Biodegradation of oil-derived hydrocarbons by marine actinobacteria: A systematic review.

The intensive use of oil and its derivatives is related to a greater frequency of accidents involving the release of pollutants that cause harmful effects on ecosystems. Actinobacteria are cosmopolitan and saprophytic microorganisms of great commercial interest, but because they are predominantly found in soil, most research into the products of this phylum's metabolism has focused on this habitat. Marine actinobacteria exhibit unique metabolic characteristics in response to extreme conditions in their habitat, which distinguishes them from terrestrial actinobacteria. This systematic review aims to describe cultivable hydrocarbonoclastic marine actinobacteria, analyze their biodegradation rates, as well as discuss their respective potential for application in bioremediation techniques and their limitations. Twenty-one actinobacteria were found to be capable of degrading one or more hydrocarbons derived from petroleum. The majority of these bacteria belonged to the genera Rhodococcus, Gordonia, Pseudonocardia, Isoptericola, Microbacterium, Citricoccus, Kocuria, Brevibacterium, and Cellulosimicrobium. The highest degradation rate was obtained by the species R. ruber, which degraded 100 % of fluorene at a concentration of 100 mg/L. On the other hand, the species Streptomyces gougerotti and Micromonospora matsumotoense were able to degrade polyethylene and use the carbon derived from it to produce polylactic acid (PLA), which represents an excellent candidate for making safely degradable bioplastics, with a view to recycling and replacing conventional petroleum-based plastics. An approach that integrates physicochemical and biological methods, and optimized growth conditions can lead to greater success in decontaminating environments. Despite the number of bacteria found in the research, this number may be significantly higher. This review provides valuable information to support further studies.