Abstract:2008年11月“第十一次全国环境微生物学学术研讨会”在江苏无锡顺利召开, 这次大会充分反映了我国环境微生物学界取得的最新进展。为了展现我国环境微生物学工作者取得的新成果,《微生物学通报》在08年“环境微生物专刊”的基础上, 针对“第十一次全国环境微生物学学术研讨会”组织出版了新一期专刊, 期望该专刊的出版能进一步推动我国环境微生物学相关领域的交流和发展。

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Abstract:A anaerobic hydrogen-producing strain HR-1 was isolated from compost. Phylogenetic analysis based on 16S rRNA sequence similarity indicates that strain HR-1 is the closest relative to Clostridium acetobutylicum ATCC 824, with the similarity of 96%. Biological characteristics and phylogenetic analysis of 16S rRNA gene indicate that HR-1 is a new species named Clostridium sp. HR-1. Cells are Gram-positive, mobile rod-shaped. Spores and flagellums were no observed. Temperature range for growth is 10°C to 45°C (optimum temperature 37°C~39°C), and range pH for growth is 4.0 to 10.0 (optimum pH 7.5~8.0). H2, CO2, acetate, butyrate and a little ethanol are the end products of PYG fermentation. Strain HR-1 has the ability to use organic nitrogen and inorganic nitrogen sources for growth and hydrogen production, and yeast extract is the optimum nitrogen source for hydrogen production. Strain HR-1 produces hydrogen from xylose (3 g/L) at 37°C and initial pH 6.5, the hydrogen yields and maximal hydrogen production rate are 1.84 mol-H2/mol-xylose and 10.52 mmol-H2/h·g-cdw, respectively. Strain HR-1 is able to utilize glucose, galactose, fructose, mannose and cellobiose for hydrogen production and the hydrogen yields from glucose is 2.36 mol-H2/mol-glucose.

Abstract:Manganese-oxidizing microorganisms are able to oxidize soluble Mn(II) into insoluble Mn oxides. Such microorganisms are very useful in treatment of Mn-contaminated water. In this research, a Mn(II)- oxidizing bacterium Bacillus sp. MK3-1 was isolated from Mn-contaminated soil. This bacterium has high MnCl2 resistance with a MIC of 20 mmol/L. The results showed that it is able to oxidize and remove more than 96% of Mn(II) in the culture medium. The immobilized solid-embedding Bacillus sp. MK3-1can removed 87.12% of manganese contaminated water. The final concentration of MnCl2 after the treatment reached the national discharge standard level. Scan electron microscope observation showed that the produced Mn oxides located on the cell surfaces of Bacillus sp. MK3-1. Energy dispersive spectrdmeter analysis indicated that the content of manganese of cell surfaces of Bacillus sp. MK3-1 was 19.60% (W/W). At last we amplified a 903 bp multicopper oxidase gene mnxG encoding the putative Mn(II)-oxidizing protein. The product of mnxG showed 86% identity to the reported multicopper oxidase.

Abstract:A moderately halophilic bacterium strain DF-B6 capable of degrading Tween 20 was isolated from solar saltern by plate method. Based on the phenotype, physiological and biochemical characteristics, and the phylogenetic analysis of 16S rDNA sequence, strain DF-B6 was identified as Idiomarina. The substrate specificity test showed that the lipolytic enzyme from strain DF-B6 was an esterase, and not a lipase. The maximum esterase activity was observed in 8% NaCl concentration at 50°C, pH 8.0. The effect of various divalent cations was studied on the activity of esterase from Idiomarina sp. DF-B6 at the concentration of 10 mmol/L, Mg2+, Ca2+ and Mn2+enhanced the esterase activity, while Zn2+, Fe3+ and Cu2+ inhibited its activity.

