Lactobacillus porci sp. nov., isolated from small intestine of a swine

Abstract

A facultatively anaerobic, Gram-stain-positive, catalase-negative, rod-shaped lactic acid bacterium, designated SG816T, was isolated from small intestine of a swine. Optimal growth occurred at 37°C and pH 7.0. Furthermore, growth occurred in NaCl up to 0.5% (w/v) but not at levels of salinity higher than 1%. Comparative 16S rRNA gene sequencing and the matrix-associated laser desorption/ionization-time-of-flight mass spectometry profiling showed that strain SG816T was closely related to Lactobacillus delbrueckiisubsp. bulgaricus KCTC 3635T (95.9%) and Lactobacillus delbrueckiisubsp. indicus JCM 15610T (95.9%), followed by other Lactobacillus delbrueckii subspecies (95.9-95.7%) and Lactobacillus equicursoris DSM 19284T (95.6%). A comparison of two housekeeping genes, RNA polymerase alpha subunit (rpoA) and phenylalanyl-tRNA synthase alpha subunit (pheS), revealed that strain SG816T formed a separate branch within the clade of the genus Lactobacillus. The DNA G+C content level of the strain SG816T was 51.5 mol%. The strain was homofermentative and produced d-lactic acid from glucose fermentation. The major cellular fatty acids (>10%) of the isolate were C18:1ω9c and C16:0. The peptidoglycan type was A4α l-Lys-d-Asp. On the basis of distinct phenotypic and phylogenetic properties, strain SG816T represents a novel species of the genus Lactobacillus, for which the name Lactobacillus porci sp. nov. is proposed. The type strain is SG816T (=KCTC 21090T=NBRC 112917T).