Biochemical Characterization of a Novel Thermostable 1,4-α-Glucoamylase from Aspergillus brasiliensis Strain Isolated in the Brazilian Atlantic Forest

Author(s)

Zaghetto de Almeida, Paula ; Alnoch, Robson Carlos ; Pinheiro, Vanessa Elisa ; Pereira Gimenez, Marita ; Polizeli, Maria de Lourdes Teixeira de Moraes

• Document type: Journal article
• Source: Applied Biochemistry and Biotechnology; v. 196, n. 10, p. 20-pg., 2024-03-21.

Abstract

Glucoamylases are exo-enzymes that cleave the ends of the starch chain, releasing glucose units. In the current work, we described a novel 1,4-alpha-glucoamylase from an A. brasiliensis strain isolated from an environmental sample. The purified glucoamylase, GlaAb, has a molecular mass of 69 kDa and showed a starch binding domain. GlaAb showed a similar sequence to other fungal glucoamylases, and the molecular 3D model analysis of GlaAb suggests an overall structure as described in the literature, except by elongation in the loop connecting the 4th and 5th alpha-helices. The enzyme showed activity over a wide range of pH and temperature, with maximum activity at pH 4.5 and 60 degrees C. GlaAb was stable at 50 degrees C for 7 h, maintaining 67% residual activity, and it was not inhibited by glucose up to 0.1 M. The glucoamylase was 65% more active in the presence of Mn2+ and showed a Km of 2.21 mg mL(-1), Vmax of 155 U mg(-1), Kcat 179 s(-1), and Kcat/Km 81.06 mg mL(-1) s(-1) using potato starch as substrate. The results obtained are promising and provide the basis for the development of applications of GlaAb in the industrial process. (AU)

• FAPESP's process: 13/01437-3 - Diversity of amylolytic potential in filamentous fungi: purification and characterization of a glucoamylase from Aspergillus brasiliensis
• Grantee: Paula Zaghetto de Almeida
• Support Opportunities: Scholarships in Brazil - Master
• 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
• FAPESP's process: 20/00081-4 - Development of strategies for immobilization and co-immobilization of enzymes involved in biomass degradation
• Grantee: Robson Carlos Alnoch
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/07522-6 - Development of eco-friendly technologies for the hydrolysis of biomass and residues of cellulose pulp and paper industry
• Grantee: Maria de Lourdes Teixeira de Moraes Polizeli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/09627-8 - Formulation of tailor-made enzymatic consortiums for the degradation of the cell wall of sugarcane varieties
• Grantee: Robson Carlos Alnoch
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• FAPESP's process: 23/01547-5 - Formulation of tailor-made enzymatic consortiums for the degradation of the cell wall of sugarcane varieties
• Grantee: Maria de Lourdes Teixeira de Moraes Polizeli
• Support Opportunities: Regular Research Grants