Banca de QUALIFICAÇÃO: JÉSSICA RENALY FERNANDES MORAIS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA RENALY FERNANDES MORAIS
DATE: 19/09/2023
TIME: 14:00
LOCAL: Via Google Meet
TITLE:

Production of cross-linked enzyme aggregates (CLEAs) using commercial cellulolytic enzyme cocktails and enzymes produced by Trichoderma reesei CCT-2768 for application in the hydrolysis step of pre-treated coconut fiber

KEY WORDS:

Immobilization of enzymes; enzymatic hydrolysis, 2G ethanol, CLEAs; magnetic nanoparticles

PAGES: 52
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

Lignocellulosic biomass, one of the most abundant renewable resources, is available for the production of several products, consisting mainly of cellulose, hemicellulose and lignin. It is noteworthy that Brazil has characteristics such as appropriate climatic conditions and large arable areas that favor agribusiness, which, consequently, results in a vast amount of residual lignocellulosic biomass. In this context, the production of green coconut (Cocos nucifera) presents a favorable scenario, but there is concern about the large amount of solid waste from the large commercialization of the fruit that is discarded improperly. Thus, there is interest in using this lignocellulosic residue from green coconut to obtain products with greater added value, such as enzymes, ethanol and chemical products.
When used for ethanol production, the lignocellulosic material must undergo a pre-treatment that aims to remove the hemicellulose and lignin, reduce the crystallinity of the cellulose and increase the porosity of the material. Different pre-treatments are used, among them the steam explosion pre-treatment stands out. In this method, the biomass is subjected to heat under pressurized steam to depolymerize the hemicellulose and expand the cellulose fibrils, decreasing the crystallinity of this polymer and increasing the surface area accessible to enzyme attack in the hydrolysis process. It is noteworthy that during the cellulose hydrolysis process, cellulases are used, most of the time, in the form of cocktails, and often the reuse of enzymes is compromised. In this context, immobilization is an effective method that allows the reuse of enzymes, increases the stability of enzymes, facilitates the separation of products, in addition to improving their selectivity, specificity and decreasing their inhibition. The method, when performed correctly, increases the productivity of processes, in addition to providing an economical and ecologically friendly catalysis approach. Within the context of immobilization, cross-linked enzyme aggregates (CLEAs) technology has been used with several types of enzymes, and has proven to be a fast, efficient, easy and suitable approach to enzyme optimization. For the formation of CLEAs, the enzymes are initially precipitated, forming aggregates and, subsequently, crosslinking is performed using a crosslinking agent, such as glutaraldehyde. Thus, the CLEA formation method traditionally does not require the use of solid supports. However, the CLEAs produced tend to have low mechanical stability and difficulties in recovery, often requiring solid materials in practice.
Currently, the use of magnetic matrices for enzyme immobilization has gained ground compared to other types of support. Magnetic supports have proven to be versatile as support matrices for enzyme immobilization. Furthermore, magnetic supports enable good recovery of biocatalysts by applying a magnetic field. In this context, the aim of the present study is the production of traditional CLEAs and magnetic CLEAs using commercial cellulolytic cocktails and cellulolytic enzymes produced by solid state fermentation (SSF). These CLEAs will be applied in the hydrolysis of lignocellulosic biomass, aiming to evaluate the increase in the yield of fermentable sugars. Thus, the study also contributes to the area of use and valorization of coconut fiber biomass using immobilization techniques.

COMMITTEE MEMBERS:
Presidente - 1346198 - EVERALDO SILVINO DOS SANTOS
Interno - 3304882 - CARLOS EDUARDO DE ARAÚJO PADILHA
Interna - 3214434 - NATHALIA SARAIVA RIOS