Abstract:Abstract:To adapt quickly to the environmental change，bacteria have evolved a protein quality control (PQC) network to remove unwanted proteins．AAA+ (ATPases associated with diverse cellular activities) proteases form a major part of this PQC network，and the discovery of Pup ( prokaryotic ubiquitin-like protein) -proteasome system revealed a novel mechanism of prokaryotic protein degradation．Proteolytic machines only degrade substrates bearing a degradation tag or degron to insure the proteolysis specificity．In addition，bacteria adopt different strategies to regulate the protein degradation．With the discovery of Ubiquitin-mediated protein degradation in eukaryotes，it has become evident that regulated protein degradation plays a crucial role in the cell response to environment change among eukaryotes and prokaryotes．Regulation by proteolysis has been shown to be involved in diverse bacterial cellular processes including growth，division，differentiation，pathogenesis and stress response．This review will focus on the structure，degradation process，and the function of AAA + proteolytic machines in bacteria.

Abstract:Abstract: TonB systems of gram-negative bacteria play an important role in transportation of nutriment from outside environments．TonB systems consist of plasma membrane proteins ExbB-ExbD and periplasmic protein TonB，which provide the energy to TonB-dependent receptors to transport substrates．These substrates include iron，hemin，vitamin B12，carbohydrate and some transition metal elements．The energy supporting function of TonB relies on its special structure which contains N-terminal domain for fixation，flexible periplasmic linker Pro-rich domain and C-terminal domain for contacting receptors．The precise mechanism of TonB system is not fully understood though its structural was studied a lot． To provide insights into direction for further research of TonB，we reviewed the TonB-dependent substrates uptake，structural features，functional mechanism and expression regulation of TonB.

Abstract:Abstract:Baculoviruses are a family of arthropod-specific viruses that mainly affect insects of the orders Lepidoptera，Hymenoptera，and Diptera．During baculovirus infection，an amplified pulse of integral membrane proteins was synthesized．The proteins use continuous membranes of the endoplasmic reticulum，outer nuclear membrane and inner nuclear membrane during their transport to the viral envelope of the occlusion-derived virus．The baculovirus encoded inner nuclear membrane sorting motif (INM-SM) functions as a sorting signal and plays pivotal roles in these processes．This review focuses on recent advances in understanding of baculovirus encoded INM-SM，including the molecular mechanisms underlining protein sorting and trafficking by INM-SM，the possible model of INM-SM involvement in integral membrane proteins trafficking and the role of INM-SM in baculovirus per os infection． These achievements and advances should help to expand the molecular understanding of protein trafficking，baculovirus molecular biology and its application in the future．

Abstract:Abstract:Unmethylated cytosine-guanine (CpG) dinucleotides motifs in bacterial DNA can be recognized by specific Tolllike receptor 9 (TLR9) in intestinal cells．As one of the intestinal immunostimulatory factors，unmethylated CpG DNA can modulate intestinal innate immune responses directly and adaptive immune responses indirectly．There is a great prospect for unmethylated CpG DNA as an immunomodulator in the rapy of intestinal diseases．This article illustrated the basic concepts of unmethylated CpG DNA，the characteristics of TLR9．We also reviewed specific applications of unmethylated CpG DNA as adjuvants in modulating intestinal immune responses．At last，we elaborated the research and application prospects of CpG DNA in the future．

