Abstract:Coupled Hot-air and Microwave(CHAM) drying is a novel methods and techniques which microwave and hot-air act on drying materials at the same time. The uniformity of microwave heating is the negative phenomenon which restrains its development and application. This paper gives an overview of CHAM drying and dryer and the latest development of laboratory equipment over the world and analyzes the main problems of its industrialization. In addition, the new scheme is proposed in this paper to solve the heating uniformity of microwave and the industrialized coupling structures of the dryer are also proposed.

Abstract:The D-psicose 3-epimerase gene was amplified through PCR and ligated with the expression vector pMA5 of Bacillus subtilis, forming the recombinant plasmid pMA5-cbdpe. The recombinant plasmid was then transformed into B. subtilis WB800, and a recombinant strain was acquired through resistance screening of Kanamycin and PCR identification method. The enzyme activity of recombinant D-psicose 3-epimerase could reach 6.8 U/mL after 18 h fermentation. The recombinant D-psicose 3-epimerase expressed in B. subtilis exhibited optimal activity at pH 7.0. And the optimal temperature was 55 ℃. It showed the same enzyme characterization as the D-psicose 3-epimerase expressed in Escherichia coli. This result indicated that the D-psicose 3-epimerase gene was successfully expressed in B. subtilis.

Abstract:The effect of limit dextrin on wheat starch retrogradation was investigated to explain the anti-firming mechanism of α-amylase. The degree of crystallinity of retrogradation wheat starch were reduced with the addition of F75 limit dextrin and F88 limit dextrin, respectively. DSC results also showed that the enthalpy change of retrogradation wheat starch were reduced with the addition of limit dextrins(F75 or F88). The growth of amylopectin recrystallization in wheat starch/limit dextrin mixtures was primary nucleation(n<1). Furthermore, the rate of recrystallization(k) reduced which indicated that the wheat starch retrogradation was inhibited. In addition, molecular dynamic simulation was adapted to predict the interaction of limit dextrin and starch fraction, and the results showed that the limit dextrin reduced starch retrogradation by the interplay between limit dextrin and starch fraction.

Abstract:The anti-proliferation and anti-migration activities of recombinant human disintegrin domain of ADAM15(rhddADAM15) were evaluated in vitro and in vivo and the related pathway was determined in this study. rhddADAM15 inhibited the proliferation and migration of human cervical cancer HeLa cells with the IC50 of 2.44 and 1.60 μmol/L respectively evaluated by SRB assay and wound healing assay. Over-expression of disintegrin domain of ADAM15 in HeLa cells by transient transfection induced the migration inhibition and partial S phase arrest. In addition, the inhibition effect of proliferation of HeLa cells aroused by rhddADAM15 was reversed by EGF, which is the agonist of MAPK signal pathways. Moreover, rhddADAM15 inhibited the growth and metastasis of HeLa cells xenograft in zebrafish. All the results showed that rhddADAM15 inhibited the proliferation and migration of HeLa cells by MAPK signal pathway and the target may exist both on the cell surface and in the cytoplasm.

Abstract:Ball milling pretreatment can be used to change the physical and chemical structure of corn straw, making it much easier to be degraded by enzymes, which will enhance the microorganism utilization rate to improve its feed quality. This study indicated that the particle size of corn straw after ball milling mainly(90%) distributed in the range of 10~100 μm and ball mill crushed corn straw had a 3.5% decrease in Acid Detergent Fiber(ADF) content and a 200% increase in soluble sugar content due to the breaking of hemicellulose chain and cellulose chain. The total content of soluble sugar and reducing sugar of ball milling corn straw hydrolysed by xylanase and cellulase increased by 3.3 fold and 9.7 fold than that without treatment, separately. The total acid content reached 26.3 mg/g and the lactic acid bacteria population was about 1.5×109 CFU/g after corn straw solid state fermentation. Furthermore, the cellulose and hemicellulose separately decreased by 9.1 and 4.9 percentage points than before, which could significantly improve the quality of the feed.

Abstract:The effects of blanching and 3% salt-water immersion pretreatments on the quality of dried sweet corn kernels by vacuum freezing drying, high vacuum drying, and vacuum microwave drying were investigated in this paper. The effect of different pretreatments on the hardness, crispness, color and sensory score of the dried product quality were studied. Parameters of included were used to evaluate the dried product quality. Results showed that using both two pretreatments, the quality characteristics of dried products were significantly improved compared with those without pretreatments. In addition, the pretreatments could significantly improve the quality of high vacuum dried sweet corn kernels. The quality of salt-water immersion pretreated dried products was better than that of blanching pretreated products. However, salt-water immersion pretreatment extended the drying time of sweet corn kernels.

