Isolation of Leptospirillum ferriphilum by single-layered solid medium

According to physiological and biochemical characteristics of Leptospirillum ferriphilum,a strain of object bacteria was isolated successfully.Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium.Colony was cultured and bacteria were collected.The morphologies of the object bacteria were observed using crystal violet staining,scanning electron microscope(SEM)and transmission electron microscope(TEM).The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1.These results indicate that this new single-layered agar solid medium is efficient and simple for isolation of Leptospirillum ferriphilum.Additionally,physiological-biochemical characteristics show that the optimum initial pH value and its growth temperature are 1.68 and 40 ℃,respectively.The culture of it is used to leach a complex concentrate chalcopyrite,the leaching efficiencies of copper and iron are 1.93 % and 13.74 %,respectively,and it is more effective than the A.ferrooxidans culture in the leaching of the complex concentrate chalcopyrite.     

金矿石生物氧化预处理研究

本文比较了三种来源不同的菌种的亚铁氧化能力，最后选用氧化能力较高的来自江西城门山的菌种为浸矿菌种，并在摇瓶中比较了使用和不使用生物预处理氰化法提金的提取率。还研究了在难处理金矿生物氧化预处理过程中的一些影响因素，比如矿浆浓度、初始Fe^3＋浓度、生物预氧化的时间等。结果表明，添加10g／L的Fe^3＋有利于增加金的提取率。采用生物氧化预处理，难处理金矿金的提取率可以高达92．1％，在生物氧化处理4天后就可以达到工业处理的要求。     

改性蛋白酶的制备及其在羊毛防毡缩整理中的应用

摘 要： 针对生物酶法处理羊毛防毡缩易出现的强力损伤问题,本文采用对蛋白酶进行聚合物接枝改性的方法增大蛋白酶体积而限制其向纤维内部扩散,使其对羊毛鳞片的分解停留在表层,降低酶分解作用对羊毛的强力损伤。本文将聚合物Eudragit L100聚合物经碳二亚胺活化后,通过共价键对碱性蛋白酶Esperase 8.0L进行接枝,形成改性蛋白酶Eudragit-Esperase（EE）,使得Esperase8.0L蛋白酶的分子量从4.1-6.5KD增大至45KD以上,经分析测试,基本达到改性要求。羊毛织物经改性蛋白酶EE处理后,与用蛋白酶Esperase 8.0L处理织物的性能相比,织物的失重率降低21.90%,拉伸断裂强力提高13.10%,说明EE可显著降低羊毛纤维的损伤。同时,经EE处理后的羊毛织物的面积毡缩率从原毛织物的8.12%降低至0.89%,表明改性蛋白酶EE处理赋予织物良好的防毡缩性能。