Microbacterium arborescens AGSB sp. nov., isolated from the rhizosphere of sand dune plant, Ipomoea pes caprae

Phenotypic and phylogenetic studies were performed for the facultative alkalophile from the rhizosphere of Ipomoea pes caprae, a plant growing on coastal sand dunes. The isolate was Gram positive and showed optimum growth at pH 10.5. Chemotaxonomic analysis revealed that the isolate contained type B1 peptidoglycans with L-lysine as the diamino acid; rhamnose and galactose were the cell wall sugars and belonged unambiguously to the genus Microbacterium. The major menaquinones were MK-11 and MK-12. The 16S rDNA sequence of the Microbacterium arborescens isolate was deposited in the GenBank with an accession number DQ287961. The phylogenetic and phenotypic distinctiveness of the strain indicates it as a novel Microbacterium sp., named as M. arborescens AGSB.   Key words: facultative alkaliphile, Microbacterium arborescens AGSB, Coastal sand dune vegetation, Ipomoea pes caprae, 16S rRNA sequencing.