Degradation of 3-chlorobiphenyl by in vivo constructed hybrid pseudomonads

Abstract

3‐Chlorobiphenyl‐degrading bacteria were obtained from the mating between Pseudomonas putida strain BN10 and Pseudomonas sp. strain B13. Strains such as BN210 resulted from the transfer of the genes coding the enzyme sequence for the degradation of chlorocatechols from B13 into BN10, whereas B13 derivatives such as B131 have acquired the biphenyl degradation sequence from BN10. During growth of the hybrid strains on 3‐chlorobiphenyl 90% chloride was released. Activities of phenylcatechol 2,3‐dioxygenase, benzoate dioxygenase, catechol 1,2‐dioxygenase, chloromuconate cyloisomerase and 4‐carboxymethyl‐enebut‐2‐en‐4‐olide hydrolase were found in 3‐chlorobiphenyl‐grown cells. The hybrid strains were found to convert some congeners of the Aroclor 1221 mixture such as mono‐ and dichloro‐substituted biphenyls.

Degradation of Aroclor 1242 Dechlorination Products in Sediments by Burkholderia xenovorans LB400( ohb ) and Rhodococcus sp. Strain RHA1( fcb )

“…We previously used an alternative approach for the construction of PCB-degrading bacteria through in vitro pathway generation with the introduction of specific chlorobenzoate degradation genes and funneling of PCBs into substrates for preexisting central metabolic pathways for Comamonas testosteroni strain VP44 (27) and Rhodococcus sp. strain RHA1 (32,33).…”

“…While there have been many experiments testing the ability of various aerobic bacteria to degrade PCBs, most of the work employed only one congener (27), employed a freshly applied contaminant (21), and/or was carried out under resting cell conditions (1,26). While providing useful information, these types of experiments do not reflect the conditions under which aerobic bacteria have to perform in a biotreatment process for PCBs.…”

Gene Islands Integrated into tRNA Gly Genes Confer Genome Diversity on a Pseudomonas aeruginosa Clone

“…The 105-kb self-transmissible clc element, encoding the degradation of 3-chlorobenzoate, is capable of integrating site and sequence specifically into Ϫ7 per recipient cell (27). Despite these low frequencies, transfer of the clc element to endogeneous bacteria seems to readily occur in complex microbial communities, such as sludges from soil or wastewater treatment plants (49,53).…”

Cloning, Nucleotide Sequencing, and Functional Analysis of a Novel, Mobile Cluster of Biodegradation Genes from Pseudomonas aeruginosa Strain JB2

“…Acquisition of catabolic genes can enhance contaminant biodegradation by increasing the diversity of organisms able to effect at least partial transformation of a compound or expanding on existing pathways so that degradation is more extensive or complete (mineralization). Pathway complementation is exemplified by strains engineered to possess the upper biphenyl degradation pathway as well as the lower chlorobenzoate and chlorocatechol pathways, resulting in an enhanced ability to mineralize polychlorinated biphenyls (18,25,35,46). Similar hybrid pathways could evolve naturally in the environment by lateral gene transfer and affect the activity of microbial communities mediating polychlorinated biphenyl (PCB) biodegradation, but relatively little is known about their occurrence.…”