Kareem Safaradeen Olateju, Adio Olayinka Quadri, Osho Michael Bamitale
Department of Microbiology, Federal University of Agriculture, PMB 2240, Abeokuta 110001, Ogun State, Nigeria.
Department of Biological Sciences, McPherson University, Seriki-Sotayo, PMB 2094, Abeokuta 110116, Ogun State, Nigeria.
Enzyme Res. 2014;2014:967056. doi: 10.1155/2014/967056. Epub 2014 Dec 31.
The potential of polysaccharide Irvingia gabonensis matrix as enzyme immobilization support was investigated. Lipase of Aspergillus niger F7-02 was immobilized by entrapment using glutaraldehyde as the cross-linking agent and stabilized in ethanolic-formaldehyde solution. The pH and temperature stability and activity yield of the immobilized enzyme were determined. Such parameters as enzyme load, bead size, number of beads, and bead reusability were also optimized. Adequate gel strength to form stabilized beads was achieved at 15.52% (w/v) Irvingia gabonensis powder, 15% (v/v) partially purified lipase, 2.5% (v/v) glutaraldehyde, and 3 : 1 (v/v) ethanolic-formaldehyde solution. There was 3.93-fold purification when the crude enzyme was partially purified in two-step purification using Imarsil and activated charcoal. Optimum lipase activity 75.3 Ug(-1) was achieved in 50 mL test solution containing 15 beads of 7 mm bead size. Relative activity 80% was retained at eight repeated cycles. The immobilization process gave activity yield of 59.1% with specific activity of 12.3 Umg(-1) and stabilized at optimum pH 4.5 and temperature 55°C. Thus the effectiveness and cost-efficiency of I. gabonensis as a polymer matrix for lipase immobilization have been established.
研究了加蓬假鹰爪多糖基质作为酶固定化载体的潜力。以戊二醛为交联剂，通过包埋法固定黑曲霉F7-02脂肪酶，并在乙醇-甲醛溶液中进行稳定化处理。测定了固定化酶的pH稳定性、温度稳定性和活性产率。还对酶负载量、珠子大小、珠子数量和珠子可重复使用性等参数进行了优化。在15.52%（w/v）的加蓬假鹰爪粉末、15%（v/v）的部分纯化脂肪酶、2.5%（v/v）的戊二醛和3∶1（v/v）的乙醇-甲醛溶液条件下，可获得形成稳定珠子所需的足够凝胶强度。当粗酶用伊马西尔和活性炭进行两步纯化时，纯化倍数为3.93倍。在含有15颗7毫米大小珠子的50毫升测试溶液中，脂肪酶的最佳活性为75.3 U g⁻¹。在八次重复循环后，相对活性保留了80%。固定化过程的活性产率为59.1%，比活性为12.3 U mg⁻¹，在最佳pH 4.5和温度55°C下稳定。因此，已证实加蓬假鹰爪作为脂肪酶固定化聚合物基质的有效性和成本效益。
