The domestication of the probiotic bacterium Lactobacillus acidophilus

Abstract

Lactobacillus acidophilus is a Gram-positive lactic acid bacterium that has had widespread historical use in the dairy industry and more recently as a probiotic. Although L. acidophilus has been designated as safe for human consumption, increasing commercial regulation and clinical demands for probiotic validation has resulted in a need to understand its genetic diversity. By drawing on large, well-characterised collections of lactic acid bacteria, we examined L. acidophilus isolates spanning 92 years and including multiple strains in current commercial use. Analysis of the whole genome sequence data set (34 isolate genomes) demonstrated L. acidophilus was a low diversity, monophyletic species with commercial isolates essentially identical at the sequence level. Our results indicate that commercial use has domesticated L. acidophilus with genetically stable, invariant strains being consumed globally by the human population.

Draft Genome Sequence of Probiotic Lactobacillus acidophilus Strain L-55 Isolated from a Healthy Human Gut

“…The genome has a G+C content of 34.6%. These features were very similar to those of 15 other sequenced L. acidophilus strains, except strain CFH, consistent with a previous report that L. acidophilus lacks genomic diversity compared to other L. acidophilus group species (6). The draft genome of L. acidophilus L-55 contained 1,884 predicted protein-coding genes, 1,760 (93%) of which were shared with the complete genome sequence of L. acidophilus NCFM (7).…”

The genomics of microbial domestication in the fermented food environment

“…Characterized by their ability to convert hexose sugars to lactic acid [21], LAB remain a diverse and prominent starter culture for many types of fermented foods and, reflecting their industrial importance, many LAB genomes have been sequenced [22–24]. Plants represent the original habitat of some LAB species used in dairy fermentation, yet isolates of plant and dairy derived Lactococcus lactis display divergent metabolic and growth characteristics on plant derived carbohydrates [25].…”

Effectiveness of probiotics in the management of inflammatory arthritis: a systematic review protocol

“…Bifidobacterium species are also well characterised. 62,63 Yeasts which have been applied as probiotic organisms are found within the kingdom of Eukaryotes. Yeasts are single-celled microorganisms classified as members of the fungus kingdom.…”