Abstract:Abstract:Human colon and animal digestive tract harbor large amount of butyrate-producing bacteria．The biosynthetic pathway of butyrate formation includes the central pathway from acetyl-CoA to butyryl-CoA and the last step converting butyryl-CoA to butyrate． The genes involved in the central pathway are clustered in genome but with different gene arrangements in different bacteria groups． The gene arrangements are coherent with their phylogenetic placements based on their 16S rRNA gene sequences． Recent researches have suggested that butyryl-CoA: acetate CoA-transferase play an important role in the last step of butyrate formation from butyryl-CoA and the genes are also widely found in bacterial strains producing butyrate． In this paper，combined with our own findings，we summarized advances in studying genes and gene clusters involved in butyrate formation.

Abstract:Abstract:［Objective］To analyze the biodiversity of halotolerant and halophilic bacteria the bacteria in saline-alkaline soils in Songnen Plain，we isolated and purified bacteria samples in the area．，［Methods］Halotolerant and halophilic bacteria were isolated from the enriched cultures of the saline-alkline soil samples through the traditional culture method， and 16S rRNA sequences were amplified and analyzed for the determination of phylogenetic relationships．［Results］Forty strains were obtained and classified into 34 species，16 genera，8 families，3 phylum (Firmicutes，γ-Proteobacteria and Actinobacteria) in the Domain Bacteria．The genus Staphylococcus is the predominant group，followed by Halomonas，Oceanbacillus，Bacillus，Kocuria and Pseudomonas． The 16S rRNA sequences of 9 strains showed 97. 2 to 99.0% similarities with their closest type strains，suggesting that they may be the potential novel species． The salt tolerance of the strains is mainly concentrated on the 5%－10% NaCl while alkaline pH resistance of the strains is between pH 9 and 12．Based on the NaCl dependence，62. 5% of the strains were grouped into the halotolerant bacteria，and the rest into the moderate halophiles．［Conclusion］The halotolerant and halophilic bacteria are very rich in the saline-alkaline soils in Songnen Plain，and the genera Staphylococcus and Halomonas are the predominant groups． Almost all the bacteria from this area could tolerate not only at the high concentration of NaCl，but also at high alkaline pH． More importantly，a number of novel species may be included in this area．

Abstract:Abstract:［Objective］In order to explore the diversity，antimicrobial activity and enzyme-producing activity of marine actinobacteria isolated from mangrove sediments in Indian Ocean． ［Methods］Eight sediments collected from mangrove sediments in Indian Ocean were treated by the plate dilution method and spread on 24 isolation media only containing sole carbon source for energy． Marine actinobacteria were isolated and identified by 16S rRNA gene sequence analysis． The antimicrobial activity and enzyme-producing activity of isolated strains were further detected by spot planting method ［Results］In total 139 representative strains were selected from 521 isolates，and they were further sequenced and performed phylogenetic analysis based on their 16S rRNA gene sequences． There were 35 strains identified as potential novel species． Antimicrobial activity was detected in Bacillus subtilis，Candida albicans，Escherichia coli，Staphylococcus aureus，Aspergillus niger． Enzyme-producing activity for protease cellulase，amylase and esterase were 36.5%，26.5%，22.4% and 15.9%，respectively．［Conclusion］Diverse marine actinobacteria were discovered in mangrove sediment in Indian Ocean，which have antimicrobial and enzyme activity．

Abstract:Abstract:［Objective］Morphology of ascomatal hairs was traditionally used as a primary character in the classification of the fungal genus Chaetomium． However，the taxonomic value of ascomatal hair morphology is questioned in modern taxonomy of Chaetomium． Chaetomium indicum and C． funicola are two species proposed only by their differences in ascomatal hairs． The aim of this study is to understand the difference between these two species and their variability in the morphology of ascomatal hairs at the level of protein expression patterns，as well as to ressess the taxonomic value of the ascomatal hairs． ［Methods］We performed microscopic examination to obtain the morphological characters of the typical and variable strains in both C． indicum and C． funicola． Then we used two-dimensional gel electrophoresis (2DE) to compare the protein expression patterns of the two species，including their typical and variable strains．［Results］The comparison of the obtained 2DE maps indicated that C． indicum and C． funicola exhibited species-specific protein expression patterns． The phylogenetic tree derived from the distance matrix of expression patterns with Neighbor-joining algorithm also revealed that the tested strains of C． indicum and C． funicola fell into two distinct clades，among which the variant strains were grouped together with the typical strains of the same species． ［Conclusion］ The consistency of species delimitation between C． indicum and C． funicola based on morphological characters of ascomatal hairs and speciesspecific protein expression patterns demonstrates that ascomatal hairs can be still used as potential morphological parameters in taxonomy of Chaetomium．

