[2] Specifically, tannase catalyzes the hydrolysis of ester and depside bonds of hydrolysable tannins to release glucose and gallic or ellagic acid.
The production of gallic acid is important in the pharmaceutical industry as it's needed to create trimethoprim, an antibacterial drug.
[3] Additionally, because tannase can break ester bonds of glucose with various acids (chebulinic, gallic, and hexahydrophenic), it can be used in the process of fruit ripening.
When tannins, specifically gallotannins, are broken down by tannase through the hydrolysis of ester bonds, gallic acid and glucose are formed.
The crystal structure shows there is a tunnel formed by two opposing domains that can fit the various substrates needed for tannase to hydrolyze.
[12] This is important, because some microorganisms use tannase to breakdown hydrolysable tannins, such as gallotannins, to form glucose and gallic acid.
Glucose and gallic acid can then be readily converted to metabolites (i.e. pyruvate, succinate, and acetyl coenzyme A) that can be used in the Krebs cycle.
[12] Many other bacterial species have been found to produce tannase by being isolated from different types of media such as soil, wastewater, compost, forest litter, feces, beverages, pickles, etc.
Bacteria and archaea species with tannase activity have been found in the genera: Achromobacter, Atopobium, Azotobacter, Bacillus, Citrobacter, Corynebacterium, Enterobacter, Enterococcus, Fusobacterium, Gluconoacetobacter, Klebsiella, Lactobacillus, Lonepinella, Methanobrevibacter, Microbacterium, Oenococcus, Pantoea, Pediococcus, Providencia, Pseudomonas, Selenomonad, and Serratia.