RESEARCH PAPER
Phytotests as tools for monitoring the bioremediation process of soil contaminated with diesel oil

The aim of the study was to determine changes in phytotoxicity levels during bioremediation of soil contaminated

with 5% (v/w) diesel oil and find their correlation with the effectiveness of hydrocarbon degradation. Bioremediation

trials were performed using a Gordonia alkanivorans S7 strain. The clean-up process was enhanced through

the addition of dried fungal enzymatic preparations obtained from fungi Phanerohaete chrysosporium and Aspergillus

niger. After 110 days of bioremediation the decrease in soil pollution ranged between 68 and 77% depending

on treatment conditions. Toxicological tests using marker plants revealed significant differences in the phytotoxicity

levels of soil during bioremediation, depending on the treatment variant. The addition of an enzymatic fungal

preparation to soil was found to accelerate the rate of contaminant degradation. The rate of hydrocarbon depletion

in subsequent phases of the remediation process was found to be correlated with the phytotoxicity level. The obtained

results provide evidence that phytotests can be useful tools for monitoring toxicity changes during

bioremediation either mediated only by bacteria or additionally stimulated by fungal enzymatic preparations.