Valorization of agro-industrial wastes towards the production of rhamnolipids

• Published in: Bioresource technology Vol. 212; pp. 144 - 150
• Main Authors: Gudiña, Eduardo J., Rodrigues, Ana I., de Freitas, Victor, Azevedo, Zélia, Teixeira, José A., Rodrigues, Lígia R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-07-2016; Elsevier
• Subjects: Agriculture; Corn steep liquor; Glycolipids - biosynthesis; Industrial Waste - analysis; Molasses - analysis; Oil mill wastewater; Oils - chemistry; Olea; Pseudomonas aeruginosa; Pseudomonas aeruginosa - metabolism; Rhamnolipid; Saccharum - chemistry; Science & Technology; Sugarcane molasses; Surface Tension; Waste Disposal, Fluid; Waste Water - chemistry; Pseudomonas aeruginosa; Oil mill wastewater; Sugarcane molasses; Rhamnolipid; Corn steep liquor
• ISSN: 0960-8524; 1873-2976; 0960-8524
• DOI: 10.1016/j.biortech.2016.04.027

•Oil mill wastewater (OMW) was evaluated as an inductor of rhamnolipid production.•A culture medium containing corn steep liquor, molasses and OMW was designed.•Pseudomonas aeruginosa #112 produced 5.1g rhamnolipid/l using that medium.•The critical micelle concentration of the purified rhamnolipids was 13mg/l.•This medium represents a sustainable alternative for rhamnolipid production.
In this work, oil mill wastewater (OMW), a residue generated during olive oil extraction, was evaluated as an inducer of rhamnolipid production. Using a medium containing as sole ingredients corn steep liquor (10%, v/v), sugarcane molasses (10%, w/v) and OMW (25%, v/v), Pseudomonas aeruginosa #112 produced 4.5 and 5.1g of rhamnolipid per liter in flasks and reactor, respectively, with critical micelle concentrations as low as 13mg/l. Furthermore, in the medium supplemented with OMW, a higher proportion of more hydrophobic rhamnolipid congeners was observed comparing with the same medium without OMW. OMW is a hazardous waste which disposal represents a serious environmental problem; therefore, its valorization as a substrate for the production of added-value compounds such as rhamnolipids is of great interest. This is the first report of rhamnolipid production using a mixture of these three agro-industrial by-products, which can be useful for the sustainable production of rhamnolipids.