Fungal bioremediation of olive mill wastewater: using a multi-step approach to model inhibition or stimulation

Olive mill wastewaters (OMWWs) possess a strong environmental impact; the use of fungi as tools for bioremediation could be a promising method.

Twenty-nine fungi were grown on minimal media supplemented with five different kinds of OMWWs (5-15%). Radial growth was assessed for 21 days and the data were modelled through the Dantigny-logistic like function to estimate τ, i.e. the time to attain half of the maximum diameter. Growth on potato dextrose agar and water agar (WA, minimal medium without supplementation) was used as reference. The differences in τ between PDA/WA and minimal media with OMWWs were modelled through a multi-factorial ANOVA, using the concentration of OMWW, the kind of wastes and fungi as categorical predictors. Finally, a principal component analysis was run to group and divide resistant and sensitive fungi. Some fungi experienced a positive Δτ, thus suggesting an inhibition by OMWW, whereas other isolates were enhanced.

Some isolates (for example Aspergillus ochraceus) showed a promising trend and could be possible candidates for a validation on a real scale. © 2016 Society of Chemical Industry.