Anhui Key Laboratory of Modern Biomanufacturing, School of Life Sciences, School of Resources and Environmental Engineering , Anhui University , Hefei 230601 , Anhui P.R. China.
J Agric Food Chem. 2018 Dec 5;66(48):12748-12755. doi: 10.1021/acs.jafc.8b03524. Epub 2018 Nov 26.
Microalgae starch is receiving increasing attention as a renewable feedstock for biofuel production. Raw microalgae starch from Tetraselmis subcordiformis was proven to be very efficiently hydrolyzed by an α-amylase (AmyP) of glycoside hydrolase subfamily GH13_37 below the temperature of gelatinization (40 °C). The hydrolysis degree reached 74.4 ± 2.2% for 4% raw microalgae starch and 53.2 ± 1.7% for 8% raw microalgae starch after only 2 h. The hydrolysis efficiency was significantly stimulated by calcium ions. The enzyme catalysis of AmyP and its mutants (Q306A and E347A) suggested that calcium ions contributed to the hydrolysis of cyclic structures in raw microalgae starch by a distinctive calcium-binding site Ca2 of AmyP. The study explored raw microalgae starch as a new resource for cold enzymatic hydrolysis and extended our knowledge on the function of calcium in amylolytic enzyme.
微藻淀粉作为生物燃料生产的可再生原料越来越受到关注。研究证明，琼胶寡糖酶家族 GH13_37 中的 α-淀粉酶（AmyP）在低于糊化温度（40°C）的条件下，可以非常有效地水解四尾栅藻淀粉。仅 2 h 后，4%的原始微藻淀粉的水解度达到 74.4±2.2%，8%的原始微藻淀粉的水解度达到 53.2±1.7%。钙离子显著刺激了水解效率。AmyP 及其突变体（Q306A 和 E347A）的酶催化作用表明，钙离子通过 AmyP 的独特钙结合位点 Ca2 有助于水解原始微藻淀粉中的环状结构。该研究探索了原始微藻淀粉作为冷酶水解的新资源，并扩展了我们对钙在淀粉分解酶中的功能的认识。
