Biosynthesis of ~(13)C-Labeled Amino Acids and Sugars by Spirulina (Arthrospira) Maxima in a Parallelepiped Photobioreactor

This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor. The kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. The continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is up to 64% versus dry mass of cells.     

Bioleaching of chalcopyrite by UV-induced mutagenized Acidiphilium cryptum and Acidithiobacillus ferrooxidans

The original strains Acidithiobacillus ferrooxidans GF and Acidiphilium cryptum DX1-1 were isolated from the drainage of some caves riched in chalcopyrite in Dexing Mine in Jiangxi Province of China.The optimum temperature and pH for growth were 30℃and 3.5 for Ac.cryptum DX1-1,and 30℃and 2.0 for At.ferrooxidans GF,respectively.For Ac.cryptum DX1-1,the optimum UV radiating time was 60 s and the positive mutation rate was 22.5%.The growth curves show that Ac.cryptum after mutagenesis reached stationary phase ...     

微生物铁硫还原耦合水体中As(V)吸附行为研究

采用循环伏安法(CV)、铁的L边和硫的K边X射线近边吸收光谱(XANES)和电感耦合离子光谱发生仪等,研究了碱性厌氧环境中S.oneidensis介导下的铁硫还原过程与水体中As(V)的吸附行为。结果表明,核黄素能够促进S.oneidensis介导的铁硫还原,电子传递过程为乙酸盐→核黄素→底物;S.oneidensis作用24 h后,沉积物中铁硫形态逐渐被还原,Fe(Ⅱ)/Fe(Ⅲ)的比例不断增加,出现硫化矿物特征峰,表明有新的铁的硫化矿物(FeS)生成;FeS对As(V)的吸附量随着时间而增加,6 h后逐渐达到平衡,120 h时吸附量为8.35 mg,吸附效率为89%。微生物铁硫还原生成的Fe S对水体中As(V)有显著的吸附效果,有良好的应用前景。     

Isolation and characterization of acidophilic bacterium from Dongxiangshan Mine in Xinjiang Province, China

One bioleaching bacterium, named as strain DXS, was isolated from acid mine drainages (AMDs) of Dongxiangshan Mine of Hami, Xinjiang Province, China. The strain DXS is gram-negative and rod-shaped with a size of (0.40±0.05) μm×(1.3±0.5) μm. The optimal temperature and pH for growth are 30 ℃ and pH 2.0, respectively. It can grow autotrophically by using ferrous iron, elemental sulfur and NaS2O3 as sole energy sources. In the phylogenetic tree, strain DXS has similarity with Acidithiobacillus ferrooxidans typ...     

初始pH对极端嗜热菌万座嗜酸两面菌作用下黄铜矿氧化溶解的影响(英文)

采用生物浸出和循环伏安试验研究初始pH对黄铜矿在65℃条件下氧化溶解的影响,分别采用XRD和拉曼光谱分析黄铜矿生物浸出过程中和电极表面形成的氧化产物。化学浸出结果表明:黄铜矿溶解速率随着初始pH的减小而增大,然而初始pH对黄铜矿生物浸出的影响却正好相反。当初始pH为1.0时,万座嗜酸两面菌的加入几乎没有促进黄铜矿的溶解,这主要是由于高酸度严重抑制了万座嗜酸两面菌的生长。电解液中存在或不存在万座嗜酸两面菌时黄铜矿的阳极氧化电流都随着初始pH的增大而增大,同时在黄铜矿电极表面检测到了单质硫和铜蓝。结果表明,在化学浸出过程中黄铜矿是在质子作用和氧化作用下溶解的,黄铜矿氧化生成了铜蓝和单质硫。     

一种新型凝固剂在固体平板分离极端浸矿菌中应用潜力研究

利用一种新型、耐高温、耐酸的基质作凝固剂,设计了一种新型的分离纯化极端浸矿菌的固体平板培养基.在此基础上,结合水盘培养法,成功的实现了高温嗜热浸矿菌、中等嗜热浸矿菌以及嗜中温浸矿菌的固体平板培养及纯化.待试验的三种极端浸矿菌:高温嗜热浸矿菌万座酸菌(Acidianus manzaensis)、中等嗜热浸矿菌(Ferroplasma thermophilum L1)、嗜中温浸矿菌(来自实际矿山酸性矿坑水)都能在此固体培养基表面形成圆形粘液状米黄色菌落;菌落扫描电镜结果表明:菌落内部结合较为松散,单个细菌通过胞外附属结构或物质与培养基基质紧密结合.实验结果表明该固体培养基在浸矿菌分离纯化、菌种鉴定、以及遗传改良等方面具有广阔的应用前景.