Some biochemical, catalytic, thermodynamic and kinetic properties of purified fructosyltransferase from wild and improved mutant-type Aureobasidium pullulans NAC8
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Date
2019-09-15
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor and Francis Online
Abstract
A low molecular weight intracellular and extracellular fructosyltransferase was purified from the
wild (Wt) and improved mutant-type (Mt) Aureobasidium pullulans and its characteristics and
thermodynamic properties determined. The Wt had been previously genetically modified by
chemical mutagenesis. The purified fructosyltransferases from the Wt and Mt had subunit
molecular weights between 13.4 and 17.0 kDa, respectively. The pH of the purified fructosyltransferase
from the Wt and Mt were within 4.0–5.5. From the KM values, the fructosyltransferase
from Mt showed higher affinity for sucrose than Wt fructosyltransferase. The optimum temperature
obtained for the Mt intracellular and extracellular fructosyltransferase were 80 and 70 C,
respectively, while the Wt extracellular and intracellular fructosyltransferase was 60 C. Most metals
enhanced fructosyltransferase activity in a concentration-dependent manner except for mercury.
Triton X-100 and Tween-80 enhanced the fructosyltransferase activity. Organic solvents
such as acetone, ethanol, methanol, toluene and dichloromethane enhanced the enzyme activity
while dimethylformamide inhibited the enzyme. From the thermodynamic and kinetic parameters
(t1=2, DH , DS , DG Þ Mt fructosyltransferase was more stable to thermal inactivation than
the Wt fructosyltransferase. Hence, it can be concluded that, after strain improvement of the Wt,
the purified Mt fructosyltransferase was more stable to organic solvents, surfactants, and thermal
denaturation, etc. compared to the Wt. This makes Mt fructosyltransferase more useful mostly in
the food industry than the Wt.
Description
Staff Publication
Keywords
Fructosyltransferase;, kinetics;, purification;, characterization;, sucrose;, Aureobasidium pullulans NAC8
Citation
Adedeji N. Ademakinwa & Femi K. Agboola (2019): Some biochemical, catalytic, thermodynamic and kinetic properties of purified fructosyltransferase from wild and improved mutant-type Aureobasidiumpullulans NAC8, Biocatalysis and Biotransformation, DOI: 10.1080/10242422.2019.1671376