Lacticaseibacillus huelsenbergensis sp. nov., isolated from grass silage and corn silage

Abstract

Two rod-shaped, facultative anaerobic, Gram-stain-positive lactic acid bacteria were isolated from corn silage and grass silage. They were characterized using a polyphasic approach and designated as HO 1656T and HO 0673. Analysis of 16S rRNA gene sequence of both strains indicated that they belong to the Lacticaseibacillus group. The most closely related species, Lacticaseibacillus casei DSM 20011T and Lacticaseibacillus zeae DSM 20178T, have digital DNA–DNA hybridization (dDDH) values of 63.9 and 53.4%, respectively, with the novel strains. In contrast, the dDDH value between strains HO 1656T and HO 0673 is 99.3 %, clearly showing that these two isolated strains belong to the same species. According to analysis of the housekeeping genes (dnaK, mutL and pheS), both strains form a distinct cluster within the Lacticaseibacillus group. Strains HO 0673 and HO 1656T could produce acid from d-arabinose, adonitol, ribose, rhamnose, dulcitol, sorbitol, turanose, l-fucose and l-arabitol, unlike their nearest phylogenetic neighbour L. casei DSM 20011T. The major cellular fatty acids of both strains are C16 : 0 and C18 : 1 ω9c. The G+C content of the genomic DNA of both strains is 48.0 mol%. Thus, strains HO 1656T and HO 0673 represent a novel species based on their chemotaxonomic, phenotypic and phylogenetic characteristics. The name Lacticaseibacillus huelsenbergensis sp. nov. is proposed with the type strain HO 1656T (=DSM 115425T=NCIMB 15466T).