Lin Lin, Du Rubing, Wu Qun, Xu Yan
Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, Laboratory of Brewing Microbiology and Applied Enzymology, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
ISME Commun. 2023 Apr 28;3(1):41. doi: 10.1038/s43705-023-00250-8.
Microbial interactions are important for the survival of species and the stability of the microbial ecosystem. Although bacteria have diverse conspecific genotypes in the natural microbial ecosystem, little is known about whether wild-type strains within species would interact with each other and how the intraspecific interaction influences the growth of the species. In this work, using Lactobacillus acetotolerans, a dominant species with diverse conspecific genotypes in natural food fermentation ecosystems as a case, we studied the interactions between different genotypic groups of this species. In interspecific and intraspecific pairwise cocultures, the growth of L. acetotolerans decreased, but the increase of the phylogenetic similarity would reduce this negative effect, indicating a potential intraspecific interaction of this species. Meanwhile, the strain classification method affected the analysis of intraspecific interactions, which can be efficiently demonstrated using 99.5% average nucleotide identity (ANI) as the strain-level classification method. Using this ANI classification method, we revealed the population fitness significantly increased in cocultures of different genotypic groups. Facilitation involving 11 amino acids was identified between different ANI genotypic groups, which was beneficial for increasing population fitness. This work revealed that wild-type conspecific strains could interact with each other via cooperative metabolic changes and benefit each other to increase fitness. It shed new light on the survival and stability of species in natural microbial ecosystems.
微生物相互作用对于物种的生存和微生物生态系统的稳定性至关重要。尽管在自然微生物生态系统中细菌具有多样的同种基因型，但对于物种内的野生型菌株是否会相互作用以及种内相互作用如何影响该物种的生长却知之甚少。在这项工作中，我们以嗜酸乳杆菌为例，它是自然食品发酵生态系统中具有多样同种基因型的优势物种，研究了该物种不同基因型组之间的相互作用。在种间和种内成对共培养中，嗜酸乳杆菌的生长下降，但系统发育相似性的增加会减少这种负面影响，表明该物种存在潜在的种内相互作用。同时，菌株分类方法影响种内相互作用的分析，使用99.5%的平均核苷酸同一性（ANI）作为菌株水平分类方法可以有效地证明这一点。使用这种ANI分类方法，我们发现不同基因型组的共培养中群体适应性显著增加。在不同的ANI基因型组之间鉴定出涉及11种氨基酸的促进作用，这有利于提高群体适应性。这项工作揭示了野生型同种菌株可以通过合作代谢变化相互作用并相互受益以提高适应性。它为自然微生物生态系统中物种的生存和稳定性提供了新的见解。
