Glycerol and propanediols degradation by Desulfovibrio alcoholovorans in pure culture in the presence of sulfate, or in syntrophic association with Methanospirillum hungatei

Abstract

SUMMARYIn a mineral medium containing sulfate as terminal electron acceptor, the sulfate-reducing bacterium Desulfooibrio alcoholouorans oxidized stoichiomet+ally 1 mol glycerol to 1 mol acetate and 1 mol 1,3-propanediol to 1 mol acetate with the concomitant reduction of 0.75 and 1 mol sulfate, respectively; 1 mol 1,2-propanediol was degraded to 0.8 mol acetate and 0.1 mol propionate, with the reduction of approximately 1 mol sulfate. The maximum specific growth rates (pmaX in h-') were 0.22, 0.086 and 0.09 with glycerol, 1,3-propanediol and 1,2-propanediol, respectively. The growth yields were 12.7 g, 11.1 g and 7.2 g dry weight/mol1,3-propanediol, glycerol ~ Correspondence lo: A.I. Qatibi. Present address: Department of Microbiology, University of Groningen. NL-9751 NN Haren, The Netherlands. 233and 1,2-propanediol degraded, respectively. The growth yields and maximum specific growth rates of the H,-transferring associations were also calculated. In the absence of sulfate, all these reduced substrates were degraded to acids and methane when D. alcoholooorans was cocultured with Methanospirillum hungatei. Changes in the metabolic pathway were observed in the degradation of 1,2-and 1,3-propanediol. The metabolic efficiency of D. alcoholouorans to degrade glycerol, 1.2-and 1,3-propanediol is discussed.