Irfan Muhammad, Nadeem Muhammad, Syed Quratualain
Food and Biotechnology Research Centre (FBRC), PCSIR Laboratories Complex, Ferozpure road Lahore, Pakistan.
Protein Pept Lett. 2013 Nov;20(11):1225-31. doi: 10.2174/09298665113209990007.
Present study dealt with the production, purification and characterization of xylanase from Bacillus subtilis- BS05 grown in submerged fermentation at 37(o)C for 48h using sugarcane bagasse as a substrate. Xylanase enzyme was purified to homogeneity by ammonium sulphate fractionation followed by sephadex G-100 chromatography. The molecular mass of xylanase enzyme was found to be 23kDa by SDS-PAGE. The optimum pH and temperature of xylanase enzyme was 5 and 50°C with stability range of 5-6 and 30°C -50°C respectively. The enzyme had half life of 1386-1155 minutes at 30°C -50°C respectively. Metal profile of the enzyme showed that Mn(2+) (127.4 %) and Fe(2+) (115%) were the activators while Hg(2+) (14%) and EDTA (19%) were the inhibitors. Kinetic parameters revealed that the enzyme is specific to birchwood xylan with Km , Kcat , Vmax and Kcat/Km value of 1.15 mg/ml, 850 s(-1), 117.64 U/mg and 739.13 s(-1)mg(-1).mL respectively.
本研究涉及以甘蔗渣为底物，在37℃下进行48小时深层发酵培养的枯草芽孢杆菌BS05所产木聚糖酶的生产、纯化及特性研究。通过硫酸铵分级沉淀，随后进行葡聚糖G - 100柱层析，将木聚糖酶纯化至同质。经SDS - PAGE分析，木聚糖酶的分子量为23kDa。木聚糖酶的最适pH值和温度分别为5和50℃，稳定pH范围为5 - 6，稳定温度范围为30℃ - 50℃。该酶在30℃ - 50℃下的半衰期分别为1386 - 1155分钟。酶的金属离子特性表明，Mn(2+)（127.4%）和Fe(2+)（115%）为激活剂，而Hg(2+)（14%）和EDTA（19%）为抑制剂。动力学参数显示，该酶对桦木木聚糖具有特异性，其Km、Kcat、Vmax和Kcat/Km值分别为1.15 mg/ml、850 s(-1)、117.64 U/mg和739.13 s(-1)mg(-1).mL。
