Abstract:Benzo-a-pyrene（BaP） is a kind of common harmful substances which is produced during the processing of plant oil. BaP has attracted significant attention due to its carcinogenicity，teratogenesis and widely distributing. The injurious effects of BaP on cells are reviewed in this paper. BaP can cause body tissue damage through inducing DNA damage，mitochondrial dysfunction，oxidative stress，autophagy and inflammatory response. Pyroptosis is a way of cell death which is dependent on the caspase-1 with the release of inflammatory factors. However，the effect of BaP on pyroptosis remains unknown. To further reveal the cytotoxicity mechanisms of BaP has an important scientific significance to the targeted intervention and the establishment of comprehensive and effective food safety control system.

Abstract:Theautoaggregation level of E.coli K-12 W3110 was tested by the comparison with its mutants in core oligosaccharide（core OS），and the relationship between autoaggragation and the structure of core oligosaccharide was analyzed. The results showed that the mutation of core OS would induced autoaggregation. The autoaggregation ratio of mutants were three times better than wild type W3110 in 12 hours of standing at 4 ℃. The mutants of core OS deficiency（ΔwaaC） and outer core OS deficiency（ΔwaaG） were used to investigate the properties of autoaggregation. In this study，the autoaggregation ratios of ΔwaaC and ΔwaaG strains were 80% after 2 hours of static culture. The autoaggregation level with different temperature and cell concentration were also tested，the results indicated that the autoaggregation was not influenced by the temperature，but enhanced by the increase of cell concentration. In order to elucidate the mechanism of autoaggregation，the transcription level of flu（gene of Ag43） was analyzed between W3110 and the mutants by RT-PCR，and the results showed that the transcription of flu was raised 2~4 times in the mutants of core OS，and it may be the reason of the increase of autoaggregation ratio in mutants. Finally，the preliminary results of gene expression of flu proved the effect of Ag43 on autoaggregation in W3110.

Abstract:The degradation of chicken manure was optimized and digested chicken manure filtrate (DCMF) was added to promote cells growth and lipid production in heterotrophic culture Chlorella protothecoides. Higher and low nitrogen DCMF were obtained by controlling dissolved oxygen (DO) level. Based on the fact that higher nitrogen DCMF favored cells growth but retarded lipid accumulation and vice versa for lower nitrogen DCMF, a two-step DCMF supplementation of feeding higher nitrogen DCMF (15 ml/L/D) at the cell growth phase (0~120 h) and lower one (15 ml/L/D) at the stationary phase(120~200 h) was adopted to enhance lipid production. Moreover, the strategies of DCMF supplementation coupled with adenosine triphosphate (ATP) regeneration from glucose feeding (1.5 g/L/D) were developed. Experimental results showed that lipid yield of 5.28 g/L was achieved after 200 h cultivation, increased by 74.8% and 21.1% respectively, compared to the control and the one without glucose addition. It was suggested that application of DCMF combined with glucose feeding as being feasible for lipid overproduction.

Abstract:In order to evaluate the effect of sucrose on Qiweibaizhusan to intestinal bacteria diversity in dysbacteriotic diarrhea mice，48 SPF mice were randomized into 4 groups. Normal control group of mice were via intragastric administration of sterile water. Model group and treated groupmice were constructed via intragastric administration of cefradine and gentamycin sulfate. Model group mice were via intragastric administration of sterile water，and treatment groups were via intragastric administration of 50% amount of ultra- micro Qiweibaizhusan powder and 50% amount of ultra-micro Qiweibaizhusan powder with 8% sugar respectively. After treatment，intestinal microbiotia metagenome DNA were extracted. The intestinal bacteria diversity was analyzed by amplified ribosomal DNA restriction analysis. The results showed that OTU and stripe numbers in 50% amount of ultra-micro powder Qiweibaizhusan group，50% amount of ultra-micro powder Qiweibaizhusan with sucrose group and normal control group were all 6. The diversity index in 50% amount of ultra-micro powder Qiweibaizhusan group，50% amount of ultra-micro powder Qiweibaizhusan with sucrose group and normal control group were respectively 2.322，2.585 and 2.585. The same similarity coefficient in 50% amount of ultra-micro powder Qiweibaizhusan group，50% amount of ultra-micro powder Qiweibaizhusan with sucrose group and normal control group were respectively 0.363 6，0.277 8 and 1.0000. The similarity coefficient in 50% amount of ultra-micro powder Qiweibaizhusan with sucrose group is lower than that in 50% amount of ultra-micro powder Qiweibaizhusan group. Cluster analysis and principal component analysis showed that 50% amount of ultra-micro powder Qiweibaizhusan group were better than 50% amount of ultra-micro powder Qiweibaizhusan with sucrose group to normal control group. Both 50% amount of ultra-micro powder Qiweibaizhusan and 50% amount of ultra-micro powder Qiweibaizhusan with sucrose could cure dysbacteriosis diarrhea. The former had better effect than the latter. It was advised to adopt the ultra-micro powder Qiweibaizhusan without the additive of sucrose.

