ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microbial and enzymatic hydrolysis of tannic acid: influence of substrate chemical quality

Mónica Lizeth Chávez-González, Juan Carlos Contreras-Esquivel, Lilia Arely Prado-Barragán, Raúl Rodríguez, Antonio Francisco Aguilera-Carbo, Luis Víctor Rodríguez, and Cristóbal Noé Aguilar

Department of Food Science and Technology, School of Chemistry, Autonomous University of Coahuila, Boulevard Venustiano Carranza, 25280 Saltillo, Coahuila, Mexico

E-mail: cristobal.aguilar@uadec.edu.mx

Abstract: Tannic acid is commonly employed as the main component in culture media for the selection of tannase-producing strains. In biotechnological processes it is the favorite substrate used to induce the tannase enzyme in both solid and submerged culture for microbial and/or enzymatic production of gallic acid. However, the results found in literature are inconsistent notwithstanding the strict control of all parameters that rule the bioprocesses. The present work, for the first time, reveals the importance of differences in the quality and chemical profile of tannic acid from different suppliers and their influence on the fungal and enzymatic hydrolytic pattern obtained when it is used as a substrate. A degree of hydrolysis between 64.7 % and 100 % has been determined in different tannic acid samples. The specific growth rate of 0.712 h⁻¹, 0.792 h⁻¹, 0.477 h⁻¹, 0.536 h⁻¹ for Jalmek®, Faga Lab®, Division Food®, and Riedel de Häen®, respectively, was obtained at the concentration of 80 g L⁻¹ of each of the tannic acids.

Keywords: tannic acid – gallic acid – enzymatic hydrolysis – fungal growth

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0112-4

Chemical Papers 66 (3) 171–177 (2012)