Abstract:Abstract:［Objective］The present work reported the isolation，identification and diversity of Bacillus species colonizing on the surface and endophyte in lichens collected from Wuyi Mountain．［Methods］ Nine lichen samples of Evernia，Stereocaulon，Menegazzia and other 6 genera belonging to 7 families were collected from Wuyi mountain nature reserve．The bacillus-like species colonizing on the surface and endophyte in these lichens were isolated and identified by 16S rRNA gene sequence analysis．［Results］ There was no bacillus-like species isolated from Evernia，Ramalina and Lecarona．A total of 34 bacillus-like bacteria were isolated from another 6 lichen samples． These bacteria were identified as 24 species and were classified into Bacillus，Paenibacillus， Brevibacillus， Lysinibacillus and Viridiibacillus．Paenibacillus and Bacillus are the dominant genera，and accounting for 41.2% and 35.3% of all isolated bacteria respectively． Brevibacillus，Lysinibacillus and Viridiibacillu were first reported being isolated from lichens．There were different species and quantity of bacillus colonizing on the surface and endophyte in different lichens．The quantity of bacillus colonizing on the surface of Physcia was more than 3.85×106 cfu/g and was the largest in the isolated bacteria，while the species of bacillus colonizing on the surface and endophyte in Stereocaulon was the most abundant．Most of the isolated bacteria were colonizing on (in) one lichen genera，but Paenibacillus taichungensis，Paenibacillus odorifer， Brevibacillus agri，Lysinibacillus xylanilyticus was respectively colonizing on( in) 2-3 lichen genera and Bacillus mycoides was colonizing on( in) Menegazzia，Cladonia Physcia，and Stereocaulon． ［Conclusion］There are species and quantity diversity of bacillus colonizing on(in) lichens.

Abstract:Abstract:［Objective］ We demonstrated the interfering effect of a new intergenic-derived sRNA of Cryptococcus neoformans.［Methods］We constructed a library of sRNAs from 20 to 25 nt，and used a reporter gene CLC1 that was fused to the testing sＲNAs to show the interference effect，i．e．the degradation of the CLC1 would gene rate an albino phenotype of the transformants．［Results］Through the CLC-sＲNA reporter system，we acquired one sRNA，sRNA-1，located to an intergenic region of the genome of C． neoformans，that displayed interfering effect on CLC1．［Conclusions］In C．neoformans，the origination of sＲNA may be diverse．The endogenous sＲNA should play interfering function via the canonical ＲNAi pathway．

Abstract:Abstract:［Objective］The purpose of this work is to studythe effects of ubiquitination of key nitrogen transporter Agp1p on nitrogen utilization in Saccharomyces cerevisiae．［Methods］ The ubiquitination detection vector to examine the ubiquitination process of Agp1p was constructed based on the bimolecular fluorescence complementation technology．The site-directed mutagenesis on the potential ubiquitination sites were performed to verify the effect on its ubiquitination regulation and nitrogen utilization．［Results］ Agp1p can be ubiquitinated on the medium with glutamine，arginine，proline or ammonium． The fluorescence levels of mutant strains were down-regulated compared to the wild type strain．The quadruple mutant Agp1pK11-14-98-112Ｒ achieved the lowest level among all strains．The ubiuitination process could be significantly repressed by removing the potential ubiquitination residues． Furthermore，flask-shaking experiments with nineamino acids or urea as sole nitrogen source showed that the effect of nitrogen utilization efficiencyinthe quadruple mutant was the highest．［Conclusion］Ubiquitination was involved in the regulation of Agp1p．Site-directed mutagenesis of potential ubiquitination sites of the transporter could significantly affect the nitrogen utilization process by altering the ubiquitination process．

Abstract:Abstract:［Objective］To determine the function of high-affinity iron permeases，Ftr1 and Ftr2，we studied cell growth and filamentation ability of the ftr1/ftr1，ftr2/ftr2，and ftr1/ftr1 ftr2/ftr2 mutants under different culture conditions．［Methods］Cells of the wild type and mutants were cultured on different solid media at different temperatures．Cell growth and filamentation were observed．［Results］Deletion of either one of the FTR genes had no effect on the growth under all conditions tested． Deletion of both FTR1 and FTR2 led to obvious growth defect on Spider media，although addition of FeCl3 restored their growth．The double mutant also grew much more slowly on nutrients-limited synthetic media such as Lee’s glucose and Lee’s GlcNAc (N-acetylglucosamine)．Moreover，deletion of FTＲ1 enhanced filamentation，whereas deletion of FTR2 weakened this ability． Deletion of both FTR1 and FTR2 recovered the ability of filamentation．［Conclusion］Ftr1 and Ftr2 are very important for C．albicans growth under iron-limited condition and may participate in the utilization of some carbon sources including GlcNAc，ethnol，and glycerol. Ftr1 plays a negative，whereas Ftr2 plays a positive role in the regulation of filamentation in C．albicans.

