Banca de DEFESA: BEATRIZ DE AZEVEDO
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : BEATRIZ DE AZEVEDO
DATE: 20/05/2022
TIME: 09:00
LOCAL: Via Google Meet
TITLE:
Production of celulases ande xylanases by a new fungal species – A. lippiae URM 7547 – using a green coconut fiver pre-treated by steam explosion.
KEY WORDS:
Endophytic fungus, green coconut fiber, submerged fermentation, enzymes.
PAGES: 95
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:
Endophytes, which can be bacteria, fungi or protozoa, are poorly studied. It is estimated that there are more than 250,000 different species of plants and one million endophytes in the world, which characterizes an average of four species associated with a plant species. Because they are inside the plant, these microorganisms can be a rich source of biomolecules of industrial interest, such as the production of hemicellulolytic enzymes. In this context, this study has the general objective of studying the ability of the endophytic fungal species, Achaetomium lippiae URM 7547, little mentioned in the literature, to produce cellulases and xylanases by means of a submerged cultivation using the fiber of the pre-green coconut husk as a substrate. - Treated by steam explosion. Initially, the potential of A. lippiae URM 7547 to produce hydrolases (amylase, lipase, protease, cellulase, xylanase and pectinase) in solid culture medium (72h at 30°C) with substrates in each specific enzyme was evaluated. configure it as an enzyme producer. For comparison of results, growth of CCT 2768 under the same induction conditions was used. A. lippiae URM 7547 presented itself as a potential producer of amylases, proteases and cellulases, with an enzymatic index greater than 1.5 (IE > 1.5) as well as T. reesei CCT 2768. It was also quantified, the yield of substrate conversion into cell biomass (Yx/s) of A. lippiae URM 7547 and its maximum growth rate (µmax) in liquid medium containing glucose and xylose and three concentrations of substrates and nutrient media with carbon sources and nitrogen in order to verify if the fungus is adept to submerged crops and what is the best condition for its growth. The best results for the liquid medium containing glucose were in 96h of culture in medium 3, containing peptone and yeast extract, with Yx/s equal to 0.062 ± 0.04 g.g-1, 0.072 ± 0.04 g.g-1, and 0.076 ± 0.03 g.g-1, for concentrations of 5, 10 and 20 g.L-1 of substrate, respectively. For the medium containing Xylose, the best result was during 144h of cultivation with Yx/s values equal to 0.52 ± 0.08, 0.59 ± 0.09 and 0.65 ± 0.03 g.g-1 for 5, 0, 10.0 and 20.0 g.L-1, respectively, also in medium 3. Finally, the submerged fermentation was started to produce cellulases and xylanases. The lignocellulosic characterization of green coconut fiber in natura and post pre-treatment by steam explosion carried out with the purpose of verifying the performance of the pre-treatment was the penultimate step of the dissertation. After pre-treatment, there was a 14% decrease in extractables in relation to in natura fiber, since it is easily removed by solvents; an 8% increase in cellulose and a 6% decrease in hemicellulose; lignin remained statistically the same (p>0.05). In FSm, the Q Assay with condition of 33°C, 109 spores.mL-1, and 30.0 g.L-1 of substrate, was the one that presented the best yield in relation to the four quantified enzymes, with enzymatic activities (U.mL-1) of 0.41 ± 0.06, 5.94 ± 0.31 and 0.08 ± 0.035 and 9.12 ± 0.28 for FPase, CMCase, Cellobiase and Xylanase, respectively. Finally, A. lippiae URM 7547 was a good producer of cellulases and xylanases, in addition to other hydrolytic enzymes such as amylases and proteases, with an excellent growth performance in submerged media.
BANKING MEMBERS:
Presidente - 1346198 - EVERALDO SILVINO DOS SANTOS
Externo ao Programa - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR
Externo à Instituição - MARCELINO GEVILBERGUE VIANA - IFPB
Externo à Instituição - PEDRO FERREIRA DE SOUZA FILHO - UFPE