Key Aromatic-Ring-Cleaving Enzyme, Protocatechuate 3,4-Dioxygenase, in the Ecologically Important Marine Roseobacter Lineage

• DOI: 10.1128/aem.66.11.4662-4672.2000
• Publication Date: 2002-07-27T09:55:30Z
• Authors: Alison Buchan; Lauren S. Collier; Ellen L. Neidle; Mary Ann Moran
• Keywords: Roseobacter; Dioxygenase

ABSTRACT Aromatic compound degradation in six bacteria representing an ecologically important marine taxon of the α-proteobacteria was investigated. Initial screens suggested that isolates Roseobacter lineage can degrade aromatic compounds via β-ketoadipate pathway, a catabolic route has been well characterized soil microbes. Six were screened for presence protocatechuate 3,4-dioxygenase, key enzyme pathway. All capable growth on at least three eight monomers presented (anthranilate, benzoate, p -hydroxybenzoate, salicylate, vanillate, ferulate, protocatechuate, and coumarate). Four group had inducible 3,4-dioxygenase activity cell extracts when grown -hydroxybenzoate. The pcaGH genes encoding this ring cleavage cloned sequenced from two isolates, Sagittula stellata E-37 isolate Y3F, both cases could be expressed Escherichia coli to yield dioxygenase activity. Additional involved branch pathway ( pcaC , pcaQ pobA ) found cluster with these isolates. Pairwise sequence analysis pca revealed greater similarity between than either strain bacteria. A degenerate PCR primer set targeting conserved region within PcaH successfully amplified fragment pcaH additional Southern hybridization indicated remaining This evidence all suggesting widespread abilities lineage.