During SiCon2021 Ing. Franco Hernán Gómez and  Dr. Alif CHEBBI, members of the research team of CREIAMO Project – Circular Economy, have presented recent advances in the treatment of hydrocarbon-contaminated soils using biosurfactants produced on winery residues:

Treatment of Petroleum-Contaminated Soil Using Novel Rhamnolpids Produced on Winery Residues: a Green Approach within the Circular Economy Framework in Italy

Summary: The present study is part of the project “Circular economy in olive oil and wine sectors-Valorization of by-products and residues through innovative processes and new business models (CREIAMO)”. The development of a CE concept requires adopting closed-loop systems, facilitating the transformation from a flow economy into a CE to improve economic and environmental sustainability. This model can be especially important in Italy, where agriculture is one of the most productive sectors and, at the same time, responsible for generating large amounts of residues with different proprieties. Within this context, our study aimed to assess the rhamnolipid production on winery and olive oil residues as low-cost carbon sources by nonpathogenic strains within the circular economy framework. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/l (13.37 mg/g of NF), with a higher purity, on raw grape marcs, predominately Rha-Rha C14-C14, in MSM medium. Our study indicated for the first time that a nonpathogenic bacterium and rhamnolipid producer could produce surface-active agents in MSM medium, using winery residues as sole carbon and energy source. The produced biosurfactant has been applied on lab-scale contaminated soils and showed promising remobilization effects of the total petroleum hydrocarbons (TPH) (including PAHs). Its ecotoxicity has also been explored before soil applications at lab-scale studies. Furthermore, various bioremediation methodologies are now being evaluated, including mesocosms’, biobiple systems and bio-slurry reactors (and others) towards confirming its feasibility before larger applications in the field. Taken together, our study highlighted the effectiveness of applying these novel rhamnolipids on petroleum-contaminated soils in the race of replacing toxic chemical surfactants.

For an effective biosurfactant production, the presentation highlighted a novel alternative for the pretreatments and hydrolysis methods of the widely-known agricultural wastes (i.e., non-fermented, fermented grape marc, and grape lees). These preliminary activities are part of the project “Circular economy in olive oil and wine sectors. Valorization of by-products and residues through innovative processes and new business models (CREIAMO)”.

CREIAMO_Project. Partners: University of Brescia  – University of Milano Bicocca–  ENEA  (Sustainability Department, Resource Valorisation Lab, Casaccia Research Center)
Funded by: Fondazione Cariplo