Abstract:Premature yeast flocculation(PYF) is a periodic occurrence phenomenon in beer brewing. The mechanism of PYF and the nature of the PYF factors have not been clearly confirmed,because of complex influence factors,which bothered the entire chain of beer brewing. In recent years,PYF has relatively increased with the advent of environment pollution and bad weather which could lead to this phenomenon. Finally,brewing industries including the maltsters and brewers suffer a serious economic loss and a damaged reputation. In this paper,the research progresses of PYF both in domestic and abroad was reviewed,including the hypothesis of mechanism,the origin and the form mechanism of PYF factors,and the control methods of PYF,with the objective to provide a thought and effective methods to solve this problem in brewing industry chain.

Abstract:Raw cereal materials are the basis for Chinese liquor making,which determine the quality of liquor. In order to have a better understanding of aroma compounds in raw brewing materials,the bound aroma compounds which exist in the style of precursors were analyzed in this study. The precursors could be got from several processes:extraction with organic solvent,dryness with rotary evaporator in vacuo,and SPE. The free compounds were released from precursors after acid hydrolysis. Then these bound aroma compounds were investigated by HS-SPME-GC-MS. In this study,bound aroma compounds in 6 cereals were analyzed and the total of 35 bound aroma compounds were identified and quantified,including 4 kinds of alcohols,3 kinds of esters,10 kinds of ketones and aldehydes,6 kinds of acids,4 kinds of aromatic compounds,6 kinds of terpenoids,and 2 kinds of heterocycle compounds.

Abstract:Through the separation and structural analysis of the pigment produced by Fusarium fermentation,the research aims to screen the anti-tumor active components. Fusarium was identified by using morphological and molecular biology methods. The pigmen was isolated by HPLC,the production structure was identified by UV,IR,NMR.,and the screening of anti-tumor activity was by MTT. The results showed that the pigment from Fusarium produced a total of six different peaks,the molecular weight is about 380,the VI peak,which is the anthocyanins,can inhibit the A539,MCF-7,MKN-45,HepG2,SW620 five different tumor cell proliferation in a concentration- dependent manner,among them MCF-7 breast cancer cells were inhibited most (P<0.01),so the VI compound with a new structure from Fusarium sp JN 158,may be a good treatment for breast cancer.

Abstract:To investigate the metabolism of soyasaponin II by human intestinal microorganisms,the in vitro metabolic transformation of soyasaponin II by intestinal flora in the Brain Heart Infusion(BHI)broth and Phosphate Buffered Saline(PBS)systems was studied for 48 hours,and its metabolites were analyzed and identified by HPLC/MS. The results showed that soyasaponin II was firstly metabolized into soyasaponin IV by intestinal flora and was eventually translated into soyasapogenol B at 48 hours. The above results suggested that soyasaponins lost their sugar moieties due to hydrolysis and yielded smaller and more hydrophobic metabolites by human gut microorganisms.

Abstract:Response surface methodology was used to optimize the fermentation medium of recombinant E. coli for arginine deiminase production on the basis of single factor optimization. Five medium factors were optimized by SAS software combined with Plackett-Burman and Box-Behnken design. The optimized fermentation medium contains 11.16 g/L tryptone,20 g/L yeast extract,6.3 g/L glycerol,16.38 g/L K2HPO4,and 2.31 g/L KH2PO4. Using the optimized medium,the activity of ADI reached 5.7 U/mL broth,which was 1.53-fold higher than that of in the initial medium (3.72 U/mL)and 2.01-fold of that in LB medium(2.83 U/mL). In a 3-L bioreactor,ADI activity of 15.17 U/mL broth was attained using optimized medium,which was remarkably enhanced compared with that of LB medium (4.32 U/mL).

Abstract:Microorganism catalase,which is an important industrial enzyme,plays an important role in textile industry. To realize the industrial production of catalase,the fermentation on B. subtilis WSHDZ-01(pSTOP1622-katA),which was constructed before,was conducted in 3 L fermentor. Furthermore,the enzyme activity reached 35 398 U/mL after optimization of carbon and nitrogen concentration,which was increased by 53.41% compared with that before optimization. Based on this result,the fermentations in 24 L and 500 L fermentor were carried out,respectively and the maximum enzyme activity was 28 940 U/mL and 23 190 U/mL respectively. The result showed the yield of catalase has met the requirement of industrial production,which lay a solid foundation for larger-scale industrial production.

Abstract:Rhizopus chinensis CCTCCM201021 is an important filamentous fungus,which was isolated from Daqu,a traditional leaven in the production of Chinese liquor. In order to understand this fungal deeply,the conditions of two-dimensional electrophoresis(2-DE) for proteome analysis of R. chinensis were investigated and optimized. Intracellular proteins of Rhizopus chinensis was extracted and separated for 2-DE. Different sample preparation methods,parameters of the gel,sample loading quantity and methods were investigated to optimize 2-DE maps of R. chinensis. Ultimately disrupt cell in liquid nitrogen and mechanical agitation,precipitate proteins with TCA/acetone,passively rehydrate proteins with 24 cm pH 4~7 linear strips were selected. The sample loading quantity for each strip was 1 200 μg,and modified colloidal coomassie brilliant blue G-250 was applied to stain gels. Finally,2D-gel map with no obvious vertical and horizontal stripes,low background,high resolution and good reproducibility was obtained. Approximately 800 protein spots were isolated from the 2-DE protein map after analyzed by PD-Quest software.

