CAJ | 학술논문

为获得高效降解卡拉胶菌株,从青岛太平角海域采集的角叉菜表面分离到1株高产κ-卡拉胶酶的海洋交替假单胞菌(Pseudoalteromonas sp.)QY202,经硫酸铵沉淀、脱盐、DEAE阴离子交换层析等步骤从该菌株发酵液上清中分离纯化得到1种专一性降解κ-卡拉胶的κ-卡拉胶酶,并研究了该酶的基本酶学性质.结果表明该酶被纯化了23.1倍,回收率为43.9%,分子量大小为33.2 kDa.酶的最适反应温度为40 ℃,最适反应pH为8.0,在0～40 ℃,pH=7.0～8.0之间酶活力较稳定.酶对底物κ-卡拉胶的米氏常数Km值为1.6 mg/mL.Na~+、K~+对酶活有促进作用,而Hg~(2+)、Cu~(2+)强烈抑制酶的活性.酶解κ-卡拉胶的主产物为硫酸新κ-卡拉二糖和硫酸新κ-卡拉四糖.
위획득고효강해잡랍효균주,종청도태평각해역채집적각차채표면분리도1주고산κ-잡랍효매적해양교체가단포균(Pseudoalteromonas sp.)QY202,경류산안침정、탈염、DEAE음리자교환층석등보취종해균주발효액상청중분리순화득도1충전일성강해κ-잡랍효적κ-잡랍효매,병연구료해매적기본매학성질.결과표명해매피순화료23.1배,회수솔위43.9%,분자량대소위33.2 kDa.매적최괄반응온도위40 ℃,최괄반응pH위8.0,재0～40 ℃,pH=7.0～8.0지간매활력교은정.매대저물κ-잡랍효적미씨상수Km치위1.6 mg/mL.Na~+、K~+대매활유촉진작용,이Hg~(2+)、Cu~(2+)강렬억제매적활성.매해κ-잡랍효적주산물위류산신κ-잡랍이당화류산신κ-잡랍사당.
A marine bacterium Pseudoalteromonas sp. QY202 with high κ-carrageenase activity was isolated from the surface of Chondrus crispus. The κ-carrageenase was purified to electrophoretic homogeneity from the culture supernatant by a procedure of ammonium sulfate precipitation, desalting and DEAE-sepharose ion exchange chromatography, and the characterization of the enzyme was studied. The results show that the enzyme is purified 23.1 folds with a total recovery yield of 43.9% and gives a single band on SDS-PAGE with a molecular mass of 33.2 kDa. The optimum temperature and pH for enzyme activity are 40 ℃ and pH8.0, respectively. The enzyme is stable at temperatures below 40 ℃ and over a range of pH7.0～8.0. For κ-carrageenan, the enzyme gave a Km value of 1.6 mg/mL. The enzyme activity could be enhanced by the presence of Na~+ and K~+, whereas enormously inhibited by Hg~(2+)and Cu~(2+). The main hydrolysis products of κ-carrageenan by the enzyme are κ-neocarradiaose and κ- neocarratetraose.