Abstract:第十三次全国环境微生物学术研讨会于2010年11月在南京大学顺利召开, 本次会议围绕“环境微生物与社会发展”的主题, 在环境微生物学研究前沿、环境微生物与节能减排、环境微生物与气候变化、环境微生物资源发掘与应用、环境保护工程、污染环境生物修复、蓝藻水华衍生污染物与生态风险等诸多领域阐述了最新研究进展并展开了深入的研讨。为了展现国内环境微生物及相关交叉领域科研工作者取得的最新进展, 《微生物学通报》针对“第十三次全国环境微生物学学术研讨会”组织出版了这期“环境微生物专刊”, 期望该专刊的出版有助于促进我国环境微生物学相关领域的交流与发展。

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Abstract:Soil samples collected from bamboo agroforestry fields in Hangzhou, China, were studied for screening and isolation of fungal strains capable of degradation of structurally different dyes. Among all isolates, an isolate (1302BG) could decolorize all of the 9 tested dyes (Aniline blue, Congo red, Orange G, Methyl red, Methyl orange, Crystal violet, Fuchsin acid, Safranine T, Fuchsin basic, and Methyl violet) on the solid agar plates. The isolate was identified as Trichaptum abietinum by morphological and molecular methods. Different parameters such as pH, temperature, carbon source, nitrogen source, co-effect of carbon and nitrogen source, and carbon/nitrogen regimes were used to find an inexpensive medium for Trichaptum abietinum 1302BG to decolorize. The results showed that the strain was very efficient at decolorizing the two tested dyes (Congo red and Fuchsin acid) in both acid and basic conditions. The inexpensive and environment-friendly medium contained 0.5 g/L starch and 0.05 g/L ammonium sulfate and could decolorize the two dyes over 90% after 24 hours incubation under both sterile and non-sterile (nature) conditions. The UV-vis absorption spectrum indicated that the decolorization by this fungus should be attributed to biodegradation. A great decrease in toxicity after the decolorization of Congo red and Fuchsin acid was observed by micronucleus tests. The results suggest that Trichaptum abietinum 1302BG is a highly promising fungus for the treatment of industrial dye effluents.

Abstract:The field remediation of the oil residue pollution in soil were carried out in Zhongyuan Oil Field, which using the optimistic techniques of in-situ microbial communities combining with the physical and chemistrial methods. The results showed that degradation rate can reach 99% as the oil content of 2 898.25 mg/kg in polluted soil after 99 d microbial and ecological remediation, which provide us the feasible technology and application of oil residue pollution remediation in soil at oilfields.

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Abstract:A simple modification was developed for construction of genomic/metagenomic libraries by T-vectors. Topoisomerase II was employed to introduce superhelical turns into relaxed circular T-A recombinant molecules, which greatly increased the transformation efficiency. By using this technique, a metagenomic library was constructed and a γ-hexachlorocyclohexane dehydrochlorinase gene linA-like was screened from it.

Abstract:In the study, four methods used for quantification of cyanobacteria and Microcystis by SYBR Green I real-time quantitative PCR (RT-qPCR) were established based on the target genes, including the 16S rRNA gene of cyanobacteria, the phycocyanin and the 16S rRNA gene of Microcystis. Then the cultured M. aeruginosa and the environmental samples of Lake Taihu were evaluated by the established methods. Comparison between the new approaches and microscope counting indicated that RT-qPCR analysis could meet the requirement of algae bloom quantification and it was convenient, rapid and specific.

