Potential tannase producers from the genera Aspergillus and Penicillium

Tannase-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 IU/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 °C in most of the potent producers, except in A. caespitosum, P. charlesii, P. crustosum and P. restrictum, which showed temperature optimum of 40 °C. Amongst the selected Aspergilli and Penicillii, tannase 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 °C after 1 h.