Paracoccus sulfuroxidans sp. nov., a sulfur oxidizer from activated sludge.

Bacterial strain LW36T was isolated from activated sludge of a wastewater-treatment bioreactor. Cells of strain LW36T were Gram-negative coccoids to short rods, 1.0-1.2x0.5 microm in size. Colonies were cream-coloured, smooth and circular. Strain LW36T was hetero-organotrophic and chemolithotrophic and was able to use reduced sulfur as an energy resource. Growth was observed at 25-36 degrees C and pH 5-10. The most abundant cellular fatty acid of strain LW36T was C18:1omega7c (64.2%). The sole respiratory quinone was ubiquinone-10. The G+C content of the genomic DNA was 61.3 mol% (Tm). 16S rRNA gene sequence analysis indicated that strain LW36T was phylogenetically related to members of the genus Paracoccus, with similarities ranging from 92.4 to 94.9%. Based on these results, it is concluded that strain LW36T represents a novel species of the genus Paracoccus, for which the name Paracoccus sulfuroxidans is proposed. The type strain is strain LW36T (=CGMCC 1.5364T=JCM 14013T).