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Hydrocarbon-degrading bacteria: the oil-spill clean-up crew.

Brooijmans RJ, Pastink MI, Siezen RJ - Microb Biotechnol (2009)

View Article: PubMed Central - PubMed

Affiliation: Kluyver Centre for Genomics of Industrial Fermentation, TI Food and Nutrition, 6700AN Wageningen, The Netherlands.

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Crude oil (petroleum) is a highly complex mixture of organic compounds of which some 1.3 million litres enters the environment each year... More then anything else, the numerous oil‐shipping disasters, such as of the Exxon Valdez (1989), the Erika (1999) and the Prestige (2003), have captured the public attention to this environmental problem (Fig.  1)... The bioremediation efforts of the Exxon Valdez oil spill have indeed shown that the (light) alkanes are depleted first and that some compounds, such as the high‐molecular weight polycyclic aromatic hydrocarbons (PAHs), may not be degraded at all... Biosurfactants increase the oil‐surface area and with that the amount of oil actually available for attack by bacteria... When oil washes up on beaches and is sequestered in the sediments, the bio‐availabilty can be severely reduced, significantly slowing down or even preventing biodegradation... These encode proteins such as alkane hydroxylases, alcohol dehydrogenases, oxidoeductases, P450 cytochromes, rubredoxin and a rubredoxin reductase (rubA and rubB)... As expected for an obligate hydrocarbon degrader, functional genes that encode typical sugar uptake mechanisms such as PEP‐dependent sugar/phosphotransferase systems are not found in the genome... Furthermore, the Na‐dependent NADH‐quinone dehydrogenase (encoded by nqrABCDEF) and a variety of H/Na antiporters (encoded by mnhABCDEFG, nhaD, nhaB, nhaP and nhaC) enables many transport processes to use a sodium gradient... The PAHs found in oil are particularly resistant to microbial degradation, by the intrinsic stability of the aromatic ring... Polycyclic aromatic hydrocarbons form a great health hazard as many are toxic or carcinogenic and persist in the oil‐polluted environments long after the (linear) alkanes are degraded... Luckily, PAHs also have biological origins and are, for example, formed by the combustion of organic matter in forest fires... A natural occurrence of compounds usually means that some bacteria can be found in Nature that can feed on them... In Pseudomonas species, the genes that are required for the breakdown of PAHs (nah, pah, dox phn, phd and nag operons) (Fig.  4) can often be found on plasmids, facilitating genetic transfer and acquisition in oil‐polluted environments... Moreover, they stimulate growth of other bacteria that can subsequently use the H2S... Their ability to use sulfate combined with their significant ecological (and economic) impact has made them the focus of current research and several sulfate‐reducing bacteria have been completely sequenced (and published) in the last few years.

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A phylogenetic tree illustrating the diversity of aerobic hydrocarbon‐degrading bacteria. Organisms shown in blue can degrade saturated hydrocarbons, whereas those in red can degrade polycyclic aromatic hydrocarbons. The organisms shown in black do not degrade hydrocarbons. Reprinted from Head and colleagues (2006) by permission from Macmillan Publishers Ltd, copyright 2006.
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f2: A phylogenetic tree illustrating the diversity of aerobic hydrocarbon‐degrading bacteria. Organisms shown in blue can degrade saturated hydrocarbons, whereas those in red can degrade polycyclic aromatic hydrocarbons. The organisms shown in black do not degrade hydrocarbons. Reprinted from Head and colleagues (2006) by permission from Macmillan Publishers Ltd, copyright 2006.

Mentions: Notwithstanding all the factors that influence the oil‐biodegrading capacity, it all comes down to the metabolic veracity of bacteria that do not mind to get their ‘hands’ dirty (or greasy to be more precise). A great number of bacteria have been identified that help clean up the hydrocarbon compounds in the aftermath of oil spills. But a significant part of the hydrocarbon content in seawater has a biological origin. Lipids and fatty acids from plants, animals and microbes and the products of their conversion in anoxic zones are ubiquitous. Evolution has created some bacteria that dine exclusively on hydrocarbons, including obligate hydrocarbon degraders of the genera Oleispira, Oleiphilus, Thalassolituus, Alcanivorax and Cycloclasticus (Fig. 2).


