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The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective
Published on: June 16, 2022
Lactococcus cremoris subsp. sagaensis subsp. nov., Isolated from Naturally Fermented Yogurt
Lin Cheng1, Tian-Xue Wang1, Chun Yan Li2
1College of Life Sciences, Northeast Agricultural University, Harbin, 150030, PR China.
Current Microbiology
|July 29, 2026
Summary
Four lactic acid bacteria from fermented yogurt were identified as a new subspecies, Lactococcus cremoris subsp. sagaensis. This discovery expands the known diversity of lactic acid bacteria in traditional fermented foods.
Area of Science:
- Microbiology
- Bacteriology
- Food Science
Background:
- Lactic acid bacteria (LAB) are crucial in fermented foods.
- Traditional fermented products, like yogurt from Xizang, are sources of novel microbial diversity.
- Accurate taxonomic classification of LAB is essential for understanding their roles in food fermentation and safety.
Purpose of the Study:
- To characterize four LAB strains isolated from naturally fermented yogurt.
- To determine the taxonomic position of these novel strains.
- To propose a new subspecies if the strains represent a distinct phylogenetic and phenotypic group.
Main Methods:
- Polyphasic taxonomic approach.
- 16S rRNA, pheS, recA, and rpoB gene sequence analyses.
- Phylogenomic tree construction, Average Nucleotide Identity (ANI), and digital DNA-DNA hybridization (dDDH) calculations.
- Phenotypic characterization.
Main Results:
- Phylogenetic analyses placed the four strains (1030T, 1245, X2047, and 5 - 2) closely related to *Lactococcus cremoris*.
- ANI (97.8-98.1%) and dDDH (81.0-83.1%) values supported their classification within the *L. cremoris* species.
- Significant phenotypic differences were observed between the novel strains and existing *L. cremoris* subspecies.
- The strains were proposed as a novel subspecies, *Lactococcus cremoris* subsp. *sagaensis* subsp. nov., with strain 1030T as the type strain.
Conclusions:
- The isolated strains represent a distinct subspecies within *Lactococcus cremoris*.
- The novel subspecies, *Lactococcus cremoris* subsp. *sagaensis*, adds to the known biodiversity of LAB.
- This finding highlights the potential of traditional fermented foods as reservoirs for discovering new microbial taxa.
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