Abstract:This paper described the physiological characteristic, storage properties of the fruit and vegetable postharvest and advanced preserving technology in the world, mainly emphasized on the characteristics and significance of various types of preservation technology. Some common problems emerged during the preservation and developments in the future were discussed.

Abstract:The branched-chain amino acids(leucine, isoleucine and valine) are synthesized by bacteria, fungi and plants. They are essential for vertebrates including humans who must receive branched-chain amino acids from their diet. They play an important role in metabolic life because of the special structure and function. Therefore, branched-chain amino acids are used in medicine, food industry and feed ingredient. Fermentation is the main method to produce branched-chain amino acids. Corynebacterium glutamicum(containing Brevibacterium flavum) is the main producer. Biosynthesis and regulations of branched-chain amino acids are analysed and the developments in metabolic engineering-breeding are summarized.

Abstract:Biotransformation of 3-cyanopyridine to nicotinic acid with immobilized Pseudomonas putida CGMCC3830 was studied. Sodium alginate was selected as the immobilization material. The cell immobilization conditions, biotransformation conditions and the batch stability were investigated. The optimized conditions for immobilization were as follows: sodium alginate 2 g/dL, calcium chloride 0.4 g/dL, curing time 6 h. The optimized immobilization conditions included: temperature 35 ℃, pH 7.0, substrate concentration 100 mmol/L. Results of batch conversion experiments showed that with the substrate concentration of 100 mmol/L, the nicotinic acid yield reached 91.8 g/g cell dry weight. The immobilized cell can be reused 10 times with the enzymatic activity retained 59.1%, while the free cell could be reused only 3 times with the enzymatic activity retained 45.6%.

Abstract:Extraction of Monascus pigments in mycelia by ultrasonic-assisted technology, on the basis of single factor experiments, using response surface method optimizes the extraction of red pigment process parameters. A quadratic regression model was established, and the optimum extraction conditions were obtained． The results showed that ethanol concentration, solid-liquid ratio, ultrasonic wave power of these three factors on the extraction of red pigment had a significant influence, ethanol concentration 76.30%, solid-liquid ratio 34.44∶1, ultrasonic wave power 304.84 W. Under the optimum conditions, the red pigment concentration of the extract reached the maximum 5 679.4 U/g, the yellow pigment was as high as 4 633 U/g. With the national standard compared to red pigment extraction, the extraction rate increased by 6.5% and 8.9% .

Abstract:In this paper, antibacterial activity of composite natural preservatives with chitosan, lysozyme, and tea polyphenols against Staphylococcus aureus were investigated. Minimal inhibitory concentration(MIC) and minimal bactericidal concentration(MBC) of composite natural preservatives were determined by stiletto method. The damage of Staphylococcus aureus which treated with composite natural preservatives were studied by cell damage experiment, such as bacteriostatic rate, antibacterial kinetics, growth curve, integrity of cell membrane, alkaline phosphatase(AKP) activity and ultra microstructure of bacteria. It concluded that the MIC and MBC of composite natural preservatives were 0.8mg/mL and 1.6mg/mL. With the extension of time, composite natural preservatives could inhibit the growth of Staphylococcus aureus, increase the quantity of AKP, and destroy the metabolic circulation, make the nucleic acid and protein leaked in cells. When treated with composite natural preservatives, Staphylococcus aureus was distorted, the cell wall was ruptured, the cytoplasm was spilled out, the stability of cell membrane and intracellular environment was destroyed, which led to the death of Staphylococcus aureus.

Abstract:The strain isolated from soil, producing an aminopeptidase, was identified by physiological, biochemical and molecular biological methods, named Pseudomonas aeruginosa NJ-814. Based on this enzyme which have been investigated a thermo-stable Lysine Aminopeptidase, the kap gene was cloned from the genomic DNA of Pseudomonas aeruginosa NJ-814 by PCR. The expression vector pET-28a-kap was constructed to partly express fusion protein in E. coli BL21(DE3). The kap gene contains 1 500 nucleotides coding 499 amino acids. The deduced amino acids of kap had a high similarities with Streptomyces exfoliates and Saccharopolyspora erythraea. The physical and chemical properties was analyzed with the biological informatics method and the kap gene was successfully expressed in the E. coli BL21(DE3), which lay the foundation for further research of the thermo-stable mechanisms and functional characterization of the aminopeptidase.

