Production and partial purification of extracellular tannase by Klebsiella pneumoniae MTCC 7162 isolated from tannery effluent

Abstract

Diverse bacteria belonging to various taxa were isolated from tannery effluent of leather industries located at Ranipet, India and were screened for the production of extracellular tannase. One of the strains identified as Klebsiella pneumoniae MTCC 7162 was found to produce tannase (3.4 U/ ml) at pH 6.0, 37°C and 100 rpm. Use of individual carbon and inorganic nitrogen sources resulted in lower tannase production. However, a combination of urea and corn steep liquor extract yielded marginal increase in tannase production (3.9 U/ ml). End-product repression was also studied with inclusion of gallic acid to the growth medium. Enrichment with various additives of metal ions and detergents resulted in inhibition of tannase production. The enzyme was partially purified using ammonium sulfate precipitation followed by the use of DEAE-cellulose. SDS-PAGE analysis indicated that the molecular weight of the protein to be 46.5 kDa. The enzyme was found to be active in a wide range of pH and temperature with an optimal activity at pH 5.5 and 40°C.

Key words: Bacterial tannase, Klebsiella pneumoniae MTCC 7162, tannery effluent, minimal media.