Biotechnology Letters 0: 767–769, 2000. © 2000 Kluwer Academic Publishers. Printed in the Netherlands. 767 Tannase production by Bacillus licheniformis Keshab C. Mondal 1 , Rintu Banerjee 2 & Bikas R. Pati 1,∗ 1 Microbiology Laboratory, Department of Botany & Forestry, Vidyasagar University, Midnapore-721102, West Bengal, India 2 Department of Agricultural & Food Engineering, Indian Institute of Technology, Khargapur-721302, West Bengal, India ∗ Author for correspondence (Fax: 91-03222-62329; E-mail: brpati@yahoo.com) Received 29 November 1999; Revisions requested 10 December 1999/17 January 2000; Revisions received 13 January 2000/8 March 2000; Accepted 9 March 2000 Key words: Bacillus licheniformis, tannase Abstract Bacillus licheniformis KBR 6 produced maximum extracellular tannase activity at 0.21 U ml −1 with 1.5% (w/v) tannic acid either in the absence or presence of glucose (1 g l −1 ) after 18–21 h growth though the organism did not attain maximum growth until 36 h. Introduction Tannase (tannin acyl hydrolase, EC: 3.1.1.20) hy- drolyzes the ester and depside linkages of tannic acid to give gallic acid and glucose. It is extensively used in food, beverage, pharmaceutical and chemical indus- tries. The enzymatic product, gallic acid, is also used in dye making, pharmaceutical and leather industries (Lekha & Lonsane 1997). Tannic acid is regarded as an anti-nutrient and anti-microbial agent although some fungi (Aoki et al. 1976, Pourrat et al. 1982, Bajpai et al. 1999) and a few bacteria (Deschamp et al. 1983) can degrade tannic acid by producing an extracellular tannase. Due to the inducible nature of tannase, tannic acid itself acts as the sole carbon source as well as inducer (Lekha & Lonsane 1997). Optimizations of tannase production by several fungal strains have been studied by different workers (Vermeire & Vandamme 1988, Hadi et al. 1994, Bradoo et al. 1997). They found that additional carbon sources in the culture media en- hance the tannase production. But no attempts have so far been made for optimal production of tannase from bacterial origin. The present communication deals with the pro- duction of extracellular tannase by previously isolated Bacillus licheniformis KBR 6 in presence of different carbon sources. Certain kinetic characteristics of the enzyme production were also taken into consideration. Materials and methods Microorganism and growth Bacillus licheniformis KBR 6 was isolated from forest soil and identified by the authors and the identification has also been confirmed from International Myco- logical Institute, Surrey, UK (IMI no. 379224). It was cultivated in a medium containing (g l −1 ) tannic acid, 10; K 2 HPO 4 , 0.5; KH 2 PO 4 , 0.5; MgSO 4 , 2.0; CaCl 2 , 1.0; NH 4 Cl, 3.0. Different additional carbon sources were added separately to the above-mentioned medium for studying their effect on enzyme produc- tion. Enzyme production was performed in 250 ml Erlenmeyer flasks containing 50 ml liquid medium with 1% (v/v) inoculum and incubated at 30 ± 2 ◦ C in a rotary shaker (200 rpm) for 20 h. Cells were removed by centrifugation and the supernatant was as- sayed for tannase activity. The growth of the organism was estimated on the basis of biomass dry weight (mg ml −1 ).