Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, Chatuchak, Bangkok 10900, Thailand; Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University (CASTNAR, NRU-KU), Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
J Biotechnol. 2018 Feb 10;267:71-78. doi: 10.1016/j.jbiotec.2017.12.022. Epub 2017 Dec 28.
Suspensions of the model microalga Chlorella sp. TISTR 8990 were pretreated by ohmic heating to facilitate release of lipids from the cells in subsequent extraction and lipase-mediated transesterification to biodiesel. After ohmic pretreatment, the moist biomass was suspended in a system of water, hexane, methanol and immobilized lipase for extraction of lipids and simultaneous conversion to biodiesel. The ohmic pretreatment was optimized using an experimental design based on Taguchi method to provide treated biomass that maximized the biodiesel yield in subsequent extraction-transesterification operation. The experimental factors were the frequency of electric current (5-10 Hz), the processing temperature (50-70 °C), the algal biomass concentration in the slurry (algal fresh weight to water mass ratio of 1-3) and the incubation time (1-3 min). Extraction-transesterification of the pretreated biomass was carried out at 40 °C for 24 h using a reaction systems of a fixed composition (i.e. biomass, hexane, methanol, water and immobilized enzyme). Compared to control (i.e. untreated biomass), the ohmic pretreatment under optimal conditions (5 Hz current frequency, 70 °C, 1:2 mass ratio of biomass to water, incubation time of 2-min) increased the rate of subsequent transesterification by nearly 2-fold.
将模式微藻小球藻 TISTR 8990 的悬浮液进行欧姆加热预处理，以促进随后的提取和脂肪酶介导的酯交换转化为生物柴油过程中细胞内脂质的释放。欧姆预处理后，将湿生物质悬浮在水、正己烷、甲醇和固定化脂肪酶的体系中，以提取脂质并同时转化为生物柴油。使用基于田口方法的实验设计对欧姆预处理进行优化，以提供在随后的提取-酯交换操作中最大限度提高生物柴油产率的处理生物质。实验因素为电流频率（5-10Hz）、处理温度（50-70°C）、浆液中藻类生物质浓度（藻体鲜重与水质量比为 1-3）和孵育时间（1-3min）。预处理生物质在 40°C 下进行 24 小时的提取-酯交换反应，使用固定组成的反应体系（即生物质、正己烷、甲醇、水和固定化酶）。与对照（即未经处理的生物质）相比，在最佳条件（5Hz 电流频率、70°C、生物质与水的质量比为 1:2、孵育时间 2min）下进行欧姆预处理，可使随后的酯交换速率提高近 2 倍。
