Ellis Elizabeth, Fulte Sam, Boylan Skyler, Flory Alaina, Paine Katherine, Lopez Sophia, Allen Grace, Warya Kanwar, Ortiz-Merino Javier, Blacketer Sadie, Thompson Samantha, Sanchez Sierra, Burdette Kayla, Duchscherer Audrey, Pinkham Nick, Shih Joseph D, Rahn-Lee Lilah
Department of Biology, William Jewell College, Liberty, Missouri, USA.
Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, USA.
J Bacteriol. 2025 Jun 24;207(6):e0007525. doi: 10.1128/jb.00075-25. Epub 2025 May 14.
Although bacteria exist in complex microbial communities in the environment, their features and behavior are most often studied in monoculture. While environmental enrichments or complex co-cultures with tens or hundreds of members might more accurately represent the natural communities of bacteria, we sought to create simple pairs of organisms to learn what conditions create successful co-culture and how bacteria change transcriptionally when a partner species is present. We grew two pairs of organisms in co-culture, and and and . At first, both co-cultures failed, with one organism outcompeting the other. However, through manipulating media and environmental conditions, we created co-cultures with stable member ratios over many generations for each community. We then show that changes in the expression of metabolic genes are present in all studied species, with key catabolic and anabolic pathways often upregulated in the presence of another organism. These changes in gene expression fail to occur in conditions that will not lead to successful co-culture, suggesting they are essential for adapting to and surviving in the presence of others.
In 1882, Robert Koch and Fanny Hesse developed the agar plate, which enabled microbiologists to separate individual microbial cells from each other and create monocultures of a single strain of bacteria. This powerful tool has been used in the almost 150 years since to develop a robust understanding of how bacterial cells are structured, how they manage and process their information, and how they respond to the environment to produce behaviors that match their circumstances. We were curious about how the behavior of bacteria, as measured by their gene expression, changes between well-studied monoculture conditions and co-culture. We found that only specific growth conditions permit co-culture and that bacteria change their metabolic strategies in the presence of a partner.
尽管细菌存在于环境中的复杂微生物群落中，但它们的特征和行为大多是在单一培养中进行研究的。虽然环境富集培养或与数十或数百个成员的复杂共培养可能更准确地代表细菌的自然群落，但我们试图创建简单的生物对，以了解哪些条件能促成成功的共培养，以及当存在伙伴物种时细菌在转录水平上会如何变化。我们将两对生物进行共培养，即[具体生物对1]和[具体生物对2]。起初，两种共培养都失败了，其中一种生物胜过了另一种。然而，通过操纵培养基和环境条件，我们为每个群落创造了在许多代中成员比例稳定的共培养物。然后我们表明，所有研究的物种中都存在代谢基因表达的变化，在有另一种生物存在时，关键的分解代谢和合成代谢途径通常会上调。在不会导致成功共培养的条件下，这些基因表达的变化不会发生，这表明它们对于在其他生物存在的情况下适应和生存至关重要。
1882年，罗伯特·科赫（Robert Koch）和范妮·黑塞（Fanny Hesse）发明了琼脂平板，这使微生物学家能够将单个微生物细胞彼此分离，并创建单一菌株的细菌纯培养物。自那以后的近150年里，这个强大的工具被用于深入了解细菌细胞的结构、它们如何管理和处理信息，以及它们如何响应环境以产生与其环境相匹配的行为。我们好奇的是，通过基因表达来衡量的细菌行为在经过充分研究的单一培养条件和共培养之间会如何变化。我们发现只有特定的生长条件允许共培养，并且细菌在有伙伴存在时会改变其代谢策略。
