Marine-Derived Biocatalysts: Importance, Accessing, and Application in Aromatic Pollutant Bioremediation

Abstract

The aim of the present review is to highlight the potential use of marine biocatalysts (whole cells or enzymes) as an alternative bioprocess for the degradation of aromatic pollutants. Firstly, information about the characteristics of the still underexplored marine environment and the available scientific tools used to access novel marinederived biocatalysts is provided. Marine-derived enzymes, such as dioxygenases and dehalogenases, and the involved catalytic mechanisms for the degradation of aromatic and halogenated compounds, are presented, with the purpose of underpinning their potential use in bioremediation. Emphasis is given on persistent organic pollutants (POPs) that are organic compounds with significant impact on health and environment due to their resistance in degradation. POPs bioaccumulate mainly in the fatty tissue of living organisms, therefore current efforts are mostly focused on the restriction of their use and production, since their removal is still unclear. A brief description of the guidelines and criteria that render a pollutant POP is given, as well as their potential biodegradation by marine microorganisms by surveying recent developments in this rather unexplored field.

Metagenomics and stable isotope probing offer insights into metabolism of polycyclic aromatic hydrocarbons degraders in chronically polluted seawater

“…Additionally, the Cycloclasticus MAG has a sigma-54-dependent transcription regulator with a potential hydrocarbon-binding domain as identified in Cycloclasticus zancles 78-ME (GenBank accession AGS40441.1), which could control transcription of hydrocarbon degradation genes. Dioxygenases require iron and an iron-binding domain, such as ferredoxin which can be shared by multiple enzymes [73,74], which we found in this MAG. As we know that our Cycloclasticus strain can degrade naphthalene, and has genes that can participate in similar pathways but none of the traditional pathway, we posit that non-traditional degradation pathways were utilized to degrade naphthalene.…”

Metagenomic Insights Into the Mechanisms for Biodegradation of Polycyclic Aromatic Hydrocarbons in the Oil Supply Chain

“…Marine microbial metagenomics can provide an increase of data in marine ecology and oceanography, and several works based on different approaches (metagenomic fosmid/cosmid libraries, Sanger and Next generation sequencing shotgun metagenomics) have been described (Gilbert and Dupont, 2011;Nikolaivits et al, 2017).…”

Exploring Marine Environments for the Identification of Extremophiles and Their Enzymes for Sustainable and Green Bioprocesses

“…strain KP7, isolated from a Kuwait beach, produces a dioxygenase that is able to degrade phenanthrene and that has been identified thanks to its detoxification action after an oil spill accident [54]. Numerous marine species have been identified as producers of enzymes catalyzing the degradation of halogenated compounds that have a significantly negative impact on the health and the environment [55]. Some interesting haloacid dehalogenases-i.e., enzymes able to catalyze the de-halogenation of 2-alkanoic acids-have been isolated from the marine bacterium Pseudomonas stutzeri DEH130 [56] and from Paracoccus sp.…”

“…DEH99 [57]. The bacterium Psychromonas ingrahamii, isolated from the sea ice interface, has been described as a producer of a haloacid dehalogenase active against chlorinated and brominated short chain (<C3) haloacids [55,58]. Alcanivorax dieselolei strain B-5, isolated for the first time from surface water of the Bohai Sea, produces different alkane hydroxylase systems that enables it to degrade either chlorinated or brominated alkanes with different chain lengths, thus displaying an interesting potential for biodegradation and other industrial applications [59]…”