López-García Elio, Benítez-Cabello Antonio, Tronchoni Jordi, Arroyo-López Francisco Noé
Department of Food Biotechnology, Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain.
Universidad Internacional de Valencia, Comunidad Valencia, Spain.
Front Microbiol. 2023 Sep 22;14:1264341. doi: 10.3389/fmicb.2023.1264341. eCollection 2023.
() is a species of lactic acid bacteria with a great relevance during the table olive fermentation process, with ability to form non-pathogenic biofilms on olive epidermis. The objective of this work is to deepen into the genetic mechanisms of adaptation of LPG1 during Spanish-style green table olive fermentations, as well as to obtain a better understanding of the mechanisms of adherence of this species to the fruit surface. For this purpose, we have carried out a transcriptomic analysis of the differential gene expression of this bacterium during 60 days of fermentation in both brine and biofilms ecosystems. In brines, it was noticed that a total of 235 genes from LPG1 were differentially expressed during course of fermentation and grouped into 9 clusters according to time-course analysis. Transport and metabolism of carbohydrates and amino acids, energy production, lactic acid and exopolysaccharide synthesis genes increased their expression in the planktonic cells during course of fermentation. On the other hand, expression of genes associated to stress response, bacteriocin synthesis and membrane protein decreased. A total of 127 genes showed significant differential expression between LPG1 planktonic (brine) and sessile (biofilms) cells at the end of fermentation process (60 days). Among the 64 upregulated genes in biofilms, we found genes involved in adhesion (), exopolysaccharide production (, and ), cell shape and elongation (), and well as prophage excision. Deeping into the genetic bases of beneficial biofilm formation by strains with probiotic potential will help to turn this fermented vegetable into a carrier of beneficial microorganisms to the final consumers.
（）是一种乳酸菌，在油橄榄发酵过程中具有重要意义，能够在油橄榄表皮形成非致病性生物膜。本研究旨在深入探究LPG1在西班牙式绿油橄榄发酵过程中的遗传适应机制，以及更好地理解该菌种附着于果实表面的机制。为此，我们对该细菌在盐水和生物膜生态系统中60天发酵过程中的差异基因表达进行了转录组分析。在盐水中，注意到LPG1共有235个基因在发酵过程中差异表达，并根据时间进程分析分为9个簇。碳水化合物和氨基酸的运输与代谢、能量产生、乳酸和胞外多糖合成基因在发酵过程中浮游细胞中的表达增加。另一方面，与应激反应、细菌素合成和膜蛋白相关的基因表达下降。在发酵过程结束时（60天），共有127个基因在LPG1浮游（盐水）细胞和固着（生物膜）细胞之间表现出显著差异表达。在生物膜中上调的64个基因中，我们发现了参与黏附（）、胞外多糖产生（、和）、细胞形状和伸长（）以及前噬菌体切除的基因。深入研究具有益生菌潜力的菌株形成有益生物膜的遗传基础将有助于把这种发酵蔬菜变成对最终消费者有益微生物的载体。
