Abstract:Abstract:The family Geodermatophilaceae is a newly established actinobacterial taxon．Normand ever proposed the family Geodermatophilaceae in 1996，which was recognized as an invalid taxon at that time．In 2006，based on the common characteristics of the genera Geodermatophilus， Blastococcus and Modestobacter，Normand summarized the typical characteristics of Geodermatophilaceae，then the family Geodermatophilaceae was finally accommodated as a validly described taxon in the phylum Actinobacteria．Up to date，the family Geodermatophilaceae consisted of 3 genera，i.e.，Geodermatophilus，Blastococcus and Modestobacter，including 25 validly described species．The members of the family Geodermatophilaceae were considered as biologic pioneers in extreme environments，exhibiting many potential advantages in the study of mechanism of stress resistance，desertification control and environmental remediation．The objective of this review is to summarize the research advances in the family Geodermatophilaceae，including the establishment and taxonomic characteristics of the family，as well as their application prospect and the roles in the field of ecology.

Abstract:Abstract: Lactic acid bacteria (LAB) could synthesize cell envelope proteinase with weak activity，which primarily degrades casein．In addition to its crucial role in the rapid growth of LAB in milk，LAB proteinases are also of industrial importance due to their contribution to the formation of texture and flavor of many fermented dairy products．The proteolytic system，properties of proteinase，the degradation product of casein and its effect on the quality of fermented dairy products were reviewed in this manuscript．

Abstract:Abstract:Invasion of pathogens into host cells is the key process to consequently induce the infection，which depends on the actin cytoskeleton rearrangement．Cofilin in the host cell is one of the most important actin depolymerization factor that is essential responsing to the infection of several viruses，bacteria and fungi．Pathogenic microbes can induce biphasic remodeling of the actin cytoskeleton in host cells，accompanied by changes of phosphorylation of cofilin，which results in changes of cofilin activity．The modulation of host cofilin activity by mutation，knockdown，or overexpression can effectively inhibit the infection．Here we review the function and possible regulatory mechanism of host cofilin during the process of infection．

Abstract:Abstract:［Objective］ The aim of this study was to screen tobacco straw and nicotine degrading microorganism．［Methods］The bacterium was isolated from tobacco field soil using medium containing tobacco straw as the sole carbon and nitrogen source．We identified the bacterium through morphological and physiological characterization combined with the result of 16S rＲNA gene sequence and data analysis．We also studied the lignocelluloses degradation and enzyme activities related to the degradation of lignin and cellulose in liquid state fermentation of tobacco stalk.［Results］The bacterium was identified as Bacillus megaterium and we had demonstrated that it has a good ability to degrade lignin in tobacco straw when fermented in liquid state．It showed the highest laccase production of 418. 52 U/L while the highest lignin peroxides and manganese peroxides activity was 19.71 U/L and 64.71 U/L．On the other hand，we also found that nicotine in tobacco stem was totally degraded 20 d after inoculation.［Conclusion］to the isolated Bacillus megaterium is capable of degrading tobacco straw partially and nicotine totally.

Abstract:Abstract:［Objective］We knocked out the genes related to lipopolysaccharide in outer membrane of Escherichia coli BL21(DE3) to study the effects on extracellular secretion of recombinant proteins.［Methods］We generated waaF or msbB knockout mutants［E.coli BL21 (ΔwaaF) or E.coli BL21(ΔmsbB)］of E.coli BL21(DE3) by using lambda-Red recombination system．Then，we transformed recombinant plasmids pET-ffase or pET-pga into E.coli BL21 (ΔmsbB)，E.coli BL21(ΔwaaF) and E.coli BL21 (DE3) respectively，to generate the engineering strains E.coli BL21 (ΔmsbB) /pET-ffase，E.coli BL21 (ΔwaaF)/pET-ffase，E.coli BL21 (DE3)/pET-ffase，E.coli BL21 (ΔmsbB)/pET-pga，E.coli BL21 (ΔwaaF)/pET-pga and E.coli BL21(DE3)/pET-pga．Finally，we studied the effects of mutants on extracellular secretion of beta- fructofuranosidase (EC 3.2. 1.26，beta-FFase) and penicillin G acylase (EC 3.5.1.11) in shaking flask fermentation.［Results］After induced expression for 4 hours，up to 19.7% of the beta-FFase activity was found in the culture medium with the msbB deletion mutant，and 50. 9% with the waaF deletion mutant，compared to the original 2.6%．Besides，after induced expression for 24 hours，up to 1708 U/L extracellular activity of penicillin G acylase was found in the culture medium with the waaF deletion mutant，which was 4.1 times of the original.［Conclusion］Knockout mutants (ΔmsbB and ΔwaaF) had significantly higher excretion of beta-FFase and the waaF deletion mutant had higher excretion of penicillin G acylase.

