Banca de QUALIFICAÇÃO: WALESKA RAYANE DANTAS BEZERRA DE MEDEIROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : WALESKA RAYANE DANTAS BEZERRA DE MEDEIROS
DATA : 30/09/2019
HORA: 09:00
LOCAL: Sala de aula do Laboratório CATRE - Departamento de Engenharia Química
TÍTULO:

OPTIMIZATION OF LIPASE PRODUCTION BY ASPERGILLUS NIGER IOC 4003 IN SOLID STATE FERMENTATION FOR CAPRILINE SYNTHESIS APPLICATION

PALAVRAS-CHAVES:

Lipase. Aspergillus niger. Solid state fermentation. Enzymatic activity. Agro-industrial by-products.

PÁGINAS: 84
GRANDE ÁREA: Ciências da Saúde
ÁREA: Farmácia
RESUMO:

Lipases are enzymes used in different industrial segments because of their versatility. Its applications include synthesis of caprilines, medium-chain acylglycerols with various applications in the food, pharmaceutical and cosmetic areas. In this context, the present study aimed to optimize lipase production by Aspergillus niger IOC 4003 by solid-state fermentation using low-cost substrates, aiming at enzyme application in the synthesis of caprilines. For this, the wheat bran, cottonseed cake and tilapia viscera oil were initially subjected to physicochemical characterization. Next, enzyme production was optimized using multivariate analysis. To select the variables with the greatest effect on lipase production, a Plackett-Burman experimental design with 11 factors (independent variables) was performed, totaling 15 trials. The factors studied were cultivation time, pH, inoculum concentration, moisture, tilapia viscera oil concentration, glucose, urea, yeast extract, KH2PO4, MgSO4 and cottonseed cake/wheat bran ratio. After, in order to optimize the cultivation conditions, a Rotational Central Composite Design 23 was performed with the variables selected in the Plackett-Burman design, using cottonseed cake as solid support. The response variable (lipolytic activity) was measured using p-nitrophenyl palmitate as reaction substrate after enzymatic extraction in 0.05 M Tris-HCl buffer (pH 8). In PB design, the selected variables were tilapia viscera oil concentration, pH and moisture. The results obtained for the CRCD revealed that the lipolytic activity was influenced by the three evaluated variables and their interactions, with a maximum value of 514.23 ± 99.81 U/g, using 60% moisture, pH 6.0 and 4% tilapia viscera oil. Furthermore, it was verified that, under the study conditions, supplementation with yeast extract, urea, glucose, KH2PO4 and MgSO4 was not necessary. This added to the use of cottonseed by-products and tilapia viscera oil, they bring promising results and higher economic viability. Thus, the excellent enzymatic activity found after multivariate optimization will allow the application of lipases obtained in the synthesis of caprilines.

MEMBROS DA BANCA:
Externa ao Programa - 2378605 - CRISTIANE FERNANDES DE ASSIS
Presidente - 1544647 - MATHEUS DE FREITAS FERNANDES PEDROSA
Externo à Instituição - PEDRO FERREIRA DE SOUZA FILHO - UFRN