Abstract:To improve the specific growth rate and CO2 fixation rate of Spirulina platensis, the research was divided into four growth period: lag phase, the early of log phase, the end of log phase, the stable phase.The purpose was to optimize two main environmental factor which is light intensity and CO2 concentration. Experimental results showed that the growth of Spirulina platensis was conditioned in a 1 L conical flaske under 30 ℃ of temperature and 16/8 of light period: the optimum condition of lag period is light intensity 3 000 lux, without bubbling the CO2; the optimum condition of the early of log phaseis light intensity 4 000 Lux, with bubbling 15% concentration of CO2; the optimum condition of the end of log phase is light intensity 5 000 Lux, with bubbling 15% concentration of CO2; the light intensity the stable phase is lower than 3 000Lux, no need to bubble CO2. In continuous cultivation of Spirulina platensis regulate culture conditions of four period, the maximum biomass and carbon fixation rates were higher than the control group at 4.126 g/L and 58.231 mg/(L·h) respectively.

Abstract:In order to improve the accumulation of Adenosine-3', 5'-cyclic monophosphate with Bacillus. subtilis jsim-1277, the effects of phosphodiesterase inhibitors were studied. The results showed that Cemadotin and Aminophylline can improve the concentration of Adenosine-3', 5'-cyclic monophosphate. Under the optimized conditions, the productivity increased 28%, reaching 9.14 g/L.

Abstract:Influence of package with 0.18 mm thickness of CPP bags with different volume fraction of O2, CO2, and N2 gasses on quality changes of early mature stage(less than 25% red surface color) fresh jujube fruits(Ziziphus zizyphus) were investigated during the 100 d storage period at (0±0.5) ℃. The results show that these modified atmosphere packages with different volume fraction of gasses slowed down the senescence of and nutrition decrease in the packed fruits. The rise of reducing sugar, MDA and ethanol accumulation, and the decrease of weight loss, firmness, color change and the contents of TA in the packed fruits were inhibited to varying degrees, while the losses of vitamin C, cyclic AMP and total flavone in the packed fruits were delayed. Package with volume fraction of 5% O2, 2% CO2 and 93% N2 exerted the best storage effect.

Abstract:The capacity of scavenging ·OH, ·O2- and H2O2 of aqueous extractions from five organs(root, aerial stem, leaf, flower and seed) of Fagopyrum megaspartanium was studied by means of nitro blue terra-zolium photochemica reduction, Fenton reaction and spectrophotometric assay. The results showed that the aqueous extractions had the capacity of scavenging ·OH, ·O2- and H2O2. The capacity of scavenging ·OH and·O2- were sorted as: root, flower＞leaf, seed＞aerial stem. The capacity of scavenging H2O2 was sorted as: leaf, flower＞root, seed and aerial stem.

Abstract:Single variable method was utilized to determine the optimum conditions of Auricularia auricula protoplasts preparation, regeneration and fusion in Shenlong A8 and Qindan 4#. After cultured for 7 d, the Auricularia auricula mycelium was treated with 0.5 mol/L mannitol as osmotic stabilizer, digested by 2.0% lywallzyme, then incubated in 30 ℃ water for 3.5 h, and the total amount of released protoplasts reached 0.94×107/mL, 1.44×107/mL in the two varieties, respectively.RM5 regeneration medium was selected and the highest regeneration rates were observed in Shenlong A8 and Qindan 4# protoplasts, which attained 1.91% and 1.53%, respectively.The optimum condition for protoplasts fusion: 30% PEG4000 and 0.05 mol/L CaCl2(pH 10)were added as fusion-aided agent, and incubated in 35 ℃ for 30 min. The resulting fusant was obtained by fluorescence microscopy and antagonistic reaction, which served as the theoretical basis for Auricularia auricular breeding.

Abstract:IMainly take cloves and cinnamon as raw materials, through thermostat stirring and repeatedly extracting preparation to get natural extracts with antibacterial effect for the corrosion studies of Lentinus edode sauce. This preliminary study found that: When each of those two extracts' single dosage reach to 0.9%, it has a significant inhibitory effect on the total colony and the growth of e. coli in the Lentinus edode sauce. At the same time, the smells of the sauce become slightly heavier. But both cloves and cinnamon, those two extracts have no significant effect on the pH and Aw of the sauce.