Abstract:Abstract:［Objective］Bacillus subtilis ATCC 13952 is an inosine-producing strain．In order to study the mechanisms of inosine accumulation and offer help for molecular breeding，it is necessary to uncover the genome sequence of ATCC 13952.［Methods］Whole-genome sequencing of ATCC 13952 is carried out by Solexa and Sanger sequencing．Genome assembly，gene prediction and functional annotation，GO/COG cluster analysis and synteny analysis are done using relevant software.［Results］The complete genomic information of Bacillus subtilis ATCC 13952 is contained on a single circular chromosome of 3876276 bp with an average GC content of 45.8%．The genome sequence is deposited in the GenBank under the accession number CP009748． Comparative genomic analysis shows that ATCC 13952 should have significant genomic synteny with other Bacillus subtilis strains．On the other hand，some point mutation and deletions occurred in purine metabolism-related genes between ATCC 13952 and the standard strain.［Conclusion］The results of this study will provide a theoretical basis for subsequent further molecular breeding.

Abstract:Abstract:［Objective］ To study the effect of adenosine monophosphate nucleosidase gene deletion on Corynebacterium glutamicum S9114 metabolism.［Methods］ We constructed the amn deficient strain △amn and studied its glutamate fermentation and acid tolerance.［Results］Compared with the wild type strain，biomass of △amn strain increased by 16.2% whereas glutamate production reduced by 58.8%. After 10，25 and 40 h，intracellular ATP level of △amn strain increased 3.0，3.7 and 2.2 times．The isocitrate lyase activity increased by 17.1%，4.9% and 44.5% ，the isocitrate dehydrogenase activity decreased by 76.9%，74.6% and 5.0%，and the glutamate dehydrogenase activity decreased by 42.4%，50.8% and 42.4%．At pH4.0，the survival of △amn strain dropped 64.9%．However，the intracellular ROS and protein carbonylation level showed an increase of 31.5% and 22. 5% respectively.［Conclusion］Knocking out of amn gene enhanced intracellular ATP level and biomass formation，whereas had negative effect on glutamate fermentation and acid tolerance．

Abstract:Abstract:［Objective］Lactobacillus casei is widely used in food production and feed industry. The aim of this study was to construct the recombinant expression mannanase Lb. casei.［Methods］The mature peptide gene of β-1，4-mannanase from Bacillus pumilus was cloned into expression vectors pELX1 and pELSH，then electroporated into Lb．casei，establishing an intracellular and a secretion expression mannanase Lb． casei respectively.［Results］After incubation，the specific activity of β-1，4-mannanase was 23 U/mg whole cell protein for intracellular expression and 8.8 U/mL forsecretion expression in supernatant.［Conclusion］Mannanase gene expression in Lb．casei provides application prospect and deserves further study．

