摘要
采用离体法对鄂尔多斯高原碱湖的钝顶螺旋藻S1、引进的钝顶螺旋藻S2和极大螺旋藻S3硝酸还原酶(NR)的活性进行测定,用4种作图法研究该酶的Km和Vmax。结果表明:4种作图法得出的Km和Vmax值均在同一个数量级,方差分析不同的作图法之间无显著差异,但3个样品间差异显著,S1的最高,S3的次之,S2的最低。在30℃±1℃、pH7.5下,以KNO3为底物,Eadie-Hofstee作图法得出的S1、S2和S3NR的Km值分别为2.729 1μmol/L、1.080 7μmol/L和1.627 4μmol/L,Vmax分别为0.017 2μmol/min、0.007 0μmol/min和0.009 8μmol/min。与某些生物比较,螺旋藻NR的Km值相对较低,对NO3-亲和力较高。
Activity of Nitrate reductase（NR） from the domestic Spirulina（Arthrospira） platensis（S1） from Ordos Plateau alkaline lakes and the imported S.（A.） platensis（S2） and S.（A.） maxima（S3） were investigated by means of in vitro method.The Michaelis constant（Km） and Vm values of NR were made using four different mapping methods.There were no significant differences in Km and Vmax values obtained using four different mapping methods.But there were significant differences in Km and Vmax values among three samples： largest for S1,medium for S3 and smallest for S2.Under the conditions of 30℃±1℃ and pH 7.5,with KNO3 as substrate,Km values for S1,S2 and S3 were 2.7291μmol/L,1.0807μmol/L and 1.6274 μmol/L respectively and Vmax values were 0.0172 μmol/min,0.0070 μmol/min and 0.0098 μmol/min respectively via Eadie-Hofstee mapping method.By comparison,Km value of Spirulina NR was relatively low and the affinity for NO-3 was relatively high.
出处
《内蒙古农业大学学报（自然科学版）》
CAS
北大核心
2009年第4期56-60,共5页
Journal of Inner Mongolia Agricultural University(Natural Science Edition)
基金
国家自然科学基金资助(30460104)
