摘要
对黑曲霉菌株Ｗ２５纤维素酶系中内切β－萄聚糖酶组分的性质进行了研究。Ⅰ－２ａ，Ⅰ－２ｂ，Ⅰ－２ｃ，Ⅰ－２ｄ，Ⅱａ，Ⅱｂ，和Ⅲａ的最适ｐＨ分别为５．５，５．５，５．０，５．５，５．０，５．５和５．５；均在ｐＨ２．０－７．０之间稳定，最适温度分别为５０，５０，５５，５５，５５和６０℃；保温１小时的半失活温度ｔ１／２分别为４９、６１、６３、５２、５７、４７和６７℃。ＳＤＳ－凝胶电脉法测得Ⅰ－２ａ。
Some properties of endo-β-glucanase(Ⅰ-2a,Ⅰ-2b.Ⅰ-2c.Ⅰ-2d.Ⅱa.Ⅱb ,Ⅲa)from Aspergillus niger W25 have been studied.Ⅰ-2a,Ⅰ-2h,Ⅰ-2c.Ⅰ-2d.Ⅱa.Ⅱb.Ⅲa showed optimal activity at pH 5.5,5.5,5.0,5.5.5.0.5.5,5.5 and 50.50,55.55,55,55,60C,respectively,Ⅰ-2a,Ⅰ-2b,Ⅰ-2c,Ⅰ-2d,Ⅱa.Ⅱb and Ⅲa werestable in the pH range 2.0-7.0.The temperature for loss half activity(1(1)/(2))in thewere,Ⅰ-2a,49C;Ⅰ-2b,61C;Ⅰ-2c,63C:7-2d,52C;Ⅱa,57C:Ⅱb.47C:Ⅲa,67C.The molecular weights of Ⅰ-2a.Ⅰ-2b,Ⅰ-2c,Ⅰ-2d,Ⅱa.Ⅱb and Ⅲawere 53 000,48 000,57 000,60 000,44 500,48 000 and 34 000 as estimated by SDSgel eleetrophoresis and their isoelectric points were 5.5,5.3,5.0,4.8.5.8.5.1 and4.1 as estimated by polyaceylemide gel isoelectric focusing.The order in randomness ofthe hydrolysis of sodium carboxymethyi cellulose(CMC-Na).expressed as the radiobetween the decrease in viscosity of CMC-Na and increase in reducing sugar was I 2bⅡa>Ⅰ-2a>Ⅰ-2c>Ⅲa>Ⅰ-2d>Ⅱ b.Cu^(2+),Ag^(?) and Hg^(?) ion showed potentinhibitory effect on Ⅰ-2a,Ⅰ-2b,Ⅰ-2c,Ⅰ-2d,Ⅱa,Ⅱb.Ⅲa.
出处
《微生物学报》
CAS
CSCD
北大核心
1993年第6期439-445,共7页
Acta Microbiologica Sinica
