Evidence for two transporters of sulfur and selenium oxyanions in Clostridium pasteurianum

Abstract
Kinetic uptake studies of the inorganic anions SO42-, SeO42-, and SeO32- into Clostridium pasteurianum showed that these dianions transport systems obeyed Michaelis-Menten kinetics. Analysis of Km and Ki values for these dianions suggest there were two ports of entry for these oxyanions into the cells, with SO42- and SeO42- having a common porter and SeO32-having a separate transporter. The practical importance of these experiments is released to the environment where some sediments contaminated with inorganic selenium compounds are in the concentration range which approximates the Km values for SeO32- (50.mu.M)/SeO42- (65 .mu.M) in C. pasteurianum.