Production and characterization of rhamnolipids produced from alternative substrates

Abstract

Biosurfactants are substances synthesized by microorganisms. They have the ability to reduce surface and interfacial tension, and can be applied in various sectors of the industry. Rhamnolipids are biosurfactants of the glycolipid class that have high surface activity and higher production yield. Rhamnolipids produced by Pseudomonas aeruginosa are made up of a mixture of homologous species, where mono-rhamnolipids and di-rhamnolipids are predominant. The ratio between these counterparts in rhamnolipid results in different properties and applicability for the compound, a fact that can be influenced by the carbon sources present. To deepen the studies in this area, it is interesting to take into account the individual contribution of each counterpart in the final properties of rhamnolipid. However, such analyzes are dependent on the development of compound separation methodologies. Thus, this research seeks to study the production of rhamnolipids from two alternative substrates, guava seed oil and d-limonene, by-products from fruit processing. The objective is to obtain a higher yield of this metabolite, in addition to evaluating the extraction and separation of the homologues present in the rhamnolipid. The experiments will be conducted in the laboratory from fermentations in flasks using P. aeruginosa LBI 2A1. Microbial growth will be evaluated from the dry mass. The quantification and characterization of rhamnolipid and its counterparts will be carried out in HPLC, TLC and HPLC-MS. The separation of the homologues will be made from column chromatography and with inclusion complexes formed by cyclodextrin. (AU)