Banca de DEFESA: DIEGO FERNANDES LIVIO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DIEGO FERNANDES LIVIO
DATE: 30/12/2022
TIME: 14:00
LOCAL: https://meet.google.com/rdf-fbvv-eog
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: 171
BIG AREA: Multidisciplinar
AREA: Biotecnologia
SUMMARY:

Iturin A, a lipopeptide biosurfactant, has efficient physicochemical properties for natural cosmetics because it is ecologically correct, has high compatibility with the skin, has a low critical micellar concentration (CMC), high foaming and emulsifying activity. However, in general, the large-scale production of biosurfactants remains limited due to their low yield, high cost of the culture medium and purification. The objective of this work was to validate the optimization of the production of the lipopeptide biosurfactant and characterize it for commercial purposes with a focus on the development of new cosmetic products. The culture medium previously optimized by the research group showed a nitrogen content of 0.019 µg.µL^-1, derived from the protein content present in the soy flour extract. The Bacillus subtilis growth curve (ATCC 19659) was related to lipopeptide production due to the decrease in surface tension until the end of the exponential phase (55 hours of cultivation), above 1x1010 CFU.mL^-1. The constituents of the culture medium and their concentrations were validated by delineating the central rotational compound (DCCR) in relation to the surface tension (TS) related to the generated lipopeptide, being, in g.L^-1, 20 of sugar, 1 of L-arginine and 50 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 characterized molecularly as iturin A. Iturin A was considered poorly soluble in deionized water; insoluble in ethanol, canola oil, corn oil and propylene glycol; very little soluble in glycerol and mineral oil. In the drop collapse test, iturin A (1 mg.mL^-1) showed surfactant activity, on average, 22% more dilation compared to the control (deionized water). The critical micellar concentration (CMC) of iturin A was 0.176 mg.mL^-1, capable of reducing the TS of deionized water from 73.1 ± 0.1 mN.m^-1 (control) to 34.5 ± 0, 05 mN.m-1, at 25 ºC and 1 mg.mL^-1 for 33 ± 0.3 mN.m^-1. Iturin A showed pI at pH 3. Iturin A showed the third best surfactant performance (35.6 ± 0.94 mN.m^-1) in relation to the TS of some commercial surfactants and remained relatively stable over a wide pH range (2 to 11); temperature (-20°C to 100°C); saline concentration (2.5 to 20%); after autoclaving and oven drying (50 ºC). Compared to some commercial emulsifiers, iturin A had the best emulsification index (IE₂₄) in long-chain oil (85%) and was the most stable in emulsions with different cosmetic oils, over the 72h evaluated. Iturin A showed the best foam stability compared to commercial surfactants; it was environmentally non-toxic at all concentrations evaluated; presented an EHL of 6, being able to stabilize cosmetic formulations. In the scale-up of production, the yield of iturin A from cultivation in 2 L Erlenmeys went from 3.8 ± 0.3 g.L^-1 semi-purified (centrifugation and acid precipitation), having a TS of 37 ± 0. 2 mN.m^-1, to 16 ± 0.5 g.L^-1 in a bioreactor containing 3 useful L of culture medium, having a TS of 37 ± 0.2 mN.m-1. After purification by foam fractionation and lyophilization, the yield of purified iturin A was 8 ± 0.4 g.L^-1 having a TS of 31.8 ± 0.1 mN.m^-1. Thus, we concluded the effectiveness of the optimization of the iturin A production bioprocess, with great potential for its application in the cosmetics industry.

BANKING MEMBERS:
Presidente - 1675931 - PAULO AFONSO GRANJEIRO
Externa ao Programa - 1080217 - FARAH MARIA DRUMOND CHEQUER BALDONI
Externo à Instituição - MARCEL OTAVIO CERRI - UNESP
Externo à Instituição - ALCIDES DE OLIVEIRA WANDERLEY NETO - UFRN
Externo à Instituição - ADRIANO GUIMARAES PARREIRA - UEMG