Organization of Novel Marine Bacterial Structures Involved in the Degradation of Agar

ronald M. WeinerSteven W. hutchesesa博士获得了一项资助。马里兰大学的Weiner和Hutcheson研究了一种不寻常的海洋细菌Microbulbifer降解不溶性复杂碳水化合物（ICP）的遗传学和细胞生物学。这种细菌是从切萨皮克湾流域分离出来的，它有能力通过形成不寻常的表面结构来降解几乎所有已知的生物聚合物，包括ICP。这些表面结构似乎是有组织的酶联合体，使细菌能够有效地降解和处理这些非常稳定的聚合物。这种ICP的降解不受传统酶学的控制；最有效的降解涉及与有组织的酶团接触。以前从未有任何单一生物被报道有能力降解如此广谱的ICP。它也是除纤维素外唯一能通过这种机制降解ICP的微生物，也是在好氧细菌中首次观察到这种降解机制。这笔拨款将资助研究，以了解哪些基因和蛋白质参与了ICP、琼脂的降解，并确定琼脂降解结构是如何在细菌表面组装的。了解这一系统的遗传学知识，将为将复杂碳水化合物加工成有用的副产品，以及对每年产生的数十亿吨含有非常稳定ICP的农业、水产养殖和藻类废弃物进行生物修复提供新的工具。此外，人们对世界海洋中每年生产的250多亿吨ICP是如何被回收到生物圈中的知之甚少。因此，该研究在生物修复和/或废物处理方面具有潜在的应用价值，并可以为细菌的进化和这种海洋细菌在碳循环中的生态作用提供有价值的见解。

DEB-0109869Ronald M. WeinerSteven W. HutchesonA grant has been awarded to Drs. Weiner and Hutcheson of the University of Maryland to investigate the genetics and cell biology of insoluble complex carbohydrate (ICP) degradation by an unusual marine bacterium, Microbulbifer degradans. This bacterium was isolated from the Chesapeake Bay watershed and has the ability to degrade almost all known biological polymers, including ICP's, by forming unusual surface structures. These surface structures appear to be organized consortia of enzymes that allow the bacterium to efficiently degrade and process these very stable polymers. The degradation of such ICP's is not governed by conventional enzymology; the most efficient degradation involves contact with organized consortia of enzymes. Never before has any single organism been reported to have the capability to degrade such a broad spectrum of ICP's. It is also the only microorganism shown to degrade an ICP other than cellulose by this mechanism and the first observation of this degradative mechanism in an aerobic bacterium. This grant will fund research to understand what genes and proteins are involved in the degradation of the ICP, agar, and to determine how the agar-degrading structure is assembled on the bacterial surface. Knowledge of the genetics of this system should provide new tools for the processing of complex carbohydrates into useful byproducts and for bioremediation of the billions of tons of agricultural, aquacultural and algalcultural waste generated each year that contain very stable ICP's. In addition, little is known about how the annual production of the more than 25 billion tons of ICP's produced in the world's oceans are recycled into the biosphere. Thus, this research has potential applications in bioremediation and/or processing of waste products and could provide valuable insights into evolution of bacteria and the ecological role of this marine bacterium in the carbon cycle.