Petroleum microbiology oil while A. borkumensis simutaneously increases synthesis of anionic glucoproteins, which are used to emulsify hydrocarbons in the environment and increase their bioavailability. The presence of crude oil along with appropriate levels of nitrogen and phosphor catalyzes the removal of petroleum either by mechanisms that enhance the efficiency of substrate uptake or by direct biodegradation of aliphatic chains. Two well-known oil spills exemplify large scale marine bioremediation applications: In 1989, the Exxon Valdez ran aground, spilling 41.6 million liters of crude oil, and launching one of the first major bioremediation efforts for an oil spill. Cleanup of Alaskan shorelines relied
Oil tanker two million barrels of oil, had peaked at $309,601 per day in 2007, and has dropped, as of 2012, to $7,085 per day, far below the operating costs of these ships. As a result, several tanker operators laid up their ships. Prices rose significantly in 2015 and early 2016, but delivery of new tankers was projected to keep prices in check. Owners of large oil tanker fleets include Teekay Corporation, A P Moller Maersk, DS Torm, Frontline, MOL Tankship Management, Overseas Shipholding Group, and Euronav. In 2005, oil tankers made up 36.9% of the world's fleet in terms of deadweight