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Original "Alcanivorax"

Alcanivorax borkumensis is an alkane-degrading marine bacterium which naturally propagates and becomes predominant in crude-oil-containing seawater when nitrogen and phosphorus nutrients are supplemented. They are currently thought to be the world's most important oil-degrading organisms.

Metabolism

A. borkumensis primarily uses alkanes as its source of energy/carbon, but it can use a few other organic compounds. Unlike most other cells, it cannot consume more common substances such as sugars or amino acids as a source of energy.

To increase the growth rate of a population of A. borkumensis bacteria, phosphorus and nitrogenous compounds can be added to the environment. These substances act as a fertilizer for the bacteria and help them grow at an increased rate.

A. borkumensis and biosurfactants

When A. borkumensis bacteria use alkanes as their source of energy, each cell forms a biosurfactant (other sources of energy do not cause the bacteria to produce this biosurfactant). A biosurfactant is an extra layer of material that forms along the cell membrane. The substances that make up the biosurfactant of A. borkumensis can reduce the surface tension of water, which helps with the degradation of oil. They are also emulsifiers, which further serve to create the oil/water emulsion, making oil more soluble. A. borkumensis forms a biofilm around an oil droplet in seawater and proceeds to use biosurfactants and metabolism to degrade the oil into a water-soluble substance.

Role in oil biodegradation

Petroleum oil is toxic for most life forms and pollution of the environment by oil causes major ecological problems. A considerable amount of petroleum oil entering the sea is eliminated by the microbial biodegradation activities of microbial communities. A. borkumensis is a recently discovered hydrocarbonoclastic bacterium and is probably the most important global oil degrader. A. borkumensis is capable of degrading oil in seawater environments. It is known as a hydrocarbonoclastic organism, with the root ‘clastic’ meaning it can divide something into parts (in this case hydrocarbons). Crude oil, or petroleum, is predominantly made up of hydrocarbons, a product that consists of a long chain of carbon atoms attached to hydrogen atoms. Whereas most organisms use sugars or amino acids for their source of carbon/energy, A. borkumensis uses alkanes, a type of hydrocarbon, in its metabolic process. This diet allows A. borkumensis to flourish in marine environments that have been affected by oil spills. Through its metabolism, A. borkumensis can break down oil into harmless compounds. This ability makes this particular species a major potential source for bioremediation of oil-polluted marine environments.

Potential as antioil spill agent

Oil spills can occur during transportation of oil or during extraction. Such spills may dump significant quantities of oil into the ocean and pollute the environment, affecting ecosystems near and far.

Normally, many years are needed for an ecosystem to recover fully (if at all) from an oil spill, so scientists have been looking into ways to expedite the cleanup of areas affected by an oil spill. Most efforts so far use direct human involvement/labor to physically remove the oil from the environment. However, A. borkumensis presents a possible alternative. Since A. borkumensis naturally breaks down oil molecules to a nonpolluting state, it would help ecosystems to quickly recover from an oil spill disaster. The organisms also naturally grow in oil-contaminated seawater, thus are a native species. If the process A. borkumensis uses to break down oil could be sped up or made more efficient, this would aid recovering ecosystems. Some examples include encouraging the growth of A. borkumensis (through phosphorus and nitrogen fertilization) so more of them are breaking down oil, or encouraging the metabolism of A. borkumensis so they metabolize faster and more.

Edit "Alcanivorax"

Alcanivorax borkumensis is an alkane-degrading marine bacterium which naturally propagates and becomes predominant in crude-oil-containing seawater when nitrogen and phosphorus nutrients are supplemented.

Metabolism

A. borkumensis primarily uses alkanes as its source of energy/carbon, but it can use a few other organic compounds. Unlike most other cells, it cannot consume more common substances such as sugars or amino acids as a source of energy. This is due to the lack of genes that code for active or passive carbohydrate transporters, hence the inability to consume monomeric sugars.

