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Tannins and their enzymatic degradation

100%

Pleszczynska M., Szczodrak J.

Biotechnologia

2005

issue 1

152-165

Tannins as compounds of plant biomass seem to be a very useful raw material for an effective bioconversion. This is due to their abundance and renewability as well as the possibility of producing various chemicals and curative preparations from this source. On the other hand, enzymatic removal of tannins from agricultural feedstocks by tannase is very important for production of digestible feed and food products, clarified beverages and fruit juices or instant tea. This article presents a review of information on tannins and their hydrolysis by microbial tannase. Special attention has been paid to chemical structure of tannins and their negative or positive effects on organisms as well as the production of tannase and its biochemical properties. Most promising prospects for the practical applications of tannase in food, pharmaceutical, cosmetic and leather industries are also discussed.

Enzymatic hydrolysis in multifunctional reactor

100%

Galwas M., Pohorecki R.

Biotechnologia

2007

issue 2

149-160

The aim of this work was to develop a multifunctional reactor to carry out the enzymatic process of biodegradation of tannins. An integrated reaction system consists of a stirred tank reactor and a spiral-wound membrane module. The system was used for simultaneous reaction and product separation during the enzymatic hydrolysis of tannic acid. On the basis of kinetic investigations, a kinetic equation for the enzymatic hydrolysis of tannic acid to gallic acid by tannase was developed. It was demonstrated that the kinetics of enzymatic hydrolysis of tannic acid catalyzed by tannase can be described by a kinetic equation of the Michaelis-Menten type with the competitive product inhibition. The design of the reactor ensured the entrapment of enzyme within the reactor volume, and, in the same time, continuous separation of gallic acid. A multifunctional membrane reactor has been designed. The reactor consisted of a stirred vessel and a spiral-wound membrane module. The process was run under optimal conditions for the enzyme activity (pH 5.5, 30oC). Prolonged use of the enzyme was achieved with good efficiency. A mathematical model describing the process in the reactor has been developed. The model, based on kinetic studies, has been demonstrated to describe properly the behavior of the reactor. A good agreement of the experimental results with the calculated ones was obtained. The experimental results were also compared with the existing literature data concerning the mass transfer in spiral membrane modules. A dimensionless correlation of the Sh=f(Re,Sc) type was used to describe the data obtained. A good agreement of the literature results with own data was observed.

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2 Biotechnologia

1 2007

1 2005

1 Galwas M.

1 Pleszczynska M.

1 Pohorecki R.

1 Szczodrak J.

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Tannins and their enzymatic degradation

Enzymatic hydrolysis in multifunctional reactor