三七根际链霉菌Streptomyces sp. YNUCC0233木聚糖酶性质研究

Isolation and Characterization of Xylan-degrading Streptomyces sp.YNUCC0233 Associated with the Rhizosphere of Panax notoginseng (Burk.) F.H.Chen

从三七根际分离到一株产木聚糖酶链霉菌Streptomycessp.YNUCC0233。该菌所产生的木聚糖酶的最适反应温度为67℃,最适pH为6.0,在pH5.0~9.0和60℃以下时相对稳定。Ba2+和K+对该木聚糖酶有较强的促进作用,Hg2+、Cu2+、Mn2+、Co2+、Ni2+和EDTA对该酶有较强的抑制作用。对Streptomycessp.YNUCC023316SrDNA的1105bp片段的序列分析结果表明,Streptomycessp.YNUCC0233的16SrDNA片段与GenBank中所有已注册的链霉菌分类单位均不同。

A strain namely Streptomyces sp.YNUCC0233 was isolated from the rhizosphere of Panax notoginseng (Burk.) F.H.Chen. The strain YNUCC0233 produced a maximum amount of xylanase (120 UmL-1) at 28 for 5 days. The crude xylanase exhibited the highest activity at pH6.00 and at the temperature 67. Xylanase was stable at an abroad pH range between pH 5.0 ~ pH 9.0 and under the temperature 60. Hg^(2+),Cu^(2+),Mn^(2+) Co^(2+),Ni^(2+) and EDTA showed strong inhibition on the activity of the xylanase, while K^+ and Ba^(2+) born a remarkable promotion on the enzyme activity. A 1105bp long fragment of 16S rDNA from Streptomyces sp.YNUCC0233 was sequenced and compared with closely related 19 taxon in GenBank. The phylogenetic tree constructed by Neighbor-joining method indicated that fragment of 16S rDNA from Streptomyces sp.YNUCC0233 was unique in GenBank.