Complete Genome Sequence of Lactobacillus harbinensis Strain NSMJ42, Isolated from Makgeolli, a Traditional Korean Alcoholic Beverage

Genotypic Stability of Lactic Acid Bacteria in Industrial Rye Bread Sourdoughs Assessed by ITS-PCR Analysis

Sourdough bread production relies on metabolically active starters refreshed daily with flour and water. The stability of sourdough microbial strains is crucial for consistent bread quality. However, many bakeries lack information on the persistence of starter cultures in ongoing sourdough production. Consequently, there is growing interest in identifying microbial strains from regularly used sourdoughs that possess good functional properties and resist changes in the complex growth environment. This study aimed to evaluate the composition and stability of lactic acid bacteria (LAB) in industrial wheat (WS) and rye (RS) sourdoughs propagated over a long period. LAB isolates (n = 66) from both sourdoughs, sampled over four seasons, were identified using phenotypic methods and genotyped via ITS-PCR and ITS-PCR/TaqI restriction analysis. Eight LAB species were detected, with Lactiplantibacillus plantarum being the most dominant and stable. Nineteen distinct LAB genotypes were observed, highlighting significant diversity. The presence of identical LAB genotypes in both sourdoughs suggests microbial transfer through the environment and bakery workers. LAB in RS were found to be more stable than those in WS. These findings underscore the importance of monitoring microbial stability and diversity in industrial sourdough production to maintain consistent bread quality.

Companilactobacillus pabuli sp. nov., a lactic acid bacterium isolated from animal feed

A Gram-positive, facultative anaerobic, catalase-negative, non-motile, non-spore-forming and rod-shaped lactic acid bacterium strain, denoted as NFFJ11^T and isolated from total mixed fermentation feed in the Republic of Korea, was characterized through polyphasic approaches, including sequence analyses of the 16S rRNA gene and housekeeping genes (rpoA and pheS), determination of average nucleotide identity and in silico DNA-DNA hybridization, fatty acid methyl ester analysis, and phenotypic characterization. Phylogenetic analyses based on 16S rRNA, rpoA and pheS gene sequences revealed that strain NFFJ11^T belonged to the genus Companilactobacillus. The 16S rRNA gene sequence of strain NFFJ11^T exhibited high similarity to Companilactobacillus formosensis S215^T (99.66 %), Companilactobacillus farciminis Rv4 na^T (99.53 %), Companilactobacillus crustorum LMG 23699^T (99.19 %), Companilactobacillus futsaii YM 0097^T (99.06 %), Companilactobacillus zhachilii HBUAS52074^T (98.86 %) and Companilactobacillus heilongiiangensis S4-3^T (98.66 %). However, average nucleotide identity and in silico DNA-DNA hybridization values for these type strains were in the range of 79.90-92.93 % and 23.80-49.30 %, respectively, which offer evidence that strain NFFJ11^T belongs to a novel species of the genus Companilactobacillus. The cell-wall peptidoglycan type was A4α (l-Lys-d-Asp) and the G+C content of the genomic DNA was 35.7 mol%. The main fatty acids of strain NFFJ11^T were C_18 : 1  ω9c (43.3 %), C_16 : 0 (20.1 %) and summed feature 7 (18.3 %; comprising any combination of C_19 : 1  ω7c, C_19 : 1  ω6c and C_19 : 0 cyclo ω10c). Through polyphasic taxonomic analysis, it was observed that strain NFFJ11^T represents a novel species belonging to the genus Companilactobacillus, for which the name Companilactobacillus pabuli sp. nov. is proposed. The type strain is NFFJ11^T (= KACC 21771^T= JCM 34088^T).