The Effects associated with Investigation & Improvement Financing about Medical Productiveness: Academic Chemistry, 1990-2009.

06 mg/kg DW, 1.47 mg/kg DW, and 2.21 mg/kg DW, respectively. The results of hydroponic experiment show that under the same concentration of Cd stress, Qiantangxuri F1, a high Cd accumulating variety, absorbed Cd faster, accumulated more Cd, used shorter oxidative stress response time and had stronger tolerance to Cd than Zhefen 3053, a low Cd accumulating variety. The typical high and low Cd accumulating varieties can provide a reference for agricultural production in heavy metal polluted areas and the development of molecular-assisted breeding methods of PSC. At present, cultivating low Cd accumulating PSC varieties and dynamic monitoring of Cd contents in tomato fruits are feasible methods in medium and light Cd-polluted areas.2,5-dimethylpyrazine (2,5-DMP) is of important economic value in food industry and pharmaceutical industry, and is now commonly produced by chemical synthesis. In this study, a recombinant Escherichia coli high-efficiently converting L-threonine to 2,5-DMP was constructed by combination of metabolic engineering and cofactor engineering. To do this, the effect of different threonine dehydrogenase (TDH) on 2,5-DMP production was investigated, and the results indicate that overexpression of EcTDH in E. coli BL21(DE3) was beneficial to construct a 2,5-DMP producer with highest 2,5-DMP production. The recombinant strain E. coli pRSFDuet-tdh(Ec) produced (438.3±23.7) mg/L of 2,5-DMP. Furthermore, the expression mode of NADH oxidase (NoxE) from Lactococcus cremoris was optimized, and fusion expression of EcTDH and LcNoxE led to balance the intracellular NADH/NAD⁺ level and to maintain the high survival rate of cells, thus further increasing 2,5-DMP production. Finally, the accumulation of by-products was significantly decreased because of disruption of shunt metabolic pathway, thereby increasing 2,5-DMP production and the conversion ratio of L-threonine. Combination of these genetic modifications resulted in an engineered E. coli Δkbl ΔtynA ΔtdcB ΔilvA pRSFDuet-tdhEcnoxELc-PsstT (EcΔkΔAΔBΔA/TDH(Ec)NoxE(Lc)-PSstT) capable of producing (1 095.7±81.3) mg/L 2,5-DMP with conversion ratio of L-threonine of 76% and a yield of 2,5-DMP of 28.8% in 50 mL transformation system with 5 g/L L-threonine at 37 °C and 200 r/min for 24 h. Therefore, this study provides a recombinant E. coli with high-efficiently catalyzing L-threonine to biosynthesize 2,5-DMP, which can be potentially used in biosynthesis of 2,5-DMP in industry.β-N-acetylglucosaminidases (NAGases) can convert natural substrates such as chitin or chitosan to N-acetyl-β-D glucosamine (GlcNAc) monomer that is wildly used in medicine and agriculture. In this study, the BcNagZ gene from Bacillus coagulans DMS1 was cloned and expressed in Escherichia coli. The recombinant protein was secreted into the fermentation supernatant and the expression amount reached 0.76 mg/mL. The molecular mass of purified enzyme was 61.3 kDa, and the specific activity was 5.918 U/mg. The optimal temperature and pH of the BcNagZ were 75 °C and 5.5, respectively, and remained more than 85% residual activity after 30 min at 65 °C. The Mie constant Km was 0.23 mmol/L and the Vmax was 0.043 1 mmol/(L·min). The recombinant BcNagZ could hydrolyze colloidal chitin to obtain trace amounts of GlcNAc, and hydrolyze disaccharides to monosaccharide. Combining with the reported exochitinase AMcase, BcNagZ could produce GlcNAc from hydrolysis of colloidal chitin with a yield over 86.93%.Scleroglucan is a high-molecular water-soluble microbial exopolysaccharide and mainly applied in the fields of petroleum, food, medicine and cosmetics. The high molecular weight of scleroglucan produced by microbial fermentation leads to low solubility, high viscosity and poor dispersibility, thus bringing a series of difficulties to extraction, preservation and application. It is important to explore suitable degradation method to adjust the molecular weight of scleroglucan for expanding its industrial application. Taking Sclerotium rolfsii WSH-G01 as a model strain, in which functional annotations of the glucanase genes were conducted by whole genome sequencing. Based on design of culture system for culture system for differential expression of β-glucanase, endogenous β-glucanase genes in S. rolfsii WSH-G01 were excavated by transcriptomics analysis. Functions of these potential hydrolases were further verified. Finally, 14 potential endogenous hydrolase genes were obtained from S. rolfsii. After heterologous overexpression in Pichia pastoris, 10 soluble enzymes were obtained and 5 of them had the activity of laminarin hydrolysis by SDS-PAGE and enzyme activity analysis. Further investigation of the 5 endogenous hydrolases on scleroglucan degradation showed that enzyme GME9860 has positive hydrolysis effect. The obtained results provide references not only for obtaining low and medium molecular weight of scleroglucan with enzymatic hydrolysis, but also for producing different molecular weight of scleroglucan during S. rolfsii fermentation process with metabolic engineering.Polyhydroxyalkanoates (PHAs) have obtained much attention in biomaterial fields due to their similar physicochemical properties to those of the petroleum-derived plastics. Poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)] is one member of the PHAs family, and has better toughness and transparency compared to existing polylactic acid (PLA) and poly[(R)-3-hydroxybutyrate] [P(3HB)]. Linrodostat ic50 First, we confirmed the one-step biosynthesis of P(LA-co-3HB) with the lactate fraction of 23.8 mol% by introducing P(3HB-co-LA) production module into Escherichia coli MG1655. Then, the lactate fraction was increased to 37.2 mol% in the dld deficient strain WXJ01-03. The genes encoding the thioesterases, ydiI and yciA, were further knocked out, and the lactate fraction in the P(3HB-co-LA) was improved to 42.3 mol% and 41.1 mol% respectively. Strain WXJ03-03 with dld, ydiI and yciA deficient was used for the production of the LA-enriched polymer, and the lactate fraction was improved to 46.1 mol%. Notably, the lactate fraction in P(3HB-co-LA) from xylose was remarkably higher than from glucose, indicating xylose as a potent carbon source for P(3HB-co-LA) production. Therefore, the deficiency of thioesterase may be considered as an effective strategy to improve the lactate fraction in P(3HB-co-LA) in xylose fermentation.Linrodostat ic50