Abstract:Abstract:［Objective］ DamH is a bifunctional hydrolase that hydrolyzes the amide and ester bonds．Previous studies demonstrated that mutagenesis of non-catalytic residues shows a negative impact on the soluble expression and specific activity of DamH．Therefore，we studied the catalytic triad of DamH and the effect of non-catalytic mutagenesis on the soluble expression and specific activity of DamH.［Methods］We performed site-directed mutation experiment of the 3 possible catalytic sites: S149，E244 and H274 and the non-active sites by using overlapping PCR．In the whole cell catalytic experiments，2 ’-methyl-6 ’-ethyl-2-chloroacetanilide ( CMEPA ) hydrolase activities of the three mutants (S149A，E244A and H274A) were assayed．Mutants of D165 and N192 were purified by affinity chromatography of Ni2+- NTA．At the same time the hydrolase activities of mutants were compared with that of the wild-type strain．［Results］S149-E244-H274 was the catalytic triad of DamH． Kinetics shows that the CMEPA hydrolase activity of mutant S149A declined to 5% of the wild-type strain and none of E244A and H274A mutants showed any CMEPA hydrolase activity．Mutations of D165 and N192 would affect the soluble expression of recombinant enzyme． The soluble expression levels of D165P and N192P were 28. 2% and 20. 8% of the wild-type strain，respectively． Furthermore，hydrolase activities of N192P and D165P were only 55. 5% and 49. 7% of the wild-type enzyme，respectively．［Conclusion］DamH uses the same active site to hydrolyze esters and amides.

Abstract:Abstract:［Objective］ To realize efficient biotransformation of (S)-1-phenyl-1，2-ethanediol by recombinant (S)-carbonyl reductase II，we expressed (S) -carbonyl reductase II from Candida parapsilosis CCTCC M203011 and embedded it in the spores of Saccharomyces cerevisiae AN120． ［Methods］(S)-carbonyl reductase II gene was cloned from C.parapsilosis genome and expressed in S. cerevisiae AN120 by PCR amplification． When cultured with potassium acetate as the sole carbon source，the yeast spores were produced，and embedded the recombinant (S)-carbonyl reductase II．Using 10% W/V spores as biocatalysts，6 g/L 2-hydroxyacetophenone as substrate，the biotransformation was carried out and the optical purity and yield of products were analyzed by HPLC. During the biotransformation of 2-hydroxyacetophenone to (S)-1-phenyl-1，2-ethanediol，the optimal temperature and pH，stability and reusability of the recombinant spores were determined.［Results］The recombinant yeast spores showed excellent performance to give (S)-1-phenyl-1，2-ethanediolwith a high optical purity of 99.3% and a high yield of 99.0% at the optimal temperature (40 ℃) and pH (6.0)．Compared with the recombinant Escherichia coli，the spores improved the yield of (S) -1-phenyl-1，2-ethanediol from 89.7% to 99.0% ，and shortened the biotransformation duration from 48 h to 4 h．After being reused for 10 times， the recombinant spores biotransformed(S) -1-phenyl-1，2-ethanediol with a stable optical purity of about 99% and a yield over 85%．［Conclusion］The heterologous expression of oxidoreductases was first realized in yeast spores，which laid a solid foundation for efficient preparation of chiralcompounds．

Abstract:Abstract:［Objective］To study the effect of fatty acids composition on swarming mobility in Pseudomonas aeruginosa.［Methods］We constructed a fabF-knockout mutant of PAO1 (YFF-1) by double exchange principle，overexpressed FabF in YFF-1 mutant to recover the mobility，and compared the swarming ability of wild type，YFF-1 mutant and mutant with plasmid pUCP18Gm-fabF．The change of fatty acids composition was analyzed using gas chromatography to explain the difference of swarming ability.［Results］Swarming ability disappeared in YFF-1 mutant and was recovered in YFF-1 with plasmid pUCP18Gm-fabF． Gas chromatography analysis revealed that fatty acids composition changed in YFF-1．The cisvaccinate acid (C18:1Δ11) content decreased from 33.6% to 8.9%，and the ratio of unsaturated fatty acids to saturated fatty acids (UFA:SFA) was deduced from 0.96 to 0.74．The recovery of cis-vaccinate acid content was 20.9% and UFA:SFA 1.09 after expression of fabF.［Conclusion］Expression level of FabF played an important role in regulating swarming ability of PAO1．The decrease of cis-vaccinate acid content and unsaturation degree of fatty acids，especially the sharp decrease of cis-vaccinate acid，may be vital causes of swarming ability disappearance in YFF-1.