Abstract:Fourteen psychrotrophic bacteria were isolated from swamp soil collected in Ruoergai plateau wetland, and their generation time and degrading ability of livestock wastewater CODcr was determined. The results showed that the generation time was within 4.9 h to 11.6 h. Based on the generation time, 9 psychrotrophic strains (NLJ1, NLJ6, NLJ7, NLJ9, NLJ10, NLJ11, NLJ12, NLJ13 and NLJ14), whose generation time was within 4.9 h to 5.6 h, were chosen to treat livestock wastewater. The results suggested that these 9 strains had different CODcr disposal ability when treating livestock wastewater singly at 6°C for 6 h, and strains NLJ6, NLJ7, NLJ9, NLJ10, NLJ11 and NLJ13 had good ability to degrade livestock wastewater, the CODcr degrading rate was about 60%~70%, hence, they were used as high efficient strains; However, the CODcr degrading rate of the other strains was less than 50%. After inoculating mixture culture of these six strains into the distilled livestock wastewater, after 6 h’s treating, the CODcr degrading rate reached to 85.42%. Furthermore, activated sludge collected from Yaan, Dujiangyan and Chengdu were inoculated by the mixture culture of those six strains, and used to treat livestock wastewater for 6 h. The results showed that the average CODcr degrading rate was 81.67%, 76.32% and 70.56%, respectively; Variance analysis showed that there was no significant differentiation between each treatment, which revealed that those six psychrotrophic strains had good adaptability to different source of activated sludge.

Abstract:As a new demulsifier, bio-demulsifier is explored recently to break the oil-water emulsion. In this study, one demulsifiying strain isolated from oil contanimated soil was identified as Dietzia sp. by 16S rRNA. When it was cultured in MMSW substrate, adding MWFO and SWFO as the carbon source, it could produce crude biodemulsifier of 4 g/L and 3.5 g/L respectively. Compared with biodemulsifier produced by paraffine as the carbon source, both of them could achieve higher demulsification ratio in breaking W/O and O/W model emulsion. Additionally, biodemulsifer produced by SWFO as the carbon source had the ability to demulsify two model emulsion effiectively. By analyzing the carbon utilization, it could be concluded that C16 and C18 fatty acid of the two waste frying oils were preferable for Dietzia sp.. The biodemulsifers produced from three different carbon sources all of which were identified as lipopeptide by TLC and FTIR. Further research should be taken to investigate its chemical structure.

Abstract:The effect of phenol concentration on the structure and function of microbial communities, which were cultured in different conditions using coking wastewater biofilm as seeding, was investigated by Biolog and denaturing gradient gel electrophoresis (DGGE) methods. The less number of bands of cultivated samples on the denaturing gradient gel electrophoresis fingerprint of 16S rRNA gene indicated reduction of diversity after enrichment and cultivation. Some bands on the DGGE gel were significantly influenced by the phenol concentration in medium. The results of Biolog showed that the original biofilm sample had the highest substrate utility capacity as measured by average well color development (AWCD). But low concentration of phenol enriched sample S7 showed more diverse activity on the utility of Carboxylic acids. The principal component analysis (PCA) of Biolog data revealed that the metabolic patterns were similar when using the same phenol concentration, although the sample S7 much less similar to other cultivated samples. These results suggested that the enrichment and cultivation with phenol supplemented decreased the diversity and also changed the metabolic function of the microbial community. Lower phenol concentration increased the microbial community metabolic activity. The phenol degrading capacity of isolates from each samples indicated that the enrichment and cultivation condition had changed the type and property of cultruable bacteria. Based on these results, we concluded that the different microorganisms will be isolated under different cultivation condition.

Abstract:To research the effect of continuous cropping on cotton soil microorganisms and soil microorganisms on grow of cotton, we studied the total numbers of aerobic self-nitrogen-fixing bacteria, potassium bacteria, cellulose decomposing bacteria, phosphate solubilizing bacteria, organic-phosphorus-dissolving bacteria distributed in continuous cropping cotton fields of regimental farm 2 and 3 of the first agricultural division through dilution spread plate method. Results showed that the total numbers of five kinds of bacteria was highest in blooming and bolling periods, lowest in seeding periods and higher in before sowing periods. The total numbers of five kinds of bacteria was no notable regular changes with continuous cropping year. The numbers of aerobic self-nitrogen-fixing bacteria at different cotton growth stages in regimental farm 2 was higher than in regimental farm 3 and the numbers change of other bacteria was varied in different cotton growth stages in regimental farm 2 and 3. Soil beneficial bacteria were negatively correlated with a variety of soil nutrient ion and free-living nitrogen fixing bacteria were significantly positive correlated with soil total nitrogen.

