Synthetic carbohydrate-binding module-endogalacturonase chimeras increase catalytic efficiency and saccharification of lignocellulose residues

Author(s)

Carli, Sibeli ; Parras Meleiro, Luana ; Salgado, Jose Carlos Santos ; Ward, Richard John

• Document type: Journal article
• Source: BIOMASS CONVERSION AND BIOREFINERY; v. N/A, p. 12-pg., 2022-05-03.

Abstract

Primary cell walls and middle lamella of higher plants include homogalacturonan, the substrate for polygalacturonases. Seeking to enhance lignocellulose saccharification, chimeras between the endopolygalacturonase I from Chondrostereum (Stereum) purpureum (EndoPG-I) and family 3, 44, and 77 carbohydrate-binding modules (CBMs) from Hungateiclostridium thermocellum (Ht) or Ruminococcus flavefaciens (Rf) were constructed, expressed, and characterized. Chimeras presented similar K-M values and pH/temperature optima as unfused EndoPG-I against citrus pectin, k(cat)/K-M values 1.6, 1.7, and 1.3-fold higher for the HtCBM3-EndoPG, HtCBM44-EndoPG, and RtCBM77-EndoPG, respectively. Commercial enzyme cocktail supplementation with HtCBM44-EndoPG and RtCBM77-EndoPG increased reducing sugar release from untreated sugarcane bagasse by 35 and 25%, respectively. All chimeras increased reducing sugar release by 20-25% against orange bagasse compared with EndoPG-I or equimolar EndoPG-I/CBM mixtures. These results show that proximity between plant cell wall components in situ influences CBM-enzyme chimera activity and improves saccharification of lignocellulosic materials. (AU)

• FAPESP's process: 16/24139-6 - Design and Characterization of Multifunctional Xylanolytic Enzymes
• Grantee: Richard John Ward
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/17582-0 - Thermostability modulation of a ß-glucosidase stimulated by glucose and xylose using site directed glycosylation
• Grantee: Luana Parras Meleiro Garcia
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/13734-3 - Engineering of an endopolygalacturonase by insertion of different Carbohydrate Binding Modules (CBMs): chimerogenesis and proximity effects
• Grantee: Sibeli de Carli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/21989-7 - Bioprospection of low molecular weight fungal enzymes involved in plant cell wall degradation
• Grantee: José Carlos dos Santos Salgado
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/50884-5 - INCT 2014: National Institute of Science and Technology of Bioethanol
• Grantee: Marcos Silveira Buckeridge
• Support Opportunities: Research Projects - Thematic Grants