Comparison of Bacillus Species Identification Based on ITS and Fatty Acid Analysis

16 strains of Bacillus species isolated from soil were studied based on ITS sequences and fatty acids analysis. The accuracy rate of FA identification was 99%. Through biological software of SPSS and Mega cluster analysis, fatty acids were found to be better for Bacillus identification than ITS sequences. In this paper, we could make all the strains cluster together by FA, but ITS not. The major fatty acid of genus Bacillus was 15:0 ANTEISO and 15:0 ISO. The major FA ratio of three group were analyzed. Bacillus cereus group was special, its major FA was 15:0ISO,and 13:0ISO,but 15:0 ANTEISO had very lower profile. The ratio of 15:0ISO/15:0 ANTEISO in Bacillus cereus group was 5.6-7.9. The ratio of 15:0ISO/15:0 ANTEISO in Bacillus simplex group was 1/6. The ratio of 15:0ISO/15:0 ANTEISO in Bacillus megaterium was 4/5-5/4,strain FJAT-4500 was Bacillus pumilus,the ratio of15:0ISO/15:0 ANTEISO was 2. Bacillus pumilus was owed to Bacillus megaterium for similar ratio of 15:0ISO/15:0 ANTEISO, but the couple had different fatty acid profiles. The profile of 15:0ISO was lower than 15:0 ANTEISO in Bacillus subtilis group, and ratio was 1/3-2/3.