Aspergillus usamii B_1-12果胶酶合成降解物阻遏的初步研究

CATABOLITE REPRESSION OF PECTINASE SYNTHESIS IN ASPERGILLUS USAMII B_1-12

Asp·usanlii B_1—12果胶酶的合成为多种碳源所阻遏。加大阻遏物浓度,阻遏效应随之增强。在酶大量合成开始以后加入阻遏物,仍能观察到阻遏现象,对果胶酶不同组分多聚半乳糖醛酸酶(PG)和多聚甲基半乳糖醛酸酶(PMG)具有相同的阻遏效果。外源 cAMP 可以消除这种阻遏效应。阻遏动力学分析和利用各种抑制剂所进行的研究表明。阻遏发生在转录水平上。

Synthesis of pectinase by Asp.Usamii B_1—12 was repressed by manykinds of carbon sources.Increasing the concertration of the reperssors incre-assed the repressible effects,and the repression can be derepressed by exogen-ous cAMP.repressors were effective even when added after synthesis of the enzymesbegan and repressed polygalacturonase(PG)and polymethygalacturonase(PMG)equally.The inhibitory kinetic and various repressors studies revealedthat catabolite repression of pectinase in this mold occurs at the level oftranscription.