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，各种有用的酶和有机酸都是利用真菌细胞大规模生产的。为了培育更多有用的真菌，我们打算构建真菌宿主-载体系统。为了构建该系统，需要质粒dna在真菌细胞中克隆和扩增基因。虽然酵母质粒dna在真菌细胞中是不稳定的，并且经常被整合到真菌基因组中，但我们还没有在真菌系统中找到可用的质粒dna，酵母质粒dna已经被利用。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了质粒dna。尽管进行了大量的筛选实验，但我们没有发现质粒dna，只在毛霉菌中发现了质粒dna样分子。另一方面，我们从黑曲霉中纯化了乙二醛酶I和甲基乙二醛还原酶。我们现在正尝试利用在M. ransence中发现的质粒DNA和这些酶的基因来构建宿主载体系统。

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.