Bioprospecting of Hydrocarbonoclastic Representative Bacteria

This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Nigeria. Heterotrophic bacteria count ranged from 8.0 × 105 cfu/gm for sample TSAS1, and 2.1 × 106 cfu/gm for sample TSAS2 while TSAS3 was too numerous to count (TNTC). Hydrocarbon utilizing bacteria count ranged from 1.1 × 105 cfu/gm for TSAS1, and 5.9 × 104 cfu/gm for TSAS2, while TSAS3 was 5.4 × 104 cfu/gm. Physiochemical parameters of the soil were determined. The ranges obtained were pH 6.6, conductivity 125 μs/cm, temperature 27.3°C, moisture 7.72, total nitrogen 0.056%, phosphate 1.554 ppm, potassium 145.87 ppm, lead 7.02 ppm, cadmium 0.41 ppm, nickel 1.96 ppm, copper 1.14 ppm, total petroleum hydrocarbon 1487.24181 ppm, polycyclic aromatic hydrocarbon 12.85287 ppm. Isolates of hydrocarbon utilizing bacteria characterized belonged to the genera Escherichia coli, Klebsiella sp., Lactobacillus sp., Enterobacter sp., Serratia sp., and Proteus sp. The findings in this study have revealed the abilities of these groups of bacteria to be employed in bioremediation/biodegradation clean-up practices. Thus the polluted soil may harbour important genera of bacterial species that may have beneficial applications in environmental microbiology for future remediation processes.

Optimal Parameters for in Vitro Development of the Fungus Hydrocarbonoclastic Penicillium sp.

México has extensive areas that have been impacted by oil spills for several decades. Current bioremediation technologies mostly used microorganisms to decontaminate sites with hydrocarbons. This research evaluated the conditions for the optimal development of the strain of a hydrocarbonoclastic fungus, which was found in samples of soil contaminated with 4.0 × 105 mg·kg-1 of Total Petroleum Hydrocarbons (TPH). A completely randomized experimental design with a 3 × 3 × 4 factor arrangement was used: three levels of temperature (T1 = 29℃, T2 = 35℃ and T3 = 40℃), three of pH (pH1 = 3.5, pH2 = 5.0 and pH3 = 6.0) and four nutrients (N1 = Urea, N2 = Triple-17, N3 = Nitrophoska-Blue and N4 = Pure-Salts). Total fungi were isolated from the sampled soil and were sown in a combined carbon medium for hydrocarbonoclastic fungi and a strain was selected to be adapted to a liquid mineral medium. The selected strain was classified as Penicillium sp. Analyses of variance and mean tests were performed, using the SPSS-11.0 statistical software. The microorganisms showed the highest population growth in the treatment N2pH2T1, which reached a value of 2.1 × 106 CFU·mL-1 in a biorreactor. To reach it, by bioaugmentation, the same development of Penicillium sp. in a conditioned soil would allow to implement a bioremediation strategy with great potential to retrieve soil contaminated with hydrocarbons both in Tabasco and in general in Mexico.