Optimisation of solid-state fermentation of Aspergillus niger JL-15 for xylanase production and xylooligosaccharides preparation
2011
Dai, X.J.,China Jiliang Univ., Hangzhou (China). Dept of Food Science | Liu, M.Q.,China Jiliang Univ., Hangzhou (China). Dept of Food Science | Jin, H.X.,China Jiliang Univ., Hangzhou (China). Coll. of Materials Science and Engineering | Jing, M.Y.,University of Manitoba, Winnipeg (Canada). Dept. of Animal Science
The production of xylanase (XylA) by Aspergillus niger JL-15 in solid-state fermentation (SSF) on orange peel was optimised by the response surface methodology. The results revealed that four factors had significant effects on the XylA production, that is the concentrations of the added glycerin and ammonium sulfate, the moisture content, and fermentation time. Exploying orange peel as the solid substrate, maximum xylanase activity (917.7 U/g dry fermentation product) was obtained at 4.2% glycerin, 3.1% (NH4)2SO4, 61% moisture content, and 73.4-h fermentation, this activity being close to the predicted one and 3.2 times higher than that of the basic medium (218.5 U/g). Optimum temperature and pH for XylA activity were 55 deg C and pH 5.0, respectively. SDS-PAGE analysis showed that the relative molecular mass of XylA was about 30.0 kDa. XylA exhibited Km and Vmax values of 9.24 mg/mL and 54.05 micromol/min/mL, respectively. XylA liberated mainly xylotriose from birchwood xylan and wheat bran, respectively. XylA was an endo-acting xylanase with transglycosylation activity, with the ability to hydrolyse xylobiose, xylotriose, xylotetraose, xylopentaose, and xylohexaose.
显示更多 [+] 显示较少 [-]