Abstract:Abstract:Based on the archaeal 16S rRNA gene phylogenetic tree，the archaeal domain is divided into two major phyla，Euryarchaeota and Crenarchaeota． During the past 20 years，diverse groups of archaea have been found to be widely distributed in moderate environments with the rapid development and application of molecular techniques in microbial ecology． Increasing evidence demonstrated that these archaea，especially ammonia-oxidizing archaea，play a major role in biogeochemical cycles of nitrogen and carbon elements． These mesophilic archaea were placed initially as a sister group of the Crenarchaeota and named as“non-thermophilic Crenarchaeota”．More recently，phylogenetic analyses based on more SSU and SLU rDNA sequences suggested that the non-thermophilic Crenarchaeota constituted a separate phylum of the Archaea that branched off before the separation of Crenarchaeota and Euryarchaeota． The Thaumarchaeota (the Greek “Thaumas”，meaning wonder) was therefore proposed for a novel phylum，as the third archaeal phylum． More studies based on r-proteins and comparative genomics confirm that the Thaumarchaeota are distinct from Crenarchaeota． In this paper，we gave a translated Chinese name for Thaumarchaeota and reviewed the recent progress on the phylogeny position，genetics，ecology and physiology of the Thaumarchaeota．

Abstract:Abstract:Candida albicans is one of the most important conditional pathogens． Calcium homeostasis systems and calcium signaling in this pathogen are closely associated with numerous physiological processes，such as pathogenesis and stress responses． Study on calcium homeostasis systems and calcium signaling pathways will illuminate its calcium-related mechanisms of pathogenesis and drug resistance，and establish new therapeutic strategies for fungal infections． This review introduced the advances in the study in these fields．

Abstract:Abstract:Chlorine dioxide (ClO2) is a highly effective disinfectant for food and potable water treatment．Till now，the action mode of ClO2 is still unclear． ClO2 can denature proteins by oxidizing tyrosine，tryptophan，and cysteine． We reviewed the pathways by which ClO2 reacts with important bio-molecules，as well as the primary target sites at individual cellular level of ClO2 -induced biocidal effects．

Abstract:Abstract:［Objective］ In order to study diversity and find antimicrobial activities of actinomycetes from pesticidecontaminated spots in Shandong Peninsula． ［Methods］ The phylogenetic analysis of 154 isolated strains was done based on 16SrDNA sequences． Antimicrobial activities of 10 non-Streptomyces strains were tested by using cylinder-plate method and hypha growth rate method． ［Results］Among the strains，154 strains belonged to 7 families，8 genera: Streptomyces (87.01%)，Kocuria，Microbacterium，Nocardiopsis，Knoellia，Pseudonocardia，Micromonospora，Actinoplanes．The fermentation broths of 10 non-Streptomyces strains had inhibitory actives against all tested phytopathogenic fungi (Botrytis cinerea，Fusarium oxysporum f．sp．niveum，Gibberella zeae，Sclerotinia sclerotiorum，Colletotrichum gloesporioides) and bacteria (Staphylococcus aureus，Bacillus subtills，Bacillus cereus，Escherichai coli，Pseudomonas aeruginos)，especially Microbacterium oxydans JN853773 and Kocuria rosea JN192402 had strong inhibitory effects． ［Conclusion］ Abundant diversity of actinomycetes existed in pesticide contaminated spots in Shandong Peninsula． Microbacterium oxydans JN853773 and Kocuria rosea JN192402 showed high antimicrobial activities and could be further exploited.