Abstract:In pot experiment, we studied the influence of four kinds of herbicides under the field conventional dose on rhizosphere soil microbe and two symbiosises of soybean with indigenous rhizobium and arbuscular mycorrhizas fungi at seeding stage. The result indicated that the herbicides influenced remarkably on AMF colonization of V2 and V3 period, nodule number of the V3 period, and restrained significantly on fungi number of V2 period and bacteria number of V3 period in soybean rhizosphere soil. That herbicides had a negative impact on fungi number may be an important factor in inhibiting the formation of mycorrhizae, then the inhibition on formation of mycorrhiza may lead to inhibit the formation of nodule further.

Abstract:Actinobacterial community structure in a soil sample from Yutian pit in Xinjiang was investigated by using Culture-independent method and phylogenetic analysis based on 16S rRNA gene sequences. The result showed 41 clones distribute in 26 OTUs, which exist in Acidimicrobidae and 7 suborders of Actinobacteridae respectively, especially the dominant community of Yutian pit was streptosporangineae instead of streptomycete, which accounting for 42.3% of sequenced clones. The similarity between 71.8% of 41 detected sequences and published clone sequences were less than 97%, which represented a new community and 15.3% of the clone sequences which identitied with GenBank clone sequences were under 85%, which may represent some new families or suborders. The results indicated that abundant actinobacterial community and new actinobacterial resources existed in Yutian pit. In addition, actinomycete community which exist in different high salt concentration environment have distinct differences for microecological effection.

Abstract:In April of 2008 water samples were collected from four different rivers, which were Wuchao gang River, Henggang River, Chaoyang River and Caoyanghuanbang River. During the sampling the physical and chemical parameters were measured. The abundance and the diversity of the bacteria of these four rivers were studied. The results showed that the population level increased in the more severely polluted river while the bacterial diversity decreased; the bacterial community structure was also affected by the different ecological conditions of each sampling spot. The bacterial composition and abundance was closely related to the water quality in the river.

Abstract:The composition of microbial communities in five waste mining water samples (from Tong lvshan copper mine, Hubei province, and Zhong tiaoshan copper mine, Shanxi province) were studied, using culture-independent 16S rDNA based cloning approach-restriction fragment length polymorphism (RFLP) analysis method. Phylogenetic analysis revealed that the bacteria in these five samples fell into 4 major groups: Proteobacteria, Nitrospira, Firmicutes and Bacteroidetes. Archaea were only detected in samples from Tong lvshan copper mine. Thermoplasma and Ferroplasma lineages were detected abundantly in these two samples. Meanwhile, the results of Principal Component Analysis (PCA) revealed that biogeochemical properties affected the diversity of microbial communities in mine water. The pH, temperature and different concentrations of elements such as S, Ni, Co and Cu seemed to be key factors resulting in the diverse distribution of microbes among water samples in this study.

Abstract:The bacterial diversity of two deep-sea sediments collected at Lau Basin hydrothermal vents were analysed by performing a restriction fragment length polymorphism (RFLP) analysis of 16S rRNA gene sequences. Analysis of sequences showed that there were a diversity of bacterial populations in sediments from Lau Basin deep-sea hydrothermal vents, and six bacterial divisions and four bacterial divisions represented in the sample DY1 and DY2 respectively. The phyla Gammaproteobacteria and Epsilonproteobacteria were the most dominant groups in both clone library DY1 and DY2. Additionally, some bacterial sequences had lower similarity to most known sequences in the database, which suggested that there were some novel taxa of bacteria in sediment from Lau Basin deep-sea hydrothermal vents.

