为获得耐高浓度丙烯腈的菌株,利用紫外线对珊瑚诺卡氏菌进行诱变,并将诱变后生长情况较好的突变株在含一定浓度丙烯腈的培养基中进行筛选.结果表明:在紫外灯功率为20 W,照射距离为10 cm的条件下,诱变时间为3 m in和4 m in,致死率均大于9...为获得耐高浓度丙烯腈的菌株,利用紫外线对珊瑚诺卡氏菌进行诱变,并将诱变后生长情况较好的突变株在含一定浓度丙烯腈的培养基中进行筛选.结果表明:在紫外灯功率为20 W,照射距离为10 cm的条件下,诱变时间为3 m in和4 m in,致死率均大于90%;而诱变时间为5 m in,致死率为100%.诱变之后,从含低浓度丙烯腈的的培养基中,筛选出了9株有利突变的菌株.通过在含高浓度丙烯腈的培养基中复筛得到2株耐5.82%丙烯腈的突变株,其诱变时间为4 m in.展开更多
The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action,high potency and reduced toxicity compared to today's standard drugs.However,production of brasilicardin has be...The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action,high potency and reduced toxicity compared to today's standard drugs.However,production of brasilicardin has been hampered since the producer strain Nocardia terpenica IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism.Previously,we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Amycolatopsis japonicum.Four brasilicardin congeners,intermediates of the BraA biosynthesis,were produced.Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization.Therefore,we used a metabolic engineering approach to increase heterologous production of brasilicardin in A.japonicum.Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate(IPP)and to channel the precursor into the direction of diterpenoid biosynthesis.Both approaches contributed to an elevated heterologous production of the brasilicardin backbone,which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.展开更多
文摘为获得耐高浓度丙烯腈的菌株,利用紫外线对珊瑚诺卡氏菌进行诱变,并将诱变后生长情况较好的突变株在含一定浓度丙烯腈的培养基中进行筛选.结果表明:在紫外灯功率为20 W,照射距离为10 cm的条件下,诱变时间为3 m in和4 m in,致死率均大于90%;而诱变时间为5 m in,致死率为100%.诱变之后,从含低浓度丙烯腈的的培养基中,筛选出了9株有利突变的菌株.通过在含高浓度丙烯腈的培养基中复筛得到2株耐5.82%丙烯腈的突变株,其诱变时间为4 m in.
基金This work was funded by Bundesministerium für Bildung und Forschung(BMBF)(FKZ 031A568B),in the frame of the ERA-NET-IB project“NeBrasCa”.
文摘The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action,high potency and reduced toxicity compared to today's standard drugs.However,production of brasilicardin has been hampered since the producer strain Nocardia terpenica IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism.Previously,we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Amycolatopsis japonicum.Four brasilicardin congeners,intermediates of the BraA biosynthesis,were produced.Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization.Therefore,we used a metabolic engineering approach to increase heterologous production of brasilicardin in A.japonicum.Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate(IPP)and to channel the precursor into the direction of diterpenoid biosynthesis.Both approaches contributed to an elevated heterologous production of the brasilicardin backbone,which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.