Abstract:Ginger（Zingiber officinale Roscoe） extract was found to have a brand new application in this paper. The antibacterial silver nanoparticles（AgNPs） were synthesized using ginger extract as a reducing agent，which avoid the disadvantages of environmental hazards in traditional methods. The as-prepared AgNPs were fully characterized by means of UV-visible（UV-vis） spectroscopy，transmission electron microscopy（TEM） and X-ray diffraction（XRD） technique. The results showed that the AgNPs was face-centered cubic structure，and the spherical-shaped nanoparticles were polydisperse in the size range 5~30 nm. The synthesized silver nanomaterials showed remarkable antibacterial activity against all tested pathogens including four kinds of multidrug resistant clinical isolates and four kinds of aquatic pathogens. The minimum inhibitory concentration（MIC） and the minimum bactericidal concentration（MBC） of the AgNPs against Staphylococcus aureus were 25.7 μg/mL and 51.4 μg/mL，respectively. Moreover，stability studies showed that the biosynthesized AgNPs had excellent long-term stability as well as thermal stability. Therefore，the ginger extract could be used to synthesize a new kind of AgNPs with stable and broad-spectrum antimicrobial activity.

Abstract:In order to obtain high enzyme activity of β-galactosidase，twenty-eight strains which produced β-galactosidase were screened from soil using lactose as inducer and X-gal as indicator.Four strains which have higher hydrolysis enzyme activity were screened by shake flask culturing. One strain B5582Y which have both of hydrolysis and transgalactosylation Activity was screened by HPLC，its hydrolysis of initial enzyme activity can reach upwards of 12 U/mL. And it was identified as Klebsiella michiganens is according to the cell morphology，physiological and biochemical characteristics，16SrDNA and rpoB functional gene sequence.

Abstract:In order to afford a reference for the study of nucleosides and quality control of caterpillar fungi products，a method for simultaneous determination 19 kinds of nucleosides using HPLC was established including CMP，UMP，uracil，GMP，IMP，hypoxanthine，uridine，AMP，thymine，adenine， dAMP，inosine，guanosine，2'-deoxyguanosine，thymidine，adenosine，2'-deoxyadenosine，cordycepin， N6-（2-hydroxyethyl）-adenosine. Chromatographic conditions：X select HSS T3 column（5 ?滋m，4.6 mm×250 mm），acetonitrile and water as mobile phase with gradient elution，flow rate 1 mL/min，column temperature 40 ℃，detection wavelength 254 nm. Methodological research showed this was an accurate and reliable method which RSD of precision ranged 0.11%~2.82%，RSD of stability ranged 0.22%~1.63%，RSD of retention time ranged 0.14%~3.47%，RSD of reproducibility ranged 1.3%~5.2%，and recovery ranged 84.9%~108.3%. The nucleoside content in some caterpillar fungi products were successfully determined using this method.

Abstract:Lipid is the main raw material of food industry，and its quality and oxidation stability directly affect the food quality. Therefore，it is highly necessary to develop a fast，reliable and sensitive technology to evaluate the quality of edible oil. In this paper，linseed oil，fish oil and camellia-seed oil were analyzed by Raman spectroscopy and surface-enhanced Raman spectroscopy. The results indicated that during the process of oxidation，the characteristic peak at 974 cm-1 which on behalf of the trans structure gradually increased，resulting in increase of relative intensity of I974/I1442，and the characteristic peak at 1 265 cm-1 which on behalf of the cis double bond gradually decreased，resulting in decrease of relative intensity I1265/I1442. With silver nanosubstrate，the highest analytical enhancement factor was achieved for linseed oil diluted 50 times with hexane by SERS analysis. The changes of intensity for the same characteristic peaks were similar between SERS and Raman spectroscopy，indicating similar structure information for fatty acids was obtained，and SERS analysis was more sensitive.