In a A. borkumensis, a number of different enzymes are tasked with oxidizing alkane molecules. The aerobic metabolism of alkanes is carried out through the terminal alkane oxidation pathway, where monooxygenases initiate the oxidation of terminal carbons. This sequential pathway first produces alcohols, then alcohol and aldehyde dehydrogenases, and ultimately aldehydes and fatty acids, respectively.

Following an oil spill, huge imbalances in the carbon/nitrogen and carbon/phosphorus ratios can be observed. For this, A. borkumensis have a myriad of transport proteins that allow fast uptake of key nutrients that are limiting in the environment. To increase the growth rate of a population of A. borkumensis bacteria, phosphorus and nitrogenous compounds can be added to the environment. These substances act as a fertilizer for the bacteria and help them grow at an increased rate.

A. borkumensis and biosurfactants

When A. borkumensis bacteria use alkanes as their source of energy, each cell forms a biosurfactant (other sources of energy do not cause the bacteria to produce this biosurfactant). A biosurfactant is an extra layer of material that forms along the cell membrane. The substances that make up the biosurfactant of A. borkumensis can reduce the surface tension of water, which helps with the degradation of oil. They are also emulsifiers, which further serve to create the oil/water emulsion, making oil more soluble. A. borkumensis forms a biofilm around an oil droplet in seawater and proceeds to use biosurfactants and metabolism to degrade the oil into a water-soluble substance.

Biotechnological applications

Role in oil biodegradation

Petroleum oil is toxic for most life forms and pollution of the environment by oil causes major ecological problems. A considerable amount of petroleum oil entering the sea is eliminated by the microbial biodegradation activities of microbial communities. As a recently discovered hydrocarbonoclastic, A. borkumensis is capable of degrading oil in seawater environments. Hydrocarbonoclastic has the root ‘clastic’ meaning it can divide something into parts (in this case hydrocarbons). Crude oil, or petroleum, is predominantly made up of hydrocarbons, a product that consists of a long chain of carbon atoms attached to hydrogen atoms. Whereas most organisms use sugars or amino acids for their source of carbon/energy, A. borkumensis uses alkanes, a type of hydrocarbon, in its metabolic process. This diet allows A. borkumensis to flourish in marine environments that have been affected by oil spills. Through its metabolism, A. borkumensis can break down oil into harmless compounds. This ability makes this particular species a major potential source for bioremediation of oil-polluted marine environments.

Potential as antioil spill agent

Oil spills can occur during transportation of oil or during extraction. Such spills may dump significant quantities of oil into the ocean and pollute the environment, affecting ecosystems near and far.

Normally, many years are needed for an ecosystem to recover fully (if at all) from an oil spill, so scientists have been looking into ways to expedite the cleanup of areas affected by an oil spill. Most efforts so far use direct human involvement/labor to physically remove the oil from the environment. However, A. borkumensis presents a possible alternative. Since A. borkumensis naturally breaks down oil molecules to a nonpolluting state, it would help ecosystems to quickly recover from an oil spill disaster. The organisms also naturally grow in oil-contaminated seawater, thus are a native species. If the process A. borkumensis uses to break down oil could be sped up or made more efficient, this would aid recovering ecosystems. Some examples include encouraging the growth of A. borkumensis (through phosphorus and nitrogen fertilization) so more of them are breaking down oil, or encouraging the metabolism of A. borkumensis so they metabolize faster and more.

Potential in biopolymer production

By disrupting an acyl-coenzyme A (CoA) thioesterase gene, Sabirova and collegues where able to mutate the organism to hyper produce polyhydroxyalkanoates (PHA). They were then able to recover the large amounts of PHA that was released by mutant Alcanivorax from the culture mediums with relative ease. Before, costly and environmentally dangerous solvents had to be used in order to retrieve PHA from intracellular granules. This allows for production of environmentally friendly polymers in factories that utilized mutant Alcanivorax.

—Farshad.F (talk) 05:54, 9 October 2017 (UTC)