| Bacillus thuringiensis has been used extensively as a biological insecticide to control a wide range of insect pests. Under conditions of nutrient limitation, this organism undergoes sporulation which is a unicellular differentiation process. Numerous genes responsible for different stages of spore formation have been characterized in Bacillus species. However, only a few sporulation genes have been identified in Bacillus thuringiensis.;Using transposon Tn917 insertional mutagenesis, a new sporulation gene was identified in Bacillus thuringiensis. Approximately 70% identity at both the DNA and the protein level was observed between the isolated sporulation gene and the spoVJ gene from Bacillus subtilis. The spoVJ mutant of Bacillus thuringiensis produced immature spores that were sensitive to heat and organic solvents but resistant to lysozyme. These phenomena were also observed in the Bacillus subtilis spoVJ mutant. Based on these results, it is concluded that the isolated gene is indeed the spoVJ gene from Bacillus thuringiensis. |
