Abstract:A β-galactosidase-producing strain was screened from bacillus species isolatated from honey. The strain was identified as Bacillus licheniformis by an in-depth study and named as Bacillus licheniformis SYBC hb15. β-galactosidase expressed by Bacillus licheniformis SYBC hb15 was purified for the study of enzymatic properties using o-nitrophenyl-β-D-galactoside（ONPG） as substrate. The result showed that the optimal reactive temperature of the β-galactosidase was 60 ℃，and it had high thermal stability when incubating the enzyme at 70 ℃ for 60 min with 65% residual activity. Compared to that of the enzyme from Talaromyces thermophilus，glucose presents less inhibition to the hydrolytic activity of the β-galactosidase. Therefore，the β-galactosidase produced by B. licheniformis SYBC hb15 has good potential in the industrial application because of its high thermostability and resistance to glucose of high levels.

Abstract:Sulfur amino acids are essential for all living organisms. Pichia pastoris is a very important expression host in industrial fermentation，while its sulfur amino acids biosynthetic pathway is still unclear. To establish the pathway，bioinformatics approach and phenotypic analysis of mutants were employed in this study. Results indicated that Pichia pastoris synthesizes sulfur amino acids from inorganic sulfate via O-Acetyl-L-Homoserine and O-Acetyl-L-serine pathways. And methionine and cysteine can be inter-conversion by trans-sulfuration pathway. In addition，cys3Δ mutant showed selenomethionine resistance without supplementation of cysteine. Taken together，these results suggest a potential use of the cys3Δ strain for the production of selenomethionyl proteins.

Abstract:To improve the temperature properties of AoXyn11A，a glycoside hydrolase family 11 mesophilic xylanase from Aspergillus oryzae CICC40186，the amino acid residue of Gly²¹ that possessing the highest B-factor value was replaced randomly based on the homology modeling of AoXyn11A and molecular dynamics（MD） simulation for its three-dimensional structure. Using the recombinant plasmid pET-28a-Aoxyn11A as a template，the codon of Gly²¹ in the xylanase-encoding gene（Aoxyn11A） was site-saturated mutagenesis with the two-stage whole-plasmid PCR technique. And then，the mutational transformant library was constructed by transforming the mutants of pET-28a-Aoxyn11A into E. coli BL21. In reference to the thermostability of enzymes，optimal mutational transformant（E. coli/Aoxyn11A^G21I） was screened from library. The DNA sequencing results showed that E. coli/Aoxyn11A^G21I expressed a mutant enzyme（AoXyn11A^G21I） with the amino acid residue of Gly²¹ changed by Ile²¹. The analytical results indicated that the optimal temperature（T^opt） of AoXyn11A^G21I was 65 ℃，which was 10 ℃ higher than that of AoXyn11A. AoXyn11A^G21I was thermostable at or below 55 ℃，being 7 ℃ higher than that of AoXyn11A. In addition，the pH properties of AoXyn11AG21I did not obviously change compared with AoXyn11A.

Abstract:Lactonase ZHD101 which can degrade ZEN effectively is being widely studied. However，its application in feed industry was limited by low thermostability. In this study，we attempted to improve the thermostability of ZHD101 through structure-based rational design and molecular engineering of disulfide bridges. Specifically，7 mutants（A110C/P196C，S136C/R189C，D143C/P181C，S147C/P181C，D199C/A202C，L200C/A231C，and R204C/G205C） were constructed for disulfide bridge formation. Two mutants，S136C/R189C and D143C/P181C，showed enhanced thermostability. Notably，D143C/P181C mutant，which exhibits similar specific activity as wild type enzyme，showed two-fold increase in thermostability after heated at 50 ℃ for 2 min. A quadruplet mutant（S136C/D143C/P181C/R189C） was subsequently constructed and examined，but it showed lower thermostability comparing to D143C/P181C mutant. This study provides significant benefit for the application of ZHD101 in further commercial utilizations.

