Xu Tao, Xiao Yue, Wang Hongchao, Zhu Jinlin, Lee Yuankun, Zhao Jianxin, Lu Wenwei, Zhang Hao
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Microorganisms. 2022 Nov 25;10(12):2332. doi: 10.3390/microorganisms10122332.
In natural settings, approximately 40-80% of bacteria exist as biofilms, most of which are mixed-species biofilms. Previous studies have typically focused on single- or dual-species biofilms. To expand the field of study on gut biofilms, we found a group of gut microbiota that can form biofilms well in vitro: subsp. , , , and . The increase in biomass and bio-volume of the mixed-species biofilm was confirmed via crystal violet staining, field emission scanning electron microscopy, and confocal laser scanning microscopy, revealing a strong synergistic relationship in these communities, with being the key biofilm-contributing species. This interaction may be related to changes in the cell number, biofilm-related genes, and metabolic activities. After quantifying the cell number using quantitative polymerase chain reaction, and were found to be the dominant flora in the mixed-species biofilm. In addition, this study analyzed biological properties of mixed-species biofilms, such as antibiotic resistance, cell metabolic activity, and concentration of water-insoluble polysaccharides. Compared with single-species biofilms, mixed-species biofilms had higher metabolic activity, more extracellular matrix, and greater antibiotic resistance. From these results, we can see that the formation of biofilms is a self-protection mechanism of gut microbiota, and the formation of mixed-species biofilms can greatly improve the survival rate of different strains. Finally, this study is a preliminary exploration of the biological characteristics of gut biofilms, and the molecular mechanisms underlying the formation of biofilms warrant further research.
在自然环境中，约40%-80%的细菌以生物膜的形式存在，其中大部分是混合物种生物膜。以往的研究通常集中在单一物种或双物种生物膜上。为了拓展肠道生物膜的研究领域，我们发现了一组在体外能很好地形成生物膜的肠道微生物群：亚种、、、和。通过结晶紫染色、场发射扫描电子显微镜和共聚焦激光扫描显微镜证实了混合物种生物膜的生物量和生物体积增加，揭示了这些群落中存在很强的协同关系，其中是生物膜形成的关键物种。这种相互作用可能与细胞数量、生物膜相关基因和代谢活动的变化有关。使用定量聚合酶链反应对细胞数量进行定量后，发现和是混合物种生物膜中的优势菌群。此外，本研究分析了混合物种生物膜的生物学特性，如抗生素抗性、细胞代谢活性和水不溶性多糖浓度。与单一物种生物膜相比，混合物种生物膜具有更高的代谢活性、更多的细胞外基质和更强的抗生素抗性。从这些结果可以看出，生物膜的形成是肠道微生物群的一种自我保护机制，混合物种生物膜的形成可以大大提高不同菌株的存活率。最后，本研究是对肠道生物膜生物学特性的初步探索，生物膜形成的分子机制有待进一步研究。
