Marine Biotechnology Fellowship: Molecular Genetics of Ammonium Assimilation in the Oligotrophic Marine Bacterium, RM-1

9321698 CIFUENTES这个研究奖学金在海洋生物技术将调查的酶，谷氨酰胺合成酶在一个真正的海洋细菌的分子遗传学和生物化学，以更好地了解海洋浮游细菌的氮代谢。本研究拟从海洋细菌RM-1中克隆glnA基因并进行序列测定。RM-1是一种需氧专性寡营养细菌，由费尔班克斯的阿拉斯加大学的D Button使用稀释培养技术分离。这种技术有助于分离最丰富的菌株，而不是那些最容易在实验室培养的菌株。如果glnA的克隆和测序按计划进行，那么在大肠杆菌中表达的RM-1谷氨酰胺合成酶将在2000年获得成功。大肠杆菌突变体将被纯化并用于产生用于探测天然样品中谷氨酰胺合成酶活性的抗血清。本研究金开发的代谢功能探针将应用于正在进行的墨西哥湾氮地球化学合作研究。了解典型海洋细菌氮代谢关键酶的分子遗传学将为贫营养环境中的生理功能提供新的信息，并提高对氮循环中重要生态相互作用和生态地球化学过程的理解。 ***

9321698 CIFUENTES This Research Fellowship in Marine Biotechnology will investigate the molecular genetics and biochemistry of the enzyme, glutamine synthetase in a true marine bacterium to better understand nitrogen metabolism of marine bacterioplankton. The glnA gene will be cloned from the marine bacterium strain RM-1 and sequenced. RM-1, an aerobic obligate oligrotrophic bacterium, was isolated using dilution culture techniques by D Button of the University of Alaska, Fairbanks. This technique helps isolate the most abundant strain rather than those which are most easily cultured in the laboratory. If the cloning and sequencing of glnA proceeds on schedule, than RM-1 glutamine synthetase expressed in an E. coli mutant will be purified and used to generate anitsera for probing of the glutamine synthetase activity in natural samples. Probes of metabolic function developed in this Fellowship will be applied to an on-going collaborative study of nitrogen biogeochemistry in the Gulf of Mexico. Understanding the molecular genetics of a key enzyme in the nitrogen metabolism of a typical marine bacterium will provide new information on physiological function in oligotrophic environments and improve the understanding of important ecological interactions and biogeochemical processes in N-cycling. ***