Abstract:Abstract:［Objetive］ The seeds of Trewia nudiflora containing maytansine (an anticancer agent)，was investigated to explore the endophytic actinomycetes diversity and screen for naphthoquinones producing strain．［Methods］The seeds of Trewia nudiflora were sliced and plated on different selective media after surface sterilization． Clones that looked like actinomycetes were selected，and classified according to the 16S rRNA sequences． Isolated strains were screened for furanonaphthoquinone biosynthesis gene by PCR， and tested for antibacterial and antifungal activity using Staphyloccocusaureus，Pseudomon-asaeruginosa，Bacillus subtilis，Rhizoctoniasolani and Gibberellasaubinetii． LC-MS and NMR were used to determine the structure of candidate compounds．［Results］ More than 100 endophytic bacteria were isolated． Among them 66 were streptomycetes． FNQ6 (polyketide synthase Type III) and FNQ21 (carboxymuconate cycloisomerase) were only detected in Streptomyces sp． HTZ 27．We got 5 mg pure furanonaphthoquinone (FNQI) from 1 liter Streptomyces sp．HTZ 27 agar fermentation medium． ［Conclusion］ The use of chemical-genetics method increased the efficiency of screening for target compound producing bacteria．

Abstract:Abstract:［Objective］ To elucidate the biological functions of a two-component system RpfCxoc/RpfGxoc in Xanthomonas oryzae pv． oryzicola (Xoc)．［Method］ Based on the genome template from Xoc wild-type strain Rs105，the rpfCxoc and rpfGxoc genes were amplified by polymerase chain reaction (PCR)．The in-frame deletion mutations of rpfCxoc，rpfGxoc and rpfGCxoc (rpfCxoc and rpfGxoc double genes) were performed by the suicide vector pK18mobsacB，and determined diffusible signal factor (DSF) biosynthesis，pathogenicity in host rice，biofilm，extracellular polysaccharide (EPS) production and cell morphology．［Result］ rpfCxoc and rpfGxoc were cloned from the genomic DNA of Rs105．PCR analysis demonstrated that the rpfCxoc，rpfGxoc and rpfGCxoc genes were in-frame deleted successfully． Compared to the wild-type strain Rs105，DSF were overproduced in ΔrpfCxoc and ΔrpfGCxoc， but DSF production was remarkably decreased in ΔrpfGxoc． The DSF production of these mutants was restored by introducing the complemented cosmid pUFRrpfCxoc，pUFR-rpfGxoc and pUFR-rpfGCxoc，respectively． Subsequent experimental results indicated that mutation of rpfCxoc，rpfGxoc and rpfGCxoc resulted in pathogenicity loss of Xoc in host rice，and decreased biosynthesis level of EPS at 34.1%－48.5% compared to that of Rs105． In L medium (Tryptoen，10 g/L; yeast extract，5 g/L; sodium chloride，5g/L;D-glucose，1g/L;pH7. 0)，Rs105 was growing at planktonic pattern，but the mutation of rpfCxoc and rpfGxoc led to Xoc cell aggregation at the wall of the flaks at the air-liquid interfaces，and ΔrpfGxoc generated reticulation biofilm at the bottom of the flaks． But ΔrpfGCxoc only generated reticulation biofilm at the bottom of the flaks． ［Conclusion］The twocomponent system RpfCxoc /RpfGxoc modulated DSF biosynthesis，EPS production and biofilm dispersal of Xoc，which was required for the pathogenicity of Xoc in host rice．

Abstract:Abstract:［Objective］ The aim of this study is to reconstruct the metabolic model of Bacillus megaterium by literature study，which would be used to elucidate physiological properties in detail and refine physiological functions． ［Methods］We built a literature database by searching B．megaterium related literatures from Web of Science，PubMed，United States Patent and Trademark Office (USPTO) Patent Databases，Derwent Innovations Index and China National Knowledge Infrastructure (CNKI)．Depending on this database，we extracted the functional genes，enzymes，metabolites and metabolic reactions (including transport reactions) through literature studies．Then，we filled gaps through KEGG Mapper and adding sink reactions．The operation of Matlab programs reconstructed the metabolic model (in the form of Systems Biology Markup Language) of B． megaterium． ［Results］ The refined metabolic network model contained 292 metabolic reactions，378 metabolites，220 enzymes and 217 genes． With the restrictive condition of 1.62 mmol/g cell/h of glucose uptake rate，the simulated specific growth rate was 0.089 h－1，a little lower than the experimental value 0.11 h－1. In addition，the accuracy of the single gene deletion simulation in pyrimidine metabolism reached 90%．［Conclusion］ The final metabolic network model covered the biochemical information of citrate cycle，glycolysis，pentose phosphate pathway，fatty acid metabolism，vitamin B12 biosynthesis and amino acid biosynthesis，and reflected the effect of substrates and genes on the growth of the bacterium to a certain extent．