Abstract:Abstract:［Objective］ A putative type II polyketide synthase (PKS) gene cluster (sah) was found in the genome sequence of Streptomyces sahachiroi ATCC 33158 by bioinformatics． In order to discover its biological function，we cloned the sah cluster and made functional analyses by gene knockout and heterologous expression．［Methods ＆ Results］Annotation of the predicted open reading frames (ORFs) by protein-protein blast revealed that the sah cluster is highly homologous with the spore-pigment biosynthetic cluster (whiE) in S． coelicolor A3 (2)，except an additional Omethyltransferase gene (sahI)．Three genes of the sah cluster，sahG，sahH and sahI，which are putatively involved in post-PKS modifications，were respectively in-frame deleted by double crossover． We observed the color of the mutant strains spores apparently changed． HPLC and LC-MS analyses demonstrated that heterologous expression of the sahminimal PKS gene and the whiE-minimal PKS gene in S．lividans ZX1 produced the same hydrophilic red pigments.［Conclusion］The sah cluster is responsible for the spore-pigment biosynthesis of S．sahachiroi ATCC 33158．It catalyzes the formation of polyketides with the same core structures as that of the whiE cluster．

Abstract:Abstract:［Objective］The objective of this study is to obtain the complete genome sequence of Bacillus Calmette-Guerin Tice (BCG Tice)，in order to provide more information about the molecular biology of BCG Tice and design more reasonable vaccines to prevent tuberculosis． ［Methods］ We assembled the data from high-throughput sequencing with SOAPdenovo software，with many contigs and scaffolds obtained． There are many sequence gaps and physical gaps remained as a result of regional low coverage and low quality． We designed primers at the end of contigs and performed PCR amplification in order to link these contigs and scaffolds． With various enzymes to perform PCR amplification，adjustment of PCR reaction conditions，and combined with clone construction to sequence，all the gaps were finished．［Results］We obtained the complete genome sequence of BCG Tice and submitted it to GenBank of National Center for Biotechnology Information (NCBI)．The genome of BCG Tice is 4334064 base pairs in length，with GC content 65. 65%．［Conclusion］The problems and strategies during the finishing step of BCG Tice sequencing are illuminated here，with the hope of affording some experience to those who are involved in the finishing step of genome sequencing． The microarray data were verified by our results.

Abstract:Abstract:［Objective］ To isolate and screen antagonistic actinomyces strains with inhibitory activity on Setosphaeria turcica from soil． ［Method］Actinomycetes were isolated by Pour Plate method． Antagonistic actinomycetes were screened by confrontation culture，cylinder plate，suppression of mycelial growth and spore germination method in vitro． Strain BZ45 were identified by morphological，cultural，physiological and biochemical characteristics and 16S rDNA sequence analysis． The fermentation condition was optimized by single factor and orthogonal experiment． ［Result］ Strain BZ45 showed antagonistic to 8 plant pathogens． Its filtrate inhibited the mycelial growth and spore germination of Setosphaeria turcica CC9．Strain BZ45 belonged to Streptomyces spectabilis． The optimum culture conditions of strain BZ45 were with a medium of 1.5% fructose，3.0% peptone，0.1% KH2 PO4，0.04% NaCl，0.1% CaCO3 at initial pH of 7.2，liquid volume 50 mL in 250 mL flask，200 rpm at 28℃，inoculation size of 10% for 4 d． ［Conclusion］ Strain BZ45 was identified as Streptomyces spectabilis and antagonistic against Setosphaeria turcica CC9．

Abstract:Abstract:［Objective］We tested the expression of immune-related gene interleukin 6 (il-6) in vitro to understand the influence from Lactobacillus plantarum NDC 75017 on host cells and further to reveal the regulatory mechanism．［Methods］Caco-2 cells were cocultured with L． plantarum NDC 75017 for 0，2，4，6，8，10 and 12 h，the total RNA were extracted; then the expressions of il-6 and tlr2 genes were analyzed by Real Time RT-PCR． The phosphorylation level of NF-κB was analyzed by Western Blot after the Caco-2 cells stimulation with L． plantarum NDC 75017 at 0，0. 5，1，2 and 4 h． Caco-2 cells were pretreated with pyrrolidine dithiocarbamate for 30 min before being treated with L． plantarum NDC 75017 for 2 h，then the total RNA was extracted and the expressions of il-6 and tlr2 genes were analyzed by Real Time RT-PCR． ［Results］Lactobacillus plantarum NDC 75017 could induce the expressions of il-6 and tlr2 in Caco-2 cells，the il-6 and tlr2 expressions peaked at 8 h and 6 h after cocultured with L．plantarum NDC 75017．L．plantarum NDC 75017 could rapidly activate the phosphorylation of NF-κB，and the expressions of il-6 and tlr2 were decreased notably after pretreated with pyrrolidine dithiocarbamate． ［Conclusion］L．plantarum NDC 75017 could up-regulate and then down-regulate the expression of il6 through rapidly activating tlr2-mediated NF-κB signaling pathway in Caco-2 cells．