Abstract:Fast conformation, good shock resistance and good suspensibility of anaerobic granular sludge are the important characteristics of a new anaerobic treatment plant dealing with high concentration organic wastewater. In order to investigate the diversity and functional characteristics of archaea, most important component of granular sludge, total archaeal genomic DNA was extracted from sample. The community structure was studied by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and cloning-sequencing based 16S rDNA. The results showed that archaeal community clones were classified into Methanosaeta, Methanosarcina, Methanobacterium and Methanomethylovorans all four clusters, accounting for 58.2%, 23.6%, 12.7% and 3.6% of the clone library capacity separately, one clone with 1.8% proportion could not be found the most similar strain. The sequences blast results and phylogenetic analysis of archaea showed that clones C10, C11, C13 and C19 had high similarity with the known strains FJ618821, AB479397, AJ244290 and AB447878 separately and their relative taxonomy groups also be found. Methanosaeta and Methanosarcina were the main clusters in archaeal community, so methane production approach was acetic acid-based. Intermediate metabolites VFAs analysis was combined with different metabolic functions comparison, which confirmed the corresponding relationship between archaeal community diversity and its metabolism function.

Abstract:To efficiently treat high concentration organic wastewater, we designed fixed carrier anaerobic reactor R1 and R2. They are improvement of anaerobic baffle reactor (ABR). Its baffles were made from active carbon fiber, quick start-up of R1 and R2 is proceeded to treat molasses wastewater in a laboratory-scale. The hydraulic retention times (HRT) and organic loading rate (OLR) are important technical parameters which affect stable efficient operation and start-up of reactor. The results indicated when HRT is 2 d, reactors show the optimum operation. In the operation of 30 d, COD removal efficiency of R1 could reach the 84.88%, R2 could reach 81.72%. Biogas production rate increased from 0.35 L/(L·d) to 4.98 L/(L·d), with influent organic loading rate (OLR) raised from 1.25 kg/(m3·d) to 10 kg/(m3·d). In the two reactors, the pH value of effluent wastewater was between 6.7 to 7.6 and the pH value of influent wastewater was between 3.9 to 4.5. During the whole experimental period, the pH value of influent wastewater was not adjusted, which proved two reactors have strong ability to resist acid. The pH value of R1 fluctuated more gently. The reactors with less sludge losing and no clogging phenomenon showed the strong ability to treat acidic high concentration organic wastewater and to resist high shock loading during the whole running processes.

Abstract:Microbial technology for the comprehensive utilization of excess activated sludge, i.e. production of PHA by adding native PHA synthesis-bacteria during domestication and fermentation for activated sludge; bioleaching activated sludge to remove heavy metals by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans; production of biological fertilization by using solid state fermentation for P-solubilizing bacteria and K-releasing bacteria. Results showed that the ratio of PHA in VSS was above 20% under the 500 L pilot scale; the contents of heavy metals in activated sludge accorded with the National Discharge Standard; the number functional bacteria for microbial fertilizer was above one hundred million.

Abstract:The formation of secondary iron minerals often is observed in sludge bioleaching system facilitated by Acidithiobacillus ferrooxidans, which affected the sludge dewaterability and heavy metals leaching. At the critical point of jarosite formation in FeSO4-K2SO4-H2O system inoculated by Acidithiobacillus ferrooxidans, a simulative experiment were carried out to study the effects of bacteria density and the resulting minerals collection time on the iron precipitation formation. The results indicated that the amount and type of precipitates formed in the bioleaching system depended, to a certain extent, on the Acidithiobacillus ferrooxidans density and mineral collection time. If the resulting iron mineral wasn’t removed through manual collection in time, monovalent cation (such as K+) existed in reaction solution would facilitate easily the resulting schwertmannite to transform into jarosite.

Abstract:A bacteria strain X-4 capable of degrading atrazine was isolated from the activated sludge from the wastewater treating system of an atrazine manufacturer. It was preliminarily identified as Arthrobacter sp. according to its physiological & biochemical characteristics and the analysis of its 16S rRNA gene sequence. This strain could use atrazine as sole carbon and nitrogen source, and degrade 95.7% of 100 mg/L atrazine within 42 h. The optimal pH and temperature for the degradation were 30 °C and pH 7.0, respectively. Strain X-4 could tolerate many kinds of heavy metals, which showed its potential in treating the co-contamination of atrazine and heavy metals. The atrazine-degrading related genes of strain X-4 were the combination of trzN, atzB and atzC.

