Production of beta-fructofuranosidase with transfructosylating activity for fructooligosaccharides synthesis by Aspergillus japonicus NTU-1249.
Microbial beta-fructofuranosidases with transfructosylating activity can catalyze the transfructosylation of sucrose and synthesize fructooligosaccharides. Aspergillus japonicus NTU-1249 isolated from natural habitat was found to produce a significant amount of beta-fructofuranosidase with high transfructosylating activity and to have the potential for industrial production of fructooligosaccharides. In order to improve it's enzyme productivity, the medium composition and the cultivation conditions for A. japonicus NTU-1249 were studied. A. japonicus NTU-1249 can produce 83.5 units of transfructosylating activity per ml broth when cultivated in a shaking flask at 28 degrees C for 72 hours with a modified medium containing 80 g/l sucrose, 15 g/l soybean flour, 5 g/l yeast extract and 5 g/l NaCl at an initial pH of 6.0. The enzyme productivity was also optimized by submerged cultivation in a 5-litre jar fermentor with aeration at 1.5 vvm and agitation at 500 rpm. Under these operating conditions, the productivity of transfructosylating activity increased to 185.6 U/ml. Furthermore, the transfructosylating activity was improved to 256.1 U/ml in 1,000-litre pilot-scale fermentor. Enzymatic synthesis of fructooligosaccharides by beta-fructofuranosidase from A. japonicus NTU-1249 was performed in batch type by adding 5.6 units of transfructosylating activity per gram of sucrose to a 50% (w/v) sucrose solution at pH 5.0 and 50 degrees C. The yield of fructooligosaccharides was about 60% after reaction for 24 hours, and the syrup produced contained 29.8% (w/v) fructooligosaccharides, 15.2% (w/v) glucose and 5.0% (w/v) sucrose.
Su
Y C
YC
Department of Agricultural Chemistry, National Taiwan University, Taipei, Republic of China.
Sheu
C S
CS
Chien
J Y
JY
Tzan
T K
TK
D001230:Aspergillus / Q000201:enzymology*; D003470:Culture Media / Q000494:pharmacology; D005285:Fermentation; D005632:Fructose / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis*; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D008828:Microbiological Techniques; D008829:Microbiology / Q000295:instrumentation; D009584:Nitrogen / Q000378:metabolism; D009844:Oligosaccharides / Q000378:metabolism; D043324:beta-Fructofuranosidase
D003470:Culture Media; D005656:Fungal Proteins; D009844:Oligosaccharides; D005632:Fructose; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D009584:Nitrogen