Abstract:In different regions of Taihu Lake, phosphorus, nitrogen and the microbial biomass C of the sediment were determined, and using the terminal restriction fragment length polymorphism (T-RFLP) technique, bacterial community structures were analyzed. The content of total nitrogen and total phosphorus of sediment No.6 and No.16 were the highest. Trend of various forms of nitrogen and phosphorus with total nitrogen and total phosphorus was basically the same. The result of microbial biomass C showed that No.6 and No.16 were significantly higher than other sites which were similar with each other. Results of T-RFLP showed that there were differences between the bacterial diversity of different regions. Bacterial diversity of No.16 was lowest, but No.1, No.6 and No.7 were higher. Both the composition and the proportion of bacteria from different regions were significantly distinct. In addition, Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria which have relationship with cycle of nitrogen and phosphorus are very rich in sediment of all the sites. And Deltaproteobacteria which is related to cycle of sulfur and iron is also rich.

Abstract:The feasibility of expression of TpmD in recombinant E .coli BL21(DE3) induced by lactose instead of IPTG was investigated. The factors affecting the induction of target gene expression such as the optimal time point for induction, the concentration and addition mode of the inducer (lactose) and the induction time were determined. It is established that the optimal induction method is to add 0.4 mmol/L (final concentration) lactose at the mid-log-phase of cell growth, (OD600≈0.8) and incubate at 37°C for 6 h. It would be better to add the lactose in 4 batches (0.1 mmol/L per batch), because lactose can be used as a carbon source by E. coli BL21(DE3). The production of TpmD enzyme induced by lactose was about 35.62% of the bacterial total protein which was no significantly different from that induced by IPTG(≈35.03%), and the expression of TpmD was a little slower than that induced by IPTG. However, the final biomass induced by lactose was higher than that induced by IPTG. These results suggested that the lactose is as effective as IPTG for T7 promoter induction and should be easily scaled up for industrial production of recombinant protein with lower cost.

Abstract:Quite recently, among new emerging contaminants, pharmaceutical and personal care products (PPCPs) and their active metabolites are an emerging environmental issue, due to their presence in the aquatic environment and potential for impacts on wildlife and humans. Carbamazepine is one of the most frequently and at the relatively high concentration levels detected pharmaceuticals in surface water and even in drinking water. Moreover, this drug has displayed high chronic ecotoxicity. A strain of carbamazepine- degrading bacterium was isolated from activated sludge treating pharmaceutical wastewater in Suzhou, China. It was identified as Acinetobacter sp. HY-7, based on biochemical test, 16S rRNA and gyrB gene sequence analysis. Strain HY-7 could grow in liquid mineral salt medium with carbamazepine as sole source of carbon, nitrogen and energy. HPLC analysis revealed the carbamazepine degradation percentage by HY-7 after 10 days was 48% at pH 6.0 and 25°C. Among carbamazepine and the similar structure compounds, indole, catechol, naphthalene, anthracene could also be utilized by strain HY-7 for growth, which exhibited a very broad substrate profile.

Abstract:The bacterium FT17, capable of degrading trichloroethylene, was isolated from trichloroethylene contaminated sediments from the Liaohe River using the water-silicon oil biphasic system. Biochemical, physiological characteristics and phylogenetic study based on the 16S rRNA gene sequences all indicated that strain FT17 should be placed in the Sporosarcina ginsengisoli. The experiment of single factor optimization about the growth of strain FT17 was carried out, and the results showed that the optimum temperature was 34.0°C and the optimum pH value was 7.8. The degradation ratio of trichloroethylene could be enhanced at the present of 100 mg/L phenol. Intracellular and extracellular degrading enzymes were both important to the degradation of trichloroethylene. Two methods were applied to extract plasmids from strain FT17, yet none of plasmids were detected. So it was presumed that the degrading gene may locate on the chromosomes instead of on the plasmids.

