Baudu Emmanuelle, Raspaud Eric, Fontagné-Faucher Catherine, Nait Chabane Yassine, Marcato-Romain Claire-Emmanuelle
IUT de Toulouse Auch Castres, LBAE URU 4565 (Laboratoire de Biotechnologies Agroalimentaire et Environnementale), Université de Toulouse, 24 rue d'Embaquès, Auch F-32000, France.
CNRS, Laboratoire de Physique des Solides, Université Paris-Saclay, Orsay 91405, France.
Curr Res Microb Sci. 2025 May 10;8:100403. doi: 10.1016/j.crmicr.2025.100403. eCollection 2025.
, a Gram-positive, endospore-forming bacterium, is ubiquitously found in diverse environments. Its resilience in harsh conditions and biofilm-forming capabilities make it a promising candidate for various agricultural applications. can also colonize the air-liquid interface by producing pellicles. Despite its potential, the characterization of biofilms remains underexplored. We investigated colony expansion and pellicle formation kinetic, followed by an analysis of the mechanical properties of the latter. This work focused on strain L-17, which produced two morphotypes on agar plate: 1) a (R) morphotype exhibiting quick colony expansion and 2) a (S) morphotype with a slower but extended colony expansion. The morphogenesis model of pellicle formation proposed in the literature for was applicable to , with few modifications for the smooth morphotype, which needed a longer period to spread over the surface. Mature pellicles were visually homogeneous and heterogeneous for R and S, respectively. Surprisingly, (i) their deformability by stretching was heterogeneous for the former and homogeneous for the latter; (ii) R produced a stiff pellicle whereas the entire smooth pellicle showed an elastic response. Taken together, results of this study confirmed that the existence of two distinct morphotypes within the same strain offers a unique opportunity to study the diversity of behaviors in , providing insights into its potential applications in agriculture and beyond. Moreover, they led to the hypothesis that surfactant production and flagella expression are differentiating factors between both morphotypes.
[细菌名称]是一种革兰氏阳性、形成芽孢的细菌，广泛存在于各种环境中。它在恶劣条件下的复原能力和形成生物膜的能力使其成为各种农业应用的有前途的候选者。[细菌名称]还可以通过产生菌膜在气液界面定殖。尽管有其潜力，但对[细菌名称]生物膜的表征仍未得到充分探索。我们研究了菌落扩展和菌膜形成动力学，随后分析了后者的力学性能。这项工作聚焦于[细菌名称]菌株L - 17，它在琼脂平板上产生两种形态类型：1）一种快速菌落扩展的（R）形态类型和2）一种菌落扩展较慢但范围更广的（S）形态类型。文献中提出的[细菌名称]菌膜形成的形态发生模型适用于[该细菌名称]，对于光滑形态类型只需进行少量修改，其在表面扩散需要更长时间。成熟菌膜在视觉上对于R形态类型是均匀的，对于S形态类型是不均匀的。令人惊讶的是，（i）它们通过拉伸的可变形性对于前者是不均匀的，对于后者是均匀的；（ii）R形态类型产生坚硬的菌膜，而整个光滑菌膜表现出弹性响应。综上所述，本研究结果证实同一菌株内两种不同形态类型的存在为研究[细菌名称]行为的多样性提供了独特机会，为其在农业及其他领域的潜在应用提供了见解。此外，这些结果引出了一个假设，即表面活性剂的产生和鞭毛的表达是两种形态类型之间的分化因素。
