Banca de DEFESA: HELOISA CARNEIRO COLARES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : HELOISA CARNEIRO COLARES
DATE: 17/09/2021
TIME: 14:00
LOCAL: https://meet.google.com/zvi-aszg-ddc
TITLE:

Optimization of biomass production by lactic acid bacteria isolates in whey and potential industrial application

KEY WORDS:

Probiotics, optimization, fractional factorial, DCCR, antioxidant activity.

PAGES: 154
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Bioquímica dos Microorganismos
SUMMARY:

Probiotics are defined as live microorganisms that have beneficial effects on the health of those who consume them. High density cultures of lactic acid bacteria (BALs) are increasingly important from an industrial point of view, as products added with these supplements have high added-value. The use of renewable and low-cost sources, such as industrial dairy residues, can make industrial production of probiotics possible. Thus, this work aimed to optimize the growth of isolates from four strains of lactic acid bactéria: P2, Ca12, M4 and M13, in whey. As well as performing physical-chemical, feasibility, yield tests, evaluation of antioxidant activity, production of lipase and amylase from the four probiotic strains. Optimization was performed through the enrichment of whey, using the fractional factorial design (DFF) and a central rotational composite design (DCCR), outlined by the Minitab18 program. After optimization, it was possible to obtain an increase in live biomass of 787% for the P2 strain, 590% for the Ca12 strain, 1074% for the M4 strain and 2542% for the M13 strain, when compared to the results of UFC mL^-1 before the optimization process. The physical-chemical tests carried out were, reconstruction time, pH and acidity of the lyophilized probiotic. All strains showed time to reconstitution in 100 s in water, pH close to neutral. The viability of lyophilized probiotics was tested at room temperature and at 4 ° C. The temperature of 4 ° C guaranteed the stability of the strains for up to 8 months with a reduction of less than 1 log cycle in viability. The production yield of the strains was verified, reaching a production above 1.90 g L^-1 for all strains. The evaluation of antioxidant activity was performed using the DPPH method. All strains showed a high antioxidant activity, being between 74% and 81% for intact strains and 46% to 65% for lysed strains. The hydrogen peroxide resistance test was also carried out. All strains showed resistance, with the M13 strain being the most resistant. Finally, it was tested whether the 4 strains were lipase producers using tributyrin as an inducer and amylase through the starch agar medium. As a result, neither amylase or lipase activity was found. The optimization of the production process of the probiotic strains made it possible to scale the bioprocesses. All strains showed antioxidant activity and potential biotechnological application in the industry.

BANKING MEMBERS:
Presidente - 1675931 - PAULO AFONSO GRANJEIRO
Externa ao Programa - 2045083 - TELMA PORCINA VILAS BOAS DIAS
Externo ao Programa - 1300132 - WHOCELY VICTOR DE CASTRO
Externa à Instituição - ANA PAULA DO CARMO - IFES
Externo à Instituição - UELINTON MANOEL PINTO - USP