초록
<P>In this work, <I>Aspergillus aculeatus</I> M105 was obtained to produce high extracellular fructooligosaccharide-producing enzyme activity. The maximum yields of fructooligosaccharides produced by its extracellular enzymes and immobilized cells were 67.54 and 65.47% (w/w), respectively. A fructosyltransferase (FTase), AaFT32A, was purified from M105. The optimal pH and temperature of AaFT32A were pH 5.0–6.0 and 65 °C, respectively. The <I>K</I><SUB>m</SUB>, <I>V</I><SUB>max</SUB>, and <I>k</I><SUB>cat</SUB> values for the transfructosylating activity of AaFT32A were 2267 mM, 1347 μmol/min/mg protein, and 1550.2 s<SUP>–1</SUP>, respectively, and those values for the hydrolytic activity of AaFT32A were 6.10 mM, 32.44 μmol/min/mg protein, and 37.3 s<SUP>–1</SUP>, respectively. The sequence of AaFT32A deduced from the cloned gene shared 99.4% identity with a FTase from <I>Aspergillus japonicus</I> CB05 and a fructofuranosidase from <I>Aspergillus niger</I> and 96.5% identity with a FTase (Aspacl_37092) from <I>A.？aculeatus</I> ATCC 16872. The fungal strain and its FTase may have potential applications in the prebiotics industry.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2016/jafcau.2016.64.issue-33/acs.jafc.6b02115/production/images/medium/jf-2016-021156_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf6b02115'>ACS Electronic Supporting Info</A></P>