Crude Oil-Degradation and Plasmid Profile of Nitrifying Bacteria Isolated from Oil-Impacted Mangrove Sediment in the Niger Delta of Nigeria

The crude oil degradability and plasmid profile of autotrophic nitrifying bacteria, Nitrosomonas and Nitrobacter species, isolated from mangrove sediment in the Niger Delta of Nigeria were studied. The effects of temperature, pH and optical density on the utilization of different carbon sources by the bacteria were also investigated. Results showed that nitrifying bacteria could utilize kerosene, diesel oil, jet fuel and engine oil as carbon sources. None utilized hexane and xylene but moderate growth was observed in benzene, phenol and toluene. However, their ability to utilized crude oil varied both in rates of utilization and in growth profiles. Mixed culture of the isolates degrades 52 % of crude oil introduced into the medium followed by Nitrosomonas sp. with 40 % degradation. The least was Nitrobacter sp. with 20 % degradation. The ability of the autotrophs to degrade crude oil was found to be plasmid-mediated through curing experiment and electrophoresis. The size of the plasmid involved was estimated to be 23 kb. The high crude oil utilization of the mixed culture implies that nitrifying bacteria isolated from contaminated ecosystem are excellent crude oil degraders and can be harnessed for bioremediation purposes

Marine Tar Residues: a Review

Abstract Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats). These residues can remain in the ocean envi-ronment indefinitely, decomposing or becoming buried in the sea floor. However, in many cases, they are transported ashore via currents and waves where they pose a concern to coastal recreation activities, the seafood industry and may have negative effects on wildlife. This review summarizes the current state of knowledge on marine tar residue formation, transport, degradation, and distribution. Methods of detection and removal of marine tar residues and their possible ecological effects are discussed, in addition to topics of marine tar research that warrant further investigation. Emphasis is placed on ben-thic tar residues, with a focus on the remnants of the Deepwater Horizon oil spill in particular, which are still affecting the northern Gulf of Mexico shores years after the leaking submarine well was capped

Fusion of two yeast strains for enhanced crude oil degradation

A hybrid strain S24 was developed from Saccharomyces cerevisiae Y5A and Saccharomyces carlsbergensis Y7B, using protoplast fusion technique. The yeast protoplasts were prepared using gut juice from Helix pomatia (Land Snail) as cell digesting enzyme. The ability of the wild and the hybrid strains to degrade medium and light crude oil was determined gravimetrically. The parental strains Y5A and Y7A caused 56.9 and 52.6% weight loss respectively of light crude, while the hybrid caused 72.4% weight loss which was 19.3% and 16.6% higher than Y5A and Y7B respectively. Strains Y5A and Y7B also caused 46.7 and 4.1% weight loss respectively of medium crude while S24 caused 63.3% weight loss, which was 19.2 and 15.3% higher than the Y5A and Y7B. The results indicate that hybrid strains are potential candidates for crude oil pollution abatement programmes in oil spilled sites. KEY WORDS: Protoplast fusion, Saccharomyces, hybrid strains, Snail juice, Biodegradation. Global Jnl Pure and Applied Sciences Vol.10(4) 2004: 491-49

Prevalence Of Micro-Organisms In Flies And Meat Cuts In Uyo Abattoir, Akwa Ibom State

A total of 100 samples, 50 each of fresh meat cuts and flies were aseptically collected from Iba-Oku Abattoir in Uyo, Akwa Ibom State periodically and processed for quantitative and qualitative microbiological analysis using cultural procedures. Results of quantitative analysis revealed microbiological load of flies ranging from 1.8 (+ 0.02) X 106 to 1.83 ( + 0.33) X 106 cfu/g-1 while that of meat cuts ranged from 1.2 (+ 0.02) X105 to 1.25 (+ 0.33) X 106 cfu/g-1. The viable plate count (VPC) of Micro-organisms on flies was significantly (P < 0.05) higher in all the weeks of analysis. Qualitative evaluation of bacterial flora of the meat cuts and flies revealed Staphylococus aureus as the most predominant organism, 48% and 50% respectively while Proteus was the least with 12% and 14% incidence in meat cuts and flies respectively. Apart from known mycotoxin producing Aspergillus and Penicillium species encountered in this work, the occurrence of Stapylococcus aureus, E. coli, Bacillus cereus, Staphylococcus epidermidis, Micrococcus roseus, Bacillus subtilis, Streptococcus, Klebsiella, Pseudomonas, and Salmonella species is indicative of gross contamination and constitute potential health hazard to consumers. Continuous microbiological surveillance of abattoirs is recommended to avert imminent danger of food borne intoxications. The public health significance of these findings are discussed in the paper. KEY WORDS: Microbial, Contamination, Meat cuts, Flies, Abattoir. Global Journal of Agricultural Sciences Vol.3(1&2) 2004:79-8