RT Journal Article SR Electronic(1) A1 Liang, Liang A1 He, Xihong A1 Liu, Gang A1 Tan, HuarongYR 2008 T1 The role of a purine-specific nucleoside hydrolase in spore germination of Bacillus thuringiensis JF Microbiology, VO 154 IS 5 SP 1333 OP 1340 DO https://doi.org/10.1099/mic.0.2007/014399-0 PB Microbiology Society, SN 1465-2080, AB A homologous gene (iunH) of a putative nucleoside hydrolase (NH), which had been identified from the exosporia of Bacillus cereus and Bacillus anthracis spores, was cloned from Bacillus thuringiensis subsp. kurstaki. Disruption of iunH did not affect the vegetative growth and sporulation of Bacillus thuringiensis, but promoted both inosine- and adenosine-induced spore germination. The inosine- or adenosine-induced germination rate decreased when the wild-type iunH gene was overexpressed in Bacillus thuringiensis. The iunH gene product was characterized as a purine-specific NH. The kinetic parameters of IunH with inosine as substrate were K m=399±115 μM, k cat=48.9±8.5 s−1 and k cat/K m=1.23×105 M−1 s−1. The optimal pH and temperature for IunH were found to be pH 6 and 80 °C. Meanwhile, the specific activity of inosine hydrolase in intact spores of the wild-type strain with inosine as substrate was 2.89±0.23×10−2 μmol min−1 (mg dry wt)−1. These results indicate that IunH is important in moderating inosine- or adenosine-induced germination of Bacillus thuringiensis spores., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2007/014399-0