Desulfovibrio marrakechensis sp. nov.. a 1.4-tyrosol-oxidizing, sulfate-reducing bacterium isolated from olive mill wastewater

A novel mesophilic sulfate-reducing bacterium, EMSSDQ₄ ^T, was isolated from olive mill wastewater in the semi-arid region of Morocco (Marrakech). Cells were Gram-negative, catalase-positive, straight rods that were non-motile and non-spore-forming and contained cytochrome c₃ and desulfoviridin. The DNA G + C content was 65.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was a member of the genus Desulfovibrio with Desulfovibrio carbinoliphilus D41^T, Desulfovibrio alcoholivorans SPSN^T, Desulfovibrio fructosivorans JJ^T and Desulfovibrio carbinolicus EDK82^T as the most closely related strains with validly published names. In addition to the classical substrates used by Desulfovibrio species, the isolate oxidized 1,4-tyrosol, one of the most abundant phenolic compounds occurring in olive mill wastewater, to 4-hydroxyphenylacetate without ring cleavage. D. alcoholivorans SPSN^T was also found to carry out this reaction. Under air, strain EMSSDQ₄ ^T exhibited limited growth on lactate and yeast extract in the absence of sulfate. On the basis of genotypic and phenotypic characteristics, it is proposed that the isolate represents a novel species, Desulfovibrio marrakechensis sp. nov. The type strain is EMSSDQ₄ ^T (=DSM 19337^T =ATCC BAA-1562^T).