Paraburkholderia tropica PKI7 and Kosakonia arachidis PKI8: Two newly reported tannase producing bacteria isolated from forest soil and study of their tannase producing potentiality

Tannins are the polyphenolic secondary metabolites of plants and having antimicrobial properties due to their protein precipitation abilities and other toxic effects towards microbes. However, with the help of an inducible enzyme called tannase, a variety of microbes including bacteria can resist tannin toxicity. Tannase catalyses the dissociation of ester bonds in gallotannins like tannic acid, resulting in release of gallic acid and glucose. Because of its vast industrial applications and ease of manipulation, interest in identifying and applying bacteria as tannase producers has grown in recent years. The bacterial strains reported in the present work were isolated from soil and identified as Paraburkholderia tropica PKI7 and Kosakonia arachidis PKI8 through morphological, biochemical, and 16s rDNA molecular approach. Simultaneous tannase and gallic acid production by these two bacterial strains were observed through submerged fermentation. This is the first report of Paraburkholderia tropica PKI7 and Kosakonia arachidis PKI8 strains as tannase producing bacteria. The initial tannase production were 0.75 U/ml and 1.49 U/ml respectively for P. tropica PKI7 and K. arachidis PKI8 after 24 h of submerged fermentation while gallic acid release was 8.4 µg/ml and 10.74 µg/ml respectively. There is a potential scope in higher tannase and gallic acid biosynthesis by the two strains.