Evaluation of microbial systems for bioremediation of petroleum refinery effluents in Nigeria

The potential of various organisms to catabolize and metabolize organic compounds has been recognized as potentially effective means of disposing of hazardous wastes. Phenolic compounds has long been recognized as one of the most recalcitrant and persistent substance in petroleum refinery effluents. This is a cause of some concern because of the high toxicity and of this compound. Bioremediation of phenolic compounds has been recognized as a potential solution for the disposal of phenolic compounds due to its scale ability, cost effectiveness and simplicity. The two species of Pseudomonas, P. aeruginosa and P. fluorescence were studied for their bioremediation potential on Refinery effluent with respect to phenol biodegradation in a batch reactor. Phenol was degraded completely by the two species. While P. aeruginosa completely mineralize phenol at the 60th hour of cultivation, only 75% (23 mg/l) of phenol was degraded by P. fluorescence; complete degradation was achieved at the 84th hour of fermentation. There was highly positive correlation between phenol biodegradation and the microbial growth. (r = +0.994 and r = +0.980 at

Unlocking preservation bias in the amber insect fossil record through experimental decay.

Fossils entombed in amber are a unique resource for reconstructing forest ecosystems, and resolving relationships of modern taxa. Such fossils are famous for their perfect, life-like appearance. However, preservation quality is vast with many sites showing only cuticular preservation, or no fossils. The taphonomic processes that control this range are largely unknown; as such, we know little about potential bias in this important record. Here we employ actualistic experiments, using, fruit flies and modern tree resin to determine whether resin type, gut microbiota, and dehydration prior to entombment affects decay. We used solid phase microextraction gas chromatography-mass spectrometry (SPME GC-MS) to confirm distinct tree resin chemistry; gut microbiota of flies was modified using antibiotics and categorized though sequencing. Decay was assessed using phase contrast synchrotron tomography. Resin type demonstrates a significant control on decay rate. The composition of the gut microbiota was also influential, with minor changes in composition affecting decay rate. Dehydration prior to entombment, contrary to expectations, enhanced decay. Our analyses show that there is potential significant bias in the amber fossil record, especially between sites with different resin types where ecological completeness and preservational fidelity are likely affected

Effect of diets containing different nutrient density on performance and faecal egg count of West African Dwarf rams

A study was conducted to determine the effect of different nutrient densities on performance characteristics and faecal egg count of West African Dwarf (WAD) rams semi-intensively managed. Twenty four yearling lambs between 10 – 15kg were used for the experiment. The lambs were allotted to two treatment groups containing 12 animals per group. They were released into the paddock containing sown pasture to graze for 6 hours per day. The animals were randomly assigned to treatments containing two levels of protein-energy density; low energy, low protein (LELP) and high energy, high protein (HEHP) in a completely randomized design. Performance characteristics of WAD rams showed that protein and energy density have significant effect (P<0.05) on weight gain, daily weight gain and protein intake. Metabolic weight gain was influenced (P<0.05) positively by the protein and energy density. Animals fed HEHP diets had significantly (P<0.05) higher protein intake (54.66 g) than those fed LELP diets (22.92 g). The slope observed for animals on HEHP diet was lower compared to that of their counterpart on LELP diet. Hence, HEHP diets improved performance of West African Dwarf sheep as well as reducing the gastrointestinal parasite infection due to lower FEC recorded.Keywords: Nutrient densities, performance, faecal egg coun