從市售納豆健康食品中篩選納豆菌並探討最適化生產納豆激酶之培養條件

Optimization of nutritional conditions for nattokinase production by a isolated Bacillus subtilis from natto health food

吳世佑(Shih-Yu Wu)

指導教授 ： 段國仁

大同大學/工程學院/生物工程學系所/碩士(2005年)

摘要

納豆激酶（nattokinase, NK）具有很強的血纖維蛋白（fibrin）溶解能力。它主要是利用枯草桿菌（Bacillus subtilis）的類緣菌，俗稱「納豆菌」。NK是屬於一種絲胺酸蛋白酶（serine protease）
，可運用於血栓症、中風等心血管疾病的預防及治療。
本研究利用一株來自納豆食品中篩選的北海道納豆菌，以500 ml的三角錐瓶內含200 ml基礎培養基，進行以醱酵培養生產NK之研究。最後以糖蜜（20 g/L）、peptone（20 g/L）、MgSO4（1 g/L）、CaCl2（1 g/L）和K2HPO4（2 g/L）為培養基，在醱酵溫度37℃，轉速180 rpm，培養47.5小時會有最高活性(63 unit)。酵素最適pH 值及溫度分別為10與37℃。pH-stat的饋料批式醱酵方式，初期以molasses為主要的碳源，之後的饋料主要是增加細胞濃度為主，有如此大量菌體就可產生較多的酵素。由於連續提供養分使的菌得以長時間生長及分泌酵素，最後的細胞濃度比以三角錐瓶醱酵培養增加了3倍，而酵素的活性也比三角錐瓶醱酵培養提高了2.7倍，酵素活性約為172 unit。

關鍵字

納豆激酶

並列摘要

Nattokinase, a potent fibrinolytic enzyme, was primarily isolated from a traditional fermented food in Japan, ‘‘Natto’’. Nattokinase, a serine protease, can prevent and cure cardiovascular system, for example, thrombus disease and apoplexy.
Nattokinase having a strong fibrinolytic activity and produced by a Bacillus natto hokaido, which was isolated from the vegetable cheese natto. Maximum activity (63.3 U ml-1) was obtained when the bacterium was grown in a 500 ml Erlenmeyer flask containing 200 ml medium containing (g/l): molasses, 20; peptone, 20; CaCl2‧2H2O, 1; MgSO4‧7H2O, 1; K2HPO4, 2 at 37℃ for 48 h incubation period with agitation of 180 rpm. The optimum pH and temperature for activity were 37℃ and 10. Fed-batch culture was performed to maximize protease activity in a bioreactor. By using suitable feeding strategies, the protease activity and biomass production in a fed-batch process was increase by 207 ﹪and 300 ﹪over that in batch process, primarily due to the longer maintenance of cell growth and enzyme production by providing continuous and controlled supply of additional substrate and nutrients.

並列關鍵字

nattokinase

參考文獻

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