Abstract:Abstract:［Objective］We observed the changes in cell membrane of Vibrio parahaemolyticus which is a prevalent foodborne pathogen by high pressure treatments． ［Methods］Pressure-resistant mutant strains of V． parahaemolyticus were selected with repeated hydrostatic pressures treatment of 80－250MPa from a pressure-sensitive V． parahaemolyticus (ZJGSMC001)．The changes of soluble cell membrane protein，fatty acid profiles and the Na + K + ATPase activity in the pressure-resistant strains and its pressure-sensitive parent strain were determined． ［Results］The pressure-resistant strains had more soluble cell membrane protein of 36 KDa． The Na + K + ATPase of the pressure-resistant strains were 83. 3% more active than the parent strain． The proportion of unsaturated fatty acids in cell membranes was 54. 23% comparing to 51. 57 % (P＜0.05) in the pressure-sensitive strain． ［Conclusion］The pressure-resistant strains may have survived pressure treatments through expressing more low-molecular soluble cell membrane proteins，enhancing the activity of Na+K+ATPase，and increasing the content of unsaturated fatty acids in cell membrane．

Abstract:Abstract:［Objective］The aim of this study was to screen hemicellulose degrading microorganisms．［Methods］ The methods used to screen the effective strains included hydrolysis spot diameter measurement of hemicellulose plate and extracellular enzyme activity． The methods used to identify the strains included culture characteristics，morphological，physiological-biochemical characteristics and molecular biological methods． ［Results］ We isolated 4 actinomycetes (NA9，NA10，NA12 and NA13)，2 fungi (NF1 and NF7) with hemicellulose degrading ability and no antagonistic effect among them． The hemicellulose degrading activity of 4 actinomyces (NA9，NA10，NA12 and NA13) was 217.6，229.8，221.1 and 211.8 U/mL． The hemicellulose degrading activity of 2 fungi (NF1 and NF7) was 217.7 and 244.2 U/mL．The hemicellulose degrading activity of complex microbial system was 299. 0 U/mL．NA9，NA10，NA12 and NA13 were Streptomyces costaricanus; NF1 was Aspergillus candidus and NF7 was Tarlaromyces flavus． ［Conclusion］the 4 actinomyces and 2 fungi screened have high hemicelluloses enzyme activity． These strains have good application value and more research value.

Abstract:Abstract:［Objective］The work aimed to obtain pyrene-degrading bacterial consortium and use it for bioremediation of polycyclic aromatic hydrocarbons-contaminated soil．［Methods］ We enriched and incubated a bacterial consortium utilizing pyrene as the sole carbon source from the contaminated soil of Beijing Coking Chemical Plant． We analyzed the degrading ability and growth of the consortium by high performance liquid chromatography (HPLC) and spectrophotometer．We investigated the degradation activities of the consortium after several times transfer and freezedrying deposit． We also investigated the shift of bacterial consortium composition after several times transfer by combining of culture-dependent and culture-independent methods． We constructed and analyzed the 16S rRNA gene clone libraries at different transfer times (3 times PYR-3，6 times PYR-6 and 9 times PYR-9) for monitoring the bacterial population changes．［Results］The degradation rate of pyrene，phenanthrene and fluoranthene reached 89%，86% and 49% respectively after incubation of the consortium for 12 days． The degradation activities of the consortium were stable after several times transfer and freeze-drying deposit．We isolated nine strains from the consortium，affiliated to genus of Achromobacter， Bacillus， Arthrobacter， Exiguobacterium and Parapedobacter． Phylogenetic analyses showed that Proteobacteria were the main group at contaminated soil sample (100%) and bacterial consortium incubated in pyrene (PYR-3，83%)．Bacterial community structure was shifted and biodiversity was increased during the transfer process，the proportions of !-Proteobacteria was decreased from 77% (PYR-3) to 33% (PYR-6) and 18% (PYR-9)，while β-Proteobacteria increased from 13% (PYR-3) to 36% (PYR-6) and 55% (PYR-9)．［Conclusion］ The bacterial consortium could utilize pyrene as sole carbon and energy source for growth and the degradation ability for pyrene was stable．

