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

Abstract

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 × 10 5 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 (T 1 = 29˚C, T 2 = 35˚C and T 3 = 40˚C), three of pH (pH 1 = 3.5, pH 2 = 5.0 and pH 3 = 6.0) and four nutrients (N 1 = Urea, N 2 = Triple-17, N 3 = Nitrophoska-Blue and N 4 = 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 N 2 pH 2 T 1 , which reached a value of 2.1 × 10 6 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.