Utilization of Decane, Heptane, Petrol and Hexadecane by Fungi Isolated from Engine Oil Contaminated Soil in Ilorin

Fungi with hydrocarbon degrading capabilities were isolated from spent engine oil contaminated soil obtained from five automobile workshops in Ilorin, Nigeria. Preliminary analysis of degradation of the hydrocarbon was performed using Mineral Salts Medium (MSM). The organisms identified include Aspergillus sp., Blastomyces dermatitidis, Cladophialophora bantiana, Mucor circinelloides, Phaeoacremonium parasiticum, Rhizopus arrhizus, Neosartorya fischeri, Cladosporium sp. and Microsporium furrigenum. They were identified based on their morphological and cultural characteristics. Findings from this study showed Aspergillus sp. and Mucor circinelloides were able to degrade hexadecane, heptane, decane and petrol as sole carbon and energy source within 20days. Hydrocarbon utilization rate ranged from 0.020 to 0.284 for heptane, 0.0120 to 0.4965 for decane, 0.079 to 0.340 for hexadecane and 0.023 to 0.268 for petrol. Measurement of optical density and pH was carried to determine hydrocarbon degradation by fungi. The results of this study shows that fungi can play important roles in the effective clean-up of hydrocarbon contaminated soils thereby making them environmentally friendly.Keywords: Engine Oil, Fungi, Soil, hydrocarbons.

Effect Of Laboratory Produced Xylanase From Aspergillus niger On Fibre Digestibility Of Rice Husk And Guinea Grass

The efficacy of laboratory produced xylanase enzyme from Aspergillus niger on highly fibrous feeds and feedstuffs was investigated. Guinea grass (Panicum maximum) from grass hay and rice husk (Oryza sativa) from crop by-product characterised with high fibre content served as substrates (Feeds and Feedstuffs) for the experiment. The enzyme xylanase was prepared from Aspergillus niger (fungal extracts). The two substrates were treated with three levels of aqueous enzymes xylanase (0.02 ml/g, 0.04 ml/g, 0.08 ml/g). Substrate with no enzyme treatment (0 ml/g) served as control. Substrates were subjected to xylanase enzyme treatment at different time interval to determine the optimum incubation period for maximum fibre digestibility. Rice husk and guinea grass were analysed to determine the level of digestibility of fibre fractions such as crude fibre, hemicellulose, acid detergent fibre, neutral detergent fibre and lignin. The results indicate an improvement in fibre digestibility for rice husk and guinea grass treated with enzyme when compared with the control. There was no significant different in the fibre digestibility of substrate treated different levels of xylanase enzyme. Results obtained on the period of application showed no significant different across the time intervals (0 hr, 24 hr, 48 hr and 72 hr). The results therefore, suggest that optimum fibre digestibility could be obtained at level 0.02 ml/g of xylanase treatment at any time interval.Key Words: Aspergillus niger, Xylanase, Rice husk, Guinea grass, Laborator

Biodegradative activities of some gram- negative bacilli isolated from kerosene treated soil grown with cowpea (Vigna unguiculata)

The biodegradative activities of three Gram negative bacilli (Aeromonas hydrophila, Vibro parahaemolyticus and Actinobacillus sp) isolated from soil contaminated with kerosene and planted with cowpea was investigated. The isolates were identified using MicrobactTM ID 24E system for the identification of Enterobacteriaceae and common miscellaneous Gram negative bacilli (MGNB). 2kg of soil collected from University of Ilorin was placed inside transparent, drilled buckets. Physicochemical properties of the soil were recorded. The soil was contaminated with kerosene at different concentrations of 0ml, 7ml, 14ml, 21ml, 56ml, 112ml, 168ml and 224ml. The setup was laid out in a randomized complete block design with three replicates. Cowpea seeds of the variety Samaru-40 were cultivated and observed for eight weeks. The results indicated that kerosene contamination of soils significantly affected the growth parameters: germination percentage, time of germination, rate of germination, plant height, number of leaves, leaf area and root nodules. A negative interaction existed between the level of the contaminant and the growth characteristics measured. Their biodegradative activities were studied and confirmed by the change in the Total Petroleum Hydrocarbon (TPH) using gravimetric method. The biodegradative abilities of the isolates were compared by measuring the optical densities, total viable count, pH and emulsification activity. The results showed that the organisms did better as a consortium rather than singly. Aeromonas hydrophila had the highest biodegradative activity followed by Vibro parahaemolyticus and then Actinobacillus sp. The study recommends the use of Aeromonas hydrophila and consortium for more effective biodegradation.Keywords: Bacterial Biodegradation, Soil, Cowpea, Kerosene, Total Petroleum Hydrocarbo

Biodegradation of Hydrocarbons by Bacillus cereus Isolated from Indoor and Outdoor Air of Selected Hospitals in Ilorin, Kwara State, Nigeria

Indoor and outdoor air of five (5) hospitals in Ilorin, Kwara state were sampled using settling plate method to isolate fifteen (15) bacteria. Bacillus cereus was the identified spore former. Biodegradation performance of Bacillus cereus on hexadecane and heptane using Mineral Salts Medium  (MSM) was studied for 20 days at four days interval using the Jenway 6320D Spectrophotometer to assess the optical density. The degradation and utilization of the hydrocarbons occurred before the fourth day with readings for optical density obtained as 1.051nm and 0.820nm for hexadecane and heptane respectively. After day 4, there was a sharp decline in the utilization of hydrocarbons. A second experiment was setup for optical density with heptane and decane utilization being checked daily for a period of 5days. Bacillus cereus utilized the hydrocarbons till the fourth day as the optical density dropped on the fifth day. The readings for decane obtained on day 4 and day 5 were 0.431nm and 0.338nm respectively. Also, there was a decline in the readings of heptane from 0.451nm obtained on day 4 to 0.343nm obtained on day 5. This study shows that Bacillus cereus is promising in the biodegradation of alkanes and can also be utilized to clean up pollution from petroleum spill which is becoming a prevalent ecological hazard. Keywords: Air, Bacillus cereus, Biodegradation, Hospitals, Hydrocarbon