Microbial tannases: biosynthesis, purification, characterization and potential industrial applications

Tannases are a family of esterases that catalyze the hydrolysis of ester and depside bonds present in hydrolyzable tannins to release glucose and gallic acid. This enzyme is widely spread in animals, plants, and microbes. In particular, fungi and bacteria are the major sources of tannase. In recent years, this enzyme has drawn the attention of investigators owing to its widespread emerging applications in different food, beverage, animal feed, pharmaceutical, and tannery effluent degradation processes. During the last decade, over-expression of the tannase gene and structural activity has gained momentum. This research focused on microbial tannases, which have sparked interest due to their various properties. The current study investigates the sources of tannase-producing microorganisms, the mechanisms of tannin metabolism, and the microbe's degradation of natural tannins. Furthermore, researchers proposed tannase's biochemical properties, cloning, expression, and structural construction. This review will help better understand microbial tannases for several important industrial and environmental applications.