Microbacterium aerolatum sp. nov., isolated from the air in the 'Virgilkapelle' in Vienna.

Three rod-shaped, Gram-positive strains were isolated from the air of the chapel 'Virgilkapelle' in Vienna. A representative of these three strains, strain V-73T, shared the highest 16S rDNA sequence similarities with members of the genus Microbacterium, in particular Microbacterium foliorum, Microbacterium testaceum, Microbacterium esteraromaticum, Microbacterium keratanolyticum and Microbacterium arabinogalactanolyticum. The strains displayed almost identical biochemical and physiological characteristics and showed no differences in their protein patterns obtained after SDS-PAGE. On the basis of Fourier-transform infra-red (FT-IR) spectra and genomic fingerprints, the three strains were grouped together and separated from the other relevant members of the genus Microbacterium. The chemotaxonomic characteristics analysed, including polar lipids, quinone systems, cell wall composition and fatty acid profiles, were in good agreement with the characteristics described for the genus Microbacterium. The G+C content of the DNAs was determined to be in the narrow range 69.3-69.7 mol %. The results of DNA-DNA hybridization, biochemical/physiological characterization, ERIC-PCR-generated genomic fingerprints and FT-IR spectra demonstrated that the three isolates represent a novel species of the genus Microbacterium. The name Microbacterium aerolatum sp. nov. is proposed for the novel species, of which strain V-73T (= DSM 14217T = CCM 4955T) is the type strain.