Brevibacillus halotolerans sp. nov., isolated from saline soil of a paddy field.

ABSTRACT

Two novel aerobic bacteria, designated strains LAM0312T and LAM0313, were isolated from saline soil samples collected from a paddy field in Dezhou city, Shandong Province, China. Cells of these strains were Gram-stain-positive, sporogenous, rod-shaped and motile with peritrichous flagella. The optimal growth temperature and pH were 30 °C and pH 7.0-8.0. Strain LAM0312T was able to grow in the presence of 12 % (w/v) NaCl. The major fatty acids were anteiso-C15 0 and iso-C15 0. The dominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, glycolipids, five unidentitied lipids and phosphatidylmonomethylethanolamine. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The predominant menaquinone was identified as menaquinone-7. The G+C content of the genomic DNA of strains LAM0312T and LAM0313 was 45.0 and 46.0 mol%, respectively, as determined by the Tm method. 16S rRNA gene sequence similarity analysis indicated that the strains were closely related to Brevibacillus laterosporus DSM 25T and Brevibacillus fluminis JCM 15716T with 98.5 and 96.4 % sequence similarity, respectively. The DNA-DNA hybridization value between strain LAM0312T and LAM0313 was 92±0.6 % (reciprocal 90±0.2 %) and the value between strain LAM0312T and Brevibacillus laterosporus DSM 25T was 48±0.5 % (reciprocal 40±0.4 %). On the basis of the phenotypic, phylogenetic and chemotaxonomic characteristics, the two strains are proposed to represent a novel species of the genus Brevibacillus, for which the name Brevibacillus halotolerans sp. nov. is proposed. The type strain is LAM0312T (=ACCC 06527T=JCM 30849T).