Reanalysis of <i>Lactobacillus paracasei</i> Lbs2 Strain and Large-Scale Comparative Genomics Places Many Strains into Their Correct Taxonomic Position

oleh: Samrat Ghosh, Aditya Narayan Sarangi, Mayuri Mukherjee, Swati Bhowmick, Sucheta Tripathy

Format: Article
Diterbitkan: MDPI AG 2019-10-01

Deskripsi

<i>Lactobacillus paracasei</i> are diverse Gram-positive bacteria that are very closely related to <i>Lactobacillus casei,</i> belonging to the <i>Lactobacillus casei</i> group. Due to extreme genome similarities between <i>L. casei</i> and <i>L. paracasei</i>, many strains have been cross placed in the other group. We had earlier sequenced and analyzed the genome of <i>Lactobacillus paracasei</i> Lbs2, but mistakenly identified it as <i>L. casei</i>. We re-analyzed Lbs2 reads into a 2.5 MB genome that is 91.28% complete with 0.8% contamination, which is now suitably placed under <i>L. paracasei</i> based on Average Nucleotide Identity and Average Amino Acid Identity. We took 74 sequenced genomes of <i>L. paracasei</i> from GenBank with assembly sizes ranging from 2.3 to 3.3 MB and genome completeness between 88% and 100% for comparison. The pan-genome of 75 <i>L. paracasei</i> strains hold 15,945 gene families (21,5232 genes), while the core genome contained about 8.4% of the total genes (243 gene families with 18,225 genes) of pan-genome. Phylogenomic analysis based on core gene families revealed that the Lbs2 strain has a closer relationship with <i>L. paracasei</i> subsp. <i>tolerans</i> DSM20258. Finally, the in-silico analysis of the <i>L. paracasei</i> Lbs2 genome revealed an important pathway that could underpin the production of thiamin, which may contribute to the host energy metabolism.