An initial understanding of the bacterial desulfonation of the natural products L-cysteate (L-cysteate sulfo-lyase, CuyA) and sulfolactate (sulfolactate sulfolyase, SuyAB) is available, but the ancillary pathways, especially uptake, regulation and sulfolactate isomerase, are unknown. HiWi projects with (a) <it>Bilphila wadsworthia</it> RZATAU and its CuyAlcuyA to yield transport and regulatory genes; (b) <it>Cupriavidus necator</it> JMP134 and its pair of SuyAB/<it>suyAB</it> genes; (c) the archaeon <it>Sulfolobus sulfataricus </it> P2 and its SuyAB/<it>suyAB</it> with a gene array, should allow genes of the ancillary pathways to be identified. There is little information on the presumably oxygenolytic desulfonation of xenobiotics (to treat Alzheimer, alcoholism, stroke) or on the ancillary pathways. A doctoral project involves physiological, biochemical and genetic methods to establish whole degradative pathways for homotaurine (3-aminopropanesulfonate) and 1,3-disulfopropane. One pathway involves simply transamination and excretion of an unknown sulfonate; enzyme(s) and excretion product will be characterized. The desulfonation reactions will be the main targets of biochemistry, which will enable reverse genetic approaches to characterize genes (and flanking regions) encoding the desulfonative enzymes.