Gasoline-eating bacteria and their enzymes in the service of industry
Gasoline eaters - bacteria that cope well where almost nothing can survive - become the industry\'s object of desire. These bacteria are already helping to create drugs - Prozac equivalents and can accelerate the production of hydroxylated vitamin D.
On a stretch of the Weser River in Germany, tankers illegally cleaned their tanks. Scientists who took samples of material from the bottom of this river in the 1990s did not expect to find much life there. And yet it turned out that certain strains of bacteria were doing quite well there.
"For example, the bacterium Aromatoleum aromaticum is a very unusual organism. It munches on petrol and breathes nitrates, it also inhabits oil deposits" - said Dr. Maciej Szaleniec, professor at the Institute of Catalysis and Surface Chemistry PAS in Kraków. He added: "The name of this bacteria comes from the fact that these organisms grow on ethylbenzene - a compound that gives gasoline a characteristic smell" - he explained.
The chemist examines the enzymes produced by these and other anaerobic bacteria. And these enzymes are interesting chemical compounds that can be useful in the production of drugs, such as synthetic drugs from vitamin D. "These enzymes are like from another planet" - he commented. He added that they contain such unusual elements as molybdenum or tungsten. For his research he received the award of the Division III of Mathematics, Physics, Chemistry and Earth Sciences of the Polish Academy of Sciences.
REACTION TO BE EXPECTED
Enzymes are, in other words, catalysts. They accelerate the chemical reaction and guide it to the right track. "Catalysis is needed so that reactions can proceed quickly and in convenient conditions - for example in the body and not in a high-pressure chemical reactor at 600 degrees C. All life processes are catalysed, for example decomposition of sugars, fats, synthesis of all biological compounds..." - said the chemist.
Catalysts are also useful in industry. The use of suitable catalysts can accelerate the production of various chemical compounds such as drugs, and reduce the costs of reactions. "Bacteria are a goldmine of new catalysts. The resources are huge, and we only slightly scratched their surface with a fingernail" - illustrated the scientist.
SO THAT FREE RADICALS BECOME SLOW
The scientist explained that reactions that occur in aerobic organisms are more typical. "Metabolising organic compounds usually involves oxidation" - said the scientist. But enzymes of anaerobic organisms still have many secrets.
The enzymes that Prof. Szaleniec studies they are responsible for hydroxylation, among other things. They precisely introduce the group -OH (derived from water) into hydrocarbons. This process is much easier when the body has oxygen molecules and of course suitable catalysts at its disposal. Meanwhile, the enzymes that Maciej Szaleniec investigates, make this process possible also with a complete lack of oxygen molecules - thanks to the use of atypical enzymes. Interestingly, these catalysts allow the introduction of a hydroxyl group into molecules with greater precision than is often the case with traditional oxygen reactions.
IDEA FOR APPLICATION!
Using such an enzyme from bacteria, it is possible to synthesize compounds that are valuable for the pharmaceutical industry. "This year we obtained a Polish patent for a practical method of synthesis of some chirally pure alcohols" - said the researcher. He noted that these compounds can be used, for example, to produce fluoxetine, also known as Prozac.
According to Prof. Szaleniec, the production of such compounds - alcohol dehydrogenases - has been commercialised by BASF, but the patent no longer applies in Poland. "We studied these enzymes in parallel with them, and our technology is available for Polish industry" - commented Maciej Szaleniec.
The second method also based on an enzyme from this class is the vitamin D hydroxylation method (enzyme from Sterolibacterium denitrificans). The chemist said that the chemical synthesis has 9 stages and takes 3 months in the laboratory. And Polish researchers can do it in one stage, which takes three days. Although the reaction efficiency is high, it is still expensive to synthesize the bacterial catalyst itself. "We will be able to further improve it" - he announced.
The scientist explained that individual enzymes obtained from petrol-eating bacteria are not enough to handle pollution - for example an oil spill from a tanker. For this you need the entire chemical route - sometimes these are reactions carried out by various bacteria that slowly clean the area.
Author: Ludwika Tomala
PAP - Science in Poland
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