 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Production of ?-Fructofuranosidase from Aspergillus niger ATCC 20611) ผู้เขียน: ดร.สาโรจน์ ศิริศันสนียกุล, ศาสตราจารย์ ,  Sanya Jitbanjongkit, Nararit Prasomsart, Pairojana Luangpituksa สื่อสิ่งพิมพ์:pdf AbstractAn increase in magnesium sulfate decreased the ratio of extracellular/intracellular ?- fructofuranosidase activity in shaking flask cultivation of Aspergillus niger ATCC 20611. At 0.4% MgSO4 concentration, the enzyme ratio was decreased to 54%, but the total enzyme activity was increased 1.12 times more than that with no salt addition. Three ammonium salts tested, (NH4)2SO4, (NH4)2HPO4, and NH4NO3 could not substitute yeast extract as a nitrogen source because of decreasing in the specific growth rate, enzyme yield and productivity. In this study, yeast extract with vitamin solution gave the highest values of specific growth rate, enzyme yield and productivity. Based on the fermentation kinetic study in aerobic batch culture under controlled pH and temperature, the specific growth rate, enzyme yield and productivity were improved to 0.0414 h-1, 65.16 ? 103 U/g sucrose and 1.89 ? 103 U/g cell h, respectively. These values were increased 1.85, 10.5 and 497.9 times, respectively, comparing with shaken flask culture. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Enzymatic Production of Fructo-Oligosaccharides from Sucrose) ผู้เขียน:ดร.สาโรจน์ ศิริศันสนียกุล, ศาสตราจารย์, Sittiwat Lertsiri, Preecha Tonsagunrathanachai, Pairojana Luangpituksa สื่อสิ่งพิมพ์:pdf AbstractTo increase an efficiency of fructo-oligosaccharide production from sucrose, a mixed-enzyme system of ?-fructofuranosidase (Aspergillus niger ATCC 20611) and glucose oxidase (Sigma Chemical Co., Ltd.) was carried out in a 2-l stirred tank reactor with the following controlled conditions; temperature 40?C, pH 5.5, aeration rate 1 vvm and agitation rate 550 rpm, for 32 hours of incubation time. With an initial sucrose concentration of 400 g/l, the optimal condition was obtained by using ?-fructofuranosidase and glucose oxidase 10 and 15 units per gram sucrose, respectively. As a result, the yields of kestose (YGF2/S) and nystose (YGF3/S) from sucrose and their volumetric productivities (QGF2/S and QGF3/S) were 0.44, 0.49 g/g, and 4.97, 5.44 g/l h, respectively. |