Abstract In the present study, a combination of immobilisation processes was utilised to prepare robust biocatalysts. First, lipase from Candida rugosa was adsorbed on polyhydroxybutyrate (PHB) particles, followed by cross-linking with glutaraldehyde. Conditions for creating immobilised lipase involved the addition of 0.6 M glutaraldehyde and 45 U mL−1 lipase while mixing at 150 rpm (4 °C) for 30 min. These conditions produced the highest yield of immobilised lipase (92 %) and the highest levels of activity (1.94 mg g−1 support). At 40 °C and pH 9 the immobilised enzyme was optimally active with a Km and Vmaxat 1.2 mM and 2.5 × 10-3 mmol min−1, respectively. The use of immobilised lipase improved thermal stability, storage stability, and reusability.The immobilised lipase retained 80 % of its activity after incubation at 30–60 °C for 2 h and 4 °C for 30 d in 0.2 M sodium phosphate buffer (pH 7.0). Moreover, the immobilised enzyme retained 50 % of its activity after more than 14 cycles under optimal conditions. The immobilised lipase was used to produce monoacylglycerol MAG. The existence of a carbonyl group at 1,743 and 1,744 cm−1 was identified using attenuated total reflectance (ATR)-Fourier transformed infrared spectroscopy. Results showed that 48 % MAG was produced.

中文翻译：

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通过吸附剂和交联剂的组合将假丝酵母脂肪酶固定在聚羟基丁酸酯上以增强酰基甘油的产生

摘要在本研究中，固定化过程的组合被用来制备强大的生物催化剂。首先，来自假丝酵母的脂肪酶吸附在聚羟基丁酸 (PHB) 颗粒上，然后与戊二醛交联。创建固定化脂肪酶的条件包括添加 0.6 M 戊二醛和 45 U mL-1 脂肪酶，同时以 150 rpm (4 °C) 混合 30 分钟。这些条件产生了最高产量的固定化脂肪酶 (92%) 和最高水平的活性 (1.94 mg g-1 支持)。在 40 °C 和 pH 9 时，固定化酶的活性最佳，Km 和 Vmaxat 分别为 1.2 mM 和 2.5 × 10-3 mmol min-1。固定化脂肪酶的使用提高了热稳定性、储存稳定性和可重复使用性。在 0.2 M 磷酸钠缓冲液 (pH 7.0) 中，在 30-60°C 下孵育 2 小时和在 4°C 下孵育 30 天后，固定化脂肪酶保留了 80% 的活性。此外，在最佳条件下，固定化酶在超过 14 个循环后仍保留 50% 的活性。固定化的脂肪酶用于生产单酰基甘油 MAG。使用衰减全反射 (ATR)-傅立叶变换红外光谱法确定了 1,743 和 1,744 cm-1 处存在羰基。结果表明产生了48%的MAG。使用衰减全反射 (ATR)-傅立叶变换红外光谱法鉴定了 744 cm-1。结果表明产生了48%的MAG。使用衰减全反射 (ATR)-傅立叶变换红外光谱法鉴定了 744 cm-1。结果表明产生了48%的MAG。