摘要
本试验采用了枯草杆菌(Bacillus subtilis)AS1.398枯草杆菌蛋白酶和自溶制备蚯蚓肽,通过前期单因素试验,设计正交试验L9(34),以氨基氮数,多肽浓度为衡量指标,对最佳酶解条件进行筛选研究,并分析了酶解液氨基酸组成和相对分子量的分布。结果表明:AS1.398枯草杆菌蛋白酶最佳酶解条为pH 6.5、酶浓度1%、温度50℃、反应时间8 h,在此条件下,酶解蚯蚓蛋白的每100 mL水解液氨基氮数可以达到16.55 mmol,多肽浓度达9.22 mg/mL;自溶酶解蚯蚓的最佳条件pH 7.0、底物浓度1∶2、温度50℃、反应时间6 h,在此条件下,酶解蚯蚓蛋白的每100 mL水解液氨基氮数可以达到21.55 mmol,多肽浓度达11.65 mg/mL;二者酶解产物分子量大部分是在5000以下的多肽、小肽及氨基酸的混合物,其中分子量在300以下占了80%,氨基酸组成平衡,含量丰富,可用来制取新型氨基酸微量元素及小肽添加剂。通过控制酶解条件,蚯蚓可以利用自身的酶源自溶来代替外源酶,从而降低成本。
Hydrolysis of the earthworm with subtilisin from Bacillus subtilis AS1. 398 and serf-enzyme of earthworm, the amino acid components and distribution of the relative molecular weight of earthworm enzymatic products were studied . The optimum conditions of enzymatic hydrolysis were determined through mono-factor analysis and orthogonal test（ L9 （3^4 ） ） using the content of amino acid nitrogen and polypeptide concentration of earthworm as testing indexes. The optimum conditions of earthworm hydrolyzed by AS1.398 subtilisin from Bacillus subtilis were pH 6.5, temperature 50 ℃, time 8 h, and 1% enzyme concentration. Under these conditions ,the content of amino acid nitrogen and polypeptide concentration of earthworm enzymatic hydrolysates can reach 16.55 mmol/100 mL and 9.22 mg/mL. The optimum conditions of autolyzed earthworm were pH 7.0, substrate concentration 1： 2, temperature 50 ℃, time 6 h. Under these conditions, the content of amino acid nitrogen and polypeptide concentration of earthworm enzymatic hydrolysates went up to 21.55 mmol/100 mL and 11.65 mg/mL. And the two enzymatic hydrolysates of earthworm mainly consisted of polypeptide, small peptide and amino acids with molecular weight below 5000, and about 80% of those with molecular weight less than 300. They have plenty of essential amino acids ,and balanced composition of amino acids which may benefit the manufacture of new additives of amino acid microelement and small peptide. Through controlling enzymatic hydrolysis, earthworm can avail itself of the enzyme instead of exogenous enzymes,which can reduce the cost.
出处
《天然产物研究与开发》
CAS
CSCD
2007年第1期16-20,共5页
Natural Product Research and Development
关键词
AS1.398枯草杆菌蛋白酶
蚯蚓
酶解
自溶
产物分析
subtilisin from Bacillus subtilis AS1. 398
earthworm
enzymatic hydrolysis
autolyze
analysis of enzymatic hydrolysate
