Production, thermal stability and immobilisation of inulinase from Fusarium oxysporum.
Fusarium oxysporum produced maximum extracellular inulinase after 9 days of its growth at 25 degrees C on a medium (pH 5.5) containing 3% fructan and 0.2% sodium nitrate. The level of this enzyme decreased on the addition of either glucose, fructose, galactose or sucrose to F. oxysporum already growing on a fructan-containing medium. A significant increase in invertase production which resulted in an increase of the invertase/inulinase (S/I) ratio, was observed on addition of inulin to this fungus growing on other carbon sources. Glycerol (10%) gave better protection to inulinase against thermal denaturation at 50 degrees C compared to ethylene glycol and sorbitol. Inulinase immobilised in polyacrylamide gel retained 45% of its original activity. The immobilised enzyme showed a higher optimum temperature (45 degrees C) compared to free enzyme (37 degrees C). The immobilised enzyme after storage at 25 degrees C for 96 h showed 58% activity. Thermal stability of entrapped inulinase increased in the presence of inulin.
Department of Biochemistry, Punjab Agricultural University, Ludhiana, India.
A K
AK
Gupta
P
P
Rathore
N
N
Kaur
R
R
Singh
D000438:Alcohols; D001709:Biotechnology; D002241:Carbohydrates; D004800:Enzymes, Immobilized; D005630:Fructans; D005670:Fusarium / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen; D013696:Temperature; D043324:beta-Fructofuranosidase
D000438:Alcohols; D002241:Carbohydrates; D004800:Enzymes, Immobilized; D005630:Fructans; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; C023086:inulinase; D009584:Nitrogen