TITLE:
Impact of Distillate Diesel Oil on the Growth of Mold Involved in Soil Bioremediation at an Electric Power Plant in Ouagadougou
AUTHORS:
Wendlassida Pauline Ouédraogo, Cécile Harmonie Otoidobiga, Cheik Amadou Tidiane Ouattara, Adounigna Kassogué, Mahamadi Nikiema, Amidou S. Ouili, Ynoussa Maiga, Aboubakar Sidiki Ouattara, Alfred Sababenedyo Traoré
KEYWORDS:
Molds, Hydrocarbons, Distillate Diesel Oil, Bioremediation, Contaminated Soil
JOURNAL NAME:
Advances in Microbiology,
Vol.15 No.12,
December
23,
2025
ABSTRACT: Hydrocarbon compounds are among the most persistent pollutants globally, contributing significantly to the degradation of soil, air, and water, and posing serious environmental risks to ecosystems and human health. Molds, through their ability to degrade, dissolve, immobilize, or mobilize pollutants like petroleum hydrocarbons, are among the main microorganisms playing a crucial role in soil remediation. This study aimed to evaluate the effect of Distillate Diesel Oil (DDO) on the growth behavior of mold strains isolated from hydrocarbon-contaminated soils at an electric power plant in Ouagadougou. During an eight-month study, two soil samples were randomly collected each month from two hydrocarbon-polluted soil piles undergoing off-site biotreatment, resulting in a total of 18 samples analyzed. Using standard microbiological techniques, 31 mold strains were isolated on Sabouraud agar and incubated at 37˚C for 5 to 7 days. The isolates were purified and preliminarily identified based on macroscopic and microscopic morphological characteristics. Their colony diameter and radial growth rate were determined on Sabouraud culture medium supplemented with 5% (w/v) DDO. The isolates were identified as belonging to four genera: Aspergillus spp. (48.39%), Penicillium spp. (25.81%), Fusarium spp. (22.58%), and Geotrichum spp. (3.23%). Despite a significant reduction in colony diameter (from 19.44% to 87.27%) and average radial growth rate (from 21.05% to 86.49%), all isolates showed the ability to grow, revealing adaptive and enzymatic potential favorable to petroleum hydrocarbon biodegradation. Among the isolates, ten isolates (C, E, L, R, S, X, AA, BB, CC, EE) presented less than 50% reduction in colony diameter, with isolate C showing the highest tolerance (only 19% reduction). These mold isolates are promising candidates for future bioremediation applications in hydrocarbon-contaminated environments.