Banca de DEFESA: PEDRO JORGE LOURO CRUGEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : PEDRO JORGE LOURO CRUGEIRA
DATA : 26/06/2019
HORA: 13:00
LOCAL: Instituto de Ciências da Saúde/ UFBA, auditório da Congregação, 2° andar
TÍTULO:

Photostimulation of a thermo-cellulolytic bacterial consortium for degradation of cellulose and hemicellulose from green coconut fibres.

PALAVRAS-CHAVES:

Lignocellulosic biomass, hydrolysis of coconut husk, bacterial consortia, low power Laser, LED, Biostimulation.

PÁGINAS: 95
GRANDE ÁREA: Outra
ÁREA: Tecnologia e Inovação
RESUMO:

The agribusiness of the green Coconut is responsible for the generation of large quantities of waste. The wide availability of these materials, as well as their composition, leaded to both need and opportunity for it to become a source of raw material to produce biotechnological products of high added value. The aim of this study was to increase, through photostimulation, the hydrolysis of lignocellulosic biomass. The Thermo-Cellulolytic consortium, in the active phase (65 to 70 ºC), was collected from a composting pile, was subjected to nutritional stress and an irradiation protocol of six either Laser (λ660 ηm) or LED (λ632±2 ηm) irradiations were carried out at 12-h intervals. Microbial quantification carried out and showed a significant stimulatory biological response in the bacterial consortia. The cultures irradiated by LED showed a higher significant (p<0.0001) cell count when compared to those irradiated by Laser. The inoculation of the consortium irradiated by distinct light sources in mineral broth was proceeded with the residual biomass (green coconut bark) pretreated either by NaOH 5% or KOH 5% and evaluated the total reducing sugars (TRS), the concentrations of glucose and xylose, over 240-h, metabolic activity was also studied. The quantification of TRS, indicated higher concentration in the irradiated samples and a higher (143%) metabolic activity was observed in the LED group in comparison to the control within the first 48-h of incubation. The glucose concentration was higher in the group irradiated by LED at the end of 48-h, presenting a metabolic activity 294.9 % higher in the substrate pretreated by 5% NaOH when compared to the control. This is indicative of greater biochemical activity triggered by light radiation. The micrographs of the coconut fibers at the end of 240 hs showed a more effective microbial action in the irradiated groups. The analysis of the ligninolytic activity showed that, both Laser and LED light, increased the bacterial proliferation, protein production, metabolic activity as evidenced by an early e increased catabolism of the RBBR dye. As economic viability is a more important factor in industrial production our results prompts as to conclude that LED photostimulation should be considered as a potential tool to optimize bioprocesses at low cost.

MEMBROS DA BANCA:
Externo à Instituição - EDGARD BACIC DE CARVALHO
Interno - 1919894 - FABIO ALEXANDRE CHINALIA
Externo ao Programa - 3065750 - LUIZ GUILHERME PINHEIRO SOARES
Presidente - 6285556 - PAULO FERNANDO DE ALMEIDA
Externo à Instituição - SUSANA CARLA PIRES SAMPAIO - UFBA