Role of Citrobacter amalonaticus and Citrobacter farmeri in dissimilatory perchlorate reduction

The article deals with the novel physiological function of dissimilatory perchlorate reduction by strains JB101 and JB109 isolated from a laboratory‐enriched mixed consortium originating from a sewage treatment facility. The biochemical and physiological data of the strains showed good correspondence with members of the family Enterobacteriaceae . The partial 16S rDNA sequence of the strains JB101 and JB109 had similarity of 99.8% to Citrobacter amalonaticus and 98% to Citrobacter farmeri , respectively. The results inferred the possibility of Citrobacter spp. to form an important group of dissimilatory perchlorate reducers among the γ subclass of Proteobacteria , since the majority of the perchlorate reducers belong to two monophyletic groups, Dechloromonas and Dechlorosoma in β subclass. The perchlorate‐grown Citrobacter strains preferred perchlorate to nitrate as an electron acceptor unlike most of the reported dissimilatory perchlorate reducers. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)