. The bacteria/fungi PLFAs and G （＋）/G （-） PLFAs of two vegetation types also changed with the seasons and the ratios in summer and autumn were higher than those in spring and winter. The correlation analysis of microbial PLFAs and soil physicochemical properties showed that the total, bacteria, fungal, actinomycic, G （＋） and G （-） PLFAs were significantly positive correlation with TOC, TN, TP, TK and moisture content. We concluded that the seasonal shifts and vegetation types affect soil microbial community composition by changing the soil physicochemical properties.
文摘The study evaluated impact of psychrophilic anaerobic digestion on levels of viable populations of fecal indicator bacteria using various inoculum-to-substrate ratios （I：S）. Laboratory-scale batch reactors were maintained at 10 ℃ and 20 ℃ for 25 days with dairy manure substrate. Five treatments included inoculum （control inoculum; inoculum only [CI]）, manure （control manure; substrate only [CM]）, and 3I：1S, II：IS, and 1I：3S. E. coli decreased in all treatments, while Enterococci decreased in only a few treatments. Treatment 1 I： 1S achieved highest E. coli decrease at 20 ℃ （3.11 log）; CM showed highest E. coli decrease at 10 ℃ （2.33 log）. The 1I：3 Streatment showed highest decrease of Enterococci at 20 ℃ （1.82 log）, whereas CM had highest, but less substantial, decrease at 10 ℃ （0.49 log）. These decreases may be the result of environmental conditions, namely substrate limitation for E. coli, and, increased VFA （volatile fatty acid） levels for Enterococci. Lower I：S showed higher levels of indicator organisms; less stable conditions with more acidic pH, higher VFAs, and lower biogas production. Results suggest II：IS is ideal for starting a digester at 20 ℃, whereas 3I：1S appears optimal for 10 ℃, Overall, I：S influenced chemical parameters and fecal indicators during batch psychrophilic anaerobic digestion of manure.
文摘A greenhouse pot experiment was conducted to evaluate pyrene degradation, microbial biomass, basal soil respiration, metabolic quotient （qCO2）, soil enzyme activities, and the FAME patterns of rhizospheric soil and nonrhizospheric soil. The results showed that the pyrene concentrations in soil decreased with time extending and were very significant less in rhizospheric soil grown with maize plants （p〈0.01）. At the end of the 45-day experiment, the ratios of pyrene degradation were 61.25% and 35.58% in rhizospheric and nonrhizospheric soil, respectively. Maize enhanced the decrease of pyrene concentration and increased the degradation rate of pyrene in soil. During the experimental period, a relatively large amount of microbial biomass biomass （Craig）, basal soil respiration, the Cmic/Corg ratio, enzyme （urease, dehydrogenase, polyphenol oxidase, and catalase） activities were detected in rbizospheric soil. Metabolic quotient was lower in rhizospheric soil than in nonrhizospheric soil at the whole experimental period. Soil microbial communities in rhizospheric soil and nonrhizospheric soil were characterized using fatty acid methyl ester （FAME） analysis. Fatty acid profiles demonstrated that soil microbial community structure was significantly altered in pyrene contaminated soil with maize. Fatty acid indicators for fungi and the ratio of fungi to bacteria significant increased, and fatty acid indicators for bacteria and Gram-negative bacteria significantly decreased. The effect gradually increased and got very significant （p〈0.01） with the time extending. The differences of fatty acid indicators for arbuscular mycorrhizal fungi （AMF）, Gram-positive bacteria and actinomycetes gradually increased, and the differences reached significant level （p〈0.05） at the end of the experiment （45 d）.
文摘Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughtered, therefore it is necessary to preserved meat, using simple techniques. One of such method of preservation is drying method to produced Intermediate Moisture Meat （IMM）. The quality attributes and microbiological status of Kundi, a West African dried meat product （IMM） were studied over three months of storage period by comparing commercial products and laboratory Kundi products. Chemical and minerals composition and microbiological counts were reported. Moisture and water activity results indicated that the experimental Kundi was sufficiently dried to minimize microbial growth. Fat oxidation levels measured by free fatty acids （FFA, %） on extracted fats were unacceptably high for the commercial Kundi （2.64%）, which may be a reflection of the oil used in spraying the products. Processing of Kundi, appears to have relative higher amounts of minerals than fresh meat but their relative solubility were lower. Aflatoxin levels far exceeded established safe limits for commercial samples while laboratory samples fell under the safe limits, resulting from the mould growth in each product, with laboratory samples having lower growth than commercial samples.
文摘In this study, moisture content, peroxide and free fatty acid values and microbial counts of 30 Karinyagi samples taken from different retail markets in Afyonkarahisar province have been investigated. The average moisture content of Karinyagi samples was found to be 17.64%. The average peroxide values of the samples was found 2.33 meq O2/kg fat. Free fatty acid values of samples ranged at 2.2-5.2 mg NaOH/g fat and the average acidity value was found to be 3.43 mg NaOH/g fat. Total aerobic mesophilic bacteria, yeast/mould, coliform group and Micrococcus/Staphylococcus counts of Karinyagi samples were 5.59, 5.54, 2.56, 1.24 log CFU/g fat, respectively.
