Banca de DEFESA: ANA PAULA MELO BIONE

PRODUCTION OF BIOSURFACTANT AND LIPIDS BY MUCOR CIRCINELLOIDES UCP 0018 ISOLATED AND IN CO-

CULTIVATION WITH CHLORELLA VULGARIS UTEX 1813 USING AGROINDUSTRIAL SUBSTRATES.

Microalgae, Mucorales, Surfactant, Fatty acids, Metabolites, Mixed culture.

Co-cultivation with microalgae has been a sustainable and promising alternative for the production of biomass and several metabolites of industrial importance. In this sense, studies were carried out with the potential of the axenic culture of the filamentous fungus Mucor circinelloides UCP 0018, as well as, in co-cultivation with the microalgae Chlorella vulgaris UTEX 1803, in the transformation of the alternative substrates cornocine and crude glycerol in the production of biosurfactant and lipids. , considering complementarity in the metabolism of these microorganisms as a promising strategy. The bioproducts were obtained in a production medium containing agro-industrial residues crude glycerol (9%) and corncin (9%), incubated for 120 h, maintained under constant aeration (peristaltic pump), in static submerged fermentation and room temperature (28oC) . The first stage of the study occurred with the production of biosurfactant by M. circinelloides exhibiting surface tension with a reduction in water from 72 to 29.7 mN/m. Furthermore, the biosurfactant demonstrated an efficient ability to form an emulsion, with an emulsification index (EI24) of 98% with burned engine oil. The preliminary analysis showed a polymeric nature of the biosurfactant, consisting of 55.7% carbohydrates, 28.2% lipids and 16.1% proteins. The biomolecule exhibited anionic character and a critical micelle dilution (CMD) of 50%. Additionally, the biosurfactant was stable at different temperatures, pH and NaCl concentrations. Continuing, studies were directed towards the production of biosurfactant from the cocultivation of M. circinelloides and C. vulgaris. The biosurfactant produced was identified as a glycolipid, exhibiting a composition of 46.1% carbohydrates and 53.9% lipids, with a notable ability to reduce surface tension, from 72 to 28.1 mN/m, critical micelle concentration. (CMC) of 1.25 g/L, anionic character and yield of 3.89 g/L. The bioproducts were evaluated for ecological safety and toxicity tests using Daphnia magna and Artemia sp., as well as in inducing germination of cabbage seeds (Brassica oleracea var. acephala). The results indicated no toxic effects, suggesting that the biosurfactant produced in co-culture is ecologically friendly and has potential for application in several areas of knowledge, especially in agriculture. The final investigations were directed towards the production of lipids by both microorganisms C. vulgaris, grown in modified Bold medium produced 1.315 g/L of biomass which accumulated with 72% total lipids. M. circinelloides, when cultivated in crude glycerol (9%) and corncin (9%), accumulated 20.438 g/L of biomass and 69% of total lipids. In the process of associating these microorganisms in co-culture, 24.9 g/L of biomass and 72% of lipids were produced under static fermentation. Regarding lipid composition, M. circinelloides presented saturated (14.41%), monounsaturated (7.58%) and polyunsaturated (78.01%) fatty acids, highlighting the potential in omega 6 (linoleic acid, C18: 2) and omega 3 (alpha-linolenic acid, C18:3). C. vulgaris revealed high potential for the production of omega 6 (arachidonic acid, C20:4). The lipids produced in co-culture presented FAM=14.22% and PUFA=85.78%, being promising in omega 6 (linoleic and gamma-linolenic acids) and omega 3 (alpha-linolenic acid). The promising results obtained demonstrated the high value and sustainability of bioprocesses in obtaining microbial oils from the co-cultivation of M. circinelloides and C. vulgaris for applications in the food, pharmaceutical and cosmetic industries, highlighting the sustainable and ecological production of the future biosurfactant molecule.