产纤维素酶海洋细菌的筛选和酶学性质的初步研究

摘要

The Gram-negative, bacterium TX-12 with high CMCase-producing activity has been screened and isolated from decaying plants of the sea. The strain is identified to be a kind of Cellulophaga sp. The results of CMCase producing research show that the optimal pH value is 8.0, and the optimal temperature is 25℃. Under this condition, the highest CMCase activity reached to 354. 8 U/mL after shaking flask culture for 56 h. The primary study on enzymatic properties show that the optimal temperature and pH for the enzymatic reaction are 60℃, and 8. 0, respectivly. The relative enzyme activity keep at 0 - 100 t. Moreover, the CMCase shows good stability at 100 X.. Studies also show that Fe2 +, Cu2+ and Mn2+ can stimulate the enzyme reaction, whreas Hg2 + and Pb2 + inhibit the reaction.%从病烂的海洋植物中分离到一株高产纤维素酶的菌株TX-12,革兰氏阴性,经鉴定为噬纤维菌属(Cellulophaga sp.)中的一个种.该菌株在温度25℃、培养基起始pH 8.0条件下培养56 h产生碱性纤维素酶活力高达354.8 U/mL.酶学性质初步研究显示,TX-12产生的纤维素酶最适反应pH值为8.0,最适反应温度为60℃,在0～100℃酶活均能保持最高酶活的70％以上.酶液在100℃时仍具有较高的稳定性.Fe2+、Cu2+、Mn2+对酶反应有一定促进作用,Hg2+和pb2+对酶反应有强烈的抑制作用.