Bacillus decisifrondis sp. nov., isolated from soil underlying decaying leaf foliage

Abstract

An aerobic bacterium, designated strain E5HC-32T, was isolated from soil underlying the decaying leaf litter of a slash pine forest located in south east Queensland, Australia. The strictly aerobic, motile rod-shaped cells (0.8–1.6x2.6–4.8 µm) produced subterminal spherical spores which distended the cells. Strain E5HC-32T grew optimally in 1 % trypticase soy broth (TSB) at 30 °C (temperature range for growth, 25–40 °C) and a pH of 8.4 (pH growth range, pH 7.1–9.1). Electron microscopic examination of negatively stained cells revealed the presence of peritrichous flagella and thin sections showed the presence of a typical Gram-positive type cell-wall ultrastructure. The strain was catalase-positive and oxidase-negative and metabolized pyruvic acid methyl ester, D-galactonic acid lactone, {alpha}-ketobutyric acid, {alpha}-ketovaleric acid, L-proline, L-alanine, urocanic acid, inosine, uridine, thymidine, glycerol, {alpha}-cyclodextrin, {alpha}-D-lactose, D-psicose, D-raffinose, L-rhamnose, D-sorbitol, turanose, cis-aconitic acid, {alpha}-hydroxybutyric acid, L-alaninamide and 2-aminoethanol. The G+C content of DNA was 41±1 mol% as determined by the thermal denaturation method. 16S rRNA gene sequence analysis revealed that strain E5HC-32T was placed equidistantly as a member of the class Bacilli, phylum Firmicutes, with Bacillus sphaericus DSM 28T and Bacillus odysseyi ATCC PTA-4993T (similarity of 93 %). In addition to its significant phylogenetic separation from its nearest relatives, strain E5HC-32T possessed phenotypic traits that also suggested that it represented a novel species, for which the name Bacillus decisifrondis sp. nov. is proposed. The type strain is E5HC-32T (=JCM 13601T=DSM 17725T).