Abstract:
Soil contamination with crude oil or petroleum residues is worldwide the major problem occurred consequently to
exploitation, transport and processing. The presence of hydrocarbons leads to increased quantities of carbon and
imbalances in C:N ratio with consequences on microbial life from soil. A wide variety of edaphic microorganisms
including bacterial and fungal species are known as hydrocarbon bio-degraders, contributing to soil decontamination.
Research has been carried out to characterize the microbial communities in soil contaminated with oil hydrocarbons by
an accidental spill from broken pipes in Icoana, Olt county. The results revealed important decrease in both bacterial
and fungal counts under the impact of contaminant hydrocarbons as compared to non-contaminated soil, accompanied
by biodiversity loss (SR2 values 1.49 for bacteria and 2.32 for fungi comparatively with 7.02 and respectively 3.27 in
non-contaminated soil). Low levels of global physiological activity of microorganisms registered in contaminated soil
and 2.34 times higher levels in non-contaminated soil. Changes in species composition of microbial populations
indicated moderate similarity between bacterial species lists (SI=67) and important dissimilarity between fungal species
lists (SI=16). Hydrocarbon utilizers from microflora included pseudomonads, bacilli and cosmopolitan fungal species
from genera Cladosporium, Fusarium, Sporothrix in contaminated soil and Trichoderma, Cladosporium, Aspergillus,
Penicillium in non-contaminated soil.