Abstract:A method for tetracycline detection was reported. It is based on fluorescence resonance energy transfer(FRET) from KGdF4：Tb3+ nanoparticals as a donor, and on graphene oxide that acts as an acceptor. The KGdF4：Tb3+ nanoparticals were modified with tetracycline aptamer. On the basis of the strong π-π effect between the nucleobases of the aptamer and graphene oxide, KGdF4：Tb3+ nanoparticals were brought in close proximity to the graphene oxide surface. Therefore, the strong fluorescence of KGdF4：Tb3+ nanoparticals can be significantly quenched. However, on addition of the target analyte, the tetracycline-aptamer-KGdF4：Tb3+ complex is formed and quenching by graphene oxide is suppressed. The fluorescence is linearly proportional to the concentration in the range from 0.5 to 100 ng/mL(R2=0.993), with detection limits as low as 0.25 ng/mL. The assay had high specificity and sensitivity, and was successfully applied to real food samples.

Abstract:Glucose-based media containing different contents of yeast extract were used to culture Clostridium acetobutylicum, either in the acidogenic or in the solventogenic phase. The fermentation performances in the different period were concerned, including gas production, glucose consumption, organic acids and solvents production, and phase-shift, in order to explore the effects of carbon/nitrogen(C/N) ratio on butanol fermentation performances. The results indicated that a moderate C/N ratio(46.7~93.4 mol/mol) in the acidogenesis could maintain the normal growth rate of strain without large accumulation of organic acids, which resulted in a smooth switch of phase-shift and shortening fermentation time. While a higher C/N ratio(93.4~186.7 mol/mol) in the solventogenesis was benefit for restraining the synthesis of by-product solvents acetone and ethanol, and simultaneously kept the butanol production upon 12 g/L, leading to a relatively high ratio of butanol to total solvent. Moreover, three kinds of biomasses which contained distinct C/N ratios were used as substrate for butanol fermentation. The results further demonstrate the conclusion acquired above about the impacts on fermentation performances brought by C/N ratio alteration of substrate.

Abstract:This sutdy intended to use whole soybean to replace part of milk powder as protein raw material to produce dual-protein ice cream. After 75~80 ℃ hot grinding and 20 times colloid mill processing, the particle size of ice cream matrix was about 100 μm with delicate taste and no beany flavor. By measuring the matrix viscosity, overrun, melting rate, hardness and sensory of ice cream, the influence of different whole soy substitute ratio on the quality of ice cream was studied. When the Whole Soybean Substitution Ratio reached 30%, palm oil content could reduce from 8% in regular ice cream to 4%~6%. Overrun and melting rate were 60.58% and 48.40% respectively. Comparing with regular ice cream, the change to overrun was not significant(60.37%), while the melting resistance improved significantly(65.76%). Besides, viscosity and hardness of soybean ice cream were 400 mPa·s and 2 440.76 g respectively, which were larger than regular ice cream. The texture of the ice cream was more closely with little ice crystal, as well as better flavor. So it was a new product with good quality, balanced nutrition and low cost.

Abstract:In heterologous protein production by methylotrophic Pichia pastoris, the methanol concentration variation in culture medium severely affects fermentation stability. An intelligent pattern recognition based fault diagnosis system was thus proposed to solve the problem. A support vector machine classifier(SVM) was firstly used to categorize the on-line measurable parameters(fermentation time, agitation rate, methanol consumption rate, O2 uptake rate OUR and CO2 evolution rate CER) within a moving-window, and then the SVM was combined with fuzzy reasoning technique to construct an unique intelligent fault diagnosis system, which could classify the fermentation physiological states into 3 catagories of methanol "in shortage", "medium", and "in excess". In the cases of improper methanol concentration, the system could accurately identify the faults and their type. Then those failure-likelihood fermentations could be rescued by adding methanol or glycerol.

Abstract:C. glutamicum SYPS-062-36 could produce L-serine from sugar directly, in order to further improve L-serine production via removing the feedback inhibition of PGDH caused by high concentration of L-serine, a mutant strain C. glutamicum SYPS-062-33a-18 was obtained by DES treatment of C. glutamicum SYPS-062-36 for two rounds and selecting positive mutant in the plate containing D-serine. The genetic stable mutant strain could accumulate 11.0 ± 0.25 g/L of L-serine, with an increase of 65.4% compared with the parental strain. These results suggested that L-serine overproduced strain can be obtained by using random mutagenesis and directed selection with D-serine as the analog, and also provide a valuable basis for further improving L-serine production with inverse metabolic engineering.

