Collaborative Research: EAGER: Salinity-based selection between sister clades of abundant coastal bacterioplankton

合作研究：EAGER：丰富的沿海浮游细菌姐妹进化枝之间基于盐度的选择

• 批准号: 1747722
• 负责人: Elizabeth Kujawinski
• 金额: $ 12.12万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1747722&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Salinity; based

Adaptation to new environments is a fundamental challenge for organisms, including microbes, in expanding their habitat range. It is important to investigate the cellular mechanisms underlying salinity tolerance in coastal bacterioplankton and their different responses to salinity in nature because (i) it will provide fundamental understanding for how microorganisms evolve to inhabit environments with different salinities, and (ii) alterations in coastal salinity are connected to climate change, so the way these alterations affect abundant coastal microorganisms also alters the biogeochemical cycling of, e.g., carbon. The project will examine microbial adaptations to salinity and determine how changes in salinity affect microbial metabolism using two closely related groups of abundant coastal bacterioplankton as model taxa. In addition, the research will continue and expand microbiology Course-based Undergraduate Research Experiences (mCUREs) in high-throughput cultivation and microbial characterization at the Lousiana State University. Sections of freshman biology laboratories will learn how to isolate, characterize, and molecularly identify microorganisms from local aquatic systems. mCURE sections will lead to newly isolated strains, genome sequences, and physiological data, these results will be published with the contributing students as co-authors. The relative success of mCURE sections will be assessed compared to traditional freshman biology sections. mCURE sections will offer unique opportunities for LSU students by creating excitement about research through discovery of new organisms and generating knowledge of the coastal habitats that are essential to the livelihood of the Gulf Coast.The evolutionary transition between salt- and freshwater environments occurs rarely in microorganisms. In one of the most abundant aquatic groups, SAR11, the transition between salt- and freshwater environments has happened only once: all freshwater SAR11 belong to subclade IIIb/LD12, which has also been found to inhabit coastal environments where salinity varies widely. The first reported isolates of the SAR11 freshwater clade LD12 and a member of the sister clade IIIa from the same region are now available. These pure culture representatives provide a powerful model for experimentally investigating adaptations to new environments in microorganisms, specifically (i) the genomic pathway and regulatory distinctions that arise during the evolutionary transition from marine to freshwater environments, and (ii) the physiological mechanisms that underlie the ecological restrictions imposed on microorganisms by ionic strength in coastal and freshwater environments. Furthermore, because these organisms have distinct differences in metabolic potential, the isolates facilitate testing (iii) the effects of changing coastal salinity on microbial contributions to other biogeochemical cycles, such as that for carbon. The project will test the hypothesis that the relative ionic strength tolerances between the sister lineages (LD12, IIIa) result from fundamental differences in metabolic flexibility at a genomic and regulatory level. To do so it will assess transcriptional and metabolic responses to varied ionic strength for both taxa and measure the distribution and activity of both groups in nature to translate laboratory findings to the field. The research will provide new understanding of LD12 habitat range and insights into how the "freshwater" lineage evolved from a SAR11 common ancestor. The project will also more generally provide important information on microbial responses to salinity changes in coastal systems and the evolutionary paths separating freshwater and marine microorganisms.This award is co-funded by Biological Oceanography, Division of Ocean Sciences in the Directorate for Geosciences and by Systems and Synthetic Biology, Division of Molecular and Cellular Biosciences in the Directorate for Biological Sciences.

适应新环境是对包括微生物在内的生物体扩大其栖息地范围的基本挑战。重要的是要研究沿海细菌泛素盐耐盐性耐受性的细胞机制及其对自然界中盐度的不同反应，因为（i）它将为微生物的发展方式提供基本的理解，以改变居住环境，改变了盐度的不同，因此（ii）沿海地区的变化也与沿海的变化相关，而沿海地区也会改变沿海的变化。例如碳的循环。该项目将检查对盐度的微生物适应，并确定盐度的变化如何使用两个密切相关的沿海细菌群作为模型分类群的两个密切相关的沿海细菌群密切相关的组影响微生物代谢。此外，这项研究将继续并扩大基于微生物学课程的本科研究经验（MCURE）在Lousiana州立大学的高通量种植和微生物表征方面。大一生物学实验室的部分将学习如何隔离，表征和分子从当地的水生系统中识别微生物。 MCURE部分将导致新隔离的菌株，基因组序列和生理数据，这些结果将与撰稿学生一起作为合着者发表。与传统的新生生物学部分相比，将评估MCURE部分的相对成功。 MCURE部分将通过发现新生物体引起对研究的兴奋，并为沿海栖息地引起人们对研究的兴奋，这对墨西哥湾沿岸至关重要的知识，为LSU学生提供独特的机会，这对墨西哥湾沿岸的生计至关重要。在最丰富的水生基团之一，SAR11中，盐和淡水环境之间的过渡仅发生了一次：所有淡水SAR11属于IIIB/LD12亚基，也发现盐度变化很大。现在可以使用同一地区的第一个报道的SAR11淡水进化枝LD12的分离株和一个来自同一地区的姐妹进化枝IIIA的成员。这些纯文化代表为实验研究对微生物的新环境的适应提供了一个强大的模型，特别是（i）在从海洋到淡水环境中的进化过渡期间出现的基因组途径和调节区别，以及（ii）生态限制对微观的生态限制构成的生物学机制和良好的生理机制构成了良好的生态限制。此外，由于这些生物在代谢潜力方面具有明显的差异，因此分离株有助于测试（iii）沿海盐度变化对微生物对其他生物地球化学周期的贡献（例如碳）的影响。该项目将检验以下假设：姊妹谱系之间的相对离子强度公差（LD12，IIIA）是由于基因组和调节水平的代谢灵活性的基本差异引起的。为此，它将评估分类单元对各种离子强度的转录和代谢反应，并测量两组在本质上的分布和活动，以将实验室发现转化为现场。这项研究将为LD12栖息地范围提供新的了解，并洞悉“淡水”谱系如何从SAR11共同祖先演变出来。该项目还将更普遍地提供有关沿海系统中盐度变化的微生物反应以及将淡水和海洋微生物分开的进化路径的重要信息。该奖由生物海洋学，地球科学局的海洋科学局共同资助，地球科学局以及系统和合成生物学，分子和蜂窝生物学生物科学生物科学委员会in Science in Sciagence in Sciagence in Science in Sci ci acies in Cacies in Science in Science in Caciate in System and Synthetic Biologicy。