Abstract:γ-linolenic acid（GLA） that is an essential polyunsaturated fatty acid（PUFA） plays a vital role in many metabolic processes. Most related studies showed that delta 6-fatty acid desaturase（FAD6） was an important rate-limiting enzyme for the synthesis of γ-linolenic acid from Mucor circinelloides. However，it has not been reported whether the delta 6- fatty acid desaturase is the only pathway to produce γ-linolenic. In this work，we constructed M. circinelloides EIM10 sp.FAD6 knockout vector pUMCD6-HmB on the basis of pUC18 to study the function of FAD6. The homologous sequences of 5' promoter and 3' terminator of FAD combined with hygromycin B resistant gene used as the selective marker were connected as the knockout fragment. Then the vector pUMCD6-HmB was transformed into the prepared protoplast of M. circinelloides EIM10 sp. The results showed that FAD6 gene was successfully disrupted and GLA accumulation of the mutant disrupted in FAD6 decrease about 50% compared to the wild type. It can be concluded that FAD6 was essential for GLA production in M. circinelloides but there is probably other ways to accumulate GLA in M. Circinelloides.

Abstract:To investigate the cytotoxic effects of formaldehyde in the food，we detect different concentrations of formaldehyde on the inhibition of cell growth，and use microarray technology to detect the influence of lymphocyte gene expression by formaldehyde in order to screen and analyze the differentially expressed genes related to toxicity and carcinogenicity of formaldehyde. By making MTT experiments，the cytotoxicity of formaldehyde was verified by comparing lymphocytes' growth curve and morphology. Peripheral blood lymphocytes were treated with 5×105 mol/L formaldehyde for 24 h.The total RNA from cells of the subjects of the treated group and the control group were isolated，then they were reversely transcribed and labeled with fluorescence dyes，and finally hybridized with human whole genome microarray（about 35 000 spots）. Microarray data was extracted after microarray scanning，and differentially expressed genes induced by formaldehyde were screened and analyzed by bioinformatics. In MTT experiments，human peripheral blood lymphocytes were treated with various doses of formaldehyde. The dose-effect relationship was also observed after treatment with high doses. 211 up-regulated and 113 down-regulated genes were screened after scanning and data extracting. Genes which significantly altered were represented by several categories，including oxidative stress，DNA repair，apoptosis，nucleic acid metabolism，cell cycle，oncogenesis，tumor suppression and so on. The result suggested the differential expression of these genes of OXR1，MLH1，TP53 may be the genetic basis of formaldehyde toxicity and carcinogenicity. The study provided theoretical evidence for elucidating the toxic and carcinogenic mechanism，detecting of the biomarker for formaldehyde exposure，and preventing the formaldehyde poisoning. It also verified the microarray technique is the feasible and advantageous in food toxicological research. It provides an experimental basis for the establishment of new methods to detect and study exposure of toxic substances.

Abstract:This research aims at investigating the effects of fermentation conditions on mycelium morphology and total triterpenoids yield during submerged culture of Poria cocos. The results indicated that the total triterpenoids main derived from middle-sized equivalent diameter and pellet in smooth shape were more conducive to enhancing the total triterpenoids production. The appropriate condition of submerged culture were broth content 50 mL，inoculate size 6%，pH 5.5，temperature 26 ℃，rotation speed 130 r/min for 11 days. The positive correlations both production of total triterpenoids and M diameter growth as well as smooth pellet have shown that the relationship between mycelium morphology and intracellular triterpenoids.

