Characterization, Genome Analysis and Probiotic Properties of L-Lactic Acid Producing Enterococcus Lactis FM11-1

Strain FM11-1 was isolated from flowers of Solanum torvum that were collected in Nakhon Si Thammarat Province, Thailand and was characterized using a polyphasic approach as Gram-positive, facultatively anaerobic with short chains and catalase-negative cocci. This strain produced L-lactic acid from glucose and was closely related to Enterococcus durans NBRC 100479^T, Enterococcus faecium NRIC 1145^T, Enterococcus hirae ATCC 9790^T, Enterococcus lactis LMG 25958^T and Enterococcus ratti DSM 15687^T (98.92-99.73 %) based on 16S rRNA gene sequence similarity. The draft genome of strain FM11-1 had 2,784,928 bp and contained 2,586 coding sequences, with a genomic G+C content of 38.07 mol%. Values of ANIb, ANIm and digital DNA-DNA hybridization (dDDH) between strain FM11-1 and the closest strain, E. lactis LMG 25958^T were 97.23%, 98.30% and 83.7%, respectively. The predominant cellular fatty acids were C_19:0 cyclo w8c and C_16:0. This strain was identified as Enterococcus lactis using polyphasic characterization and genome analysis. Strain FM11-1 contained genes involved in carbohydrate fermentation and specialty genes of antibiotic resistance. This strain showed adhesion ability (0.43±0.11) on Caco-2 cells but had no cytotoxicity against Caco-2, HepG2 and Vero cells.

Keywords: Enterococcus lactis; flower; genome analysis; polyphasic taxonomy; probiotics

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                                             E-mail: Somboon.T@chula.ac.th