Abstract:Abstract:［Objective］ To study whether Termitomyces albuminosus can degrade lignocelluloses and to understand the symbiotic relationship between termite mushroom and fungus-growing termite．［Methods］cDNA library of T．albuminosus was sequenced by the Roche 454 GS FLX Titanium platform，and the diverse enzymes relevant to degradation of cellulose and lignin of symbiotic fungus T．albuminosus were analyzed．［Results］ Eighth sequencing run resulted in a total of 82386 reads (express sequence tags，EST)．After removing the vector and primer sequences，the remained 54410 reads were assembled into 3301 contigs and 3193 singletons． Comparing sequence similarity with known proteins， these sequences，representing approximately 2681 unique genes，were successfully annotated using BLAST searches (E-value ≤1e－10) against the Nr，SwissProt and CDD databases．The T．albuminosus transcripts included 33 enzymes putatively involved in cellulose and hemicelluloses biodegradation． 5 enzymes could hydrolyze cellulose and others had catalytic activities for degradation of hemicelluloses，starch and glycogen and chitin． Moreover，four genes encoding laccases and a single aryl-alcohol oxidase which could degrade lignin were also identified． These results revealed symbiosis fungus T．albuminosus had many laccases and possibly decomposed phenolic compounds from plant litter． ［Conclusions］ Data presented in this study indicated that T．albuminosus had the ability to degrade lignin，which made cellulose more easily degraded by the cellulase produced by fungus-growing termite．

Abstract:Abstract: ［Objective］We analyzed the community and diversity of microorganisms involved in nitrification and denitrification of nitrogen cycle in typical aquaculture water in order to manage microbiological degradation of NH+4 and NO－2，to control nitrogen pollution and nitrogen cycle in shrimp-farming water． ［Methods］ Samples were analyzed by Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) graph． We constructed clone libraries of the typical sample based on the functional gene ammonia monooxygenase gene (amoA)，nitrite oxidoreductase gene (nxrA)，and nitrite reductase gene (nirS)．These three libraries were analyzed by using Restriction Fragment Length Polymorphism (RFLP)． ［Results］Phylogenetic analysis showed that all sequences from amoA library were clustered into β-Proteobacteria，including Nitrosomonas (81%) and Nitrosospira (19%)．Clones from nxrA library were clustered into α-Proteobacteria and δ-Proteobacteria，including Nitrobacter (92%) and Desulfobacteraceae (8%)．Clones from nirS library were clustered into α-Proteobacteria，β-Proteobacteria and Actinobacteria．β-Proteobacteria was the dominant group that consisted of Azoarcus (25%)，Brachymonas (5%)，and Thauera (20%)．In α-Proteobacteria group，Sophophora (10%)，Polymorphum (25%)，Ruegeria (5%) were detected． In the Actinobacteria group，Streptomyces (10%) was detected．［Conclusion］ Microorganisms involved in nitrification and denitrification of nitrogen cycle were abundant． In the aquaculture water，Nitrosomonas was the main performer of ammoxidation，Nitrobacter was the main performer of nitrification，and many kinds of populations played important roles in the denitrification．

