Potential tannase producers from the genera Aspergillus and Penicillium

Tarmase-producing ability of 35 Aspergilli and 25 Penicillii was examined both qualitatively on tannic acid agar plates and quantitatively in broth. Twenty-five Aspergilli and 20 Penicillii produced tannase in culture broth. Potent tannase-producing Aspergilli are Aspergillus fumigatus (8.3 IU/ml), Aspergillus versicolor (7.0 IU/ml), Aspergillus flavus (4.95 lU/ml) and Aspergillus caespitosum (4.47 IU/ml) and amongst Penicillii, Penicillium charlesii (4.82 IU/ml), Penicillium variable (4.70 IU/ml), Penicillium crustosum (4.7 IU/ml) and Penicillium restrictum (4.47 IU/ml). The crude tannase from these fungi showed pH optima of 5.0, except in A. caespitosum, P crustosum and P. variable, which had pH optima of 6.0. Optimum tannase activity was at 60 degrees C in most of the potent producers, except in A. caespitosum, P. charlesii, P. crustosum and P restrictum, which showed temperature optimum of 40 degrees C. Amongst the selected Aspergilli and Penicillii, tarmase from A. versicolor and P. restrictum was stable in a broad pH range of 3.0-8.0 for 24 h. The tannase from A. versicolor is heat stable as it retained 67% activity at 70 degrees C after I h. (c) 2004 Published by Elsevier Ltd.