The investigation of the presence of microfungi in petroleum reservoirs

Produced water is a mixture of oil and natural gas that has water underground and the water used during extraction. These produced waters, which can be several times the volume of petroleum extracted to the surface, contain hydrocarbon compunds, salt and various minerals in their structers. Although produced water has unfavourable living conditions such as high salinity rate and presence of heavy metals for the viability of microorganisms, microfungi are known to adapt these conditions. Studies made in recent years, it has been reported that Aspergillus, Cladosporium, Fusarium, Mucor, Penicillium, Rhizopus and Trichoderma microfungi genuses which isolated from produced water can be used for the breakdown of petroleum hydrocarbons. In this study, the presence, total colony number and diversity of the culturable microfungi that can be cultivated by using spread plate method in 5 different media (PDA, SDA, CDA, MEA and DG18) and also amylase, cellulase, lipase and gelatinase enzyme activity index values of isolated microfungi were investigated in 7 oil wells in different oil fields in Adıyaman province. In this context, the presence of microfungi was determined in all oil wells sampled. Among cultivated media it was determined that the highest species diversity is in CDA, DG18, PDA, SDA and MEA media, respectively. A total of 53 microfungi were isolated from 7 different produced water samples and 43 of these isolates produced amylase and cellulase and 23 of them produced lipase enzymes. Of the 53 isolated microfungal isolates, 26 are Aspergillus versicolor, 8 are Penicillium chrysogenum, 7 are Penicillium solitum, 4 are Aspergillus flavus, 3 are yeast, 2 are non-sporulating fungus, 1 is Aspergillus sp., 1 is Chaetomium sp. and 1 of them was identified as Cladosporium cucumerinum. The obtained results emphasizes that microfungal biodiversity is present in oil production wastewater of different oil fields in Adıyaman province, that the isolated microfungi have the ability to produce some industrially important extracellular enzymes, the enzymatic activity index values can vary depending on the strain and use of different media is necessary for the isolation of metabolically different microfungi.