Abstract
A moderately halophilic bacterial isolate has been found to possess high levels of enzymatic activity against several highly toxic organophosphorus compounds. The predominant enzyme, designated organophosphorus acid anhydrase 2, has been purified 1,000-fold to homogeneity and characterized. The enzyme is a single polypeptide with a molecular weight of 60,000. With diisopropylfluorophosphate as a substrate, the enzyme has optimum activity at pH 8.5 and 50 degrees C, and it is stimulated by manganese and cobalt.