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Mycelial and extracellular inulinases from Fusarium oxysporum grown on aqueous extract of Cichorium intybus roots
Author(s) -
Gupta Anil K.,
Nagpal Bela,
Kaur Narinder,
Singh Rangil
Publication year - 1988
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280420108
Subject(s) - cichorium , inulin , inulinase , fructan , raffinose , food science , chemistry , mycelium , maltose , sucrose , extracellular , fusarium oxysporum , biochemistry , chromatography , botany , biology
Mycelial as well as extracellular inulinase (2,1‐β‐ D ‐fructan fructanohydrolase, ED 3.2.1.7) were produced by Fusarium oxysporum grown on the aqueous extract of Cichorium intybus roots. At 12 days growth of fungus, 86% of this enzyme activity was observed in the medium. The enzymes were partly purified by Sephadex G‐100 column chromatography. The optimum pH and temperature for mycelial and extracellular inulinases were 5.8 and 6.2; and 30°C and 37°C, respectively. The energy of activation for extracellular inulinase was 40.1 kJ mol −1 . The molecular weight of both inulinases was about 300 000. High concentrations of inulin did not protect the activity of inulinase against rising temperature. The enzymes did not release oligomers or sucrose from inulin, indicating that they are primarily exo‐acting. The inulinases hydrolysed sucrose and raffinose, but had no effect on melezitose and maltose. Compared with inulinases from other sources, the extracellular and mycelial inulinases have very low K m (Michaelis–Menten constant) values (16.7 and 20 μmol dm −3 , respectively) for inulin.