Abstract:Abstract:［Objective］We evaluated the role of syntrophic acetate oxidation coupled with hydrogenotrophic methanogens in three different methanogenic consortia．［Methods］Three methanogenic hexadecane degrading consortia named Y15，M82 and SK were taken from the same oily sludge of Shengli oil-field and enriched．They were incubated at 15，35 and 55℃，respectively．The consortia amended with acetate and inhibitors of NH4 Cl or CH3 F were further transferred and incubated at corresponding temperatures．The cultures atlate logarithmic phase were collected for terminal restriction fragment length polymorphism (T-RFLP) combined with cloning and phylogenetic analysis of 16S rRNA gene fragments． ［Results］Gas chromatograph analysis showed that all of the consortia could grow and produce methane，but the lag phase was delayed and the growth rate was retarded in the cultures amended with inhibitor． Combination analysis of T-RFLP and clone library revealed the predominance of obligate aceticlastic Methanosaeta in the acetate cultures of Y15，M82 and SK．Under the mesophilic and thermophilic conditions，after add inginhibitor the relative abundance of aceticlastic methanogen decreased but hydrogenotrophic methanogen increased．［Conclusion］Syntrophic acetate oxidation during methanogenic degradation of petroleum hydrocarbons occurs under mesophilic and thermophilic conditions，although the situation at low temperature seems uncertain．

Abstract:Abstract:［Objective］We studied soil bacterial community composition，abundance and diversity of transition zone along eutrophic lakeside wetland sediments and soils．［Methods］The total DNA was extracted according to the sediment DNA extraction．Then high-throughput pyrosequencing was used to detect soil bacterial community composition，abundance and diversity based-on 16S rRNA gene．Soil physicochemical properties were tested to analyze its effects on bacterial community according to standard methods．［Results］The soil bacterial community composition and relative abundance were very different across transition zone in littoral wetland．Bacteria groups mainly include Proteobacteria，Bacteroidetes，Chloroflexi，Actinobacteria，Planctomycetes and Gemmatimonadetes at phylum level．The diversity index of bacterial communities gradually increased according the land distribution，especially the phylum Proteobacteria and the genus Sulfurimonas． Correlation analysis indicated that the combination of total phosphorus，total water soluble salt and ammonium has the most significant effects on the whole bacterial community structure，and Mantel Test results indicated that the correlation was statistically significant (R=0.8857，P=0.037)．［Conclusion］ The bacterial community structure of transition zone is quite different in littoral wetland of Wuliangsuhai eutrophic lake，where Sulfurimonas play potential important roles in biogeochemical cycles of sediments in Wuliangsuhai Lake.

Abstract:Abstract:［Objective］We studied the formation of carbonate minerals induced by microorganism to explore the possibility of mineral capture．［Methods］Culture experiments of carbonate precipitation were done using B4 medium with 6:1 molar ration of Mg/Ca for 50 days． The same medium without inoculation was used as the control．During the cultivation，bacterial density，precipitate quantities，pH and conductivity of the medium，calciumand magnesium concentration were determined．The morphologies of precipitated carbonates were observed using scanning electron microscopy，and mineral species of carbonate were determined by X-ray diffraction．［Results］ The main results were: (1) In the inoculation process of the Lysinibacillus sp．(GW-2 strain)，we found that precipitate quantities were gradually increased with time，while precipitate was not collected in the aseptic experiments; (2) There were significant positive correlations between bacterial density and average precipitation rate (r=0.67，P＜0.05)，precipitate quantities and pH value (r=0.79，P＜0.05);(3) Precipitate quantities negatively correlated with conductivity，Ca2+ and Mg2+ concentration with correlation coefficients r of 0.89，0.93，0.98 (P＜0.001)，respectively; (4) The three carbonate minerals by Lysinibacillus sp．formed according to following trend: amorphous calcium carbonate→Huntite→High-Mg calcite．［Conclusions］The main conclusions were: (1) Lysinibacillus sp．(GW-2 strain) might induce the formation of carbonate minerals precipitation; (2) The bacterial density directly affected the precipitation of carbonate minerals，whereas pH value indirectly controlled the precipitation of carbonate minerals; (3) Decreased of conductivity，calciumand magnesiumconcentration of the medium could indirectly indicate the occurrence of carbonate precipitate; (4) Huntite might be formed through ageing of amorphous calcium carbonate，whereas high-Mg calcite might be formed through demagnesium of the huntite.

