包埋提高异常威克汉姆酵母醛脱氢酶的稳定性

Preliminary study of encapsulation to improve stability of ALDH of Wickerhamomyces anomalus

目的:提高威克汉姆酵母醛脱氢酶在冷藏和胃肠道环境中的稳定性,开发消减胃肠道内活性醛的产品。方法:从6株异常威克汉姆酵母(Wickerhamomyces anomalus)中选取醛脱氢酶(ALDH)活性最高的菌株提取ALDH,采用海藻酸钠—氯化钙法对ALDH进行包埋,研究了包埋对ALDH在冷藏及模拟胃肠道环境中的稳定性。结果:W.anomalus菌株J3、J7、J8、J9、J12、J18产生的ALDH比活力在86.77~482.14 U/mg,菌株J9的ALDH的比活力最高,为482.14 U/mg;最优包埋条件为海藻酸钠3.0%,氯化钙3.0%,包埋酶的活力为480.71 U/g;游离酶在4℃下放置5 d酶活下降至50%以下,包埋酶酶活维持在90%以上;在体外模拟胃肠道环境下,游离酶在模拟胃液中10 min内完全失去活性,而包埋酶在胃液环境中3 h酶活保留率为56.39%,肠液中1 h酶活保留率为56.35%。结论:海藻酸钠—氯化钙包埋法可显著提高异常威克汉姆酵母ALDH的稳定性。

Objective:This study aimed to improve the stability Wickerhamomyces anomalus aldehyde dehydrogenase in cold storage and gastrointestinal environment,so as to develop products that reduce active aldehydes in gastrointestinal tract.Methods:ALDH was extracted from 6 Wickerhamomyces anomalus strains with the highest activity of aldehyde dehydrogenase(ALDH),and encapsulated by sodium alginate and calcium chloride method.The stability of ALDH by embedding was studied in cold storage and simulated gastrointestinal environment.Results:The specific activity of ALDH produced by W.anomalus J3,J7,J8,J9,J12 and J18 ranged from 86.77 U/mg to 482.14 U/mg,and that of J9 was the highest at 482.14 U/mg.The optimal embedding conditions were sodium alginate 3.0%and calcium chloride 3.0%,and the activity of the enzyme was 480.71 U/g.When the free enzyme was placed at 4℃for 5 days,the enzyme activity decreased to below 50%,and the enzyme activity of embedding enzyme remained above 90%.In the simulated gastrointestinal tract environment in vitro,the free enzyme completely lost its activity in simulated gastric juice within 10 min,while the retention rate of immobilized enzyme in gastric juice for 3 h and intestinal juice for 1 h was 56.39%and 56.35%,respectively.Conclusion:Sodium alginate-calcium chloride embedding method can significantly improve the ALDH stability of W.anomalus.