Hydrocarbon-degrading bacteria: the oil-spill clean-up crew.

Brooijmans RJ, Pastink MI, Siezen RJ - Microb Biotechnol (2009)

A phylogenetic tree illustrating the diversity of aerobic hydrocarbon‐degrading bacteria. Organisms shown in blue can degrade saturated hydrocarbons, whereas those in red can degrade polycyclic aromatic hydrocarbons. The organisms shown in black do not degrade hydrocarbons. Reprinted from Head and colleagues (2006) by permission from Macmillan Publishers Ltd, copyright 2006.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815313&req=5

f2: A phylogenetic tree illustrating the diversity of aerobic hydrocarbon‐degrading bacteria. Organisms shown in blue can degrade saturated hydrocarbons, whereas those in red can degrade polycyclic aromatic hydrocarbons. The organisms shown in black do not degrade hydrocarbons. Reprinted from Head and colleagues (2006) by permission from Macmillan Publishers Ltd, copyright 2006.
Mentions: Notwithstanding all the factors that influence the oil‐biodegrading capacity, it all comes down to the metabolic veracity of bacteria that do not mind to get their ‘hands’ dirty (or greasy to be more precise). A great number of bacteria have been identified that help clean up the hydrocarbon compounds in the aftermath of oil spills. But a significant part of the hydrocarbon content in seawater has a biological origin. Lipids and fatty acids from plants, animals and microbes and the products of their conversion in anoxic zones are ubiquitous. Evolution has created some bacteria that dine exclusively on hydrocarbons, including obligate hydrocarbon degraders of the genera Oleispira, Oleiphilus, Thalassolituus, Alcanivorax and Cycloclasticus (Fig. 2).

View Article: PubMed Central - PubMed

Affiliation: Kluyver Centre for Genomics of Industrial Fermentation, TI Food and Nutrition, 6700AN Wageningen, The Netherlands.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Crude oil (petroleum) is a highly complex mixture of organic compounds of which some 1.3 million litres enters the environment each year... More then anything else, the numerous oil‐shipping disasters, such as of the Exxon Valdez (1989), the Erika (1999) and the Prestige (2003), have captured the public attention to this environmental problem (Fig.  1)... The bioremediation efforts of the Exxon Valdez oil spill have indeed shown that the (light) alkanes are depleted first and that some compounds, such as the high‐molecular weight polycyclic aromatic hydrocarbons (PAHs), may not be degraded at all... Biosurfactants increase the oil‐surface area and with that the amount of oil actually available for attack by bacteria... When oil washes up on beaches and is sequestered in the sediments, the bio‐availabilty can be severely reduced, significantly slowing down or even preventing biodegradation... These encode proteins such as alkane hydroxylases, alcohol dehydrogenases, oxidoeductases, P450 cytochromes, rubredoxin and a rubredoxin reductase (rubA and rubB)... As expected for an obligate hydrocarbon degrader, functional genes that encode typical sugar uptake mechanisms such as PEP‐dependent sugar/phosphotransferase systems are not found in the genome... Furthermore, the Na‐dependent NADH‐quinone dehydrogenase (encoded by nqrABCDEF) and a variety of H/Na antiporters (encoded by mnhABCDEFG, nhaD, nhaB, nhaP and nhaC) enables many transport processes to use a sodium gradient... The PAHs found in oil are particularly resistant to microbial degradation, by the intrinsic stability of the aromatic ring... Polycyclic aromatic hydrocarbons form a great health hazard as many are toxic or carcinogenic and persist in the oil‐polluted environments long after the (linear) alkanes are degraded... Luckily, PAHs also have biological origins and are, for example, formed by the combustion of organic matter in forest fires... A natural occurrence of compounds usually means that some bacteria can be found in Nature that can feed on them... In Pseudomonas species, the genes that are required for the breakdown of PAHs (nah, pah, dox phn, phd and nag operons) (Fig.  4) can often be found on plasmids, facilitating genetic transfer and acquisition in oil‐polluted environments... Moreover, they stimulate growth of other bacteria that can subsequently use the H2S... Their ability to use sulfate combined with their significant ecological (and economic) impact has made them the focus of current research and several sulfate‐reducing bacteria have been completely sequenced (and published) in the last few years.

Show MeSH