采用 Jspecies 软件分析芽孢杆菌全基因组之间平均核苷酸同源性（ANI）的特征性。结果表明，芽孢杆菌属间、种间及亚种间两两菌株间 ANI 与其分类地位相关，具有明显属种特异性，其中芽孢杆菌科不同属之间的ANI 值分布于50％～65％；芽孢杆菌种间 ANI 值均低于95％，分布范围为65％～90％，加权平均数为70.12％，其中90％的 ANI 值低于70％；芽孢杆菌亚种间 ANI 值分布主要范围为90％～96％，占90％。因此，芽胞杆菌属间的ANI 鉴定标准建议定为50％～65％，芽胞杆菌种间的 ANI 鉴定标准建议定为65％～90％，芽胞杆菌亚种间的 ANI鉴定标准建议定为90％～96％。同时，基因组中的四核苷酸（Tetra）回归系数与 ANI 值具有相关性，表现明显属种特征性，回归拟合显示两者呈现一元二次方程关系，y ＝271-573.58 x ＋399.65 x2（R2＝0.9812），同时高于70％的ANI 值与相应的 Tetra 回归系数呈线性正相关，方程式为 y ＝178.58x -81.521（R2＝0.8767）。%The characteristic of average nucleotide identity (ANI) based on the whole genomes from Bacillus species in Bacillus - like genus was analyzed using the soft of Jspecies . The results showed that there have a species specificity based on the ANI distribution and which correlate with the relationship of taxonomic and evolutionary affinities .The ANI values computed from different Bacillus - like genus were below a 65% identity or above a 50%different in orthologous genes identity .The ANI values from different Bacillus species were below 94% with a wide range from 63.77 to 93.81 and the most of them ranging from 64.77% to 68.4% with the weighted average of 70.12% .The ANI value between subspecies was mainly ranged from 90% to 96% .Our results suggest that the ANI criterion of the identification for genus ,species and subspecies within Bacillus are 50% - 65% , 65% - 90%and 90% - 96% , respectively . Furthermore , Tetra regression index was correlated with the ANI value and displayed the species specificity . Regression fitting analysis showed that the equation of y = 271 - 573.56x +399.65 x2 with the correlation coefficient of 0.981 2 occurred between the Tetra and the ANI values above a identity of 70 were positive correlated with Tetra regression index with the equation of y = 178.58 x - 81.521 and the correlation coefficient of 0.876 7 .
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