Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Songkhla, Thailand.
Prep Biochem Biotechnol. 2021;51(6):536-549. doi: 10.1080/10826068.2020.1836654. Epub 2020 Oct 23.
The partially purified lipase from ST11 was immobilized on the surface-modified electrospun polyacrylonitrile (PAN) nanofibrous membrane. The effects of time and concentrations of glutaraldehyde and bovine serum albumin (BSA) were studied. The immobilized lipase reached the maximum activity at 180 min with the recovered activity of 44.2% (0.22 U/mg-support) in the absence of BSA. After adding 6 mg/mL BSA and 40 mM glutaraldehyde gave the recovered activity at 86.9% (0.43 U/mg-support). It showed the highest stability at pH 7.5 but the soluble lipase was at pH 7.0. In addition, the immobilized lipase was more stable at pH 4.0 and 9.0. The immobilized lipase preserved 56% activity at 70 °C but the soluble lipase had 34% activity. It conserved 86% activity while the soluble lipase had 18% activity after 13 days of storage at 4 °C. The operating parameters such as biocatalyst concentration, water content, and the molar ratio of methanol and palm oil were optimized for biodiesel production. The highest biodiesel conversion (95%) was obtained with the immobilized lipase 15% (w/w), 40% (w/w) 50 mM Tris-HCl buffer pH 7.0 and methanol/palm oil (3.5:1.0). This immobilized lipase could be reused with 82.9% conversion after 10 cycles of batch production.
ST11 的部分纯化脂肪酶被固定在经过表面修饰的聚丙烯腈（PAN）纳米纤维膜上。研究了戊二醛和牛血清白蛋白（BSA）的时间和浓度的影响。在没有 BSA 的情况下，固定化脂肪酶在 180 分钟时达到最大活性，回收活性为 44.2%（0.22 U/mg-载体）。添加 6mg/mL BSA 和 40mM 戊二醛后，回收活性为 86.9%（0.43 U/mg-载体）。它在 pH 7.5 时表现出最高的稳定性，但可溶性脂肪酶在 pH 7.0 时表现出最高的稳定性。此外，固定化脂肪酶在 pH 4.0 和 9.0 下更稳定。固定化脂肪酶在 70°C 时保持 56%的活性，而可溶性脂肪酶保持 34%的活性。在 4°C 下储存 13 天后，固定化脂肪酶保持 86%的活性，而可溶性脂肪酶保持 18%的活性。优化了生物催化剂浓度、含水量以及甲醇和棕榈油摩尔比等操作参数，用于生产生物柴油。在固定化脂肪酶 15%（w/w）、40%（w/w）50mM Tris-HCl 缓冲液 pH 7.0 和甲醇/棕榈油（3.5:1.0）的条件下，生物柴油转化率最高（95%）。这种固定化脂肪酶在 10 次批处理生产循环后可以重复使用，转化率为 82.9%。
