New Frontiers of Anaerobic Hydrocarbon Biodegradation in the Multi-Omics Era

Abstract

The accumulation of petroleum hydrocarbons in the environment substantially endangers terrestrial and aquatic ecosystems. Many microbial strains have been recognized to utilize aliphatic and aromatic hydrocarbons under aerobic conditions. Nevertheless, most of these pollutants are transferred by natural processes, including rain, into the underground anaerobic zones where their degradation is much more problematic. In oxic zones, anaerobic microenvironments can be formed as a consequence of the intensive respiratory activities of (facultative) aerobic microbes. Even though aerobic bioremediation has been well-characterized over the past few decades, ample research is yet to be done in the field of anaerobic hydrocarbon biodegradation. With the emergence of high-throughput techniques, known as omics (e.g., genomics and metagenomics), the individual biodegraders, hydrocarbon-degrading microbial communities and metabolic pathways, interactions can be described at a contaminated site. Omics approaches provide the opportunity to examine single microorganisms or microbial communities at the system level and elucidate the metabolic networks, interspecies interactions during hydrocarbon mineralization. Metatranscriptomics and metaproteomics, for example, can shed light on the active genes and proteins and functional importance of the less abundant species. Moreover, novel unculturable hydrocarbon-degrading strains and enzymes can be discovered and fit into the metabolic networks of the community. Our objective is to review the anaerobic hydrocarbon biodegradation processes, the most important hydrocarbon degraders and their diverse metabolic pathways, including the use of various terminal electron acceptors and various electron transfer processes. The review primarily focuses on the achievements obtained by the current high-throughput (multi-omics) techniques which opened new perspectives in understanding the processes at the system level including the metabolic routes of individual strains, metabolic/electric interaction of the members of microbial communities. Based on the multi-omics techniques, novel metabolic blocks can be designed and used for the construction of microbial strains/consortia for efficient removal of hydrocarbons in anaerobic zones.

Microalgae–Bacteria Consortia: A Review on the Degradation of Polycyclic Aromatic Hydrocarbons (PAHs)

“…Else, the analogous CoA thioesters and subject of non-oxygenolytic ring cleavage can metabolize aromatic hydrocarbons in the presence of oxygen [70]. In the lack of oxygen (anaerobic biodegradation), hydrocarbons are activated by different reactions such as direct carboxylation, independent hydroxylation, fumarate addition, oxygen-hydration and reverse methanogenesis [71]. Many biodegrading bacterial species have been isolated from diverse environments that can utilize PAHs through different metabolic pathways.…”

Anaerobic oxidation of petroleum hydrocarbons in enrichment cultures from sediments of the Gorevoy Utes natural oil seep under methanogenic and sulfate-reducing conditions

“…Deep petroleum reservoirs and deep sediments associated with oil discharge have long been considered biotopes unsuitable for life [1]. In recent decades, the use of a set of methods has described microbial diversity in petroleum reservoirs, revealed dominant groups of microorganisms that carry out anaerobic oxidation of oil, determined metabolic pathways and the resulting oxidation products [2][3][4][5][6][7][8][9][10][11]. Comparison of microbial diversity in petroleum reservoirs throughout the world indicated an obvious correlation of prokaryotic communities with temperature and depth of reservoir as well as no in uence of the geographical distance between reservoirs.…”

Növényi és állati eredetű hulladékok hasznosíthatósága biogáz előállítására

“…Emellett funkcionális jellemzés is végrehajtható [150]. Az összeszerelt binek pedig minőségileg jól jellemezhetők azok teljességével és kontaminációjával markergének alapján [151].…”