Huijboom Linda, Rashtchi Parisa, Tempelaars Marcel, Boeren Sjef, van der Linden Erik, Habibi Mehdi, Abee Tjakko
Food Microbiology, Wageningen University, Wageningen, 6708WG, the Netherlands.
Physics and Physical Chemistry of Foods, Wageningen University, Wageningen, 6708WG, the Netherlands.
Biofilm. 2024 Apr 22;7:100197. doi: 10.1016/j.bioflm.2024.100197. eCollection 2024 Jun.
is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.
是一种革兰氏阳性非运动性细菌，能够产生生物膜，有助于在一系列不同环境中在表面定殖。在本研究中，我们使用自行设计的流动装置，比较了WCFS1和CIP104448这两种菌株在静态和动态（流动）环境中产生生物膜的能力。这种流动装置使我们能够在孔中施加不均匀的流速分布。在静态和流动条件下，两种菌株的生物膜形成均发生在孔底部，在后一种条件下，与WCFS1相比，CIP104448由于细胞疏水性更高和初始附着效率增加，在孔壁处的生物膜形成也增加。荧光和扫描电子显微镜显示在流动条件下形成了开放的三维结构生物膜，CIP104448的生物膜包含活细胞和约30%的受损/死亡细胞，而WCFS1生物膜显示活细胞紧密聚集在一起。比较蛋白质组分析显示，各菌株的浮游细胞和静态生物膜细胞之间变化极小，表明24小时内生物膜形成仅仅是一个被动过程。值得注意的是，在WCFS1和CIP104448流动生物膜细胞中观察到的蛋白质组变化表明了相似和独特的反应，包括两种菌株代谢活性、氧化还原/电子传递和细胞分裂蛋白的变化，以及WCFS1独特的肌醇产生和CIP104448独特的氧化应激反应和DNA损伤修复。暴露于DNase和蛋白酶处理以及致死浓度的过氧乙酸显示流动生物膜具有最高的抗性。对于后者，CIP104448流动生物膜从孔底部和孔壁分散后甚至仍保持其高抗消毒性。综合所有结果突出表明，生物膜结构和基质以及细胞的生理状态和抗逆性因菌株而异，并且在流动条件下受到强烈影响。得出的结论是，考虑流动对生物膜形成的影响对于更好地理解包括食品加工环境在内的不同环境中的生物膜形成至关重要。
