Banca de QUALIFICAÇÃO: ALAN DE OLIVEIRA CAMPOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALAN DE OLIVEIRA CAMPOS
DATE: 23/02/2022
TIME: 14:00
LOCAL: Via Google Meet
TITLE:

GREEN COCONUT FIBER (Cocos nucifera) PRETREATED BY STEAM EXPLOSION COMBINED WITH ALKALINE FOR THE PRODUCTION OF CELLULOLYTIC ENZYMES BY Trichoderma reesei CCT-2768 IN SEMI-SOLID FERMENTATION

KEY WORDS:

pre-treatments, cellulases, semi-solid fermentation, green coconut fiber

PAGES: 86
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

Lignocellulosic biomass is the most abundant renewable resource on Earth, being considered a sustainable raw material for the production of cellulosic ethanol. Its composition is variable, but it consists mainly of cellulose, hemicellulose and lignin. For the production of biofuels, the biomass pretreatment step is crucial to reduce the lignocellulose recalcitrance and the lignin and hemicellulose content in the material, as these compounds limit the accessibility of enzymes and microorganisms to cellulose and can lead to irreversible adsorption. of cellulases. In addition, studies indicate that, for a better induction of cellulase production by fermentation processes, pre-treatment or their combination, such as pre-treatment by steam explosion followed by alkaline treatment, exposes more efficiently to cellulose for filamentous fungi, especially when it comes to materials with a high content of lignin and hemicellulose. Currently, it is known that the production of green coconut reaches approximately 2.33 million tons/year, with 80% of the gross weight of the fruit corresponding to the green coconut husk, which is generally discarded in the environment. Therefore, this study aimed to evaluate the production of cellulases usinThis residue causes a series of environmental problems and an alternative for its use would be in the application in lignocellulolytic enzyme production processes. Therefore, this study aimed to evaluate the production of cellulases using coconut fiber pre-treated by steam explosion combined with alkaline pre-treatment (PV+A) by semi-solid fermentation (FSS) using filamentous fungus Trichoderma reesei CCT- 2768, evaluating the cultivation conditions (water activity and amount of substrate) through central rotational composite design (CCR), with CMCase and FPase as response variables. In addition, the use of solvents capable of optimizing the extraction of enzymes was evaluated. It was observed that the combination of pre-treatments was more favorable for the removal of hemicellulose from green coconut fiber, reducing the content of this polymer from 10.15%, in relation to untreated biomass, to 5.38%. Regarding the SSF of the coconut fiber pre-treats PV+A, it was observed that only the water activity proved to be a significant factor in the cultivation. Furthermore, a higher production of cellulolytic enzymes in semi-solid cultivation conditions in which the water activity is 0.995 and 5.25 g of substrate, obtaining an enzymatic activity of CMCases close to 3.0 IU/g and for FPases, a value of 0.31 IU/g. When the best solvent for cellulase extraction was evaluated, the saline solution of NaCl 154 mM was more efficient in the recovery of the enzymes, evidencing the prevalence of the salting out effect in the extraction of cellulases after the FSS of the biomass under study.

BANKING MEMBERS:
Presidente - 1346198 - EVERALDO SILVINO DOS SANTOS
Externo ao Programa - 089.656.434-73 - CARLOS EDUARDO DE ARAÚJO PADILHA - UFRN
Externo ao Programa - 027.194.253-38 - SÉRGIO DANTAS DE OLIVEIRA JÚNIOR
Externo à Instituição - PEDRO FERREIRA DE SOUZA FILHO