Figure 3.

(a) Overview of the native spoVA operon (spoVA¹) in B. subtilis 168 and the spoVA^2mob operon found in B. subtilis strains producing spores with high-level heat resistance. (b) The calculated time to achieve a decimal reduction at 112.5 °C for spores of strains of B. subtilis that possess zero, one, two or three spoVA^2mob operons. (c) The calculated time to achieve a decimal reduction at 112.5 °C of spores of nine strains of B. licheniformis. Three strains possess one Tn1546 transposon (including the spoVA^2mob operon), and spores of these strains had significantly higher heat resistances than those of the six strains that did not contain this transposon. (d) The calculated time to achieve a decimal reduction at 112.5 °C of spores of nine strains of B. amyloliquefaciens. Two strains possess at least one Tn1546 transposon (including the spoVA^2mob operon), and produce spores with significantly higher heat resistances than the seven strains that did not carry the transposon.