Abstract:Abstract:［Objective］To investigate the dynamics of bacterial community in Xiamen sea during the bloom mainly caused by Skeletonema costatum and Akashiwo sanguine in August 2011． ［Methods］Bacterial community structures of samples from two bloom sites and one non-bloom site were evaluated by PCR-DGGE ( Denaturing gradient gel electrophoresis，DGGE)．The genetic diversity of bacterial community was analyzed based on the DGGE fingerprint． The correlation between bacterial community and environmental parameters was studied by Canoco． ［Results］The bacterial community was largely related to pH and N /P during the start-up stage of the bloom; while in the demise stage，it was mostly correlated to salinity and temperature． According to the results of sequence analysis of DGGE dominant bands，Gammaproteobacteria accounted for 47. 7% during the bloom and Pseudoalteromonas，Pseudomonas，Alteromonas，Hydrogenophaga，Actibacter and Oleibacter were dominant genus in bacterial community． The Shannon-Weaver diversity index showed that the diversity of bacterial community in bloom site increased firstly and then decreased during this bloom．Hydrogenophaga was dominant in the start-up stage of bloom，while Pseudomonas and Pseudoalteromonas were dominant in the demise stage of bloom． The diversity of attached bacteria and free-living bacteria in bloom sites reached maximum in the same day ( the concentration of algae was high)，both of them changed greatly during the bloom while the environment factors which correlated with the two communities were different． ［Conclusion］It is the first report about dynamics of bacterial community during the bloom caused by several algae together． This work is helpful to understand the dynamics of bacterial community during the bloom，and provides a theoretical basis for bloom's control in the future．

Abstract:Abstract:［Objectives］In order to provide new source for discovering new lead compounds of drugs and other products，the diversity and some bioactivities of culturable actinobacteria in animal feces were studied． ［Methods］Five animals' fecal samples were collected from Yunnan Wild Animal Park． The pure cultures of actinobacteria were isolated from these samples by using 5 different media． The 16S rRNA gene sequences of 119 selected strains were determined; the phylogenetic analysis was carried out; and antimicrobial and anti-tumor activities were determined by using agar diffusion method，tumor cell lines k562and HL60 respectively． ［Results］In total 20 genera of actinobacteria from the 5 animals' feces were identified． Many strains inhibited Bacillus subtilis，Staphylococcus lentus，Mycobacterium tuberculosis，Candida albicans and Aspergillus niger． Some strains presented antitumor activities． Some known secondary metabolites and Sannastatin，a novel macrolactam polyketide glycoside with bioactivities，were isolated and identified． ［Conclusion］Fecal actinobacteria are a new potential source for discovering drug lead and other industry products．

Abstract:Abstract:［Objective］ In order to collect basic data for the analysis of metabolic mechanism，the composition and distribution patterns of yeasts at different fermentation stages for Maotai-flavor Chinese liquor production． ［Methods］By using plate screening techniques，a large number of yeast cultures were obtained from fermenting grains． Based on 26S rDNA D1 /D2 region sequencing，the yeasts were identified． According to quantitative change，species composition，relative frequency，diversity indices and similarity coefficients，the composition and distribution patterns of yeasts were studied． ［Results］The numbers of yeasts in fermenting grains showed a rule of“higher-lower-higher-lower”． A total of 13 species，8 genera of the yeasts were identified． The whole diversity index of the yeasts was comparatively high． That the similarity coefficient in most cases was significantly higher than 0. 5 showed that the species composition and distribution of yeasts were relatively stable． Issatchenkia orientalis，Pichia kudriavzevii and Saccharomyces cerevisiae play a very important role in the process of liquor fermentation． ［Conclusion］There were abundant yeast resources in fermenting grains of maotai-flavor liquor．

Abstract:Abstract:［Objective］The aim of this study was to investigate the composition and distribution variation of endophytic bacteria and fungi in Achnatherum inebrians． ［Methods］The DNA of seed，leaf，stem and root was extracted with liquid nitrogen grinding method． Then，16S rDNA and Internally Transcribed Spacer (ITS) sequence were digested with restriction enzymes HhaⅠ，RsaⅠand HhaeⅢ，HinfⅠto obtain terminal restriction fragments． The terminal restriction fragments were matched to bacterial and fungal genera by the T-RFLP Analysis Program，and the community component and similarity of endophyte in Achnatherum inebrians were analyzed． ［Results］The diversity of endophytic bacteria and fungi was the most abundant in root and seed of Achnatherum inebrians． All the predominant bacterial population was Bacillus (above 29%) in different organs of Achnatherum inebrians． The predominant fungal population was Mycosphaerella (6.5%)，Teratosphaeria (4.5%)，Fragum (1.1%)，Sebacina (11.3%) in seed，leaf，stem and root，respectively． The structure of the bacterial communities in the stem and leaf were similar，whereas the structure of the bacterial communities in the seed and other tissue were different． The structure of the fungi communities in the stem and seed were similar，whereas the structure of the fungi communities in the leaf and other tissue were different．［Conclusion］There was abundant endophytic microbial diversity in Achnatherum inebrians．