Construction of host・vector system in mold: Function and structure of extranuclear DNA in fungi

真菌是工业上重要的微生物，并且通过使用真菌细胞以大工业规模生产各种有用的酶和有机酸。为了培育出更多有用的真菌，我们打算构建真菌中可用的宿主-载体系统。为了构建该系统，需要质粒DNA来克隆和扩增真菌细胞中的基因。然而，我们没有质粒DNA可用于真菌系统，并且已经利用酵母质粒DNA，尽管酵母质粒DNA在真菌细胞中不稳定并且经常整合到真菌基因组中。为了克服这一障碍，使用真菌固有的质粒DNA被认为是合适的。因此，我们在各种真菌细胞中筛选质粒DNA。尽管进行了大量的筛选实验，但除了在毛霉中发现了质粒DNA样分子外，我们没有发现质粒DNA。另一方面，我们从尼日尔曲霉中纯化了glycoprotein酶I和甲基乙二醛还原酶。我们现在正试图利用我们在M.这些酶的遗传和基因。

Fungi is industrially important microbe and various useful enzymes and organic acids are producing by using fungi cells in a large industrial scale. To breed more useful fungi, we intended to construct host-vector systems available in fungi. For the construction of the system, plasmid DNAs are required to clone and amplify the genes in fungi cells. However, we have no plasmid DNAs available in fungi system, and yeast plasmid DNAs have been utilized, although the yeast plasmid DNAs are unstable in fungi cells and frequently integrated into fungi genomes. To overcome this barrier, the use of plasmid DNAs inherent to fungi is thought to be suitable. So, we screened the plasmid DNAs in various fungi cells. despite the voluminous screening experiments, we could not find the plasmid DNAs, except that plasmid DNA-like molecule was found in Mucor jansence. On the other hand, we purified glyoxalase I and methylglyoxal reductases from Aspergillus niger. We are now attempting to construct host-vector systems by using plasmid DNA we found in M. ransence and genes for these enzymes.