Abstract:In order to gain the δδ-ADH from human stomach，the target gene was synthesized according to the sequence of human stomach alcohol dehydrogenase δδ-ADH gene ADH7 in GeneBank，inserted into plasmid pET-32a（+） which was transformed into E.coli BL21（DE3）. IPTG was used to induce the experssion of δδ-ADH in E.coli BL21（DE3）. δδ-ADH still existed in the form of inclusion body even after optimizing the expression conditions. Active crude enzyme solution was obtained after the inclusion body was solubilized with 1 mol/L urea and the target protein was purified by HisTrap^TM excel affinity chromatography column. Then the specific activity of the enzyme and its essential enzymatic properties were studied. The results showed that the specific activity of δδ-ADH was 2.085 U/mg，Km was 28.43 mmol/L and Vmax was 316.46 μmol/（L·min）. The optimum reaction temperature of δδ-ADH was 40 ℃，and its specific activity decreased to a value which was about half of the maximal activity after a water bath in 30~50 ℃ for 60 min. The optimum pH of δδ-ADH was 9.0，after a water bath in different pH buffer in 25 ℃ for 30 min，the enzyme activity of δδ-ADH kept almost consistent at pH 6.0~11.0，while the relative enzyme activity was only 60% remained at pH 5.0. After a water bath in different concentrations of alcohol（0、500、1 000、1 500 mmol/L）in 37 ℃，the relative enzyme activities of δδ-ADH were 65.6%、51.1%、45.4% and 44.4%，respectively.

Abstract:The effects of adding nano zero valent iron（NZVI） on the anaerobic disposal of molasses alcohol wastewater，the effects of NZVI on the anaerobic microbial activity were studied in this study. Batch experiments were carried out by adding 0，0.025 g，0.05 g，0.10 g，0.25 g，0.50 g and 2.50 g NZVI，respectively to the anaerobic digestion systems. The results indicated that the treatment efficiency of molasses alcohol wastewater was first increased then decreased when NZVI was added. The COD degradation rate，biogas generation rate and methane content was maximum at the group of 0.50 g NZVI was added，the values were 71.1%，310.9 mL/g COD and 58% ，which was 14.7%，35.6 mL/g COD and 18.8% higher than those of the control group，respectively. The concentration of COD and sulfide in the wastewater were the lowest at the end of the reaction，which were 2 400 mg/L and 33.3 mg/L，respectively. The degradation rate of sulfate radical and the concentration of extracellular polymeric substance（EPS） were the highest in the experimental group with 2.50 g NZVI. Finally，the concentration of sulfate radical was 288.2 mg/L and the removal rate of sulfate radical was 72.8% ，which was 1.93 times as much as that of the control group. The concentration of protein and polysaccharide in this group were 46.00 mg/gVSS and 5.05 mg/gVSS，which were 4.43 and 1.66 times of the control group，respectively. The activity of dehydrogenase reached the maximum value of 340.3 TF μg/（mL·h） when 0.5g NZVI was added，it was192.5 TF μg/（mL·h） higher than the control group.

Abstract:The aim of this study is to analyze the dominant bacteria distribution and the changes of salmon bacterial community during refrigerated storage to provide theoretical basis for the preservation of ice salmon. Salmon refrigerated at 4 ℃ was used in the study，and total bacteria DNA on the fish was extracted on 0，2，4 d. Then，chandes of salmon bacterial communities were analyzed and the dominant bacteria were determined using high-throughput sequencing. The results showed that 281 known genus were classified. Meanwhile，the amount of genus which were accounted for more than 1% and 0.1% were 6 and 16，respectively. The salmon bacterial community changed during refrigerated storage whereas its dominant bacteria remains the same which were Pseudomonas，Photobacterium，Shewanella，Acinetobacter，Flavobacterium and Staphylococcus. And with the extension of storage time，Pseudomonas abundance（dominance） gradually increased.

