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Purification and immobilisation of inulinase from Aspergillus candidus for producing fructose
Author(s) -
Kochhar Anuradha,
Gupta Anil K,
Kaur Narinder
Publication year - 1999
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(19990315)79:4<549::aid-jsfa216>3.0.co;2-0
Subject(s) - inulinase , inulin , chemistry , chromatography , fructose , cellulose , sucrose , biochemistry
A high‐inulinase‐producing strain of Aspergilluscandidus (10 units cm −3 of medium) forproducing fructose from inulin has been identified. The extracellularinulinase from this fungi was purified 56‐fold by ammoniumsulphate fractionation, DEAE cellulose and Sephadex G‐150column chromatography. Invertase to inulinase ratio of 1.8 in culturefiltrate was reduced to 0.14 in the purified preparation. The pH andtemperature optima were 5.5 and 45°C, respectively. The molecularweight of inulinase was determined as 54±4 kDa. K m of inulinase with inulin as a substrate was 3.8 mmole dm −3 . The purified preparation produced only fructoseas the product of inulin, indicating that inulinase has primarilyexo‐inulinase activity. Inulinase was immobilised on chitinand casein using glutaraldehyde as a linking agent and on celluloseusing FeCl 3 ‐HCl as a metal chelation agent. Maximumimmobilisation of 45.8% was achieved on cellulose. All threeimmobilised preparations had a higher temperature optima of 55°C.The inulinases immobilised on cellulose and casein were stable at pH5–7. The cellulose‐immobilised preparation was morestable than the other two preparations after heating for 1 h at55°C. © 1999 Society of Chemical Industry