Combined bioremediation and enzyme production by Aspergillus sp. in olive mill and winery wastewaters

Abstract

Olive mill wastewaters (OMW) and vinasses (VS) are effluents produced respectively by olive mills and wineries, both sectors are of great economic importance in Mediterranean countries. These effluents cause a large environmental impact, when not properly processed, due to their high concentration of phenolic compounds, COD and colour. OMW may be treated by biological processes but, in this case, a dilution is necessary, increasing water consumption. The approach here in proposed consists on the bioremediation of OMW and VS by filamentous fungi. In a screening stage, three fungi (Aspergillus ibericus, Aspergillus uvarum, Aspergillus niger) were selected to bioremediate undiluted OMW, twofold diluted OMW supplemented with nutrients, and a mixture of OMW and VS in the proportion 1:1 (v/ v). Higher reductions of phenolic compounds, colour and COD were achieved mixing both residues; with A. uvarum providing the best results. In addition, the production of enzymes was also evaluated during this bioremediation process, detecting in all cases lipolytic, proteolytic and tannase activities. A. ibericus, A. uvarum and A. niger achieved the highest value of lipase (1253.7 ± 161.2 U/L), protease (3700 ± 124.3 U/L) and tannase (284.4 ± 12.1 U/L) activities, respectively. Consequently, this process is an interesting alternative to traditional processes to manage these residues, providing simultaneously high economic products, which can be employed in the same industries.

Mediterranean agro‐industrial wastes as valuable substrates for lignocellulolytic enzymes and protein production by solid‐state fermentation

“…In these results, it is possible to observe that the concentration of total phenols after SSF was very similar to the values obtained in the control; no significant differences were observed ( P < 0.05) with the exception of EOP, where it is possible to observe a clear decrease of total phenols concentration. It was expected that the phenolic compounds could decrease after SSF because the fungi have the ability to degrade phenolic compounds present in wastes …”

“…It was expected that the phenolic compounds could decrease after SSF because the fungi have the ability to degrade phenolic compounds present in wastes. 35 Relationship among substrates, fungi and SSF performance A principal components analysis was carried out in order to assess the relationship between substrate composition, fungi used, enzymes produced and protein increase. This study allowed us to obtain a small number of lineal combinations of the 10 variables studied to explain the variability of the data.…”

Improved lignocellulolytic enzyme production and antioxidant extraction using solid‐state fermentation of olive pomace mixed with winery waste

“…39 The capacity for the reduction of total phenols was also observed in the fermentation of olive mill wastewater by A. ibericus. 40 The degradation of ferulic, coumaric, and syringic acids by A. niger was also observed. 41 The increase in TP in the SSF of EOP may be due to the action of β-glucosidase and xylanases that can hydrolyze phenolic compounds linked to polysaccharides of agro-industrial waste.…”

Grape Winery Waste as Feedstock for Bioconversions: Applying the Biorefinery Concept

“…Other studies include the use of grape seed oil for the production of rhamnolipid, a biosurfactant generated successfully from the propagation of Pseudomonas aeruginosa J4, while grape marc was used as substrate for lactobacilli spawned anti-allergic substances [74]. Grape marc has been also successfully used in solid state fermentations for the production of hydrolytic enzymes such as exo-polygalacturonase, xylanase, b-glucosidase, pectinase and cellullase [79][80][81][82], substances effective against allergies or bioethanol [83]. Efforts to recover phenols from grape marc, using ultrasound [84] and solvents (ethanol, methanol) [85] and supercritical fluid consecutive [86] extraction method, have been made with a high success rate.…”