Abstract:Abstract:［Objective］To analyze the microbial diversity in healthy and HLB-affected Catharanthus roseus under manualgrafting conditions and to find the association between the endophytic bacteria and the HLB pathogen．［Methods］ The endophytic bacterial communities were delineated by using the traditional culturable approach and cultivation-independent techniques based on 16S rRNA gene． The endophytic bacteria were isolated from surface-sterilized C． roseus midribs of leaves and phloem of stems and roots by plating and restriction fragment length polymorphism ( RFLP)．［Results］ By anaerobic culture，we obtained 67 strains that were identified 29 genus by GenBank． Curtobacterium sp., Erwinia sp., Bacillus cereus and Brevundimonas sp． ，Bacillus sp． were the dominant bacterial population in diseased and healthy C. roseus． However，Staphylococcus equorum was the common dominant isolate in both C． roseus． We picked 188 and 182 positive clones in 16S rDNA libraries of diseased and healthy C． roseus that were respectively restricted by the HaeIII，MspI，RsaI restriction endonuclease． Based on the similarity of the RFLP banding profiles in diseased and healthy C．roseus，we obtained 16，23 OTUs (Operational Taxonomic Units，OTUs) respectively． In addition to Candidatus Liberibacter asiaticus，Candidatus Liberibacter sp． was the dominant bacterial population only in diseased C． roseus． ［Conclusions］With the infection of‘Ca.L. asiaticus'，the diversity in diseased C． roseus decreased． The endophytic bacteria isolated from diseased and healthy C． roseus are abundant and have remarkable differences in the composition and function，suggesting that its endophytic bacteria might be inhibited by the HLB pathogen.

Abstract:Abstract:［Objective］We clarified the pathogenic influence of the absence of Streptococcus suis type 2 capsular saliva acid on BLAB/c mice． ［Methods］The virulence of the experimental strains were compared; the distribution of strains in vivo was determined by quantitative plating． Histopathological analysis was used to qualitatively compare the different pathogenicity of wild strain and knockout strains． ELISA was used to test the levels of cytokine in whole blood cells for the stimulation of strains． ［Results］ The virulence of mutant strains was significantly reduced，and when the genes were restored，toxicity levels were recovered to that of the wild type strain． The distribution in blood and in the brain between wild strain and knock out strains has significant difference，and Streptococcus suis type 2 strains can cause different degrees of brain damage． During the in vitro test，the mutant strains can stimulate the whole blood cells to secrete higher levels of MCP-1 and IL-6. ［Conclusion］ Capsular saliva acid affects bacterial virulence and host cell inflammation response． As an important virulence factor of Streptococcus suis type 2，it can damage the blood brain barrier and cause meningitis．

Abstract:Abstract:［Objective］Establishing a new method of microbial prospecting for oil and gas based on microbial community metabolic function． ［Methods］In this study，45 shallow reservoir soil samples and 25 non-reservoir soil samples were collected． Carbon catabolic activity of the microbial community was measured by biolog microplate，and microbial anomaly of reservoir was judged by discriminant function． ［Result］We screened 10 typical carbon sources of 95 carbon sources which could reflect the differences of reservoir and non-reservoir soil microbial community structure and made the validation test set to experimental zone and controlled zone samples using the discriminant function． The discriminate rate of reservoir and non-reservoir were 97. 8% and 100% respectively and the overall accuracy was 98.6%.［Conclusion］ Biolog technology provided a highly efficient and precise method for preliminarily predicting oil and gas reservoir．

Abstract:Abstract:［Objective］Members of Xenorhabdus are symbiotic bacteria of entomopathogenic nematodes Steinernema，and can be applied as biopesticides against insects． Therefore，a rapid and accurate method for classification and identification of Xenorhabdus is essential． ［Methods］ An 845bp-fragment of 23S rDNA sequence of 26 strains of Xenorhabdus representing 20 described species was PCR amplified and sequenced． A phylogenetic tree of Xenorhabdus based on the sequences obtained was constructed and compared to that based on nearly complete 16S rDNA sequences for suitability as molecular maker for classification and identification of Xenorhabdus． ［Results］ The 23S rDNA fragment contained more variable and parsimony-informative sites proportionally，and with greater pairwise distances among sequences compared to those of 16S rDNA．［Conclusion］ The 23S rDNA fragment can be used to identify Xenorhabdus，especially for a large number of Xenorhabdus strains obtained from field survey．

