Effect of amino acids on tannase biosynthesis by Bacillus licheniformis KBR6.
OBJECTIVE
Microbial tannase (tannin acyl hydrolase, EC 3.1.1.20), a hydrolysable tannin-degrading enzyme, has gained importance in various industrial processes, and is used extensively in the manufacture of instant tea, beer, wine, and gallic acid. Tannase is an inducible enzyme, and hydrolysable tannin, especially tannic acid, is the sole inducer. This study is of the effect of various amino acids and their analogues on tannase biosynthesis by Bacillus licheniformis KBR6 to ascertain the mode of action of these growth factors on tannase biosynthesis from microbial origin.


METHODS
Enzyme production was carried out in enriched tannic acid medium through submerged fermentation for 20 h at 35 degrees C. Different amino acids at a concentration of 0.05 g% (w/v) were added to the culture medium immediately after sterilization. Culture supernatant was used as the source of the enzyme and the quantity of tannase was estimated by the colorimetric assay method. Growth of the organism was estimated according to biomass dry weight.


RESULTS
Maximum tannase (2.87-fold that of the control) was synthesized by B. licheniformis KBR6 when alanine was added to the culture medium. Other amino acids, such as DL-serine, L-cystine, glycine, L-ornithine, aspartic acid, L-glutamic acid, DL-valine, L-leucine and L-lysine, also induced tannase synthesis. L-Cysteine monohydrochloride and DL-threonine were the most potent inhibitors.


CONCLUSIONS
Regulation of tannase biosynthesis by B. licheniformis in the presence of various amino acids is shown. This information will be helpful for formulating an enriched culture medium for industrial-scale tannase production.
Mohapatra
Pradeep K Das
PK
Department of Microbiology, Vidyasagar University, Midnapore, India.
Pati
Bikas R
BR
Mondal
Keshab C
KC
D000596:Amino Acids / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis*; D003124:Colorimetry / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D013696:Temperature
D000596:Amino Acids; D003470:Culture Media; D002265:Carboxylic Ester Hydrolases; C022711:tannase