Abstract:Hydrogen production of photosynthetic bacteria group was studied using corn stalk hydrolyzate as hydrogen production substrate. The affects of sulfuric acid concentration, solid-liquid ratio, hydrolysis time and hydrolysis temperature on hydrogen production were investigated. The optimum process conditions were as follows: the sulfuric acid concentration was 1%, the solid-liquid ratio was 1:12, the hydrolysis time was 0.5 h and the hydrolysis temperature was 110 °C, respectively. Three hydrolyzate detoxification methods were compared and the method of calcium hydroxide obtained the optimal detoxification effect. NH4+ played a stimulatory role to the hydrogen production within certain concentration.

Abstract:Some de-odorizing microbes and litter materials were combined to decrease ammonia emission from chicken manure and minimize its dangerous effect on environment. The de-odorizing microbes (F468, M1?M9) could significantly decrease ammonia emission from chicken manure and F468 was the optimal. The ability of F468 to decrease ammonia emission could not be improved significantly by mixture with other de-odorizing microbe (M1?M9), and some microbes hindered its ability, therefore the method of application of single microbe (F468) was preferred. Ammonia was not efficiently decreased by adding litter material such as wheat bran, wheat straw and cottonseed bran. Ammonia emission was abundantly decreased by mixing litter materials with F468, such as 88% (w/w) ammonia loss was retrieved within 0?5 d by adding 5% (w/w) F468 and 10% (w/w) wheat straw. In general, the application of de-odorizing microbe and straw to decrease ammonia emission from chicken manure not only minimized its dangerous effect on environment, but also represented an alternative practice of open air burning of straw.

Abstract:The microbial community WSD-5 could not only degrade wheat straw but also secret extracellular enzyme efficiently. In order to further study the synergistic decomposition mechanism of WSD-5 and optimize the microbial combination, 11 bacterial strains and 3 fungal strains were isolated from the microbial community WSD-5. The closest relatives of 11 bacterial strains were Pseudomonas sp., Pseudomonas aeruginosa, Achromobacter sp., Stenotrophomonas sp., Bacillus fusiformis, Bacillus cereus, Brevundimonas sp., Ochrobactrum sp., Cytophaga sp., Benzo(a)pyrene-degrading bacter, Flavobacterium sp. by sequencing nearly complete 16S rDNA and the closest relatives of 3 fungal strains were Pseudallescheria boydii, Coprinus cinereus by sequencing 26S rDNA. Whereas transparent circles were detected on carboxymethylcellulose (CMC) plates with 4 bacterial strains and 3 fungal strains, there were only 3 fungal strains which had the enzymatic productivity by determining the enzyme activity. The results of dynamic trend of enzyme activity showed that the peak heights occurred at 7?14 days. The F1 expressed the highest filter paper activity (1.05 U/mL), the highest cellulose endonuclease activity (5.53 U/mL) and the highest exonuclease activity (0.56 U/mL). The highest β-glucosidase activity (0.44 U/mL) and xylanase activity (58.95 U/mL) were expressed by the FC. The highest xylanse activity of FC was 6 times higher than that of F1.

Abstract:In order to enhance the production of laccase and reduce the cost of laccase production, the culture medium for the growth of Coriolus hirsutus, a laccase production strain, was studied using molasses distillery wastewater (MDW) as carbon source. The different concentrations of molasses distillery wastewater and proportion of urea were optimized consequently through Box-Behnken experiment design under the foundation of signal factor experiment. As the optimization result, the production of laccase with the concentration of MDW 47% and proportion of urea 0.5% was six times higher than that from the original medium used previously. This indicates that the laccase production using MDW as carbon source is feasible. At the same time, the study makes the theoretical foundation for the exploitation and utilization of MDW to produce high value product.

