Determination of tannin acyl hydrolase activity of Streptomyces mirabilis TBGS10 by measuring gallic acid using high-pressure liquid chromatography

Abstract

Tannase is a hydrolytic enzyme known as tannin acyl hydrolase that acts on the ester bonds of hydrolyzable tannins and produces gallic acid. Tannase enzymes are obtained from various sources. Tannase from microbial sources, especially fungi like Aspergillus spp., has been used in the food, brewing, and pharmaceutical industries. Tannin acyl hydrolase activities of Actinomycetes are seldom reported, though they are known to produce a wide range of industrial enzymes. This communication deals with the tannase activity of a Streptomyces isolate from the shola forests of Munnar in the Western Ghats of Kerala. The isolate is identified as S. mirabilis TBGS10 based on morphological characters and 16s rDNA homology. The isolate showed promising tannase activity in plate assays, submerged, and solid-state fermentation conditions. High-pressure liquid chromatography determines the industrially important intermediate gallic acid produced through solid-state fermentation using cashew apple bagasse as substrate. The extract observed a gallic acid (GA) content of 142.624 g/mL with a retention time of 2.506 min. The tannase gene of the strain TBGS10 was PCR amplified using specific primers designed based on similar Streptomyces sequences available in the NCBI-GenBank