Marine Biotech Fellowship: The Development and Use of Molecular Genetic Techniques for the Study of Fe Reduction in a Marine Eubacterium

生理学数据表明， 氧化剂的利用可写为希瓦氏菌 腐败菌单独从好氧区的好氧生长， 硫代硫酸盐还原在无硫化物和 亚氧/缺氧海洋盆地和孔隙水的亚硫酸盐带。与 其多功能的碳代谢和兼性的性质，S。 腐败菌和类似的有机体很可能会与硫酸盐竞争， 硫代硫酸盐和其他消耗的还原菌 海洋缺氧盆地和沉积盆地中的硫中间体 孔隙水这些生物体可能在 控制海洋环境中的硫形态。通过 利用有机碳并产生硫化物，这些生物 会与化学跃层的平衡密切相关 这一项目将提供关于海洋生物的新的基本科学数据。 分子遗传学的一个广泛的和非常多才多艺的厌氧- 呼吸有机体通过分离和测序编码 硫还原酶，该项目将能够研究的调控 基因表达的机制。体内基因操作 将有助于我们更好地理解 S.腐败菌和 可能是其他海洋真细菌基因操作也可以 有助于比较硫还原酶活性的调节， 硝酸还原酶或铁还原酶活性。腐败菌这 这项工作将导致合作开发一种探测器， 非硫酸盐还原菌利用硫中间体， 天然沉积物这种探测沿着了关于 硫中间体还原可用于探索 非硫酸盐还原菌如S. 腐殖酸的地球化学的S，铁，和C在各种各样的 亚氧/缺氧的海洋环境中，这些硫物种 存在.

Physiological data suggest that a thermodynamic hierarchy for the utilization of oxidants could be written for Shewanella putrefaciens alone from aerobic growth in the oxic zone to thiosulfate reduction at the interface between sulfide-free and sulfitic zones of suboxic/anoxic marine basins and porewaters. With its versatile carbon metabolism and facultative nature, S. putrefaciens and organisms like it may well out compete sulfate- reducing bacteria for the consumption of thiosulfate and other sulfur intermediates in marine anoxic basins and sedimentary porewaters. These organisms may play a substantial role in the control of sulfur speciation in the marine environment. By utilizing organic carbon and producing sulfide, these organisms would be intimately involved in the poise of the chemocline. This project will provide new, basic scientific data on the molecular genetics of a widespread and very versatile anaerobic- respiring organism. By isolating and sequencing genes that code for sulfur reductase, this project will be able to study the regulatory mechanisms of gene expression. Manipulation of the genes in vivo will lead to a better understanding of the relationships between the various sulfur reduction pathways in S. putrefaciens and possibly other marine eubacteria. Genetic manipulation could also aid in comparing the regulation of sulfur reductase activity to that of nitrate reductase or Fe reductase in S. putrefaciens. This work will lead to the collaborative development of a probe for nonsulfate-reducing bacteria which utilize sulfur intermediates in natural sediments. Such a probe along with data on the mechanism of sulfur intermediate reduction could be used to explore the potential contribution of nonsulfate-reducing bacteria such as S. putrefaciens to the geochemistry of S, Fe, and C in a variety of suboxic/anoxic marine environments where these sulfur species exist.