Abstract:A high epothilone B producing mutant SoF5-H23 was screened from Sorangium cellulosum SoF5-76 by combination treatment with UV and NTG. This mutant has good stability of producing epothilone B and production was 79.83 mg/L, which was 1.27 times higher than that of original strain. Plackett-Burman design and the response surface methodology(RSM) were applied to optimize medium for fermentation and conditions. The obtained optimal fermentation conditions were potato starch 4.8 g/L, skim milk powder 2.3 g/L, glucose 0.5 g/L, soybean powder 2 g/L, magnesium sulfate 2 g/L, chlorine calcium 2 g/L, EDTA-Fe3+ 2 mL/L, trace elements 0.5 mL/L, absorbent resin 2%, pH 7.4, liquid volume 50 mL/250 mL, inoculum size 8%, temperature 30 ℃. Under this optimal conditions, epothilone B production reached up to 108.67 mg/L which is the highest yield of epothilone B on home and overseas and was 36.13% higher than preliminary conditions.

Abstract:The gene of maleate cis-trans isomerase(MaiA) from Serratia marcescens was cloned and successfully expressed in Escherichia coli BL21(DE3) and was purified. The specific activity of the purified enzyme was 48.01 U/mg. The optimum temperature was 37 ℃ and the optimum pH was 8.4. Under the optimum condition, the Km value was 4.2 mmol/L, the Vmax value was 1.27 mmol/(L·min), the kcat value was 4.38 s-1 and the catalytic efficiency(kcat/Km) was 1.04 L/(mmol·s). Furthermore, the research showed that the MaiA had high thermostability(t1/2=1.5 h). Meanwhile, maleate could almost be converted to fumarate completely by the recombinant MaiA with high efficiency up to 99%. The results in this study will be useful for further research and industrial applications of maleate cis-trans isomerase.

Abstract:Quality of iron yam dried by four different drying methods was compared in terms of appearance, nutrient value, rehydration ratio and microstructure. Freeze dried(FD) iron yam has the best quality. The quality of iron dried by combination FD and microwave vacuum drying(MVD) was very close to FD products and the drying time could be decreased by 31%. Drying time was the shortest during MVD but the quality was worse than FD and FD-MVD products. Appearance and vitamin C of air dried(AD) product loss a lot but the polysaccharide in AD sample was not significant different from other dried samples. Moreover, it show that the microstructure of MVD and AD samples were destroyed seriously and the microstructure of FD and FD-MVD samples were maintained very well.

Abstract:Croton fruits(Euphorbiaceae) has been applied for the treatment of some types of cancer in traditional Chinese medicine for a long time. Lingba Junzhi is a fermented product of croton fruits by Ganoderma lucidum(Curtis：Fr.) P. Karst. The paper was fixed to screen the effective fractions about resisting tumor in Lingba Junzhi in vitro. Soxhlet extraction was used to extract Lingba Junzhi with the gradient solvents, and four extract fractions were obtained, petroleum ether extracts(PEE), dichloromethane extracts, normal butanol extracts and methanol extracts. Then methanol extracts were dealt with the alkali-solution and acid-isolation and solvent extraction, to prepare alkaline methanol extracts(AME). Screening anti-tumor effects of PEE and AME to SMMC-7721, MGC-803, A549, HepG-2 tumor cells were investigated by means of quick and sensitive MTT colorimetry. Compraring with crotonoside(Cro), PEE and AME inhibited the proliferation of A549 cells significantly in a dose-dependent manner, and had nearly no influence on MGC-803 cells. Within a certain concentration range, AME played a strong inhibited effect only to the SMMC-7721 proliferation, while PEE and AME worked for the promotion of the HepG-2 proliferation. All these mentioned above suggest that the effects on proliferative activity of different parts of Lingba Junzhi is quite different. But PEE and AME all have the obvious anti-tumor effects on A549 cell proliferation.

Abstract:A total of 14 strains were screened that they initially isolated from homemade traditional fermented milk, which was sourced from Inner Mongolia, China. The results showed that all strains could remove cholesterol from culture medium of MRS-CHOL(P<0.05), and the percentage of Cholesterol-degrading rate ranged from 6.84% to 42.97%. Among them, strain N59-1 was selected after screening, which was based on their cholesterol removal abilities. The cholesterol removal rate was 42.97％. The strain N59-1 with the highest level of cholesterol removal from the media was identified using physiological and biochemical characteristics and 16S rDNA sequences, the homology of N59-1 with L. plantarum was 99.7%. As a result N59-1 was named L. plantarum. 30 days feeding test results showed that the organ growth and blood biochemical index of mice in each group had no significant difference compared with the control group(P>0.05).

Abstract:In order to prepare the adenosine-3', 5'-cyclic monophosphate by fenmetation, the ferment conditions of Bacillus. subtilis jsim-1277 were studied in shake flask, auto fermentor, and 20 M3 fermentor. The results showed that the optimal conditions for the fermentation were identified as follow：pH at 6.7, the optimal concentration of K2HPO4 was 1.0 g/dL, the optimal concentration of NaF was 0.05 g/dL. Under the optimized fermentation conditions, the productivity in shake flask, auto fermentor, or 20 M3 fermentor was 7.17, 6.01, 7.10 g/L, respectively.