Abstract:A new dyes-decolorizig bacterial strain N-4 was isolated from soil sample. It was indentified as Leucobacter sp. by 16S rDNA gene sequence analysis. The optimal conditions for the decolorization of the reactive dark blue K-R determined by response surface methodology (RSM) were as follows: 10 g/L of strains N-4, 222 mg/L of initial dye concentration, 1.5 g/L of (NH3)2SO4 and 3.5 g/L of fructose. It was shown that about 100% of 222 mg/L dye could be decolorized within 10 h under these conditions. Besides, strain N-4 could decolorize 9 kinds of dyes effectively. And K+, Ca2+, Mg2+, Ba2+, Mn2+ could improve the decolorizaion, while Ni2+, Cu2+ and Hg2+ inhibite the decolorization obviously.

Abstract:Two cellulose producing strains were isolated from decayed leaf and soil around it. According to morphology, biochemical and physiological characterization, and 16S rRNA sequence analysis, CT1 was identified as Bacillus licheniformis and CM2 was identified as Bacillus subtilis. Through deteminations of CMC enzyme activity and filter paper enzyme activity using liquid fermentation. The result of the CMCasae activity of CT1 is 163.3 U/mL and CM2 is 167.17 U/mL after 4 d, the FPA activity of CT1 is 211.17 U/mL after 2 d and CM2 is 207.83 U/mL after 3 d. The effect of carbon sources on the optimum cellulase-producing conditions of these strains were studied. By silver staining after SDS-polyacrylamide gel electrophoresis preliminary separation cellulose enzyme special bands. The result showed that the utilization capabilities to different source cellulose were different.

Abstract:14 strains of endophytic actinomycetes were isolated from the roots of ethnomedical plants, Forsythia suspensa and Forsythia suspensa, collected in Chengdu. The results of antimicrobial and anticancer activity assays of the fermentation crude extracts showed: 10 strains displayed inhibition to HepG2 cell line in varied degrees, accounting for 71% of total isolates; 3 strains exhibited antibacterial activity; and strain A263 showed acute cytotoxic activity and wide-spectrum of antibacterial activity. Based on similarity analysis of 16S rRNA gene partial sequences, strain A275 was indicated affiliate to genus Kribbella, and the remaining 13 strains were belong to genus Streptomyces. PCR screening of biosynthesis genes revealed 5 strains possess PKS-I, PKS-II, NRPS genes simultaneously, and strain A255, A263 possessed 3,5-AHBA synthetase gene additionally, while strain A275 was the only one found with oxyB gene. These results may deduce Streptomyces was the dominant actinomycetes in the roots of these ethnomedical plants. PCR screening of biosynthesis genes compensate the limitation of traditional screening model for bioactive substances tremendously. Endophytic actinomycetes were acknowledged with enormous potential of producing prolific bioactive compounds.

Abstract:A novel membrane-bound hydrogen sulfide dehydrogenase was purified to homogeneity by a four-step procedure from Thiobacillus thioparus D6, an neutrophilic, obligately chemolithoautotrophic bacteria obtained from aerobic magnetic stabilized fluidized bed reactor of flue gas biodesulfurization system. The natural hydrogen sulfide dehydrogenase had a molecular mass of 95 kD and comprised two subunits named α and β with molecular masses of 42.6 kD and 51.3 kD determined by exclusion chromatography and SDS-PAGE. Spectral and pyridine hemochrome analysis revealed that the enzyme contained 1 mol flavin and 1 mol haem c per mol αβ hydrogen sulfide dehydrogenase, assumed a characteristics of the member of redox proteins. Biochemical determination and nonlinear regression analysis showed that the sulfide dehydrogenase catalyzed sulfide-dependent horse heart cytochrome c reduction at the optimum pH of 8.6 with a kcat of 32.4 s?1, a Km of 6.1 μmol/L for sulfide, and a Km of 2.5 μmol/L for cytochrome c. The yield of 1.9 mol of cytochrome c reduction per mole of sulfide suggested that the product was sulfur or polysulfide. The activity of the sulfide dehydrogenase was inhibited by sulfur and sulfite like that cyanide (100 μmol/L) inhibited sulfide dehydrogenase activity at pH 6.0 by 72%.

