Department of Food, Aroma and Cosmetic Chemistry, Tokyo University of Agriculture, Hokkaido 099-2493, Japan.
NODAI Genome Research Center, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
Microb Genom. 2021 Apr;7(4). doi: 10.1099/mgen.0.000560.
is a well characterized lactobacillus for dairy fermentations that is also found in malt whisky fermentations. The two environments contain considerable differences related to microbial growth, including the presence of different growth inhibitors and nutrients. The present study characterized strains originating from dairy fermentations (called milk strains hereafter) and malt whisky fermentations (called whisky strains hereafter) by phenotypic tests and comparative genomics. The whisky strains can tolerate ethanol more than the milk strains, whereas the milk strains can tolerate lysozyme and lactoferrin more than the whisky strains. Several plant-origin carbohydrates, including cellobiose, maltose, sucrose, fructooligosaccharide and salicin, were generally metabolized only by the whisky strains, whereas milk-derived carbohydrates, i.e. lactose and galactose, were metabolized only by the milk strains. Milk fermentation properties also distinguished the two groups. The general genomic characteristics, including genomic size, number of coding sequences and average nucleotide identity values, differentiated the two groups. The observed differences in carbohydrate metabolic properties between the two groups correlated with the presence of intact specific enzymes in glycoside hydrolase (GH) families GH1, GH4, GH13, GH32 and GH65. Several GHs in the milk strains were inactive due to the presence of stop codon(s) in genes encoding the GHs, and the inactivation patterns of the genes encoding specific enzymes assigned to GH1 in the milk strains suggested a possible diversification manner of strains. The present study has demonstrated how strains have adapted to their habitats.
是一种经过充分研究的用于乳制品发酵的乳杆菌，也存在于麦芽威士忌发酵中。这两种环境包含与微生物生长相关的很大差异，包括存在不同的生长抑制剂和营养物质。本研究通过表型测试和比较基因组学对来自乳制品发酵（称为牛奶菌株）和麦芽威士忌发酵（称为威士忌菌株）的 菌株进行了表征。威士忌菌株比牛奶菌株更能耐受乙醇，而牛奶菌株比威士忌菌株更能耐受溶菌酶和乳铁蛋白。几种植物来源的碳水化合物，包括纤维二糖、麦芽糖、蔗糖、低聚果糖和水杨苷，通常仅由威士忌菌株代谢，而牛奶来源的碳水化合物，即乳糖和半乳糖，仅由牛奶菌株代谢。牛奶发酵特性也将这两组区分开来。一般的基因组特征，包括基因组大小、编码序列数量和平均核苷酸同一性值，将这两组区分开来。两组间碳水化合物代谢特性的差异与糖苷水解酶 (GH)家族 GH1、GH4、GH13、GH32 和 GH65 中完整特定酶的存在有关。由于编码 GH 的基因中存在终止密码子，牛奶菌株中的几种 GH 失去活性，并且分配给 GH1 的特定酶的基因失活模式表明了 菌株的可能多样化方式。本研究表明了 菌株如何适应其栖息地。
