Microbial Degradation of Hydrocarbons—Basic Principles for Bioremediation: A Review

Abstract

Crude oil-derived hydrocarbons constitute the largest group of environmental pollutants worldwide. The number of reports concerning their toxicity and emphasizing the ultimate need to remove them from marine and soil environments confirms the unceasing interest of scientists in this field. Among the various techniques used for clean-up actions, bioremediation seems to be the most acceptable and economically justified. Analysis of recent reports regarding unsuccessful bioremediation attempts indicates that there is a need to highlight the fundamental aspects of hydrocarbon microbiology in a clear and concise manner. Therefore, in this review, we would like to elucidate some crucial, but often overlooked, factors. First, the formation of crude oil and abundance of naturally occurring hydrocarbons is presented and compared with bacterial ability to not only survive but also to utilize such compounds as an attractive energy source. Then, the significance of nutrient limitation on biomass growth is underlined on the example of a specially designed experiment and discussed in context of bioremediation efficiency. Next, the formation of aerobic and anaerobic conditions, as well as the role of surfactants for maintaining appropriate C:N:P ratio during initial stages of biodegradation is explained. Finally, a summary of recent scientific reports focused on the removal of hydrocarbon contaminants using bioaugmentation, biostimulation and introduction of surfactants, as well as biosurfactants, is presented. This review was designed to be a comprehensive source of knowledge regarding the unique aspects of hydrocarbon microbiology that may be useful for planning future biodegradation experiments. In addition, it is a starting point for wider debate regarding the limitations and possible improvements of currently employed bioremediation strategies.

Biosurfactants: Eco-Friendly and Innovative Biocides against Biocorrosion

“…They all show diverse emulsification, interfacial, and surface tension properties. These compounds are known to exhibit broad-spectrum antimicrobial activity, and different classes of biosurfactants are being used by the agricultural, oil, food, cosmetic, biotechnological, and pharmaceutical industries, as well as in a wide range of environmental remediation technologies [24,[28][29][30][31][32][33][34][35]. The review of Fenibo et al [36] offers an overview of diverse applications of biosurfactants, with emphases on petroleum biotechnology, environmental remediation, and the agriculture sector.…”

Intensification of Ex Situ Bioremediation of Soils Polluted with Used Lubricant Oils: A Comparison of Biostimulation and Bioaugmentation with a Special Focus on the Type and Size of the Inoculum

“…Even if the introduced strains survived on a field scale, their biodegradation performance might be less effective than it was when it had been previously detected under laboratory conditions [28,29]. Although bioaugmentation remains a promising rehabilitation procedure, as a result of the contradictory observations mentioned above, its advantages and capacity have been frequently debated [13,[30][31][32][33][34][35].…”

“…Bioremediation, which exploits the degradative pathways of microorganisms or plants to neutralize pollutants, is a widespread clean-up technology for petroleum hydrocarbon-contaminated soils either conducted in situ (at the contaminated site) or ex situ (on excavated samples) [9][10][11][12][13][14]. ULOs are less volatile and less biodegradable as compared to other hydrocarbons [15], hence, physicochemical remediation technologies are often preferred, despite the high costs and irreversible damages inflicted to the soil matrices [16,17].…”

Metagenomic Functional Profiling Reveals Differences in Bacterial Composition and Function During Bioaugmentation of Aged Petroleum-Contaminated Soil

“…Total petroleum hydrocarbons (TPH) are a broad family of organic compounds that originate from crude oil and contain many carcinogens and neurotoxic pollutants ( Ławniczak et al, 2020 ). According to the European Environment Agency (2017), the pollution caused by petroleum products is considered to be one of the most serious global environmental problems.…”