Biodegradation of Kerosene by Aspergillus niger and Rhizopus stolinifer

Abstract

This study investigated the abiliy of two fungi to utilize Kerosene. The fungal isolates obtained in this study were Aspergillus niger and Rhizopus stolinifer. In the present study, a significant differences in the percent of Kerosene degrading fungi were evident among the time of biodegradation. The growth profiles were determined by monitoring growth ability in (potato dextrose agar PDA) medium containing 0.0, 5%, 10%, 15%, 20% v/v Kerosene, dry weights and pH of utilizing Kerosene as carbon and energy source were determined. There was no significant in dry weights of fungi at the 7 days of incubation. A.niger had the highest dry weight value of 0.530 gm in 10% concentration while R.stolinifer had the low dry weight value of 0.522 gm. The pH values decreased in a fungal cells metabolized after 28 days of incubation. R.stolinifer had the highest pH value of 6.3 after 28 days incubation, but A.niger had the lowest PH of 4.6 on Kerosene and there was no significant. The ability of fungi to degrade Kerosene was measured directly by determination the residual Kerosene by FTIR Spectroscopy and indirectly by gravimetric estimation of residual Kerosene left after biodegradation was made by weighing the quantity of Kerosene in a tared flask. The highest percentage loss of Kerosene concentration by the cultures of fungi was 93% by A.niger after 28 day of biodegradation, but the loss of Kerosene concentration in the culture of R.stolinifer reached to 88% after 28 day. Both strains A.niger and R.stolinifer were capable of consuming kerosene as a sole carbon. The data obtained in the present investigation advance our knowledge of kerosene resistance in Aspergillus niger isolated from Iraqi marshes and may make this promising candidates for further investigations regarding their ability to remove kerosene from contaminated environment.