基金Supported by the National Basic Research Program (973 Program) of China (No.2007CB109305)the National Natural ScienceFoundation of China (No.3197859)
文摘Water and nitrogen （N） are considered the most important factors affecting rice production and play vital roles in regulating soil microbial biomass, activity, and community. The effects of irrigation patterns and N fertilizer levels on the soil microbial community structure and yield of paddy rice were investigated in a pot experiment. The experiment was designed with four N levels of 0 （NO）, 126 （N1）, 157.5 （N2）, and 210 kg N ha^（-1） （N3） under two irrigation patterns of continuous water-logging irrigation （WLI） and water- controlled irrigation （WCI）. Phospholipid fatty acid （PLFA） analysis was conducted to track the dynamics of soil microbial communities at tillering, grain-filling, and maturity stages. The results showed that the maximums of grain yield, above-ground biomass, and total N uptake were all obtained in the N2 treatment under WCI. Similar variations in total PLFAs, as well as bacterial and fungM PLFAs, were found, with an increase from the tillering to the grain-filling stage and a decrease at the maturity stage except for actinomycetic PLFAs, which decreased continuously from the tillering to the maturity stage. A shift in composition of the microbial community at different stages of the plant growth was indicated by principal component analysis （PCA）, in which the samples at the vegetative stage （tillering stage） were separated from those at the reproductive stage （grain-filling and maturity stages）. Soil microbial biomass, measured as total PLFAs, was significantly higher under WCI than that under WLI mainly at the grain-filling stage, whereas the fungal PLFAs detected under WCI were significantly higher than those under WLI at the tillering, grain-filling, and maturity stages. The application of N fertilizer also significantly increased soil microbial biomass and the main microbial groups both under WLI and WCI conditions. The proper combination of irrigation management and N fertilizer level in this study was the N2 （157.5 kg N ha^（-1）） treatment under the water-controlled irrigation pattern.
文摘Objective To explore the effects of acupuncture on nutritional status in patients in a persistent vegetative state.Methods A prospective randomized controlled trial was designed.A total of 66 patients in a persistent vegetative state were randomized into a control group and an observation group,with 33 cases in each group.The control group was given conventional treatment plus enteral nutrition support.The observation group was treated with additional Tiao Shen Jian Pi acupuncture therapy(acupuncture for spirit-regulating and spleen-invigorating)based on the same interventions in the control group.Both groups were treated for 8 weeks.The levels of total protein(TP),prealbumin(PA),albumin(Alb),and hemoglobin(Hb)were measured before and after treatment.The upper arm circumference and skinfold thickness of triceps brachii were measured.And the intestinal flora and fecal short-chain fatty acids contents were determined.Results After treatment,the levels of TP,PA,Alb,and Hb in the control group were decreased(P<0.05),while in the observation group,compared with those before treatment,the levels of TP,PA,Alb,and Hb had no statistical differences(P>0.05),and the levels were all higher than those in the control group(P<0.05).The upper arm circumference and skinfold thickness of triceps brachii in both groups decreased(P<0.05),and the values of these two items in the observation group were higher than those in the control group(P<0.05).In the control group,the contents of Bifidobacterium and Lactobacillus in feces decreased(P<0.05),and the content of Enterococcus increased(P<0.05).In the observation group,the contents of Bifidobacterium and Lactobacillus in feces increased(P<0.05),and the content of Enterococcus decreased(P<0.05).The differences between the two groups were statistically significant(P<0.05).In the control group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces decreased(P<0.05).In the observation group,the total content of fecal short-chain fatty acids and the contents of acetic acid and butyric acid in feces increased(P<0.05)and were all higher than those in the control group(P<0.05).Conclusion Acupuncture can improve nutrition-related blood indicators in patients in a persistent vegetative state and delay the decrease of upper arm circumference and skinfold thickness of triceps brachii,which may be related to the regulation of intestinal flora and fecal short-chain fatty acids contents.
基金supported by National Basic Research Program of China(Grant No.2011CB808800)National Natural Science Foundation of China(Grant No.41130207)‘111’Project(Grant No.B08030)
文摘The temperature gradient along the altitude transect of Mt. Jianfengling provides a good opportunity to establish and evaluate the microbial lipid-based environmental proxies. The soils collected from 14 different altitudes of Mt. Jianfengling contain abundant microbial fatty acids and fatty alcohols, including iso/anteiso fatty acids （i/aC12：0-i[aCl9：0）, 10-Me-C16：0 fatty acid, iso/anteiso fatty alcohols （i/aC13-iC26）, 10-Me-C16：0 fatty alcohol and unsaturated fatty alcohols, which can indicate a strong microbial activity in the Jianfengling soils. The branched and unsaturated fatty alcohols can be only detected when saponifica- tion is performed, implying that these lipids are present as the constituents of bacterial wax esters in the soils. The ratio of aC15/iC15 fatty acids is positively correlated with altitude, suggesting that the decrease in temperature can induce the increase in the relative abundance of anteiso C^5 fatty acid. In contrast, the ratio of aCJiC15 fatty alcohols and of aCjs/nC15 fatty alco- hols both decrease with increased altitude or decreased temperature. Similarly, the ratio of nC18：l/nCi8：0 fatty alcohols also de- creases with decreased temperature, which is opposite to the previous observation that unsaturation of fatty acids in microor- ganism increases in response to decreased temperature. Besides, the average chain length （ACL） of long chain fatty alcohols （C22-C30） from leaf waxes and carbon preference index （CPI） of all n-fatty alcohols are also significantly correlated with alti- tude or mean annual temperature, demonstrating their potential for paleoclimate reconstruction. The correlation of microbial fatty acids and alcohols as well as ACL and CPI of plant wax-derived fatty alcohols with altitude may provide novel ways to reconstruct paleotemperature and paleoaltimetry.