Abstract:To investigate the effects of high-fat diet（HFD） on the bone of obesity resistant（OR） and obesity prone（OP） mice and the intervention of quercetin. Mice were randomly divided into two groups：regular diet group（C） and HFD group. After 7 weeks，HFD-fed mice were devided into OP and OR group according to body weight and treated with quercetin. Femur parameters，redox status and expressions of osteoblast and osteoclast differentiation related genes were measured before and after quercetin treatment. The results showed that HFD treatment significantly decreased femur parameters of OP and OR mice. The expressions of osteoclast differentiation related genes were significantly up-regulated while the osteoblast differentiation related genes were down-regulated significantly in both OP and OR mice. Femur properties were improved after quercetin treatment. Consistent with the above mentioned，the content of MDA was higher，while the antioxidant indexes and the expression of antioxidant related genes were significantly lower in OP and OR mice. Redox status was improved after quercetin treatment. HFD treatment led to oxidative stress in femurs of OR and OP mice，may by affecting the expressions of osteoblast and osteoclast differentiation related genes，consequently reduced the femur properties. Quercetin can improve redox status，thereby improving femur properties of HFD-fed OP and OR mice.

Abstract:In order to reduce costs in the Spirulina platensis culture and harvest process，a membrane photobioreactor（MPBR） was used for Spirulina platensis cultivation and pre-harvsting. The results showed when the biomass attained about 1.8 g/L，microalgae could be harvested. And when the initial algal biomass concentration was 1.828 g/L，the maximum volume concentration factor was 2 in MPBR. The optimum dilution rate was 0.08 d^-1 and the concentration of biomass product was up to 3.319 g/L during the cultivation in MPBR. The amount of water saving，nitrogen saving and phosphorus saving were 0.301 L，0.248 g and 0.053 g respectively when per 1 g biomass product was harvested in MPBR. The costs of microalgae cultivation and harvesting could be reduced in MPBR compared with the traditional photobioreactor（PBR）.

Abstract:The condition for laccase production of spent compost of Pleurotus eryngii under solid fermentation and the application in dye decolourization by crude enzyme were preliminarily investigated in this study. The results showed that，when added 4% bagasse，1.2% ammonium nitrate，1.0% alkali lignin，the spent compost displayed the strongest enzyme production capacity，reaching 386.9 U/gds. Relative to the initial laccase activity 18.9 U/gds ，the optimized condition improved by more than 20 times. Under optimal conditions，the crude enzyme solution without mediate caused 85.8%、85.6%、68.3%、71.2% decolourization for methyl red，reactive brilliant blue K3R，acid blue 209，reactive blue KNR，respectively，and 88.8%，93.4%，89.7% decolourization for reactive brilliant blue K3R，acid blue 209，reactive blue KNR when added with mediates，which means a good prospect in environmental applications of laccase from spent compost of Pleurotus eryngii.

Abstract:The freshwater duckweed（Lemna minor） from the campus lake is cultured in the alcohol waste water（oxidation pond effluent）. The optimum dilution ratio of alcohol waste water is 10 times. The maximum Relative Growth Rate（RGR） and protein content are 9.11% and 28.50%,respectively when the initial seeding density is 149 g/m²（wet weight）；The removal efficiencies of TN，TP，NH4+-N and COD of alcohol wastewater are similar under different seeding density. They are 46%~49%，70%~79%，78%~82% and 35%~38% respectively after culturing the duckweed for 8 days. The results show that duckweed has the ability to produce methane individually by the anaerobic digestion process；Methane-producing acidification period is shortened and the gas production capacity is improved for the advantages of complementary substrate by mixing the duckweed with excess sludge. The actual value of cumulative gas production is 2 963 mL，which is 11% higher than calculated value of 2 669 mL；In addition，methane purity is improved，from 50.29% of duckweed group to 56.93% of mixed group.

Abstract:In order to compare the start-up period and the adaptability to the shock load of two lab-scale bioreactors of two kinds of materials employed as biofilm carrier inoculated sediments of river，the biofilm forming rate and the efficiencies of treating polluted river water at four different hydraulic retention time（HRT） were studied. The experimental results showed the startup speed of bioreactor filled with elasticity plastic was more rapid compared to the bioreactor filled with suspend packing，reducing the start-up period for its earlier maturation in removing NH4^{+-N；In the steady running stage，the removal efficiencies of NH4+-N and CODMn in two bioreactors both reached 97% and 80% respectively；The average removal efficiency of ammonia nitrogen dropped from 98.18%，98.76% to 78.32%，87.63% respectively，the average removal efficiency of CODMn dropped from 84.52%，83.69% to 60.90%，64.71% respectively with hydraulic retention time（HRT） shortened from 14.80 h to 7.99 h；The biofilm attaching on elasticity plastic filler has higher activity at four different hydraulic retention time（HRT） and the examination showed more impacted structure within biofilm attaching on elasticity plastic than the biofilm attaching on suspend packing at hydraulic retention time of 7.99 h；which showed the startup speed of elasticity plastic was more rapid compared to suspend packing and elasticity plastic filler had a stronger resistance to impact load than suspend packing in river water treatment.}