Abstract:The experiment isolated three actinomycete strains XJSS-21, XJSS-39 and XJSS-58 from soil sample collected from typical desert areas in Shanshan County, Turpan City, Xinjiang Province. Based on the polyphasic studies, including its morphology, physiological and biochemical characteristics, denitrifying capability, chemotaxonomy and 16S rRNA gene sequence analysis, we found that three desert actinomycetes are able to produce cellulase, amylase and protease, the strain XJSS-21 has a strong capacity to denitrification, XJSS-58 belongs to the mild salt-tolerant bacteria. XJSS-21, XJSS-39 and XJSS-58 were primarily identified as Streptomyces Humidus subsp. antitumoris, Nocardiopsis dassonvillei and Streptomyces mutabilis.

Abstract:In this study, we isolated and characterized chlorobenzene degrading bacteria from the effluent and sludge samples of one chemical plant. Minimal medium supplemented with chlorobenzene as sole carbon source was used during the enrichment and domestication process. Seven major bacterial isolates were obtained and purified. Their 16S rRNA genes were amplified by PCR for sequencing and their identities were determined with homology comparisons. Five of the seven isolates belong to Actinomycetales including Kocuria KD139, Rhodococcus KD140, Rhodococcus KD142, Arthrobacter KD230, and Arthrobacter KD232; one is classified as Bacillus d KD178; and another one as Stenotrophomonas KD237. The phylogenetic tree was also constructed based on the analysis of 16S rRNA gene sequences. Chloro- benzene concentrations were quantified with gas chromatography to investigate the bio-degradation rates of the isolated strains. Stenotrophomonas KD237 degraded 60.78% chlorobenzene in the minimal medium within 24 h.

Abstract:A slight halophilic denitrifying bacteria (designated GYL) was screened from the activated sludge which was used to treat high-salinity wastewater. According to the results of morphological observation, physiological and biochemical test, sequence analysis of the 16S rDNA, strain GYL was identified as Halomonas sp.. This strain could survive at 10% salinity and the optimal salinity range for growth was 2%~7%. The suitable pH value for growth was 7.5~8.5 and sucrose was the most effective carbon source. The nitrogen removal efficiency exceeded 80% when the temperature ranged from 25°C to 30°C. Meanwhile heterotrophic nitrification characteristics of this strain were measured. Results showed that this strain was able to realize SND and ammonia removal rate was 98.3%. It showed that this strain could perform the whole process of bacteria denitrification independently.

Abstract:A strain JY01 (Bacillus sp. JY01) isolated from wastewater of insulating materials plant had strong ability of phenol degradation. The morphological and physiological characteristics of JY01 were almost the same as Bacillus. The sequence alignment algorithm of the 16S rDNA gene of JY01 shared 99.01% similarity with the typical strain Bacillus simplex (AM921637). Under the conditions of incubation amount of 2%, it could preserve high degradation activities of phenol in the range of the pH 6.0~9.0 and the temperature 18°C~36°C. With the phenol concentration of 1100 mg/L and 1300 mg/L, the degradation rates were 99.16% and 74.76%, respectively. The experiment offered a comparatively reliable parameter for the phenolic wastewater treatment.

Abstract:A predominant chrysene-degrading strain was isolated and screened from biological sludge sampled from a coking plant, which can use chrysene as sole carbon source for growth in the selective culture medium. The phylogenetic tree of the strain was produced on the basis of morphology observation by SEM, experimental results of physiology and biochemistry and analysis of 16S rDNA sequence. The strain was identified as Achromobacter xylosoxidans. The effect of initial concentration of chrysene solution, inoculating dose and pH on degradation efficiencies was investigated. The results indicate that the degrading characteristics of the strain is fine. The optimal degrading conditions are: initial concentration of chrysene solution 40 mg/L, inoculating dose (V/V) 10%, pH 7.0~7.5, respectively. Under the optimal conditions, the degrading efficiency can reach more than 80% after 5 days at 30°C.