基金Project (No. 2006C12098) supported by the Bureau of Science and Technology of Zhejiang Province, China
文摘The purpose of this study was to clarify effects of selected oligosaccharides on concentrations of cecal short-chain fatty acids （SCFAs）, total large bowel wet weight and wall weight, and cecal microbiota levels in mice. Mice were respectively given gavage of selected fructooligosaccharides （FOS）, galactooligosaccharides （GOS）, mannanoligosaccharides （MOS）, and ehitooligosaccharides （COS） [1000 mg/（kg body weightd）]. Control group was given physiological saline solution. After 14 d treatment, SCFAs and lactate in mice cecum were significantly increased （P〈0.05） by intake of oligosaccharides, especially FOS and GOS. Thus, providing these oligosaccharides as ingredients in nutritional formulas may benefit the gastrointestinal tract.
基金National Natural Science Foundation of China(31370458,31600432,41807331)Bingwei Outstanding Young Talents Program of Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences(2018RC202)+2 种基金National Key Research Projects of China(2016YFC0502005,2016YFC0502006,2017YFA0604801)Youth Innovation Research Team Project of Key Laboratory of Ecosystem Network Observation and Modeling(LENOM2016Q0002)Tibet Science and Technology Major Projects of Pratacultural Industry(XZ201801NA02)
文摘No studies have examined the effect of experimental warming on the microbial biomass and community composition of soil in agricultural ecosystem on the Qinghai-Tibet Plateau. Thus it is unclear whether the influences of experimental warming on microbial communities in soil are related to warming magnitude in croplands on this Plateau. This study performed warming experiment(control, low-and high-level) in a highland barley system of the Lhasa River in May 2014 to examine the correlation between the response of microbial communities in soil to warming and warming magnitude. Topsoil samples(0–10 and 10–20 cm) were collected on September 14, 2014. Experimental warming at both low and high levels significantly increased soil temperature by 1.02 ℃ and 1.59 ℃, respectively at the depth of 15 cm. Phospho lipid fatty acid(PLFA) method was used to determine the microbial community in soil. The low-level experimental warming did not significantly affect the soil’s total PLFA, fungi, bacteria, arbuscular mycorrhizal fungi(AMF), actinomycetes, gram-positive bacteria(G+), gram-negative bacteria(G–), protozoa, the ratio of fungi to bacteria(F/B ratio), and ratio of G+ to G–(G+/G– ratio) at the 0–10 and 10–20 cm depth. The low-level experimental warming also did not significantly alter the composition of microbial community in soil at the 0–10 and 10–20 cm depth. The high-level experimental warming significantly increased total PLFA by 74.4%, fungi by 78.0%, bacteria by 74.0%, AMF by 66.9%, actinomycetes by 81.4%, G+ by 67.0% and G– by 74.4% at the 0–10 cm depth rather than at 10–20 cm depth. The high-level experimental warming significantly altered microbial community composition in soil at the 0–10 cm depth rather than at 10-20 cm depth. Our findings suggest that the response of microbial communities in soil to warming varied with warming magnitudes in the highland barley system of the Lhasa River.
基金Supported by the European Union's LIFE Programme PROSODOL (No. LIFE07 ENV/GR/000280)
文摘An incubation experiment was designed in order to determine the further microbiological response to an addition （500 m3 ha-1） of fresh olive mill wastewater （FOMWW） in a soil that has been frequently amended with uncontrolled doses of OMWW since the 1990s in an active disposal site （ADS soil）. To achieve this aim, the phospholipid fatty acid （PLFA） profiles, microbial biomass C （Cmic）, and dehydrogenase （DHA） and urease activities （URA） were monitored at the beginning （To）, 3 h （T1） and 97 d （Tf, i.e., the end） of incubation after FOMWW addition. After the FOMWW addition, an increase in the ratio of fungal to bacterial PLFAs was observed in ADS soil. Moreover, a relative increase of monounsaturated fatty acids （MUFAs） with respect to saturated fatty acids （SATFA） was found in the ADS soil. An increase of the Gram-positive to Gram-negative ratio was observed in this soil at the end of the incubation. While DHA and Cmic increased in the ADS soil after FOMWW addition, URA showed a decrease. Fungi and Gram-positive bacterial biomass experienced an increase after addition of a high dose of FOMWW in laboratory conditions.
