State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
FEMS Microbiol Ecol. 2021 Jul 13;97(8). doi: 10.1093/femsec/fiab096.
Bacterial species in the human gut predominantly exist in the form of mixed-species biofilms on mucosal surfaces. In this study, the biofilm-forming ability of many human gut bacterial strains (133 strains recovered from human faeces) on mucin-coated and non-coated polystyrene surfaces was determined. A significant variation (P < 0.05) in the biofilm-forming ability of many bacterial species on both surfaces was noticed. Based on some preliminary trials, four bacterial species were selected (Bifidobacterium bifidum, Bifidobacterium longum subsp. infantis, Parabacteroides distasonis and Bacteroides ovatus), which could not form any abundant biofilm individually under the in vitro conditions investigated, but produced abundant biofilms when co-cultured in different combinations of two, three and four species, giving an evidence of synergistic interactions in multispecies biofilm formation. There was a 4.74-fold increase in the biofilm mass when all strains developed a biofilm together. Strain-specific qPCR analysis showed that B. bifidum was the most dominant species (56%) in the four-species biofilm after 24 h, followed by B. longum subsp. infantis (36.2%). Study involving cell free supernatant of the cooperating strains showed that cell viability as well as physical presence of cooperating cells were prerequisites for the observed synergy in biofilms. The molecular mechanism behind these interactions and subsequent effects on the functionality of the strains involved were not determined in our study but merit further work.
肠道细菌主要以混合物种生物膜的形式存在于黏膜表面。在这项研究中，测定了许多人类肠道细菌菌株（从人类粪便中回收的 133 株）在粘蛋白涂层和非涂层聚苯乙烯表面上形成生物膜的能力。在两种表面上，许多细菌物种的生物膜形成能力存在显著差异（P<0.05）。根据一些初步试验，选择了四种细菌（双歧双歧杆菌、长双歧杆菌亚种婴儿双歧杆菌、副拟杆菌和卵形拟杆菌），它们在研究的体外条件下单独不能形成任何丰富的生物膜，但在两种、三种和四种物种的不同组合中共同培养时会产生丰富的生物膜，证明了在多物种生物膜形成中存在协同相互作用。当所有菌株一起形成生物膜时，生物膜质量增加了 4.74 倍。菌株特异性 qPCR 分析显示，在四种菌株的生物膜中，双歧双歧杆菌是最优势的物种（56%），其次是长双歧杆菌亚种婴儿双歧杆菌（36.2%）。涉及合作菌株无细胞上清液的研究表明，细胞活力以及合作细胞的物理存在是观察到生物膜协同作用的前提条件。在我们的研究中，没有确定这些相互作用背后的分子机制以及对所涉及菌株功能的后续影响，但值得进一步研究。