Abstract:Endoglucanase is one of the most important cellulose enzymes, However, the large-scale industrialized application of these enzymes was restricted by the low activity and high cost price. Improving their activity through genetic engineering and protein engineering was considered an efficient approach to cut down the cost price. In this study the site-directed mutation technology was used to improve the activity of the F-10 endoglucanase gene. The cellulose of endoglucanase 91 lysine(AAA) was replaced by glutamic acid(GAA)(K91E), 369 lysine(AAA) was replaced by arginine(AGA)(K369R) and the 91 and 369 were replaced by arginine(AGA). Mutation plasmids were transfored into E. coli, the expression product was induced by IPTG. The result showed that protein molecular weight was 53 000. The optimum reaction pH unchanged, was pH 6.8. The optimum temperature of K369R and K91E/K369R were 50 ℃, the optimum temperature of the mutant K91E have great change, is 40 ℃. The specific activity reached 162.8、77.9、202 U/mg. The thermal stability of the three mutants increased, when the temperature reached 70 ℃, the activity of F-10 fell sharply, surplus energy is only 12%, 36%, 30% and 41%, when the temperature reached 80 ℃, the residual activity of K91E is still about 22%. By site-directed mutation technique, we obtain the efficient expression in E. coli and good thermal stability of endoglucanase gene engineering strains. This research can provide the basis for the further investigations of cellulose.

Abstract:Selecting fresh goose as the main raw material, single factor experiments was conducted under six different factors such as the proportion of goose and fat, the proportion of sucrose and glucose, quantity of starter, fermented temperature, fermented time, and quantity of tenderness. Based on the results, orthogonal test of L9(34) was carried out , and the best technological conditions with perfect flavor and sour taste were as follows: the proportion of sucrose and glucose was 2∶3, quantity of starter was 3.0%, fermented time was 20 h, fermented temperature was 36 ℃, quantity of tenderness was 0.006%.

Abstract:To industrialize Cordyceps militaris hyperproduction mutant strain, investigating and optimizing fermentation conditions, and laying a experimental foundation for industrial production. Comprehensively considering the yields of mycelium biomass, the content of polysaccharides and cordyceps acid, adenosine, optimizing fermentation conditions of high production mutant strain through applying single factor test method in 5 L fermentor. Meanwhile, implementing the validation experiments under the optimum conditions, and investigating the mass-culture of hyper-yield mutant strain in 15 L and 100 L fermentor. The optimal fermentation conditions of 5 L jar were obtained as follows: rotating speed 250 rpm, the initial pH of fermentation media 7, volume of inoculation 6%, temperature 26 ℃, air flow speed 250 L/h. The yields of mycelium biomass and the content of polysaccharide, adenosine and cordyceps acid were obtained as 23.29 g/L, 0.94 g/L, 162.84 mg/L and 2.06 g/L respectively in 5 L fermentor; 30.84 g/L, 1.10 g/L, 233.22 mg/L and 1.89 g/L with optimal culture time as 72 hours in 15 L fermentor and 32.05 g/L, 1.33 g/L, 187.20 mg/L and 3.51 g/L with optimal culture time as 47 hours in 100 L fermentor. The results were stable. With evaluating the yields of mycelium biomass, the content of polysaccharides, cordyceps acid and adenosine at the same time, plotting fermentation growth curve of 15 L and 100 L fermentor for the first time, This study provides valuable data for industrial production of Cordyceps militaris high production mutant strain.

Abstract:Pyrazines are one of the most important flavors in Chinese liquor. The method was developed for determination of nitrogenous compounds in Chinese liquor, especially pyrazines composition in Moutai liquor. The method was optimized by adjusting the extraction process and introducing the purification steps for removing the esters and polyhydric alcohol, which improved the the instruments detection rate of the target components effectively. A total of 56 kinds of nitrogenous compounds were detected in Moutai liquor, including 35 kinds of pyrazines and 21 kinds of other nitrogenous compounds.