聚-β-羟基丁酸(PHB)具有生物可降解性,其分解产物可全部为生物利用,对环境无污染。该研究从污水处理厂的活性污泥中筛选产PHB的菌株,通过菌落形态观察、生理生化特征与16S r DNA系统树的构建、红外光谱分析、对菌株及采用氯仿乙醇法提...聚-β-羟基丁酸(PHB)具有生物可降解性,其分解产物可全部为生物利用,对环境无污染。该研究从污水处理厂的活性污泥中筛选产PHB的菌株,通过菌落形态观察、生理生化特征与16S r DNA系统树的构建、红外光谱分析、对菌株及采用氯仿乙醇法提取的发酵产物进行了鉴定。采用常压室温等离子体(ARTP)快速诱变产PHB野生菌株,结合苏丹黑染色及摇瓶复筛方法,筛选产PHB产量高且遗传特性稳定正向突变株。分离筛选到一株产PHB的原始菌株,被鉴定命名为Bacillus toyonensis GR-6,结果表明胞内聚合物PHB含量达43.04%(干细胞含量),产量为1.33 g/L。ARTP快速诱变的突变株PHB含量可达77.43%,产量为2.78 g/L,是原始菌株的2倍多,对突变株进行连续7代的传代发酵实验,各代表现出良好的遗传稳定性。突变株PHB产量与细胞干重比原始菌株显著提高,并具有良好的遗传稳定性,在微生物法生产可降解塑料的应用领域具有较大的潜在应用价值。展开更多
In this paper,the method of UV-visible reflection spectrum（UV method） was theoretically and experimentally proposed to investigate the initial kinetic characters of the solid-solid reaction with the mixture of dimet...In this paper,the method of UV-visible reflection spectrum（UV method） was theoretically and experimentally proposed to investigate the initial kinetic characters of the solid-solid reaction with the mixture of dimethylglyoxime and Ni（Ac）2·4H2O,and the mixture of dimethylglyoxime and anhydrous Ni（Ac）2 as the modeling reaction examples.The results indicated that the UV method was very sensitive in the initial period of solid-solid reaction.The reactive rates for above two reaction systems were varied non-linearly with the change of reaction time.The fastest reaction rates can be reasonably explained by the formation of the cold-melting layer or cold-dissolvingmelting layer.展开更多
文摘In this paper,the method of UV-visible reflection spectrum（UV method） was theoretically and experimentally proposed to investigate the initial kinetic characters of the solid-solid reaction with the mixture of dimethylglyoxime and Ni（Ac）2·4H2O,and the mixture of dimethylglyoxime and anhydrous Ni（Ac）2 as the modeling reaction examples.The results indicated that the UV method was very sensitive in the initial period of solid-solid reaction.The reactive rates for above two reaction systems were varied non-linearly with the change of reaction time.The fastest reaction rates can be reasonably explained by the formation of the cold-melting layer or cold-dissolvingmelting layer.