Abstract:The surface modification of homodimeric creatinase by poly-lysine was carried out to study the effect of enhancing enzyme stability. The influences of different modification condition on enzyme catalytic efficiency and stability were studied by L9（34）orthogonal experiment， the optimal condition were set as molar ratios of CRE-COOH to poly-lysine-NH2 and CRE-COOH to EDC were 1∶100 and 1∶10， in pH 7.0. The covalently binding of poly-lysine onto enzyme surface was tested by SDS-PAGE. The catalytic kinetic parameters （Km and kcat） of modified enzyme were determined as 4.75×10^-5 mol/L and 2.50×10² S^-1， respectively. Moreover， compared to the native enzyme， the thermal and pH stabilities of the modified creatinase were improved， as Tm of modified enzyme was raised by 2.07 ℃， and more than 50% of initial activity of modified enzyme was maintained at pH 4.0 and 10.0， but the control sample was almost no activity. After further exploitation， poly-lysine modification would be one of the effective methods for improving stability of homodimeric creatinase.

Abstract:Ability of Bacillus amyloliquefaciens SYBCH47 to degrade nitrite and the effect of fermentation condition on degradation of nitrite by B.amyloliquefaciens SYBCH47 was studied. The results showed that among the nitrite concentration of 50~200 mg/L，nitrite degradation rate by B. amyloliquefaciens SYBCH47 was more than 99%. The OD600 of B. amyloliquefaciens SYBCH47 under aerobic cultivation was 2.34，while under anaerobic cultivation was 1.07. However，nitrite degradation by B. amyloliquefaciens SYBCH47 under both cultivation were more than 99% and the tread of degradation rate is in line with the growth. Among the temperature of 30~40 ℃，the nitrite degradation rate was more than 99%. Inoculation1% had benefited on nitrite degradation.

Abstract:In order to prepare oxygen-rich drinking water in high oxygen content contained，good stability and low cost, static spiral cutter and the sets of equipment are specially designed to make oxygen bubbles much fine. The best process parameters the four key parameters-oxygen pressure, water flow rate, the pressure of the water, oxygen flow rate are obtained. For preparation of oxygen-enriched water by dividing the level of experimental factors and the orthogonal experimental arranged. By use of the static spiral cutting device for diameter DN25，the optimized parametes combination are as follows：the oxygen flow rate，0.90 L/min；oxygen pressure，0.20 MPa；the water flow rate，0.70 m3/h；the pressure of the water，0.40 MPa respectively. Further several tests repeated under this combination of these parameters，the value of oxygen contest of the prepared oxygen-enriched water is up to 45.12 mg/L，the proportion increases by 32.40%. Also，the dissolved oxygen can keep in more than 25 mg/L when it is last for 60 days. Therefore，the preparation of oxygen-rich water by current rig or machine will be in high dissolved oxygen content，good stability，and which can used in large-scale industrial production with a broad application prospect.

Abstract:This study aims to investigate the influence of Ziyang se-rich tea on the proliferation and apoptosis of HepG2 cells（a kind of human hepatoma cells）. The inverted fluorescence microscope and the flow cytometer are used to observe and test the changes of the cellular morphology，cell cycle and apoptosis. The results show that Ziyang se-rich tea could inhibit the growth of HepG2 cells. The cell morphology changes significantly. The cells cycle of HepG2 are arrested at the S-phase and the amount of the apoptotic cells increases obviously. It is concluded that Ziyang se-rich tea could inhibit the growth of HepG2 cells by blocking the cell cycle and induce the mitochondrial apoptotic pathway in a dose-dependent manner.