Uptake and Utilization of Sulfonic Acids in the Cyanobacterial Strains

Growth of several cyanobacteria was examined on ethane sulfonate and taurine as only sulfur source. Comparing two strains with differential utilization of sulfonic acids (Anabaena variabilis and Synechococcus 6301) demonstrated that actual growth was coupled to the presence of an active sulfonate transport system due to species specific properties and nutritional conditions. Sulfonate uptake in Anabaena variabilis was characterized by a pH optimum of 6.5, a structural specificity for sulfonates, missing N a+ dependence, and phosphate stimulation. Radiolabeled ethane sulfonate and taurine was metabolized to products of normal sulfur metabolism. Also considerable amounts of 35S-labeled volatiles (mercaptanes and sulfide) could be detected, sug­ gesting a degradation mechanism via reduction to mercaptanes and cleavage of the C —S bond.