Characterization of Phenol-Degrading Bacteria From Wastewater Treatment Plants By 16S Rrna and Phenol Hydroxylase Genes

Abstract

Phenol-degrading bacteria from different units of wastewater treatment plants were investigated by molecular analyses based on 16S rDNA and LmPH (Large subunit multicomponent phenol hydroxylase) gene. Phenol-degrading bacteria play a key role in the conversion of phenol in wastewater treatment systems. Characterization of these bacteria requires the use of both cultural and molecular techniques. In the present work, the samples were taken from different units of two different wastewater treatment plants in October 2015. In total, 89 phenol-degrading and/or utilizing bacteria were isolated from wastewater samples in mineral salt medium agar with phenol as a sole carbon source. PCR amplification of the 16S rRNA gene and LmPH (Large subunit multicomponent phenol hydroxylase) gene were applied. Sixty-five isolates which have LmpH gene were sequenced. Sequence analysis revealed that these isolates were Pseudomonas denitrificans, Pseudomonas nitroreducans, Pseudomonas linyingensis, Pseudomonas sp., Ideonella sp., Burkholderia multivorans and Alcaligenes sp. These results showed that phenol utilizing isolates belong to Proteobacteria phylum, especially Gamma and Betaproteobacteria classes' gram negative representatives. In addition, our work has shown the potential use of these isolates in biological treatment of wastewater treatment systems due to degrading phenol.