一种来源于青霉的β-半乳糖苷酶酶学性质研究  

Enzymatic properties of a novel β-galactosidase from Penicillium sp.

作　　者：黎丽[1] 王瑞明[1] 李丕武[1] 任良栋[1] 

机构地区：[1]山东轻工业学院食品与生物工程学院山东省微生物工程重点实验,济南250353

出　　处：《中国食品添加剂》2013年第3期121-126,共6页China Food Additives

摘　　要：从土壤里筛选到20株产β-半乳糖苷酶的菌株,其中β-半乳糖苷酶活力最高的是菌株L7,通过形态学观察和18SrDNA序列分析,得出该菌株为斜卧青霉;并研究了其β-半乳糖苷酶的酶学性质。结果表明:β-半乳糖苷酶最适作用温度为60℃,最适pH为6.0,在60℃以下和pH3.0 7.0有较高的稳定性;Mg2+、Mn2+对β-半乳糖苷酶活性有显著的激活作用,Cu2+、Fe2+、和Zn+对酶活有较强的抑制作用;以ONPG为底物采用双倒数做图法测得Km为6.25mmol/L;经过聚丙烯酰胺凝胶电泳鉴定,该酶蛋白的分子量约为110kDa。An β-galactosidase-producing fungus was screened from 20 strains isolated from the soil,and L7 strain produced highest β-galactosidase enzyme.By morphological and 18SrDNA sequence analysis,Penicillium decumbens were identified;and enzymatic properties of β-galactosidase from L7 was further studied.The results showed that the optimal pH and temperature in the reaction of this enzyme were 6.0 and 60℃,respectively.The enzyme was stable at temperatures below 60℃ or in a pH range between 3.0 and 7.0.Its activity was notably promoted by Mg2 ＋,Mn2 ＋,whereas Cu2 ＋,Fe2 ＋,and Zn＋had high inhibition to the enzyme.The Km towards ONPG was determined to be 6.25 mmol / L.The SDS-PAGE analysis showed the weight of the enzyme was 110 kD.

关 键 词：青霉 菌种筛选 Β-半乳糖苷酶 酶学性质 

分 类 号：Q556.2[生物学—生物化学]