Advanced Materials Research Vols. 690-693

Abstract: Simulating dynamic behaviors of metabolic networks of a living cell plays an important role in system biology. As a part of dynamic model, the choice of objective function has a large influence on simulation accuracy for these behaviors. In this work, in order to precisely describe the biomass yield and substrate utilization in glycolytic metabolism of Escherichia coli, we try to modify the objective function of the existing dynamic model by using maximization of glucose utilization to replace the traditional objective one. After that, the dynamic model with the new objective is converted to a standard optimal control problem. And then we compute such model through the use of the penalty function methods. The results illustrate that the simulation curves perfectly agree with experiment data, especially with biomass concentration. Thereby, we conclude that completely utilizing substrate glucose is feasible to describe and improve the simulation accuracy on concentrations of some important metabolites in Escherichia coli. The completeness of investigating such models will be helpful and instructive for the application of bioengineering.

Abstract: The novel exopolysaccharide (EPS) was produced by a streptococcus thermophilus strain isolated from Tibetan kefir grain, and it was purified using DEAE cellulose 52 and DEAE Sepharose CL-6B column chromatography. Then it was eluted as a single symmetrical narrow peak on high-performance gel-permeation chromatography (HPGPC) and the average molecular mass was estimated to be 30,092Da. Infrared spectrum analysis indicated it had characteristic glycosidic structures. Gas chromatography showed that the EPS is composed of mannose and glucose in a molar ratio of 2.6:1 with trace galactose. The structural features of EPS were investigated by partial hydrolysis with acid, methylation analysis and NMR spectroscopy analysis. The results revealed that the main backbone chain of EPS was (23)-β-D-Manp, (34)-β-D-Manp, (23,6)-α-D-Glcp and trace amounts of galactose.

Abstract: To study the optimum deproteination conditions of polysaccharide from corn silk with cetyl trimethyl ammonium bromide(CTAB). The removal rate of protein and residual rate of polysaccharide was chosen as the index. The optimal deproteination condition of CTAB was that NaCl was 0.010g, pH was 6.0, the volume ratio of CTAB was 10%, dissociated time was 24h. Deproteinization rate was 58.17%, the residual rate of polysaccharide was 25.29%.

Abstract: In this paper, furfural was produced from hemicelluloses of bagass by hydrolization reaction with sulfuric acid and acetic acid respectively. The effect of several variables such as temperature , liquid-to-solid ratio ,time and catalyst charge（KCL） on furfural yield was studied. The results showed that the better yield of furfural was obtained in acetic acid hydrolysis system. However, compared to yield of acetic acid hydrolysis system, it need more time and higher temperature at the same liquid-to-solid ratio. At last, when sulfuric acid as catalyst, liquid-to-solid ratio was 1:6 and time was 5h at 150°C, furfural yield can reach 75 %.

Abstract: Some chemical compounds in petroleum ether extract of Mikania micrantha H.B.K. can strongly influence seedling growth of Phaseolus radiaus. In this study, we provide evidence that the chemical compounds in active fraction chromatographed on normal phase silica gel columns from petroleum ether extract of M. micrantha have strong activity to promote P. radiaus taking root. But meanwhile, these chemical compounds could be inhibitors for P. radiaus root growth. Two main chemical constituents, α-Bisabolol and Eudesma-5,11(13)-dien-8,12-olide, in the active fraction were confirmed by GC-MS analysis.

Abstract: In order to know better about the properties of tilapia skin gelatin, we discussed the oil-holding capacity, emulsifying property of the gelatin, and modified the structure of gelatin by pectin to improve its emulsifying property. The results indicated that the gelatin has strong oil-holding capacity, and shows well EAI and ESI under the following conditions: concentration of gelatin 1% (w/v), concentration of NaCl 0.2M, pH far away from 5. The emulsifying property of the gelatin was significantly improved by pectin,

Abstract: The isothiocyanates were isolated from different organize of wasabi with extraction and distillation methods for the development of its’ medical value. An experiment of isothiocyanates anti-cancer cells of the liver was designed. The results showed that the contents of the isothiocyanates were 0.53 mg ml-1in the root, 0.80 mg ml-1in the stem, and 0.27 mg ml-1in the leaf of the wasabi, respectively. Allyl isothiocyanate (AITC) and (2-isothiocyanatoethyl)-benzene were the major volatile compounds of wasabi stem. The wasabi distillate inhibited the liver cancer cells and caused the death of liver cancer cells in 90 min treatment. The results of this study provided a scientific basis for the anti-cancer medical value and isolation of isothiocyanates from wasabi.

Abstract: To study the extraction technology of polysaccharide from Pleurotus ostreatus. In order to explore the influence of temperature, time, and solid-liquid ratio on polysaccharide yield, single factor test had been done. The optimum extraction conditions was obtained though orthogonal test and interactive analysis: extraction temperature 50°C, extraction time 2h, and solid-liquid ratio 1:30. Under those conditions, the extraction rate of Pleurotus ostreatus polysaccharides was 28.79%.

Abstract: The objective of this study is to examine the protection effect of CPCC treatment in hepatic injury and the role of Calreticulin (CRT) in hepatic injury. The control and alloxan groups were given water and the CPCC group was given CPCC (Cr3+40μg/kg.d) every day, respectively. After 4 weeks, the alloxan and CPCC groups were injected with alloxan (40mg/kg) for 6d. Total protein was extracted from mice liver. SDS-PAGE and two-dimensional electrophoresis (2-DE) were performed in this study from the total protein of mice hepatic. The samples of 2-DE were analyzed through Time of Flight Mass Spectrometer . The mRNA of CRT was detected using fluorescence quantitative polymerase chain reaction (qPCR) in mice liver. The results of 2-DE and qPCR showed the expression of CRT had significant difference among controlalloxan and CPCC mice both on the transcriptional and protein levels. CRT is a potential target as the roles of treatment and prevention in hepatic injury. CPCC is expected to become new health product for prevention and treatment of the hepatic injury.

Abstract: The objective of this study was to research the influence of the sweet sorghum straw fermented by the Compound Microbial Agent on the milk yield and milk composition of the cows. The results indicated that sweet sorghum straw bio-feed fermented by the Compound Microbial Agent in bags could increase the feed intake (11.4%) and milk yield(14.2%) compared with the control group, it also has improved milk protein (14.03%) and butterfat rate (16.3%) ,and has reduced the somatic cell's number(5.15%) compared with the control group. The sweet sorghum straw fermented by the Compound Microbial Agent has reduced the milk-feed ratio (20.8%).It has improved the feed digestibility and utilization and reduced the costing.