DESULFOVIBRIO INOPINATUS, SP. NOV., A NEW SULFATE-REDUCING BACTERIUM THAT DEGRADES HYDROXYHYDROQUINONE (1,2,4-TRIHYDROXYBENZENE)

A new sulfate-reducing bacterium was isolated from marine sediment wit h hydroxyhydroquinone (1,2,4-trihydroxybenzene) as the sole electron a nd carbon source. Strain HHQ 20 grew slowly with doubling times of > 2 0 h and oxidized hydroxyhydroquinone, lactate, pyruvate. ethanol, fruc tose, and ribose incompletely to acetate and carbon dioxide, with conc omitant reduction of sulfate to sulfide. Cells were large, vibrio-shap ed, and gram-negative with a G+C content of 49.7 mol%, and contained d esulfoviridin. Based on analysis of the 16S rRNA sequence, strain HHQ 30 was found to be related to the genus Desulfovibrio but formed a sep arate line, thus justifying the establishment of a new species within this genus. Hydroxyhydroquinone was the only aromatic compound utilize d amen numerous hydroxybenzoates, hydroxybenzenes, methoxybenzoates, a nd methoxybenzenes tested, suggesting that phloroglucinol and resorcin ol are not degradation intermediates. Cell-free extracts of strain HHQ 20 did not contain pyrogallol-phloroglucinol transhydroxylase activit y. First experiments indicated that this strain uses a new reductive p athway for anaerobic hydroxyhydroquinone degradation.