Distribution and Some Properties of Bacterial Cholinesterase

Abstract

The distribution of cholinesterase activity among microorganisms was investigated using three kinds of thiocholine esters as substrate. Acetylthiocholine-hydrolyzing activity was present in some species belonging to the fluorescent group in genera Pseudomonas. Ps. aeruginosa species exhibited intense activity. An isolated strain, Ps. aeruginosa A-16, showed the highest activity specific for acetylcholine and acetylthiocholine, and was inhibited by neostigmine. Enzyme formation was induced by choline, and was repressed by glucose. Ps. polycolor IFO 3918, which could grow on butyrylcholine as well as acetylcholine as its carbon and nitrogen source, was found to produce two kinds of esterase which hydroyzed acetylcholine or butyrylcholine. These esterases of Ps. polycolor were fractionated with ammonium sulfate. One of them, the butyrylcholine-hydrolyzing enzyme, was inhibited by atropine and eserine, but was not sensitive to repression by glucose.