When inoculated on the surface of soft agar containing nutrients, many species of motile bacteria can grow into a dense population and spread across the surface by a form of motility called swarming. We study the swarming behavior of Enterobacter sp. SM3, a species of bacteria that exhibits a swarm-dependent reduction in symptoms associated with inflammatory bowel disease (IBD). In this report, we focus on how incorporating mucin into agar gels affects the swarming motility of SM3. We found that mucin enhances SM3′s swarm rate, defined as the rate at which bacteria cover an agar surface. We show that mucin promotes wetting of aqueous droplets by inhibiting the pinning of the contact line, which is caused by structural or chemical inhomogeneity. This effect results in a more slippery agar surface. As a macromolecular biosurfactant, mucin promotes an increase in the bacterial swarm rate on agar by masking surface inhomogeneities, thereby inhibiting contact line pinning and allowing for better spreading of an expanding bacterial swarm.

中文翻译：

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粘蛋白通过使琼脂表面更光滑来促进细菌聚集


当接种在含有营养物质的软琼脂表面时，许多种类的运动细菌可以生长成密集的种群，并通过一种称为蜂群的运动形式传播到整个表面。我们研究了肠杆菌属 SM3 的蜂群行为，这是一种表现出与炎症性肠病 （IBD） 相关的症状呈蜂群依赖性减轻的细菌。在本报告中，我们重点介绍将粘蛋白掺入琼脂凝胶中如何影响 SM3 的蜂群运动。我们发现粘蛋白增强了 SM3 的蜂群速率，SM3 的蜂群速率定义为细菌覆盖琼脂表面的速率。我们表明，粘蛋白通过抑制由结构或化学不均匀性引起的接触线的固定来促进水性液滴的润湿。这种效果会导致琼脂表面更滑。作为一种大分子生物表面活性剂，粘蛋白通过掩盖表面不均匀性来促进琼脂上细菌群速率的增加，从而抑制接触线固定并允许扩大的细菌群更好地传播。