Abstract:Abstract:［Objective］This study aimed to screen high-performance ammonia oxidizing bacteria (AOB) resistant to a high concentration of ammonia-nitrogen and low C/N ratio，for the development of novel AOB agents.［Methods］Multipoint sampling，compulsory domestication，gradient dilution of domestication liquid were conducted to screen AOB with efficient and stable ammonia-nitrogen removing ability，and effects of different factors on its ammoxidation ability including C/N ratio，shaking speed and ammonia-nitrogen concentration were studied． Dominant strains were screened and identified by morphological observation，physiological and biochemical properties test and 16S rRNA sequence analysis．［Results］Three efficient AOB were obtained，among them a micro-flora named JQ8 showed the highest activity． The ammonia-nitrogen removal rate reached 95.07% in a simulated wastewater with 17.86 mmol/L of initial ammonia-nitrogen at C/N 4 treated by JQ8 for 6 days． Moreover，its ammonia nitrogen removal rate kept above 95% and net nitrogen removing rate nearly 80% in the solution with a C/N ratio above 4 and an NH +4 -N concentration below 28. 57 mmol/L．The circuit board industry wastewater was treated using the laboratory-simulated aerobic active sludge disposal system．The removal rate of NH +4 -N and total nitrogen reached 87.8% and 67. 6% respectively after 7 days’treatment using JQ8．Defluvibacter sp． ，Paracoccus sp． and Aquamicrobium sp． were identified as the dominant strains after the composition analysis of JQ8．［Conclusion］An ammonia oxidizing bacteria consortium JQ8 screened from the landfill leachate showed a strong ammonium-nitrogen removal and endurance ability under low C /N ratio and high ammonia-nitrogen concentration，thus is probably applicable to intensify the ammonia-nitrogen removal treatment of industrial wastewater with sewage disposal system．

Abstract:Abstract:［Objective］We explored which internal genes of influenza virus that affect the titer of recombinant viruses and contribute to the high yield of Influenza A seed virus in ovo.［Methods］ Six internal genes or mutant or polymerase complex of A/Puerto Rico/8/1934 (H1N1) (PR8) virus genes were replaced individually by corresponding gene of A/chicken/ZJ/China/2013 (H5N1) virus，and the hemagglutination titers of recombinant viruses were compared by HA assay.［Results］PB2 gene had the greatest influence，its replace failed to generate recombinant virus． When PB1，PA，or M gene was replaced，the titers of recombinant viruses dropped by 3.7，3.4，3.0 (log2)，respectively．NS gene had little influence upon HA titer． When polymerase complex genes were replaced，virus titer dropped slightly to 7.6 log2，and it did not confer the same growth characteristics (8.4 log2) found when a complete polymerase complex was of PR8 origin．When amino acids of position 627 of PR8 PB2 gene were mutated to glutamic acid，virus titer rose from 8.4 log2 to 8.7 log2.［Conclusion］ The optimal gene combinations may facilitate replication through viral RNA and protein interaction with cellular components as well as interaction of viral RNA and protein or protein-protein interactions within the virus．These multi-factorial contributions resulted in selection of a high replication competent reassortant in embryonated chicken eggs in comparison to the respective low yield wild type viruses，and laid the foundation for high yield of influenza vaccine production.

Abstract:Abstract:［Objective］To study the effects of temperature and lixivium return on the concentrate bio-oxidation and rate of gold cyanide leaching.［Methods］ The bioleaching of a high-sulphur (S) and high-arsenic (As) refractory gold concentrate was conducted，and we studied the effects of different temperature (40 ℃ and 45 ℃) and lixivium return (0 and 600 mL) on the bio-oxidation efficiency．The bacterial community structure also was investigated by 16S rRNA gene clone library.［Results］ The results showed that both the temperature and lixivium return significantly influenced the oxidation system． The temperature rising elevated the oxidation level，while the addition of lixivium depressed the oxidation． Dissimilarity and DCA (detrended correspondence analysis) indicated the effect of temperature on oxidation system was much greater than lixivium． The bacterial community was comprised by Acidithiocacillus caldu (71%)，Leptospirillum ferriphilum (23%) and Sulfobacillus thermosulfidooxidans (6%) indicated by the clone library，and the OTU coverage based on 97% sequence similarity was as high as 93.67%.［Conclusion］Temperature rising to 45 ℃ would improve the oxidation efficiency while lixivium return would decrease it．This study is helpful to provide an important guiding value for the industry cost optimization of mesophile bacterial oxidation and reduction process.