Alcanivorax

Crude oil is toxic for most life forms, and environmental pollution by petroleum hydrocarbons causes major ecological problems, especially in marine environments. Fortunately, a considerable amount of petroleum entering the sea is eliminated by the activities of naturally occurring microbial communities. Bacteria such as Alcanivorax spp. provide a major route for the breakdown of these pollutants, and demonstrate how marine bacteria keep the environment in check. Of all the Alcanivorax species and other oil-degrading microbes, Alcanivorax borkumensis is one of the most important worldwide. This obligate hydrocarbonoclastic bacterium (petroleum hydrocarbons serve almost exclusively as its source of carbon and energy) is cosmopolitan and found in various marine environments. The whole-genome sequencing followed by annotation and functional analyses revealed astonishing adaptive capacities of A. borkumensis. Characteristics that enable A. borkumensis to obtain an ecologically competitive advantage to both adapt rapidly to the presence of oil and thrive in most oceans of the world include: its oligotrophic lifestyle and high affinity for hydrocarbon substrates, biofilm formation at the oil-water interface, niche-specific stress responses, and its ability to overcome carbon/nutrient imbalances typical of oil spills by specific systems for scavenging of nutrients, particularly organic and inorganic nitrogen. It degrades a range of petroleum hydrocarbons and typically dominates oil-degrading microbial communities by virtue of a combination of streamlined and efficient central metabolic functions and diverse hydrocarbon degradation and emulsification abilities.