Abstract:Halohydrin dehalogenase catalyzes the synthesis of optically pure epoxides,β-substituted alcohol and other similar high-value chiral drug intermediates. Our laboratory screened an encoding gene Y from contaminated soil in Wuxi new district industrial park using metagenomic technology. The gene Y contains 765 bp nucleotides and encodes 254 amino acids. According to the Blast analysis,the amino acids sequence shares 81% homology with HheC from Agrobacterium tumefaciens and also has Ser132-Thr145-Arg149 catalytic triad which is the same with the known Halohydrin dehalogenases. Thus,we speculated it belongs to HheC. According to Escherichia coli BL21 codon preference,the optimized gene was synthesized and named as SyhheC. The constructed expression plasmid pET28a-SyhheC was transformed into E. coli BL21. The expressed enzyme with an apparent molecular weight of 34 000 by SDS-PAGE analysis was purified to homogeneity using Ni-NTA affinity chromatography and characterized using the substrate of 2-bromo-1-(4-nitrophenyl)ethanol. The activity of purified reSyHheC was 5.2 U/mg. This study provides a new strategy to excavate new enzymes with excellent characters from the soil.

Abstract:In this study,we aims to study the main factors such as magnetic separation time,target capture rate,specificity,sensitivity that affect the performance of immunomagnetic beads (IMB). IMB were prepared chemically and the capture rate of target bacteria were determined by plate culture counting. The target bacteria capture rate varies in different magnetic separation time,which affected the capture rate,and the capture rate of IMB would reach the highest level. The amount of magnetic balls and antibody affect the capture performance of IMB. When the Feed ratio was 200 μg of magnetic ball and 25 μg of antibody,the capture rate would get more than 50%And IMB has a sensitivity (the capture rate is above 50% on target bacteria with 100 cfu /mL).The target capture rate of IMB with the large diameter(1 000 nm)is less than that of those with the small diameter (180 nm)at the same mass. The nonspecific capture rate for Escherichia coli,Staphylococcus aureusand Shigella was below 10%,which affected the immune specificity of IMB. This study provided a foundation and some data for application of IMB and detection of microorganisms.

Abstract:The EPS welan gum batch fermentation dynamics of Sphingomonas sp. were demonstrated. The mathematics models of the dynamic parameters of Sphingomonas sp. growth in 7 L fermentation reactor,synthesis of welan gum,and consumption of nitrogenous source were depicted. The estimated model parameters were confirmed bythe batchfermentation experiment data. These models offered the evidences for large scale production of welan gum.

Abstract:A Gram(＋),non-motile,facultatively anaerobic,rod-or coccoid-shaped bacterium,designated strain ORC4,was isolated from the dry fermented sausages. The 16S rRNA gene sequence analysis showed that strain ORC4 belonged to the genus Weissella,with highest sequence similarity to Weissella viridescens NRIC1536(100%). The intact cells and intracellular extract of strain ORC4 could inhibit O2-·,DPPH·,and ·OH. Three free radicals-scavenging ratios of intracellular extract were positively correlated with bacterial density,respectively,the intact cells could do the same. The intracellular extract had higher scavenging ratios on three free radicals than the intact cells. At a concentration of 5×108 CFU/mL,scavenging ratios of intracellular extract on O2-·,DPPH· and ·OH were 45.17%,56.17% and 54.01% respectively. In addition,strain ORC4 could reduce 35.87 μg/mL cholesterol,and the unit cell dry weight of cholesterol removal rate was 19.89 μg/mg.

Abstract:Hyriopsis cumingii visceral organ and Nacl solution were used as material and extraction liquor to study the hyriopsis cumingii glycoprotein extraction and separation under low temperature and the antioxidant activity. Through single factor experiment and orthogonal experiment,the optimized extraction condition was as below:extraction temperature at 4 ℃,0.3 mol/L NaCl solution,solid-liquid ratio in 1∶15,and extraction for 9 h. Glycoprotein extraction rates under optimal condition interms of sugar content and protein content were (9.259±0.083)% and (3.763±0.107)% respectively. Crude glycoprotein sample,that comprises three different components,was obtained,after the extraction liquor was fractionally precipitated by ammonium sulfate. The different component had a different ability to scavenge surperoxide anion radicals and hydroxyl radicals. Crude glycoprotein sample was Electrophoresed by 10%SDS-PAGE and dyed by Coomassie Brilliant Blue R250 and PAS,and the result showed the three components contained different glycoprotein bands.

