Description of strain 3CB-1, a genomovar of Thauera aromatica, capable of degrading 3-chlorobenzoate coupled to nitrate reduction

A Gram-negative bacterium. strain 3CB-1. isolated from a 3-chlorobenzoate enrichment culture inoculated with a sediment sample is capable of degrading various aromatic compounds and halogenated derivatives with nitrate as electron acceptor. Compounds capable of serving as carbon and energy sources include 3-chlorobenzoate. 3-bromobenzoate. 2-fluorobenzoate. 4-fluorobenzoate, benzoate, 3-hydroxybenzoate. 4-hydroxybenzoate, 3-aminobenzoate, protocatechuate, m-cresol and p-cresol. Oxygen. nitrate and nitrite were used as electron accepters for growth. Cells are Gram-negative short rods with peritrichous flagellation. The predominant fatty acids are cis-9-hexadecenoic acid (16:1 omega 7c). hexadecanoic acid (16:0), octadecanoic acid (18:0). octadecenoic acid (18:1), 3-hydroxydecanoic acid (10:0 30H) and dodecanoic acid (12:0). The sequence of the 16S rRNA gene, as well as the fatty acid composition, indicate that the strain is a member of the genus Thauera in the beta-subclass of the Proteobacteria and very close to Thauera aromatica. DNA-DNA hybridization and nutrient screening indicate that strain 3CB-1 is a genomovar of Thauera aromatics with the proposed name Thauera aromatics genomovar chlorobenzoica.