Biodegradation of phenol using recombinant plasmid-carrying Rhodococcus erythropolis strains

• Published in: International biodeterioration & biodegradation Vol. 84; pp. 179 - 184
• Main Authors: Zidkova, L, Szoekoel, J, Rucka, L, Patek, M, Nesvera, J
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2013
• Subjects: biodegradation; bioremediation; Construction; Degradation; enzymes; Gene cloning; Genes; multigene family; Phenol; Phenol degradation; Plasmid; plasmid vectors; plasmids; Recombinant; Rhodococcus; Rhodococcus erythropolis; Strain; transcription factors; Waste water; Wastewater; Plasmid; Gene cloning; Rhodococcus erythropolis; Phenol degradation; Wastewater
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2012.05.017

The aim of the study was to utilize current knowledge of the phenol catabolic genes in Rhodococcus erythropolis CCM2595 to construct improved phenol degraders and test their bioremediation potential using real industrial wastewater. The genes pheA2A1-pheR-catR-catABC, coding for enzymes of the phenol degradation pathway and transcriptional regulators in R. erythropolis CCM2595, were cloned in various combinations in the multicopy R. erythropolis plasmid vector pSRK21 and the resulting constructs were introduced into R. erythropolis cells. All plasmid-carrying strains showed increased phenol hydroxylase activity. The strains harboring constructs pSRKAphe-cat and pSRKBphe-cat (both carrying all enzyme-coding genes of the phenol catabolic gene cluster) exhibited the highest phenol hydroxylase activities and proved to be the most efficient phenol degraders in minimal medium with 0.3 g L−1 phenol. The recombinant strains were up to 50% more efficient than the wild-type strain in the bioremediation of medium based on wastewater containing phenol (0.6 g L−1). The plasmids pSRKAphe-cat and pSRKBphe-cat with the unchanged size were isolated from R. erythropolis cells after a 288-h cultivation in wastewater medium under non-selective conditions. The results provide a basis for the construction of further manipulated phenol-degrading strains and for the development of consortia of various R. erythropolis derivatives. ► We analyzed phenol degradation by the plasmid-carrying strains of R. erythropolis. ► Phenol hydroxylase activity in the recombinant strains increased as much as 4-fold. ► Phenol degradation with the recombinant strains increased as much as by 50%. ► Plasmids carrying the phe-cat genes were reisolated from R. erythropolis cells.