Katyal, PriyaAvneet Kaur2018-05-112018-05-112018http://krishikosh.egranth.ac.in/handle/1/5810045350Tannase (tannin acyl hydrolase, E.C.3.1.1.20) is an inducible enzyme that has wide applications in different food and feed industries including production of beverages, cosmetic chemicals and in clarification of beer and fruit juice. It has also been used for bioremediation of tannins from effluents of leather industries. Attempt was made for isolation of tannase producing microbes (bacteria/fungi) from tannery effluents using tannic acid supplemented media. On the basis of qualitative (zone of hydrolysis) assay, four fungal isolates – AV1, AV2, AV3 and AV4 were found to be more efficient than bacterial isolates for tannase production and the maximum zone was shown by AV3 isolate i.e. 2.3 cm. For the morphological characterization of fungal isolates, lactophenol cotton blue staining and Scanning Electron Microscopy were done. Isolate AV1, AV2, AV3 and AV4 were found to show morphological similarities to genera Penicillium, Fusarium, Aspergillus and Trichoderma, respectively. Quantitative tannase production by the selected four isolates (AV1, AV2, AV3 and AV4) for seven consecutive days revealed AV3 to be the maximum tannase producer (25.33 U/ml) on 5th day of incubation. Four different agrowastes i.e. spent tea powder, coconut coir, corn husk and fruit baggase were used as substrates for tannase production using selected isolate AV3 and the maximum tannase production (35.62 U/ml) was obtained using spent tea powder as substrate at pH 5.5 and temperature 40oC. Optimization of process parameters for maximum tannase activity with central composite design using response surface methodology reveals maximum tannin hydrolysis (93.33µMmin-1) at a temperature of 600C, pH 8.0 and 5% substrate concentration. On partial purification, by ammonium sulphate precipitation followed by dialysis using membrane-70, activity of the tannase increased to 153.33µMmin-1 and the yield of the enzyme was 83.33%. Partially purified enzyme was used for detannification of pomegranate juice and was found to reduce tannin content from 2.76 mg/ml to 1.03 mg/ml but with slight decolorization of juice.ennullThesis