‘ Hydrocarbonoclastic ’ means ‘ hydrocarbon dismantling . ’ These bacteria were named as such because they can degrade the major components of oil . ( 2 ) Both the genus '' Marinobacter '' and the species '' Marinobacter hydrocarbonoclasticus '' were first identified and described in 1992 by Gauthier et al . Using polymerase chain reaction to analyze by 16sRNA DNA , Gauthier showed that it was a member of the gamma group of the Proteobacteria , with sufficient distance to other described Proteobacteria to warrant the creation of a new genus . ( 2 ) In 2005 , Marquez and Ventosa from the Department of Microbiology and Parasitology of the University of Sevilla in Spain used “ G+C content , fatty acid composition , and DNA-DNA hybridization … to understand the taxonomic positions ” of '' Marinobacter hydrocarbonoclasticus '' and '' Marinobacter aquaeolei '' . ( 7 ) “ Marquez suggests that the two species be united under the same name since they are heterotypic synonyms due to phenotypic and phylogenetic traits . ” ( 7 ) In 2011 , Hamdan & Fuller discovered that '' Marinobacter hydrocarbonoclastus '' , die when exposed to the chemical dispersant COREXIT EC9500A used to treat the Deepwater Horizon oilspill . ( 3 ) The genome of '' Marinobacter hydrocarbonoclasticus '' has a 52.7 % guanine cytosine content . ( 2 ) '' Marinobacter hydrocarbonoclasticus '' are a type of eubacteria . ( 2 ) 16sRNA DNA analysis indicates that these organisms are related to the gamma group of Proteobacteria . ( 2 ) Initial 16sRNA phylogenetic analysis did not reveal any close relatives to '' Marinobacter hydrocarbonoclasticus '' . Therefore , the organism was placed in a genus of its own , with scientists believing that '' Pseudomonas aeruginosa '' was its closest modern relative . ( 2 ) In 1999 , 16S rDNA sequence analysis revealed '' Marinobacter hydrocarbonoclasticus '' to have a very close relative in '' Marinobacter aquaeolei '' . ( 6 ) The two organisms contain 16S rDNA sequences with 99.4 % similarity . ( 6 ) The organisms from the genus '' Marinobacter '' have been found to have high diversity in terms of the environments they inhabit . '' Marinobacter '' species have been discovered in “ hypersaline bacterial mats , marine hot-water springs in Japan , and cold seawater as in Arctic and Antarctic regions . ” ( 5 ) '' Marinobacter hydrocarbonoclasticus '' are Gram-negative and rod shaped . ( 2 ) Their cells are , on average , are 0.3-0.6 µm in diameter and 2-3 µm long . ( 2 ) Their ability to produce flagella is largely dependent on the NaCl concentration of their environment . ( 2 ) In solutions with NaCl concentrations of 0.6-1.5 M , '' Marinobacter hydrocarbonoclasticus '' produce and move by the movement of “ a single unsheathed polar flagellum . ” ( 2 ) In solutions with NaCl concentrations 1.5 , '' M. hydrocarbonoclasticus '' are unable to produce flagella , and are thereby unable to influence their movement through medium . ( 2 ) '' Marinobacter hydrocarbonoclasticus '' cells contain no cytochrome P450 , which is the key enzyme for degrading aromatic rings , a major component of petroleum hydrocarbons . ( 2 ) These organisms are adapted to growing on long non-cyclic alkanes , which are common in petroleum hydrocarbons . ( 2 ) Cells can grow on aromatic hydrocarbons , such as hydrocarbons containing aromatic rings . ( 2 ) '' Marinobacter hydrocarbonoclasticus '' are not obligate hydrocarbonoclastic organisms ( 2 ) ; they can also grow on standard medium , without hydrocarbons . Moreover , '' Marinobacter '' cells can denitrify , producing nitrogen gas . ( 2 ) They can use either nitrate ( NO3 − ) or nitrite ( NO2 − ) as their terminal elector . ( 2 ) '' Marinobacter hydrocarbonoclasticus '' cells can grow in aerobic liquid medium culture and form colonies on agar , showing that they are not obligate anaerobes . ( 2 ) '' Marinobacter '' form discrete well-rounded colonies on plates , indicating that they reproduce via binary fission . '' Marinobacter hydrocarbonoclasticus '' can grow with or without the presence of oxygen . ( 2 ) Their cells are tolerant of high salinities . ( 2 ) They are capable of growing up to 3.5 Molar NaCl , but grow best at around 0.6 Molar , which is the molar of the Mediterranean seawater where they are isolated . ( 2 ) They can grow as free plankton or as fixed elements of a biofilm . ( 5 ) '' Marinobacter hydrocarbonoclasticus '' cells degrade hydrocarbons and excrete osmoprotectant ectoine ( Site du Genoscope ) . They also excrete Petrobactin , “ a bis-catechol α-hydroxy acid siderophore that readily undergoes a light-mediated decarboxylation reaction when bound to Fe ( III ) . ” ( 4 ) '' Marinobacter hydrocarbonoclastus '' degrade petroleum hydrocarbons , including those found in oceanic oil spills . ( 3 ) In 2011 , it was discovered that '' Marinobacter hydrocarbonoclastus '' are inhibited when exposed to the chemical COREXIT EC9500A . This chemical is a dispersant widely used to assist in the clean up after oceanic oil spills . ( 3 ) In their tests , Hamdan and Fuller ( 2011 ) obtained data suggesting that , “ hydrogen-degrading bacteria are inhibited by chemical dispersants , and that the use of dispersants has the potential to diminish the capacity of the environment to bioremediate spills . ” '' Marinobacter hydrocarbonoclasticus '' are able to grow in liquid culture and on agar plates , where they produced beige colonies . ( 2 ) They are tolerant of high salinity and can grow aerobically and anaerobically . The ability to grow in heterogeneous environments could prove beneficial for scientists seeking new , bacterial based , techniques for oceanic oil spill clean up
Deepwater Horizon oilspill
Deepwater Horizon oil spill
Marinobacter hydrocarbonoclasticus