Abstract:Abstract:［Objective］To investigate the bacteria community and biodiversity of four-years pickled Yanshan Dongcai．［Methods］We studied the bacterial communities of Dongcai by 16S rDNA diversity analysis and the cultured species isolated from Dongcai sample by Restriction Fragment Length Polymorphism (RFLP) and 16S rRNA gene sequence analysis．［Results］ The 16S rDNA diversity showed that the bacteria belonged to the phyla Proteobacteria (87.9%) and Firmicutes (7.1%)，including many moderately halophilic bacteria such as Virgibacillus kekensis，Marinococcus albus，Salinicoccus sp.，Lactobacillus halophilus and Halomonas． Only 5% of clone sequences belonged to the phylum Actinobacteria． Thirty-five strains were isolated from Dongcai sample，and 16S rDNA-RFLP analysis indicated that 34 isolates affiliated with the phylum Firmicutes，including Virgibacillus，Bacillus megaterium and Gracilibacillus saliphilus which were moderately halophilic bacteria，but only one isolate belonged to the phylum Actinobacteria． ［Conclusion］The bacterial diversity is low in Dongcai，dominated by moderately halophilic bacteria.

Abstract:Abstract:［Objective］We constructed Pasteurella multocida strain C51-17 aroA mutant and characterized its virulence．［Methods］ Suicide recombinant plasmid of pBC-aroA-Tn903 was constructed with kanamycin gene and transformed into Pasteurella multocida by electroporation． aroA mutant strain of P． multocida was screened by kanamycin resistance and chloromycetin sensitivity and identified by PCR． Virulence of aroA mutant strain was tested in mice by intraperitoneal injection． ［Results］ The aroA mutant strain of P． multocida C51-17 was successfully constructed． Growth rate of aroA mutant strain was slower within the first 6 hour and similar to the wild-type strain in vitro． The virulence test indicated that aroA mutant strain was significant attenuated and no death was found in mice even inoculated at a dosage of 1.0×106 CFU.［Conclusion］ The virulence of aroA mutant strain of P． multocida was highly attenuated in mice． The results of this study will contribute to a better understanding of pathogenesis of P． multocida．

Abstract:Abstract:［Objective］The predicted amino acid sequence of locus plu4437-plu4436 in the genome of Photorhabdus luminescens TT01 (referred to as pirA2B2) has a consistency of 50% and 45% with locus plu4093-plu4092( referred to as pirA1B1)，respectively． PirA1B1 has been confirmed with oral insecticidal activity against Plutella xylostella and mosquito．The purpose of the present study was to examine whether pirA2B2 possesses insecticidal activity． ［Methods］ pirA2，pirB2 and pirA2B2 genes were PCR amplified and cloned． The recombinant expression vector pQE-pirA2，pQE-pirB2 and pQEpirA2B2 were constructed and transferred into E． coli M15，individually． The soluble PirA2，PirB2 and PirA2B2 proteins were detected from the supernatant of the recombinant M15 induced with IPTG by both SDS-PAGE and Western-blot． The proteins expressed in the three recombinant E． coli M15 strains were purified by affinity chromatography combined with desalination technology and then quantified individually． The heamocoal and oral insecticidal activities of the expressed proteins were analyzed against the larvae of Galleria mellonella and Spodoptera litura． ［Results］ The results show: 1.PirA2B2 had heamocoal insecticidal activity against the fifth instar larvae of both G． mellonella and S． litura，with an LD50 of 4. 0 and 2. 8 μg / larvae，respectively，2. neither PirA2 nor PirB2 alone had heamocoal insecticidal activity against the insects tested，while the mixture of PirA2 and PirB2 reconstituted full activity，and 3. PirA2B2 showed no oral insecticidal activity to the first instar larvae of either G． mellonella or S． litura． ［Conclusion］pirA2B2 in the genome of P． luminescens TT01 is a binary insecticidal toxin gene． ［Significance］ The successful expression and purifcation of PirA2B2 laid a foundation for further study on the function，insecticidal mechanism and expression regulation of the binary toxins．