Abstract:Antioxidant peptides of Pleurotus ferulae lenzi were separated using ultra-filtration,ion-exchange and gel filtration chromatography,and its antioxidant properties were also studied in this study. Two kinds of peptides(＞10 000 polypeptide components and ＜10 000 polypeptide components )were isolated from the hydrolyzed solution of Pleurotus ferulae lenzi protein. The polypeptide components under 10 000 have higher ·OH radical scavenging and DPPH· radical scavenging capacity than those above 10 000. After detaching of polypeptide components under 10 000 by DEAE-32,three elution peaks were obtained and P3 component showed higher hydroxyl scavenging capacity,reaching 50.22%. Five elution peaks at 220 nm were further isolated from P3 component by Sephadex G-25,and P3-2 component showed best capacity of ·OH radical scavenging,reaching 77.23%. According to standard equation,the molecular weight of P3-2 was about 1 862. The results provide a theoretical basis for further studies of active ingredient from Pleurotus ferulae lenzi in Xinjiang province.

Abstract:In eukaryotic cells,most of membrane fusion processes are mediated by SNARE proteins. However,its functional and regulatory mechanisms have not been fully understood. Previous study have shown that yeast sporulation was an ideal model system to manipulate and investigate vesicle fusion machinery including SNARE proteins. The t-SNARE protein Sso1 involved in this process is an orthologue of syntaxin 1A which is required for the synaptic vesicle fusion,both share 51% homology at the SNRE domains. However,although their functional and amino acid sequence are similar,Sso1/syntaxin 1A chimera cannot complement the sporulation deficiency of sso1?驻 mutant when SNARE domain of Sso1 is replaced completely by syntaxin 1A. To determine which residues are critical for Sso1 function,chimera and mutational analyses are further conducted. The results showed that the SSO1/syntaxin 1A chimera gain the functionality by replacing Ala220 residue to Glu in the syntaxin 1A SNARE domain. By contrast,Sso1 lose its function by mutating the corresponding amino acid residue,Glu218 into Ala. Thus,Glu218 residue is specifically required for Sso1 function.

Abstract:The β-D-glucan from Saccharomyces cerevisiae is a potent biological response modifier. But it is insoluble in water. This is the major obstacle for its application in the food and medical fields. In order to improve the water-solubility of β-D-glucan from S. cerevisiae,mechanical activation was performed here in the solid state by using a planetary ball miller. The water-solubility of β-D-glucan increased sharply from 11% to 37%,as the mechanical force and activation time increased. After mechanical activation,the particle size of β-D-glucan decreased obviously and its morphological structure became to be irregular and rough. The basic chemical structure of β-D-glucan was not destroyed based on FTIR analysis,but the energy of hydrogen bond decreased. These changes would be benefit for β-D-glucan to interact with water molecule and therefore to increase its solubility. Most importantly,the soluble β-D-glucan prepared by this method could significantly stimulate the macrophage cells to secrete TNF-α,IL-6 and NO. Their concentrations were 29.3-,28.3- and 5.6-folds that of the controls,respectively. These results indicate that mechanical activation is a simple,environmentally friendly and efficient method to improve water-solubility of β-D-glucan.

Abstract:The fermentation production of expolysaccharide from Cordyceps militaris was studied at different temperature. The results showed that the optimal growth temperature was at 26 ℃ and the highest yield of expolysaccharide accumlation temperature was at 28 ℃. Thus,the two-stage temperature control strategy was developed based on RSM. When pre-fermentation temperature was kept at 26 ℃ for 17 hours and changed to 28.5 ℃ ,the yield increased to 10.92 g/L which was 25.5% higher than that of fermentation at single temperature at 28 ℃.

Abstract:The sulfation of extracellular polysaccharides of Ganoderma lucidum(GLP)from the submerged fermentation broth can dramatically enhance their antitumor activity. The structure and conformation of GLP might change due to the sulfation. The structure of the sulfated GLP was analysized with glycosyl residual composition analysis,IR,UV and NMR. The polysaccharide consists of rhamnose,arabinose,mannose,glucose and galactose with a molar ratio of 9∶3∶2∶4∶48. The main chain of the polysaccharide may consist of the unit of α-D-Glc(1→6)or the side chain is mixed of α-D-Glc,Rha,α-D-Man,and Ara. The sulfate groups may be connected to C-3,C-4,and C-6 of the sugar unit. Meanwhile,the sulfated polysaccharides present very different conformation comparing to the native polysaccharides. The sulfated polysaccharides possessed a triple helix whereas the native polysaccharide preferred the single helical,which was also confirmed by x-ray diffraction.

Abstract:In order to achieve the homologous expression of asparaginase gene asp in Aspergillus niger CICC2462,the asparaginase engineering strains were construced. The specific primers were designed according to asparaginase gene asp sequence in the NCBI(GI:145231287)to amplify the coding region of asp and pSZHG-asp expression vector was constructed. Then agrobacterium mediated method was utilized to transform Aspergillus niger,and homologous recombinations which glucoamylase gene(glaA) was replaced by Asp were screened. The expression products of the transformant were analyzed using SDS-PAGE and enzyme activity detection. Eight homologous recombination strains,where glaA locus was replaced,were obtained,and the supernatant in 4 of them were measured. The result of SDS-PAGE showed protein bands at 42 000,the amount of the recombinated protein was 185~417 μg/mL,and the highest enzyme activity of fermentation broth was up to 21 111 U/mL.