Laboratory and Field Studies of Bacterial Manganese Reduction

该项目的长期目标是阐明细菌在自然界中锰循环中的作用。近期工作目标侧重于细菌在减少锰方面的作用。在纯培养的实验室研究中，将研究细菌还原锰的机制。利用这些纯培养物，以及来自不同环境的浓缩物(混合培养物)，PI还将开发出区分生物还原和(严格)化学还原的方法，并确定不同类型的生物还原锰。最后，他将把这些方法应用于实地研究锰的还原，包括在淡水中(纽约州奥奈达湖)。和海洋(黑海)环境。机理研究将从SK13sp菌株开始，这是一种海洋芽孢杆菌，是一种有效的锰还原剂。这些研究将集中在分离和鉴定细胞产生的胞外锰还原剂。在进行这些研究的同时，尼尔森还将对其他纯文化进行定性，并开始对其他机制进行详细分析。现场方法的开发将侧重于使用类似物、抑制剂和毒物来识别锰还原的机制。B.Tebo博士将在不列颠哥伦比亚省萨尼奇湾的Oneida湖测试这些方法，并于1987年在黑海进行野外工作。

The long term goal of this project is to elucidate the role of bacteria in the manganese cycle in nature. The work immediate objective focuses on the role of bacteria in reducing manganese. In laboratory studies with pure cultures, the mechanisms by which bacteria reduce manganese will be investigated. Using these pure cultures, and enrichments (mixed cultures) from a variety of environments, the PI will also develop methods for distinguishing biological from (strictly) chemical reduction, and for charact- erizing the different types of biological Mn reduction. Finally, he will apply these methods to the study of Mn reduction in the field, both in fresh water (Oneida Lake, N.Y.) and marine (Black Sea) environments. Mechanistic studies will begin with strain SK13sp, a marine Bacillus that is a potent reducer of manganese. These studies will focus on isolation and identification of the extracellular Mn reductant produced by the cells. Concomitant with these studies, Nealsen will be characterizing other pure cultures, and beginning detailed analyses of other mechanisms. Development of field methods will focus on identifying mechanisms of Mn reduction, using analogues, inhibitors, and poisons. These methods will be tested in Oneida Lake, in Saanich Inlet, B.C. by Dr. B. Tebo, and used for field work in the Black Sea in 1987.