Abstract:To know the differences in antioxidant composition of Pyracantha fortuneana（Maxim.）Li from different growing regions of Guizhou Province，China，we investigated the nutritional composition and antioxidant activity of Pyracantha fortuneana（Maxim.）Li and evaluated the differences，correlation coefficient，principal component and clustering analysis by using the software IBM SPSS Statistics 20. The results indicated that the differences among the nutritional composition and antioxidant activity from different growing regions are significant. The highest contents of total ascorbic acid and protein content were detected in Pyracantha fortuneana（Maxim.）Li from Yulianghe AAE（7.35±0.08 mg/hg and BAE（10.48±0.30） mg/hg，respectively）. The total polyphenol and total flavonoids of Pyracantha fortuneana（Maxim.）Li from Huaxi were highest GAE（218.14±0.70） mg/hg and RE（159.80±0.45） mg/hg，respectively）. The total acidity of Pyracantha fortuneana（Maxim.）Li from Yanshang were highest，citric acid（7.18±0.00） g/kg. The reducing sugar of Pyracantha fortuneana（Maxim.）Li from Zhonghuoxiang were highest（4.91±0.01）%. The total reducing power of Pyracantha fortuneana（Maxim.）Li from Huaxi was the strongest，while Pyracantha fortuneana（Maxim.）Li from Yanshang possessed the highest superoxide radical scavenging activity and Pyracantha fortuneana（Maxim.）Li from Zhongxincun possessed the highest hydrogen peroxide scavenging activity. The contents of total polyphenol，total flavonoids，protein and total acidity highly correlated with total reducing power and superoxide radical scavenging activity. The Pyracantha fortuneana（Maxim.）Li of different growing regions were classified into three groups by principal component and cluster analysis. The regularity and difference of Pyracantha fortuneana（Maxim.）Li from different growing regions in Guizhou was revealed by principal component and cluster analysis.

Abstract:Ethanol is widely used in renewable fuels，chemical engineering，medicine and food industry. In developed countries there is a growing trend towards employing modern technologies and ef?cient bio-energy conversion using a range of biofuels. In order to improve Very High Gravity（VHG） ethanol fermentation efficiency the optimization process of VHG ethanol fermentation from liquefied VHG cassava mash filtrate with micro-aeration were investigated in this thesis. Changes of fermentation parameters during the ethanol fermentation from VHG liquefied starch filtrate with aeration rate （0，0.04，0.08，0.16，0.24，0.35 L/min） by Saccharomyces cerevisiae GGSF16 under batch condition in a 5-L bioreactor were studied. The optimum condition for ethanol fermentation was shown as a continuous aeration rate of 0.08 L/min. The verification experiments under the optimum condition clearly indicated that the aeration strategies improved ethanol production. The biomass and fermentation efficiency were 5.40×108 cells/mL and 90.00%，respectively，representing about 56.52% and 2.45% increase compared to anaeration fermentation. In conclusion，micro-aeration can improve VHG ethanol fermentation efficiency because it can enhance cell viability.

Abstract:The purpose of this paper is to screen actinomycetes to inhabit the growth of O157：H7，and identify them by Morphological and physiological identification ，then optimize the fermentation medium of producing antibacterial substance. The antibacterial ability of the actinomycetes were detected by the method of tube plate detection. We obtained two actinomycete strains AM-8 and AM-10 which restrained O157：H7，and the genus were identified as Streptomyces. In the single factor test，the highest yield of antibacterial substances occured in the medium with corn flour as carbon source，and pep-tone as nitrogen source. After optimization of fermentation medium by response surface method，The optimum fermentation medium of AM-8 was：corn flour 20.10 g/L，peptone 2.00 g/L，K2HPO4 0.50 g/L，MgSO4·7H2O 0.50 g/L，NaCl 5.92 g/L，F2SO4 0.01 g/L，CaCO3 1.89 g/L.

Abstract:To investigate influence of Maitake Polysaccharide（MP） on expression and replication of HBV in HepG2.2.15 cell. MP from fresh Maitake fruiting bodies was extracted by water. The cell growth inhibition rate of HepG2.2.15 cells was detected by MTT assay in 4，2，1，0.5，0.25 mg/mL concentration respectively and the half cell toxicity concentration（CC50） was calculated. HepG2.2.15 cells were treated by MP with different concentration or 0.1 mg/mL lamivudine，and the Hepatitis B surface antigen and e antigen（HBsAg and HBeAg） in cell supernatant were evaluated by enzyme-linked immunoassay assay（ELISA），HBV DNA contents after cells were treated 9 days were detected using quantitative PCR method. Then each inhibition rate，the half inhibition concentration（IC50） and the therapeutic index（TI50） were calculated respectively based on the data. The CC50 of MP treated to HepG2.2.15 cells is 5.154 mg/mL. The inhibition rate of MP in HBsAg，HBeAg and of HBV DNA are dose dependent and the IC50 are 4.814，0.806，0.621 mg/mL，TI50 are 1.071，6.398 and 8.306 respectively. MP has strong inhibitory effect on HBV replication and expression in vitro.