Non-conventional yeasts are increasingly applied in fermented beverage industry to obtain distinctive products with improved quality. Among these yeasts, Lachancea thermotolerans has multiple features of industrial relevance, especially the production of l(+)-lactic acid (LA), useful for the biological acidification of wine and beer. Since few information is available on this peculiar activity, the current study aimed to explore the physiological and genetic variability among L. thermotolerans strains. From a strain collection, mostly isolated from wine, a huge phenotypic diversity was acknowledged and allowed the selection of a high (SOL13) and a low (COLC27) LA producer. Comparative whole-genome sequencing of these two selected strains and the type strain CBS 6340^T showed a high similarity in terms of gene content and functional annotation. Notwithstanding, target gene-based analysis revealed variations between high and low producers in the key gene sequences related to LA accumulation. More in-depth investigation of the core promoters and expression analysis of the genes ldh, encoding lactate dehydrogenase, indicated the transcriptional regulation may be the principal cause behind phenotypic differences. These findings highlighted the usefulness of whole-genome sequencing coupled with expression analysis. They provided crucial genetic insights for a deeper investigation of the intraspecific variability in LA production pathway.

非常规酵母越来越多地应用于发酵饮料行业，以获取具有更高品质的独特产品。在这些酵母中，耐热长春花具有多种与工业相关的特征，特别是生产l（+）-乳酸（LA），可用于葡萄酒和啤酒的生物酸化。由于很少有关于这种特殊活动的信息，因此本研究旨在探讨嗜热乳杆菌的生理和遗传变异性。株。从主要从葡萄酒中分离出的菌株中，我们认识到巨大的表型多样性，并允许选择高（SOL13）和低（COLC27）洛杉矶生产者。这两个选定菌株和CBS 6340 ^T型菌株的比较全基因组测序在基因含量和功能注释方面显示出高度相似性。尽管如此，基于靶基因的分析显示，在与LA积累有关的关键基因序列中，高生产者与低生产者之间存在差异。对核心启动子的更深入研究和ldh基因的表达分析，编码乳酸脱氢酶，表明转录调控可能是表型差异背后的主要原因。这些发现突出了全基因组测序与表达分析相结合的有用性。他们提供了关键的遗传学见解，可用于深入研究LA生产途径中的种内变异性。