Banca de DEFESA: Raul Alcântara Teixeira Lima

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Raul Alcântara Teixeira Lima
DATE: 30/10/2023
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Bioprospection of Synthermes wheeleri gut microbiome using the bacteria metagenome for mining enzymes able to convert lignocellulose into chemicals with a high added value.

KEY WORDS:

Glycosyl hydrolases; metagenome; Syntermes wheeleri; lignocelulose.

PAGES: 163
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Termites consume approximately 3 to 7 billion tons of lignocellulosic materials per year and therefore represent one of the most prolific and efficient lignocellulose decomposers on Earth. The bioconversion of cell wall polysaccharides by termites is a highly coordinated process achieved by microbial symbionts residing in the gut. In this work we aimed to use the biotechnological potential of these microorganisms to obtain enzymes capable of converting polysaccharides into high value-added chemicals and to understand how GHs are distributed in the gut of the species. The process was carried out with the bacterial gut metagenome of Syntermes wheeleri, an endemic termite species from the Brazilian cerrado. Here we developed integrated bioinformatics analyses that suggested groups of proteins in phylogenetic trees with potential for innovation. The domains of these proteins were distributed in Glycosyl Hydrolases (GHs) - 3, 5, 9 and 10 with representatives of the phyla Firmicutes, Proteobacteria, Bacteroidetes and Spirochaeta, among others. In order to characterize and evaluate their biotechnological potential, we used E. coli BL21(DE3) and pET plasmid systems to synthesize some of them. The biochemical results showed 40-50ºC as the best activity temperature for Exo8574 (exoglucanase) and Bgl7226 (β-glucosidase), as well as acidic and basic pH as the optimum pH, respectively. Circular dichroism showed the dependence of the secondary structure on pH according to the change in the quantities of α-helices and β-sheets. These characteristics provided the best conditions for saccharification. This process can be used on different biomasses, such as sugarcane and corncob, using heat treatment as an environmentally sustainable pretreatment process, compared to chemical pretreatment, to improve protein access to polysaccharides. Our results will help elucidate the capacity of selected enzymes from the S. wheeleri gut bacteria metagenome in lignocellulose bioconversion biotechnology processes.

COMMITTEE MEMBERS:
Externo à Instituição - ARMANDO GARCIA RODRIGUES - UFG
Externa à Instituição - DASCIANA DE SOUSA RODRIGUES - EMBRAPA
Interna - 2222088 - ELIANE FERREIRA NORONHA
Presidente - 1661623 - RICARDO HENRIQUE KRUGER
Interno - 2644635 - ROBERT NEIL GERARD MILLER