A novel species of lactic acid bacteria, Ligilactobacillus pabuli sp. nov., isolated from alfalfa silage
Masanori Tohno, Yasuhiro Tanizawa, Hiroyuki Sawada, Mitsuo Sakamoto, Moriya Ohkuma, Hisami Kobayashi
Abstract
In this study, we isolated a novel strain of lactic acid bacteria, AF129 T , from alfalfa silage prepared locally in Morioka, Iwate, Japan. Polyphasic taxonomy was used to characterize the bacterial strain. The bacterium was rod-shaped, Gram-stain-positive, non-spore-forming and catalase-negative. The strain grew at various temperatures (15–40°C) and pH levels (4.0–8.0). The optimum growth conditions were a temperature of 30°C and a pH of 6.0. AF129 T exhibited growth at salt (NaCl) concentrations of up to 6.5 % (w/v). The G+C content of the strain’s genomic DNA was 41.5 %. The major fatty acids were C 16 : 0 , C 18 : 1 ω9 c , C 19 : 0 cyclo ω8 c and summed feature 8. 16S rRNA gene sequencing revealed that AF129 T represents a member of the genus Ligilactobacillus and it has higher sequence similarities with Ligilactobacillus pobuzihii (98.4 %), Ligilactobacillus acidipiscis (97.5 %) and Ligilactobacillus salitolerans (97.4 %). The digital DNA–DNA hybridization values for AF129 T and phylogenetically related species of the genus Ligilactobacillus ranged from 19.8% to 24.1%. The average nucleotide identity of the strain with its closely related taxa was lower than the threshold (95 %–96 %) used for species differentiation. In the light of the above-mentioned physiological, genotypic, chemotaxonomic and phylogenetic evidence, we confirm that AF129 T represents a member of the genus Ligilactobacillus and constitutes a novel species; we propose the name Ligilactobacillus pabuli sp. nov. for this species. The type strain is AF129 T =MAFF 518002 T =JCM 34518 T =BCRC 81335 T .