过表达米曲霉AoNarmp1基因对米曲霉生长和曲酸合成的影响

Effects of Overexpression of AoNarmp1 on Growth and Kojic Acid Synthesis in Aspergillus Oryzae

Nramp(natural resistance associated macrophage protein)家族蛋白是一类广泛存在于生物界的膜转运蛋白,在金属离子的转运和利用中起着非常重要的作用。尽管米曲霉Nramp家族基因AoNramp1已被克隆,但它对米曲霉生长和曲酸合成的影响还不明确。本研究利用米曲霉α淀粉酶基因amyB启动子构建了AoNramp1过表达菌株。表型分析表明,过表达AoNramp1抑制了米曲霉菌丝生长、孢子形成,增加了菌球和孢子的直径。曲酸含量和基因表达分析表明,转运蛋白AoNramp1可能是通过抑制曲酸合成相关基因kojA、kojR、kojT的表达来抑制米曲霉曲酸的合成。

The Nramp(Natural Resistance Associated Macrophage Protein)family of proteins are membrane transporters that play an important role in the transport and utilization of metal ions,and are widely distributed throughout the biological world.Although the Nramp family gene AoNramp1 has been cloned in Aspergillus oryzae,its effect on the growth and kojic acid synthesis in A.oryzae remains unclear.In this study,we constructed an AoNramp1 overexpression strain using the promoter of the A.oryzaeα-amylase gene amyB.Phenotypic analysis showed that overexpression of AoNramp1 inhibited hyphae growth and conidia formation but increased the diameter of conidia and pellet.The analysis of gene expression and kojic acid suggests that the transporter AoNramp1 may inhibit the synthesis of kojic acid by suppressing the expression of kojA,kojR,and kojT in A.oryzae.