Collaborative Research: MIP: Bacterial Interactions and Processes that Regulate Biodiversity on Marine Organic Particles

海水中细菌的丰富度和多样性在毫米级上变化，富含有机物质的颗粒代表着微生物活动的“热点”。值得注意的是，附着在颗粒物上的细菌与周围水中的细菌在基因上是不同的。定植颗粒的细菌使用特定物种的酶，以不同的速度分解有机内容物。由于海洋中的下沉颗粒是影响全球碳通量的主要机制，细菌在海洋颗粒上的代谢活动是生物地球化学循环中的一个重要因素。然而，关于调节海洋颗粒及其周围微生物多样性的变量知之甚少。这项研究将研究控制微尺度多样性的机制以及定植颗粒的海洋微生物之间的相互作用。一个特别的焦点将是微生物竞争，以及抗生素生产影响远洋细菌种群结构的可能性。将进行实验，以量化细菌拮抗相互作用在分子、单个细菌细胞、联合体和群落水平上的影响。根据荧光标记的拮抗菌株的反应，将测量微生物自然组合对模型颗粒的定植。将测量敏感菌株在靠近拮抗细菌的地方的生长和呼吸，以量化单细胞水平的相互作用。拮抗细菌产生的分子将被鉴定并测试它们对单个菌株和自然细菌群体的颗粒定植的影响。这是第一次深入研究细胞-细胞拮抗相互作用作为参与构建海洋微生物群落的微尺度因素。关于悬浮颗粒上微生物多样性的知识将得到提高，表面定植过程中涉及的相互作用和具体适应将得到更好的理解。这一努力将进一步融合海洋细菌化学生态、微生物多样性和生物地球化学循环之间的联系。本科生和研究生将接受化学生态学和分子微生物生态学的交叉培训，未来的教师将在为期一年的实习中学习分子和微生物技术和概念。

Bacterial abundance and diversity in ocean waters varies at the millimeter scale, and organic-rich particles represent "hot spots" for microbial activity. Remarkably, the bacteria found attached to particles are genetically distinct from those in the surrounding water. Bacteria that colonize particles employ species-specific enzymes that breakdown the organic content at different rates. Since sinking particles in the ocean represent a major mechanism influencing global carbon flux, bacterial metabolic activity on marine particles is an important factor in biogeochemical cycling. However, little is known regarding the variables that regulate microbial diversity on and around marine particles. This study will investigate mechanisms controlling micro-scale diversity and interactions among marine microorganisms colonizing particles. A specific focus will be microbial competition, and the possibility that pelagic bacterial population structures are influenced by the production of antibiotics. Experiments will be conducted to quantify the effects of bacterial antagonistic interactions at the molecular, single-bacteria cell, consortia, and community levels. The colonization of model particles by microbial natural assemblages will be measured in response to fluorescence-tagged antagonistic strains. Growth and respiration of sensitive strains in close proximity to antagonistic bacteria will be measured to quantify interactions at the single-cell level. Molecules produced by antagonistic bacteria will be identified and tested for their effects on particle colonization by single strains and natural consortia of bacteria. This is the first, in depth investigation to probe cell-cell antagonistic interactions as a micro-scale factor involved in structuring marine microbial communities. Knowledge of microbial diversity on suspended particles will be advanced, and the interactions and specific adaptations involved in surface colonization will be better understood. This endeavor will further fuse connections between marine bacterial chemical ecology, microbial diversity, and biogeochemical cycling. Undergraduate and graduate students will be cross-trained in chemical ecology and molecular microbial ecology, and future teachers will learn molecular and microbiological techniques and concepts during one-year internships.