Microbial Genome Sequencing: Genomic Biodiversity in Hypersaline Environments

极端嗜盐的古菌生活在含有3-5M氯化钠的卤水池中，盐度、pH、温度、压力、营养物质等都是非常多样化和动态的。除了它们特有的嗜盐特性外，有些还具有嗜酸、嗜碱、嗜冷、嗜压或轻微嗜热的特性。极端嗜盐菌很容易在实验室中培养，是拥有完善基因工具的优秀实验系统。然而，到目前为止，只有一个极端嗜盐古细菌--盐生细菌NRC-1的基因组被测序。为了研究极端嗜盐菌的基因组多样性，我们计划对Haloarcula marismortui的基因组进行测序，Haloarcula marismortui是一种具有高分辨率核糖体结构的代谢多功能嗜盐菌。如果时间和资源允许，将对不同的菌株进行更多的基因组分析，包括亚洲钠盐，一种非色素的嗜碱细菌。梭状芽孢杆菌，一种能够在低至4摄氏度的温度下生长的嗜冷菌；Haloimplex carlsbadense，一种很可能的古代嗜盐菌，最近从二叠纪海水包裹体中分离出来，似乎是一种基因嵌合体；以及嗜盐杆菌种GRB，一种与NRC-1关系密切的菌株。测序将在系统生物学研究所进行，注释将在马里兰大学生物技术研究所海洋生物技术中心进行。该项目将更好地了解极端嗜盐生物的生物多样性，包括基因组结构和进化、对极端环境的适应以及横向基因转移。从长远来看，拟议的工作应该在生物技术方面提供新的应用，例如设计农作物的耐盐性和开发新的抗生素。这是一个微生物基因组测序奖，由国家科学基金会和农业部未来农业和食品系统倡议合作项目资助。

Extremely halophilic archaea inhabit brine pools containing 3-5 M NaCl, which areextraordinarily diverse and dynamic with respect to salinity, pH, temperature, pressure, nutrients,etc. In addition to their obligately halophilic character,some are also acidophilic, alkaliphilic,psychrophilic, barophilic, or slightly thermophilic. Extreme halophiles are easily cultured in thelaboratory and are excellent experimental systems with well-developed genetic tools. However,thus far, only a single genome from an extremely halophilic archaeon, Halobacterium speciesNRC-1, has been sequenced. In order to study the genomic diversity of extreme halophiles, weplan to sequence the genome of Haloarcula marismortui, a metabolically versatile halophile witha high-resolution ribosome structure. If time and resources permit, additional genomic analysiswill be conducted on diverse strains, including Natrialba asiatica, a non-pigmented alkaliphile.Halorubrum lacusprofundi, a psychrophile capable of growing at temperatures down to 4oC,Halosimplex carlsbadense, a likely ancient halophile recently isolated from a Permian brineinclusion, which appears to be a genetic chimera, and Halobacterium species GRB, a closelyrelated strain to NRC-1. Sequencing will be conducted at the Institute for Systems Biology andannotation will be done at the University of Maryland Biotechnology Institute, Center of MarineBiotechnology. This project will provide better understanding of biodiversity among extremehalophiles, including genome structure and evolution, adaptation to extreme environments, andlateral gene transfer. In the long term, the proposed work should provide novel applications inbiotechnology, e.g. engineering salt tolerance in crop plants and development of new antibiotics. This is a Microbial Genome Sequencing Award funded through a collaborative program between the National Science Foundation and the Department of Agriculture Initiative for Future Agriculture and Food Systems.