TAURINE-SULFUR ASSIMILATION AND TAURINE-PYRUVATE AMINOTRANSFERASE ACTIVITY IN ANAEROBIC-BACTERIA

We demonstrated the ability of strictly fermentative, as well as facul tatively fermentative, bacteria to assimilate sulfonate sulfur for gro wth. Taurine (2-aminoethanesulfonate) can be utilized by Clostridium p asteurianum C1 but does not support fermentative growth of two Klebsie lla spp. and two different Clostridium spp. However, the latter are ab le to assimilate the sulfur of a variety of other sulfonates (e.g., cy steate, 3-sulfopyruvate, and 3-sulfolactate) anaerobically. A novel ta urine-pyruvate aminotransferase activity was detected in cell extracts of C. pasteurianum C1 grown with taurine as the sole sulfur source. T his activity was not detected in extracts of other bacteria examined, in C. pasteurianum C1 grown with sulfate or sulfite as the sulfur sour ce, or in a Klebsiella isolate assimilating taurine-sulfur by aerobic respiration. More common aminotransferase activities (e.g., with aspar tate or glutamate as the amino donor and pyruvate, oxalacetate, or alp ha-ketoglutarate as the amino acceptor) were present, no matter what s ulfur source was used for growth. Partial characterization of the taur ine-pyruvate aminotransferase revealed an optimal temperature of 37 de grees C and a broad optimal pH range of 7.5 to 9.5.