Microbacterium amylolyticum sp. nov., isolated from soil from an industrial waste site

Abstract

A Gram-staining-positive, heterotrophic, aerobic, non-motile, non-endospore-forming, yellow-coloured rod, designated strain N5T, was isolated from a soil sample collected at an industrial waste site in Noida, on the outskirts of Delhi, India. In phylogenetic analyses based on 16S rRNA gene sequences, strain N5T was most closely related to members of established species in the genus Microbacterium (with sequence similarities of approximately 94.0–97.6 %), particularly Microbacterium indicum LMG 23459T (97.59 %) and Microbacterium gubbeenense LMG 19263T (97.18 %). In DNA–DNA hybridization studies, however, none of the DNA–DNA relatedness values between strain N5T and members of the genus Microbacterium exceeded 11.3 %. The genomic DNA G+C content of the novel strain was 68 mol%. The chemotaxonomic characteristics of strain N5T, which had MK-11 and MK-10 as its major menaquinones and anteiso-C15 : 0 (45 %), anteiso-C17 : 0 (37 %), iso-C16 : 0 (8.5 %) and C16 : 0 (4.5 %) as its predominant fatty acids, were consistent with classification in the genus Microbacterium . Peptidoglycan in the novel strain, which contained ornithine, alanine, glycine, homoserine, glutamic acid, 3-hydroxyglutamic acid, muramic acid and traces of N-glycolyl residues, was of type B2β. The polar lipid profile of strain N5T comprised diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The novel strain’s major cell-wall sugars were glucose and galactose. Based on the phylogenetic, DNA–DNA hybridization, chemotaxonomic and phenotypic data, strain N5T represents a novel species within the genus Microbacterium for which the name Microbacterium amylolyticum sp. nov. is proposed; the type strain is N5T ( = DSM 24221T = CCM 7881T).