BIODEGRADATION OF CRUDE OIL POLLUTANT EXTRACTED FROM CONTAMINATED SOIL SAMPLES USING SINGLE AND COMBINATION CULTURES OF FILAMENTOUS FUNGI

The crude oil pollution of the soil is one of the most important current problems that pose a future threat to the environment and human health, therefore, the present study aims to determine the ability of single and mixed cultures of some filamentous fungi isolates to decompose the cude oil pollutant. The isolates Aspergillus niger 4RS, Fusarium avanecium 12RS, and Aspergillus niger 7RW were used to degrade the oil pollutants in contaminated soil as a single and mixed culture.

Results of degradation were obtained after different periods of treatment (7, 15, 21, and 30 days) were conducted in single and mixed cultures. Data revealed that single and mixed cultures appeared a good ability to consume the oil pollutants during the periods studied and that the biggest degradation has occurred after 30 days of incubation in single and mixed cultures compared with other periods. The results noted that the single culture of Aspergillus niger 4RS, Fusarium avanecium 12RS and, Aspergillus niger 7RW showed the highest ability to decompose the oil compared with the mixed culture, where the degradation percentage was 61.2%, 48.4%, 78.1%, and 45.8% respectively. Also, the results indicated that the best fungal isolate Aspergillus niger 7RW was degraded the oil pollutants after 7, 14, 21, and 30 days of incubation at a rate greater than other studied cultures, where the rate of degradation reached 11.5%, 29.4%, 52.3%, and 78.1% respectively. The results of biodegradation percentage, according to GC analysis, of oil pollutants using the best isolate Aspergillus niger 7RW showed that this isolate was degrading the oil pollutants at the same value of degradation rate (77.8%) when using the previous weighting method and this also occurred after 30 days of incubation.