Quantitation by enzyme immunoassay of spirosin from Lactobacillus reuteri and Escherichia coli

Abstract Three EIA methods (Direct, Indirect and Sandwich EIA) were studied to quantify spirosin in Lactobacillus reuteri and Escherichia coli cultured under various conditions in an attempt to get some insight into the function of spirosome. Both Direct and Indirect EIA were suited well for the quantitation of L. reuteri spirosin while Direct EIA was appropriate for spirosin of E. coli . Sandwich EIA could not be applied successfully in either case. By use of these methods, the amounts of spirosin produced by E. coli were determined to be 1.4, 36.2 and 46.5 μg per mg protein of the cell lysate under aerobic, standing and anaerobic culture conditions, respectively. Since the production profile of spirosin coincided entirely with that of alcohol dehydrogenase, these findings supported the identity of spirosin to alcohol dehydrogenase in E. coli . In the same way, L. reuteri spirosin was quantified to be 73.5 and 65.4 μg/ mg protein of the lysate in standing and anaerobic culture, respectively. The production pattern of spirosin did not parallel that of alcohol dehydrogenase among three strains of L. reuteri , suggesting that spirosin might not be identical to alcohol dehydrogenase.