Banca de QUALIFICAÇÃO: DIEGO FERNANDES LIVIO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DIEGO FERNANDES LIVIO
DATE: 30/03/2022
TIME: 13:30
LOCAL: google meet
TITLE:

OPTIMIZATION OF THE BIOPROCESS OF PRODUCTION OF BIOSURFACTANTS AND EVALUATION OF ITS APPLICABILITY IN THE COSMETICS INDUSTRY

KEY WORDS:

Optimization; Bioprocess; Biosurfactants; Lipopeptides; ituirin A; Bacillus sp.; cosmetics.

PAGES: 147
BIG AREA: Multidisciplinar
AREA: Biotecnologia
SUMMARY:

 Iturin, a lipopeptide biosurfactant, has exceptional physicochemical properties for natural cosmetics such as being eco-friendly, having low irritation and high skin compatibility, having low critical micelle concentration (CMC), high foaming and emulsifying activity. However, large-scale production of biosurfactants remains limited due to their low yield, high cost of culture and purification media. The objective of this work was to validate and improve the optimization of the production of lipopeptide biosurfactant and characterize it for commercial purposes with a focus on the development of new cosmetic products. The culture medium used was previously optimized by the research group. From this medium, the protein content of soy flour extract (76.76 µg.µL^-1) was analyzed as a nitrogen source (14 µg.µL^-1) for the production of the targeted lipopeptide, as well as the soy flour precipitate. (16.06 µg.µL^-1) with a nitrogen concentration of 2.94 µg.µL^-1. The growth curve of Bacillus subtilis (ATCC 19659) was related to the production of lipopeptide due to the decrease in surface tension until the end of the exponential phase (55 hours of culture), above 1x10¹⁰ CFU.mL^-1. The culture medium was validated by the design of the central rotational compound (DCCR) in relation to the surface tension (TS) of the generated lipopeptide, being, in gL^-1, 20 of sugar, 1 of L-arginine and 50 of soy flour (extract). The lipopeptide was purified using a foam fractionation utility model (in patent process). Alternative sources of nitrogen derived from soybeans such as bran, flour and protein were evaluated in relation to the yield of the lipopeptide produced, in dry mass, being, respectively, in g.L^-1, 0.28; 1.43 and 0.34. The lipopeptide was molecularly characterized as iturin A. Iturin A was considered sparingly soluble in deionized water; insoluble in ethanol, canola oil, corn oil and propylene glycol; very slightly soluble in glycerol and mineral oil. . In the droplet collapse test, iturin A (1 mg.mL^-1) showed surfactant activity, on average, 22 % more dilated than the control (deionized water). The critical micellar concentration (CMC) of iturin A was 0.083 mg.mL^-1, capable of reducing the surface tension of deionized water from 73.1 ± 0.1 mN.m^-1 (control) to 39.5 ± 0 .05 mN.m^-1 at 25 °C and 1 mg.mL-1 for 31.8 ± 0.05 mN.m^-1. Iturin A presented the third best surfactant performance (35.6 ± 0.94 mN.m^-1) in relation to the TS of some commercial surfactants. The surfactant activity of iturin A remains relatively stable over a wide pH range (2 to 11); in the temperature range (-20 ºC to 100 ºC); in the saline concentration (2.5 to 20 %); after autoclaving and drying in an oven (50 ºC). In comparison with some commercial emulsifiers, iturin A showed better emulsification index (IE₂₄) in motor oil (85 %); 59 % in canola oil, 48 % in corn oil, 16 % in toluene and petroleum ether. In different cosmetic oils, iturin A presented IE₂₄ 10 % for coconut oil, 5 % for almond oil and 10 % for mineral oil, over the 72 h. Thus, it was possible to minimize the production costs of iturin A and attest to its good physicochemical characteristics that justify its use in the cosmetics industry. We concluded the effectiveness of the optimization of the biprocess of iturin production, with great potential for its application in the cosmetics industry due to its physicochemical characteristics.

BANKING MEMBERS:
Presidente - 1675931 - PAULO AFONSO GRANJEIRO
Externo ao Programa - 1673648 - JOSE CARLOS DE MAGALHAES
Externo à Instituição - MARCEL OTAVIO CERRI - UNESP
Externa à Instituição - FABIANA TESTA MOURA DE CARVALHO VICENTINI - USP
Externo à Instituição - ALCIDES DE OLIVEIRA WANDERLEY NETO - UFRN