Abstract

A thermostable bacterial lipase from Geobacillus zalihae was expressed in a novel yeast Pichia sp. strain SO. The preliminary expression was too low and discourages industrial production. This study sought to investigate the optimum conditions for T1 lipase production in Pichia sp. strain SO. Seven medium conditions were investigated and optimized using Response Surface Methodology (RSM). Five responding conditions namely; temperature, inoculum size, incubation time, culture volume and agitation speed observed through Plackett–Burman Design (PBD) method had a significant effect on T1 lipase production. The medium conditions were optimized using Box–Behnken Design (BBD). Investigations reveal that the optimum conditions for T1 lipase production and Biomass concentration (OD₆₀₀) were; Temperature 31.76 °C, incubation time 39.33 h, culture volume 132.19 mL, inoculum size 3.64%, and agitation speed of 288.2 rpm with a 95% PI low as; 12.41 U/mL and 95% PI high of 13.65 U/mL with an OD₆₀₀ of; 95% PI low as; 19.62 and 95% PI high as; 22.62 as generated by the software was also validated. These predicted parameters were investigated experimentally and the experimental result for lipase activity observed was 13.72 U/mL with an OD₆₀₀ of 24.5. At these optimum conditions, there was a 3-fold increase on T1 lipase activity. This study is the first to develop a statistical model for T1 lipase production and biomass concentration in Pichia sp. Strain SO. The optimized production of T1 lipase presents a choice for its industrial application.

摘要

在新的酵母毕赤酵母属中表达了来自扎利海芽孢杆菌的热稳定细菌脂肪酶。SO菌株。初步表述过低，不鼓励工业生产。这项研究旨在调查在毕赤酵母中生产T1脂肪酶的最佳条件sp。SO菌株。使用响应表面方法（RSM）对7种培养基条件进行了研究和优化。五个响应条件是：通过Plackett–Burman设计（PBD）方法观察到的温度，接种量，孵育时间，培养量和搅拌速度对T1脂肪酶的产生有重要影响。使用Box–Behnken设计（BBD）优化了培养基条件。研究表明，T1脂肪酶生产和生物量浓度（OD ₆₀₀）的最佳条件为：温度31.76℃，孵育时间39.33h，培养物体积132.19mL，接种量3.64％，搅拌速度288.2rpm，PI低至95％；OD _600为12.41 U / mL和13.65 U / mL的95％PI高的; PI低至95％；PI为19.62和95％；由软件生成的22.62也得到了验证。对这些预测参数进行了实验研究，观察到的脂肪酶活性的实验结果为13.72 U / mL，OD ₆₀₀为24.5。在这些最佳条件下，T1脂肪酶活性增加了3倍。这项研究是第一个为毕赤酵母中T1脂肪酶生产和生物量浓度建立统计模型的研究。应变SO。T1脂肪酶的优化生产为其工业应用提供了选择。