Abstract:Abstract:［Objective］ The purpose of this study was to examine the relationship between the microbial community structure of soil actinomycetes and geochemical characteristics in Xinghu wetland sediments.［Methods］ The diversity and composition of the actiniobacterial community in sediments collected from 10 locations were studied using PCＲdenaturing gradient gel electrophoresis．Canonical correspondence analysis was carried out to examine the relationship between environmental variables and actinobacterial community composition．［Result］There were significant differences among the Shannon-wiener index，Ｒichness and Evenness．Similarity analysis of actinobacteria communities in different station showed certain trends in similarity coefficients，and actinobacteria community structure similarity of the same transect was much higher than others．According to the results of sequence analysis of DGGE dominant bands belonged to the orders Nocardioidaceae， Streptomycetaceae， Micromonosporaceae， Micrococaceae， Cellulomonadaceae and Promicromonosporaceae．Canonical correspondence analysis showed that sediment water-soluble organic carbon and available phosphorus were identified as the key factor in regulating the variations of actinobacterial community composition．［Conclusion］ Xinghu Wetland is the potential place for actinobacteria diversity．This study provides fundamental data for further studies of the underline mechanisms of structure microbial groups and the isolation of actinobacteria strains of interest．

Abstract:Abstract:［Objective］ The environmental fitness of metalaxyl-resistant isolate of Phytophthora capsici was studied for assessing the risk of metalaxyl-resistant P．capsici．［Methods］We studied the main biological characteristics，competitive ability on plate，pathogenicity on pepper plant and adaptability in soil of the laboratory-induced metalaxyl-resistant isolate of P．capsici (Pc2-3 strain)，with the metalaxyl-sensitive isolate (Pc2 strain，the wild-type) as the control.［Results］The zoosporangia production，releasing rate of zoosporangia and germination rate of zoospores of Pc2-3 were less than that of Pc2．The temperature range，optimum temperature range and initial pH range for mycelia growth of Pc2-3 were consistent with that of Pc2，but mycelia growth rate of Pc2-3 was lower than that of Pc2． Pc2-3 exhibited significantly weak competitive ability compared with Pc2 on carrots plate．Disease incidence of pepper inoculated with Pc2-3 (14.3%) was significantly lower than that of Pc2 (88.6%)．When pepper plant was inoculated by mixtures of zoospore suspension of Pc2-3 and Pc2 at same ratio，the disease incidence，closing to that by Pc2 strain，was 75.7%．And all the strains isolated from diseased plants in the treatment were metalaxyl-sensitive．The density of P．capsis Pc2-3 was 0.28 times of Pc2 after the soil inoculated with Pc2-3 and Pc2 respectively at same zoospores density was incubated for 20 days．Otherwise，the ratio of Pc2-3 to Pc2 was 0. 42 if the metalaxyl concentration in the soil was 300 mg/kg dry soil．No matter the soil temperature and humidity were beneficial to survival of P．capsici or not，Pc2-3 showed lower soil adaptability than Pc2．［Conclusion］ The environmental fitness of metalaxyl-resistant P．capsis Pc2-3 was weaker than the metalaxylsensitive strain Pc2 (the wild-type)．

