Microbial Metabolic Potential of Phenol Degradation in Wastewater Treatment Plant of Crude Oil Refinery: Analysis of Metagenomes and Characterization of Isolates

Abstract

The drilling, processing and transportation of oil are the main sources of pollution in water and soil. The current work analyzes the microbial diversity and aromatic compounds degradation potential in the metagenomes of communities in the wastewater treatment plant (WWTP) of a crude oil refinery. By focusing on the degradation of phenol, we observed the involvement of diverse indigenous microbial communities at different steps of the WWTP. The anaerobic bacterial and archaeal genera were replaced by aerobic and facultative anaerobic bacteria through the biological treatment processes. The phyla Proteobacteria, Bacteroidetes and Planctomycetes were dominating at different stages of the treatment. Most of the established protein sequences of the phenol degradation key enzymes belonged to bacteria from the class Alphaproteobacteria. From 35 isolated strains, 14 were able to grow on aromatic compounds, whereas several phenolic compound-degrading strains also degraded aliphatic hydrocarbons. Two strains, Acinetobacter venetianus ICP1 and Pseudomonas oleovorans ICTN13, were able to degrade various aromatic and aliphatic pollutants and were further characterized by whole genome sequencing and cultivation experiments in the presence of phenol to ascertain their metabolic capacity in phenol degradation. When grown alone, the intermediates of catechol degradation, the meta or ortho pathways, accumulated into the growth environment of these strains. In the mixed cultures of the strains ICP1 and ICTN13, phenol was degraded via cooperation, in which the strain ICP1 was responsible for the adherence of cells and ICTN13 diminished the accumulation of toxic intermediates.

Microbially competent 3D skin: a test system that reveals insight into host–microbe interactions and their potential toxicological impact

“…The selection of these organisms followed practical considerations and with the intended later application of studying potential microbiome-mediated substance toxification in mind. Both species are biologically relevant (Chiller et al 2001 ; Wang et al 2019 ), have an established potential for xenobiotic metabolism (Egea et al 2017 ; Hanafy et al 2016 ; Sowada et al 2014 ; Viggor et al 2020 ) and have been isolated repeatedly from healthy volunteers at different sites (Khayyira et al 2020 ; Sowada et al 2014 ; Steglinska et al 2019 ; Wang et al 2019 ). Amongst the skin’s Micrococcaceae M. luteus is the predominant species (Chiller et al 2001 ).…”

Biogasification of methanol extract of lignite and its residue: A case study of Yima coalfield, China

“…This result demonstrated that these compounds could be degraded and utilized by the flora. Different studies have reported that microorganisms of the Firmicutes and Proteobacteria can degrade polycyclic aromatic hydrocarbons [ 31 , 32 ], and the microorganisms of the Bacteroidetes can degrade phenols [ 33 – 35 ]. These microorganisms in the inoculum might be involved in the degradation of organic matter in the extract.…”

Genetic diversity of phenol hydroxylase-encoding genes among wastewater sludge bacteria

“…These substrates would be depleted due to microbial activities in the aeration tank, which would then provide the opportunity of certain bacteria that are capable of using remaining phenol and other unused compounds to grow in the microbial recovery tank. In addition, various levels of tolerance to phenol have been reported in different bacteria and mixed cultures (Bera et al 2017;Viggor et al 2020). Such difference in response to varying phenol concentrations will allow for growth of bacteria with diverse capability of phenol catabolism in both tanks.…”