Microbial Production of Potent Phenolic-Antioxidants Through Solid State Fermentation - Sustainable Biotechnology: Sources of Renewable Energy - page 229

Microbial Production of Potent
Phenolic-Antioxidants Through Solid
State Fermentation

Silvia Martins, Diego Mercado, Marco Mata-Gómez, Luis Rodriguez,
Antonio Aguilera-Carbo, Raul Rodriguez, and Cristóbal N. Aguilar

Abstract The agroindustrial residues including plant tissues rich in polyphenols
were explored for microbial production of potent phenolics under solid state fer-
mentation processes. The fungal strains capable of hydrolyzing tannin-rich materials
were isolated from Mexican semidesert zones. These microorganisms have been
employed to release potent phenolic antioxidants during the solid state fermentation
of different materials (pomegranate peels, pecan nut shells, creosote bush and tar
bush). This chapter includes the critical parameters for antioxidants production from
selective microbes. Technical aspects of the microbial fermentation of antioxidants
have also been discussed.

Keywords Phenolic antioxidants · Solid-state fermentation · Gallic acid · Ellagic

acid · Nordihydroguayaretic acid

1 Introduction

Antioxidants are bioactive compounds capable of slowing or preventing the oxida-
tion of other molecules. This process is a chemical reaction that transfers electrons
from a compound to an oxidizing agent. Free radicals are generally produced in the
oxidation reactions, which start the chain reactions that damage cells. Chemically,
antioxidants act modifying this chain of reaction removing free radical intermedi-
ates and inhibit other oxidation reactions by being oxidized themselves. As a result,
antioxidants are often reducing agents such as polyphenols, which are natural com-
pounds present in numerous plants, located in fruits, flowers, cases, ferns, crusts,
wood, etc. The distribution of these compounds in plant cells varies depending on
the vegetal [1]. Polyphenols, constitute an important kind of chemical substances,