NIGERIAN researchers and their Canadian counterparts have isolated fungi capable of biodegrading or eating up petroleum oil within 40 days.A professor of economic botany at the University of Lagos, Prof. Dotun Adekunle, and his team conducted a research to source fungi capable of biodegrading petroleum oil from some Nigerian oilseeds such as soybean, maize, melon, Detarium senegalense (tallow tree) Treculia Africana (African breadfruit), and Irvingia gabonensis (bush mango, ogbonno in Yoruba).They wrote: 'We discovered that the pathogenic fungi isolated from oil seeds are capable of biodegrading the petroleum oil within 40 days. The oilseeds contain triacylglyceride, which is the vegetable oil hydrocarbon and it is biodegradable by the pathogenic fungi. This group of fungi was also able to biodegrade the hydrocarbon in the petroleum oil.'Adekunle in his recent inaugural lecture titled Fungi: Friends or Foes to Mankind' wrote: 'We also used some Nigerian mushrooms in the biodegradation of petroleum products. A collection of mushrooms in the Lagos area was made for up to four years. The mushroom, Ganoderma lucidum and Ganoderma applanatum, biodegraded petroleum crude oil, diesel, spent and unspent engine oil. The gas chromatogram showed that Ganoderma lucidum used up some carbon atoms after 40 days of incubation.'The mycelium of these mushroom is able to breakdown organic pollutants like polycyclic aromatic hydrocarbons (PAH) found in petroleum oil. The mushroom mycelium releases enzymes that breakdown long polymer chains into their basic subunits, such as sugars which can then be absorbed through their walls.'Also, a professor of biological sciences and researcher at the University of Montreal's Institut de recherche en biologie vgtale (IRBV), Mohamed Hijri, has found that when mushroom spores were sprinkled over crude petroleum in a Petri dish, the mushrooms consumed the petroleum within six weeks. The strong odour distinctive of the toxins that make up the fossil fuel disappeared after six weeks.'Adekunle said many species of bacteria, fungi and algae (microorganisms) have enzymatic capabilities to use petroleum hydrocarbons as food. 'Single cultures of fungi are reported to be better biodegraders of petroleum than the traditional bioremediation techniques involving bacteria. Fungi are able to biodegrade the petroleum oil to much smaller non toxic compounds,' he said.The botanist said most reports on the biodegradation or bioremediation using fungi have been mainly on fungi isolated from soil or aquatic environment.With the collaboration of an oil company from the Montreal area, the researchers had access to a microbiological paradise: an area where practically nothing can grow and where no one ventures without protective gear worthy of a space traveler. This is where Hijri collected microorganisms specialised in the ingestion of fossil fuels.'If we leave nature to itself, even the most contaminated sites will find some sort of balance thanks to the colonisation by bacteria and mushrooms. But by isolating the most efficient species in this biological battle, we can gain a lot of time,' Hijri said.
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