A strain of bacteria XT-025 for producing ornithine by arginase was screened from soil.This strain was identified as Bacillus thuringiensis according to its morphology,physiological characteristics and 16S ribosomal RNA gene sequence.This is the first report of the production of ornithine by this microbe.The optimum culture time was found to be 24 h with a cushion solution composed of 0.3 mol/L carbonate and V(Na2CO3)∶V(NaHCO3)=8∶2.It was found that Mn2+ can activate arginase and by adding appropriate conce...