Characterization of Aspergillus fumigatus CAS-21 tannase with potential for propyl gallate synthesis and treatment of tannery effluent from leather industry

Author(s)

Farias Cavalcanti, Rayza Morganna ; Jorge, Joao Atilio ; Souza Guimaraes, Luis Henrique

• Document type: Journal article
• Source: 3 BIOTECH; v. 8, n. 6, p. 11-pg., 2018-05-25.

Abstract

One of the tannase isoforms produced by the fungus Aspergillus fumigatus CAS-21 under submerged fermentation (SbmF) was purified 4.9-fold with a 10.2% recovery. The glycoprotein (39.1% carbohydrate content) showed an estimated molecular mass of 60 kDa. Optimum temperature and pH for its activity were 30-40 degrees C and 5.0, respectively. It showed a half-life (t(50)) of 60 min at 45 and 50 degrees C, and it was stable at pH 5.0 and 6.0 for 3 h. The tannase activity was insensitive to most salts used, but it reduced in the presence of Fe-2(SO4)(3) and FeCl3. On contrary, in presence of SDS, Triton-X100, and urea the enzyme activity increased. The K-m value indicated high affinity for propyl gallate (3.61 mmol L-1) when compared with tannic acid (6.38 mmol L-1) and methyl gallate (6.28 mmol L-1), but the best K-cat (362.24 s(-1)) and K-cat/K-m (56.78 s(-1) mmol(-1) L) were obtained for tannic acid. The purified tannase reduced 89 and 25% of tannin content of the leather tannery effluent generated by manual and mechanical processing, respectively, after 2-h treatment. The total phenolic content was also reduced. Additionally, the enzyme produced propyl gallate, indicating its ability to do the transesterification reaction. Thus, A. fumigatus CAS-21 tannase presents interesting properties, especially the ability to degrade tannery effluent, highlighting its potential in biotechnological applications. (AU)

• FAPESP's process: 16/11311-5 - Potential of Filamentous Fungi for Production of Exo Hydrolases with Biotechnological Interest: Influence of Fermentative Process on Morphology, Cytoskeleton and Secretion of ²-D-fructofuranosidases, Phytases and Tannases
• Grantee: Luis Henrique Souza Guimaraes
• Support Opportunities: Regular Research Grants