Bacillusthaonhiensis sp. nov., a New Species, was Isolated from the Forest Soil of Kyonggi University by Using a Modified Culture Method

Using a new culture method for unculturable soil bacteria, we discovered a novel species, NHI-38T, from the forest soil of Kyonggi University campus, South Korea. It was a Gram-positive, rod-shaped, and endospore-forming bacterial strain. It grew over a wide pH range (6.5–9.5), with an optimum range of pH 7–9, and in a wide range of temperatures (15–60 °C), with an optimum range of 35–45 °C. Growth was possible at 0–2 % NaCl concentration, and the optimal range was between 0.5 and 1.5 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that this new species clustered within the genus Bacillus; it was closely related to “Bacillus abyssalis” SCSIO 15042T (98.86 %), B. methanolicus NCIMB 13113T (95.97 %), B. vietnamensis 15-1T (95.8 %), B. seohaeanensis BH724T (95.5 %), B. timonensis MM10403188T (95.33 %), and B.subtilis subsp. subtilis NCIB 3610T (94.87 %). The main fatty acid components of this bacterium were iso-C15:0 (35.92 %), summed feature 3 (C16:1ω7c/C16:1ω6c; 16.92 %), and anteiso-C15:0 (14.19 %). The predominant quinone in this bacterial strain was MK-7. The polar lipid profile primarily comprised phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. The genomic DNA G+C composition of the isolate was 40.7 mol%. The DNA–DNA hybridization results indicated that this strain was distinct from other Bacillus species, the degree of similarity being 50 % with “B. abyssalis”, 56 % with B. methanolicus, 47 % with B. vietnamensis, 43 % with B. seohaeanensis, 46 % with B. timonensis, and 32 % with B. subtilis. Based on our results, we regard strain NHI-38T as a novel member of the Bacillus genus, and we propose the name Bacillus thaonhiensis (=KACC 17216T = KEMB 9005-019T = JCM 18863T).