Abstract:Abstract:［Objective］In order to get excellent yeast strains for aquiculture water purification，we isolated，screened and identified yeasts from the aquacultural environment and intestinal tract of shrimp．［Methods］ The potential water purification ability of yeasts，isolated from the activated sludge of aquacultural environment and intestinal tract of white shrimp and mantis shrimp under normal and low temperature，was evaluated in the simulated wastewater．Morphological physio-biochemical characteristics，5.8S rDNA ITS gene sequence analysis were used to identify the strains．［Results］Thirty-seven yeast strains were isolated from 3 samples，among them 16 strains were isolated under normal temperature (25℃) while 21 strains were isolated under low temperature (15℃)．Water purification test suggested 5 strains isolated under 25℃ and 6 strains isolated under 15℃ had higher removal ability of nitrite and ammonia from water．After 48 hours treatment with DN9 and CN6，10.64 mg/L nitrite in the water was completely removed．After 96 hours treatment，CODcr degradation rates of the 2 strains were 52% and 67%，respectively．According to morphological，physio-biochemical characteristics and 5.8S rDNA ITS gene sequence analysis，the strain DN9 was identified as Rhodotorula mucilaginosa and CN6 as Ｒhodosporidium paludigenum．［Conclusion］Strains DN9 and CN6 would be promising for water purification in aquiculture.

Abstract:Abstract:［Objective］In order to study the role of SS2 Type Ⅳ Secretion System VirD4 in evasion of the host innate immune killing，we constructed a knockout mutant ΔVirD4．Then we studied its biological activity and virulence．［Methods］The two VirD4 flanking DNA sequences were amplified using genome of 05ZYH33 as template．We also amplified the Cm sequence of shuttle vector pSET1，and through overlap extension PCR we connected the three fragments together． Using suicide vector pSET4s，we constructed the recombinant gene knockout vector pSET4s∷ VirD4． The mutant ΔVirD4 was successfully constructed by allelic replacement．Virulence of mutant strain was compared with wild type strain 05ZYH33 through in vitro bactericidal assays，competitive infection and challenge experiment of CD1 mice．［Results］Mutant strain ΔVirD4 was constructed successfully，its virulence attenuated compared to the wild type strain．［Conclusion］These findings indicated that Type Ⅳ Secretion System component VirD4 contributed to the virulence of S．suis with important functions in evading innate immunocyte killing．

Abstract:Abstract:［Objective］Pyroptosis is a caspase-1 dependent programmed cell death and involves pathogenesis of infectious diseases by releasing many pro-inflammatory cytokines to induced inflammation．TLR-4 plays an important role in mediating pathogenesis of some infectious diseases． In this study，we detected the expression of TLR-4 and some molecules (e．g caspase-1，TNF-α，IL-1β，IL-6，IL-18) related with pyroptosis to determine its involvement and mechanisms of pulmonary inflammation in mice infected by A．pleuropneumoniae．［Methods］ Mice were intranasally infected by A．pleuropneumoniae and killed 48 hours post infection．Pulmonary gross lesion and histological pathology by H-E were observed． Expression levels of caspase-1，caspase-3，TNF-α，IL-1β，IL-6，IL-18，and TLＲ-4 in lung of mice were detected by RT-PCR and qPCR．［Results］Serious pulmonary hemorrhage and inflammation in infected mice were observed． Expression levels of caspase-1，caspase-3，TNF-α，IL-1β，IL-6，IL-18 and TLR-4 increased，and expression levels of caspase-3 were not changed in lung of infected mice．［Conclusion］ TLＲ-4 might be involved in pulmonary inflammation of mice infected by A．pleuropneumoniae． After induced by activated TLR-4 some cells in this lesion expressed pro-inflammatory cytokines．These cytokines would induce pulmonary inflammation． This lesion might involve pyroptosis with caspase-1 expression．