Banca de QUALIFICAÇÃO: DÁVIDA MARIA RIBEIRO CARDOSO DOS SANTOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DÁVIDA MARIA RIBEIRO CARDOSO DOS SANTOS
DATE: 10/12/2021
TIME: 14:00
LOCAL: por videoconferência
TITLE:

Production, isolation, characterization and biotechnological application of endoglucanase from the filamentous fungus Pycnosporus sanguineus

KEY WORDS:

Agroindustrial waste, filamentous fungi, endoglucanase, purification, characterization and biotechnology.

PAGES: 73
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SPECIALTY: Proteínas
SUMMARY:

The growth of the world population demands a greater quantity of food and is generating greater investment in agribusiness. Consequently, there is greater production of agro-industrial residues, mostly ligninocellulosic, which are often incorrectly disposed of, harming the environment. In an attempt to minimize this problem, clean alternatives for the reuse of agro-industrial residues have been sought around the world. Among the alternatives is the use of residues as a source for fungal growth and production of enzymes of biotechnological interest, giving great added value to residues. Filamentous fungi are important sources of enzymes, they are used in several industrial processes replacing the chemical catalysts of the processes. Among the most used enzymes in industries are proteases, glycosidases and amylases. Among the glycosidases, cellulases are the most used, associated with this enzymatic complex, there are the endoglucanases, which cleave specific regions of the polysaccharide chain and present great stability. Thus, the objective of this work was to favor the production, isolate, characterize and biotechnologically apply the endoglucanase produced from the filamentous fungus Pycnosporus sanguineus. Five different agro-industrial residues (wheat bran, sugarcane bagasse, wood dust, coconut fiber and filter paper) were used to produce the enzyme. The enzyme was isolated using ethanol fractionation followed by ion exchange chromatography. Isolation was confirmed by submitting the enzyme to a polyacrylamide gel (SDS-PAGE) under reducing and denaturing conditions. The isolated endoglucanase was characterized for temperature, pH, halotolerance, enzymatic kinetics and applied biotechnologically through the saccharification of agro-industrial residues for the production of reducing sugars. Wheat bran was the residue where the fungus showed the highest enzyme production in less time 72 h. Ethanol fractionation managed to fractionate the enzymatic extract into 5 fractions, the 80-100% fraction concentrated greater activity and was subjected to ion exchange chromatography (DEAE-Sepharose), where the enzyme was isolated in a single fraction, as observed in SDS -PAGE. The biochemical characterization of the enzyme determined the optimum temperature of 50°C and thermal stability between 30 and 60°C with up to 50% of the enzymatic activity, the optimum pH was 5.0, with stability at pH between pH 4.0 and 8.0. The isolated enzyme managed to maintain more than 100% of the activity in up to 5 M NaCl and presented Km 3.18 ± 100 mg/mL and the Kcat equal to 4.53 S-1 and managed to produce reducing sugars 273.096 mg/mL in 24 hours on rice husks. The present work concluded that the fungus Pycnosporus sanguineus is a producer of an important endoglucanase, with biochemical characteristics compatible with various industrial processes, which can be produced, isolated and applied quickly and at low cost.

BANKING MEMBERS:
Presidente - 1811274 - HUGO JUAREZ VIEIRA PEREIRA
Interno - 2089586 - FRANCIS SOARES GOMES
Interna - 2024367 - MELISSA FONTES LANDELL
Externa ao Programa - 1121008 - SONIA SALGUEIRO MACHADO