Banca de DEFESA: LÍGIA MARIA GONÇALVES FERNANDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LÍGIA MARIA GONÇALVES FERNANDES
DATE: 19/07/2024
TIME: 14:00
LOCAL: sala do PGBA
TITLE:

PRODUCTION, PURIFICATION, AND CHARACTERIZATION OF PROTEASES WITH COLLAGENOLYTIC ACTIVITY FROM Aspergillus heteromorphus URM0269 AND IMMOBILIZATION OF THE ENZYME IN BIOPOLYMERIC HYDROGEL

KEY WORDS:

Aspergillus heteromorphus, Protease with collagenolytic activity, Solid state fermentation, Submerged fermentation, Bioreactor, Ion exchange chromatography, Biochemical characterization, Kinetics and thermodynamics

PAGES: 146
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

This thesis aimed to produce, purify, and characterize proteases with collagenolytic activity from Aspergillus heteromorphus URM0269 and immobilize the enzyme in a biopolymeric hydrogel. The enzyme production used substrates such as wheat bran for solid-state fermentation (SSF) and soybean flour and yeast extract for submerged fermentation (SF). Subsequently, the enzymes were purified by ion exchange chromatography, and biochemical, kinetic, and thermodynamic characterization was performed. The enzyme immobilization was performed in galactomannan and k-carrageenan hydrogel to evaluate a possible biotechnological application. In the SSF experiment, it was observed that the production occurred successfully, resulting in a proteolytic activity of 57.43 U/mL and collagenolytic activity of 394.6 U/mL. Both protease and collagenase demonstrated stability over a range of pH (5.0 to 10.0) and temperature (20°C to 30°C), with highest activity at pH 7.0 and 50°C. Serine protease was purified (purification factor 7.2, and molar mass 14.7 kDa) and collagenase was purified (purification factor 16.1). Optimized protease and collagenase production was performed by FS, using an experimental design and scaled up from 50 mL (Erlenmeyer) to 1.5 L in a stirred tank bioreactor. Collagenase production increased as a function of scale-up by 343%, while protease production decreased by 30%. The hydrogel containing immobilized purified collagenase showed the highest collagenolytic activity (92%) after being stored for 100 days at 4°C. These results demonstrate the potential of Aspergillus heteromorphus URM0269 to produce protease and collagenase by two fermentative processes and distinct substrates with potential use in the industrial area, as well as the use of galactomannan and k-carrageenan hydrogel containing immobilized collagenase for possible uses in the medical and pharmaceutical industry.

COMMITTEE MEMBERS:
Presidente - TATIANA SOUZA PORTO
Interno - EMMANUEL VIANA PONTUAL
Externo ao Programa - 2170781 - ANDRE FELIPE DE MELO SALES SANTOS - UFRPEExterna à Instituição - MARIA DAS GRAÇAS CARNEIRO DA CUNHA - UFPE
Externo à Instituição - THIAGO PAJEÚ NASCIMENTO - UFPI