Fungal cellulases: production by solid-state cultivation in packed-bed bioreactor using solid agro-industrial by-products as substrates and application for hydrolysis of sugarcane bagasse

Author(s)

Frassatto, Priscila Aparecida Casciatori ; Casciatori, Fernanda Perpetua ; Thomeo, Joao Claudio ; Gomes, Eleni ; Boscolo, Mauricio ; da Silva, Roberto

• Document type: Journal article
• Source: SEMINA-CIENCIAS AGRARIAS; v. 41, n. 5, p. 19-pg., 2020-01-01.

Abstract

Cellulases are essential for the hydrolysis of lignocellulosic materials in the production of second generation ethanol. Solid-state cultivation is a process that provides high concentrations of enzymes that can be used in this hydrolysis. The objectives of this work were to produce cellulases by cultivating the fungus Myceliophthora thermophila I-1D3b in a packed bed bioreactor with sugarcane bagasse (SCB) and wheat bran (WB) as substrate and to evaluate the efficiency of the enzymatic extract in the hydrolysis of SCB in natura (BIN) and pretreated with ozone, alkali and ultrasound (BOU). The conditions for enzyme production in the bioreactor were SCB:WB at a ratio of 2.3:1 (w/w), 75 % moisture content; 45 degrees C; aeration rate 240 L h(-1) and 96 h. The enzyme production was evaluated by endoglucanase, xylanase, filter paper (FPU) and beta-glycosidase activities. For the application of the enzymes, a central composed response surface design with 5 repetitions of the central point was used, taking enzyme volume and hydrolysis time as factors. Such cultivation yielded the following enzymatic activities: 723 U gss(-1) of endoglucanases, 2024 U gss-1 of xylanase, 12.6 U gss(-1) of FPU and 41 U gss-1 of beta-glucosidase. The results of the application tests indicated the best conditions as 7.0 mL of the enzyme extract (4.2 FPU) and 6 hours for BIN and BOU. The best cellulose-glucose conversions were obtained for BOU, reaching 32.1 % at 65 degrees C. In conclusion, the enzyme production in the packed bed bioreactor was efficient and BOU pretreatment improved the hydrolysis of biomass, increasing the efficiency of conversion of cellulose to glucose. (AU)

• FAPESP's process: 17/16482-5 - Purification and immobilization of beta-glucosidase from Thermoascus aurantiacus using supermacroporous cryogels and application in bioprocesses
• Grantee: Roberto da Silva
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 11/07453-5 - Fixed bed bioreactors to solid state fermentation: scale-up to cellullase fungal production
• Grantee: Fernanda Perpétua Casciatori
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/01756-1 - Production of cellulolytic enzymes by fungi Trichoderma reesei and Myceliophthora thermophila and application on saccharification of sugar cane bagasse
• Grantee: Priscila Aparecida Casciatori
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 10/12624-0 - Application of physical-chemical and enzymatic methods in the saccharification of sugar cane bagasse: studies on microorganisms, fermentative processes and hydrolyses methods
• Grantee: Eleni Gomes
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/00996-2 - Development of a pseudo-continuous packed-bed bioreactor for solid-state fermentation
• Grantee: Fernanda Perpétua Casciatori
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 11/21239-6 - Production of cellulolytic enzymes associated and growth kinetics of fungi Trichoderma reesei and Thermoascus aurantiacus in solid state fermentation
• Grantee: Priscila Aparecida Casciatori
• Support Opportunities: Scholarships in Brazil - Scientific Initiation