ANAEROBIC DEGRADATION OF ALPHA-RESORCYLATE BY A NITRATE-REDUCING BACTERIUM, THAUERA-AROMATICA STRAIN AR-1

A facultatively anaerobic bacterium growing with alpha-resorcylate (3, 5-dihydroxybenzoate) and nitrate was isolated from activated sludge. C ells of strain AR-1 were Gram-negative, motile rods with a G+C content of the DNA of 66.4 +/- 0.3 mol%. Strain AR-1 was assigned to the spec ies Thauera aromatica on the basis of 16S rRNA sequence analysis. It o xidized alpha-resorcylate (3,5-dihydroxybenzoate) completely to CO2 wi th concomitant reduction of nitrate to N-2. in the presence of nitrate , strain AR-1 grew with short-chain fatty acids, alcohols, and benzoat e derivatives. Sugars, long-chain dicarboxylic acids, and phenolic com pounds such as resorcinol and phloroglucinol were not degraded. Althou gh strain AR-1 was able to grow aerobically with, e.g., benzoate no ae robic growth was found with alpha-resorcylate as substrate. Only nitri te or nitrous oxide was used as alternative electron accepters.