Abstract:Utilizing the enrichment substrate, an aerobic denitrifying bacterial strain with the capability of phosphorus removal was screened from the activated sludge which had been domesticated by actual living sewage. By the morphological observing and identification of the physiological and biochemical indexes, the strain was identified to belong to Pseudomonas. The aerobic denitrifying bacterial strain was applied to deal with the simulated and actual living wastewater. By inspecting the changes of total nitrogen, inorganic phosphorus and CODcr in the wastewater, it was ascertained that the optimal wastewater treatment conditions of the bacterial strain were C/N= 3, inoculated ratio= 10%, pH 6.8, 30°C, treatment time= 2 d. After the activated sludge was strengthened by the aerobic denitrifying bacterial strain, its treatment capability for actual living sewage was improved, evidently.

Abstract:Petroleum-field emulsions, which are produced in the process of exploration, production and recovery, represent a major environmental and processing problem for the petroleum industry. Biological demulsifier as a biological agent, will become a novel method of petroleum-field emulsions demulsifier instead of chemical demulsifier for its high efficiency, low cost, high adoptability, environment-friendly, repeated use. A set of high efficiency and convenient method was established to isolate de-emulsification strain and studied on the characteristics of the de-emulsification strains. A de-emulsification strains, isolated from a petroleum-contaminated site, was evaluated for its de-emulsification capabilities using a kerosene/water model emulsion system keeping stable for more than 200 hours which was mixed by stirring Tween 60-water (0.072%, V/V) and Span 60-oil (0.028%, V/V) at the ratio (oil:water) of 6.5:3.5. We have isolated two strains with high and steady de-emulsification activity by separation and purification, blood-plate test, excluding-oil test and de-emulsifying test. The average de-emulsification rates were more than 80.0% at 24 h. The two strains are both belonging to bacillus by traditional and molecular genetic identification. By optimizing the demulsification bacteria fermentation conditions, the fermentation conditions, which is the most suitable for accumulating the fermentation products, were determined as follows: temperature 25°C, stirring speed160 r/min, pH 9, inoculated quantities 20%. When the fermentation conditions were temperature 35°C, stirring speed120 r/min, pH 9, inoculated quantities 2%, the fermentation products appeared the highest activities of demulsification.

Abstract:An aerobic denitrifying bacterial strain CY1 was isolated from soil. The denitrifying experiment results showed that under anaerobic or aerobic conditions the reduction efficiency within 30 hours was up to 99.98% (anaerobic) and 60.16% (anaerobic) respectively with initial NO3-N concentration of 137.25 mg/L. According to its morphologica, physiological and biochemical characters, as well as 16S rDNA sequence homology comparison, strain CY1 was identified as a member of Paracoccus pantotrophus.

Abstract:A desulfurizing chemoautotroph strain TL-1 was isolated and further identified in this study. Moreover a phylogenetic tree was constructed by comparing with the published 16S rDNA sequences of the relative bacteria species. Based on the colony and cell morphology, this strain was identified to be the strain of Thiobacillus neapolitanus. The effect of different temperature and pH on the strain was studied in shake flask. In the airlift reactor, the desulfurizing efficiency and the characteristics of the sulfur particles were investigated using Oxidation Reduction Potential (ORP) as the control factor. The results indicated that the optimal condition for desulfurizing in shake flask was 30°C and initial pH of 7.5. In the airlift reactor, the optimal ORP was at -370 mv, under this condition, sulfide removal rate was over 95% and over 85% sulfide was transferred into sulfur. Moreover the sulfur particles size was enlarged with the increase of ORP.

Abstract:Denitrification is carried by a diversity of bacteria belonging taxonomically to the various genus, which precludes the use of 16S rRNA-based routine methods to study denitrifiers. However, as a molecular marker, the functional genes of encoding denitrifying enzyme can be employed to investigate the community structure, abundance and activity of denitrifying bacteria in environmental samples. In this review, we introduced the denitrifying functional genes and their amplifying primers, compared the phylogenetic relationship of the denitrifying functional genes with 16S rRNA genes and community distribution of nirS denitrifiers with nirK denitrifiers. The article also summarized the studies and applications recently of denitrifying functional genes, discussed the problems unresolved in researches, which would be expected to be a reference for studying complex microorganisms.