Microbacterium luticocti sp. nov., isolated from sewage sludge compost

Abstract

Strain SC-087B(T), isolated from sewage sludge compost during a study of bacterial diversity in composts, was characterized. The isolate was a Gram-positive, short rod that was motile, catalase- and oxidase-negative and able to grow at 27-45 degrees C, pH 5.5-9.7 and in up to 10 % NaCl. The peptidoglycan was of the B2beta type, containing the characteristic amino acids ornithine, homoserine and hydroxyglutamic acid. The muramic acid residues of the peptidoglycan were partially glycolylated. The major cell-wall sugar was mannose; traces of xylose were also detected. The predominant fatty acids, comprising more than 70 % of the total, were anteiso-C(17 : 0) and anteiso-C(15 : 0), the major respiratory quinone was menaquinone-12 (MK-12) and the G+C content of the genomic DNA was 72 mol%. Based on analysis of the 16S rRNA gene sequence, the closest phylogenetic neighbours of strain SC-087B(T) were members of the family Microbacteriaceae, showing sequence similarity values of around 96 % with members of the species Microbacterium barkeri (96.0 %), Microbacterium gubbeenense (95.6 %) and Microbacterium indicum (95.7 %). The chemotaxonomic and phenotypic traits analysed supported the inclusion of this strain within the genus Microbacterium and the proposal of a novel species. The name Microbacterium luticocti sp. nov. is proposed and the type strain is SC-087B(T) (=DSM 19459(T)=CCUG 54537(T)).