Abstract:The amount and distribution of nitrogen cycling bacteria in sediments of Meiliang Bay and Gonghu Bay of Lake Taihu were studied by FISH analysis. The amount of archaea decreased along the sediment depth, however, its ratio to total microorganisms increased. The amount of Ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in Meiliang Bay was higher than that in Gonghu Bay although the amount of both bacteria decreased along the sediment depth. Our results indicated that the existence of aquatic macrophyte in Gonghu Bay might affiliate transformation of nitrogen. Crenarchaeota was universally detected in surface sediments and overnumbered AOB, which indicated that it might play an important role in nitrogen cycling.

Abstract:Denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rRNA gene clone library methods were used to analyze the microbial communities of a water injection well (G) and an oil production well (L) at two sampling time points (A and B) in Gudao block of Shengli oilfield. DGGE profile showed that the microbial similarity of sample G at two sampling time was 48.1%, that of sample L was 28.7%, respectively. Sequence analysis of 16S rRNA gene clone libraries showed that bacteria in G library at time point A were mainly Betaproteobacteria and Gammaproteobacteria, and also with low percentage of Deferribacteres, Firmicutes and Bacteroidetes; But in L library, 97% bacteria belong to Moraxellaceae of Gammaproteobacteria. Whereas, the main type of bacteria in sample G at time point B were Betaproteobacteria and Deferribacteres. The bacterial composition of sample L was dominated by Gammaproteobacteria, Betaproteobacteria and Firmicutes. Both DGGE and clone library indicated the distinct temporary shift of microbial communities of production well, but much less change happened in injection water sample. Our results will benefit to the better understanding of mechanisms of microbial enhanced oil recovery.

Abstract:With traditional microbiological culture and enzyme method, the effect of 1,3-dichlorobenzene (1,3-DCB) on reed wetland soil microbial and enzyme activities was studied. Results demonstrated that different groups of oil microorganisms have different responses to 1,3-DCB, in which the actinomycetes was significantly inhibited. When the 1,3-DCB concentration was higher than 120 μg/g, the bacterial amounts were significantly inhibited. The soil fungi amounts were initially increased at the beginning of the experiment but inhibited with time. During the experiment, 1,3-DCB treatment could significantly inhibit the soil catalase and polyphenol oxidase activity. Results indicated that these two enzymes are sensitive to 1,3-DCB contamination.

Abstract:In a pot experiment, effects were investigated of inoculation with arbuscular mycorrhizal fungi isolated from soil of a mining area on root colonization and biomass, Cd uptake and translocation of Tagetes erecta L. under different Cd addition levels (0, 5, 20, 50 μg/g). Results indicated that mycorrhizal inoculation significanty increased root colonization and biomass of marigold plants. Plant Cd concentrations markedly increased with increasing Cd addition levels. For all treatments, shoot Cd contents were significantly higher than root Cd contents, while under each Cd addition level shoot Cd contents of inoculated plants were significantly higher than those of uninoculated controls. Especially, under Cd addition level of 50 μg/g, shoot to root ratio of Cd content in inoculated plants was 3.48, in contrast to 1.67 for uninoculated plants. In general, inoculation with arbuscular mycorrhizal fungi from contaminated soil can increase Cd uptake in plants and enhance Cd translocation from roots to shoots, showing promises in phytoextraction.

Abstract:Denitrification, a microbial process, is a major branch of the geography nitrogen cycle. Although the denitrifying ability has been widely found in bacteria, fungi and Archaea, the genes encoding the denitrifying reductases have been studied in few species. Modern molecular biology techniques provide effective methods to study the microbial ecosystem, and important knowledge has been accumulated on using functional genes for molecular techniques in the case of denitrification. Recent investigations on functional genes and molecular ecology in denitrifiers have been summarized.

Abstract:As the new scientific field of studying the gene function and interactions of microbial community, metagenomics has largely contributed to the development and utilization of microbial resources, and made breakthrough progress in various fields, such as soil, oceans, human medical, pharmaceutical and so on. Metagenomics provided a novel approach for the discovery of new bioactive substances. Here we discuss some recent progress with emphasis on the opportunities and challenges in metagenomics applications.