Interrogating laboratory-adapted strains of Bacillus subtilis to elucidate the selective pressures of laboratory conditions on multicellular bacterial behaviors

摘要 细菌执行各种影响其发病机制和环境作用的多细胞过程。 在自然环境中。然而，很明显，当这些生物体在 在实验室，随着时间的推移，它们会经历重大的基因改造。这个项目的长期目标是 了解实验室环境本身如何选择和/或改变健身效果 多细胞细菌行为，包括生物膜的形成、运动和次级色素的分泌 代谢物。然而，这些特征是至关重要的，因为它们对细菌的致病机制和它们的 积极或消极的环境影响。PI将对实验室适应的枯草杆菌菌株进行表征 分离自在普通实验室培养基中生长了大约300代的种群。 这些菌株在运动性、生物膜形成和色素产生方面都有明显的变化。这样做的目的是 该项目将使用这些实验室适应的菌株来：1)确定导致急性呼吸道综合征的分子机制(S)。 不寻常的“社交游泳”行为在一个实验室适应了品系，令人惊讶的是，这种品系活跃地形成 肉汤培养物中的大的多细胞聚集体。2)量化实验室培养中移动性的成本和收益； 正如初步数据显示的那样，许多实验室适应的菌株降低或改变了运动能力。3)确定 一株实验室适应菌株和野生型枯草杆菌菌株NCIB3610在不同的条件下产生的色素 实验室条件，并量化这些色素的生产对实验室健康的影响。4) 确定导致色素产生的环境和代谢途径 天然产物枯草芽孢杆菌，重点是普尔樱草素；并测定了色素之间的关系 生产和生物膜的形成。这项研究具有创新性，因为社会游泳是一种新的表型， 可以帮助我们理解多细胞的进化。此外，初步数据确定了差异 在我们的观察和目前的模型之间，解释了色素PulCherrimin在芽孢杆菌中的作用 该色素在枯草杆菌中的作用尚需进一步研究。这事很重要 由于PulCherrimin在生物被膜形成中的作用及其抗菌性能。此外，这项工作将 为在实验室中研究多细胞过程(如运动性)的科学家提供见解，因为这项工作将 确定实验室环境本身可能产生的影响。此外，这项拟议项目将加强 锡耶纳学院的研究环境显著改善，为更多的本科生提供支持 在研究方面，增加研究能力，由于锡耶纳的学生人数，将有助于实现更大的目标 增加STEM的多样性。

Abstract Bacteria carry out a variety of multicellular processes that influence their pathogenesis and environmental roles in the natural environment. However, it has become apparent that when these organisms are studied in the laboratory, they undergo significant genetic modification over time. The long-term goal of this project is to understand how the laboratory environment itself selects against and/or changes the fitness effects of multicellular bacterial behaviors including biofilm formation, motility, and the secretion of pigmented secondary metabolites. These features, however, are critical due to their influence on bacterial pathogenesis and their positive or negative environmental effects. The PI will characterize laboratory adapted strains of B. subtilis isolated from populations that grew in the common laboratory medium LB for approximately 300 generations. These strains have distinctive changes in motility, biofilm formation, and pigment production. The goals of this project are to use these laboratory-adapted strains to: 1) Identify the molecular mechanism(s) that causes an unusual “social swimming” behavior in one laboratory adapted strain, as surprisingly, this strain actively forms large, multicellular aggregates in broth culture. 2) Quantify the costs and benefits of motility in laboratory culture, as preliminary data suggest many laboratory-adapted strains have reduced or altered motility. 3) Identify the pigments produced by a laboratory-adapted strain and the wildtype B. subtilis strain NCIB3610 under distinct laboratory conditions, and quantify the effects of the production of these pigments on fitness in the laboratory. 4) Identify the environmental and metabolic pathways responsible for the triggering of production of pigmented natural products by Bacillus subtilis, focusing on pulcherrimin; and determine the relationship between pigment production and biofilm formation. This research is innovative because social swimming is a novel phenotype that could inform understanding of the evolution of multicellularity. Also, preliminary data identify discrepancies between our observations and the current model explaining the role of the pigment pulcherrimin in Bacillus subtilis, suggesting that additional research on the role of this pigment in B. subtilis is needed. This is important due to the role of pulcherrimin in biofilm formation and its antimicrobial properties. Additionally, this work will provide insights to scientists studying multicellular processes like motility in the laboratory, as this work will identify probable effects of the laboratory environment itself. Furthermore, this proposed project will enhance the research environment at Siena College significantly by providing support to involve more undergraduate students in research, increasing research capacity, and due to Siena’s student population, will aid in the larger goal of increasing diversity in STEM.