@article{Dung_Tuan_2020, title={Heterologous phytase expression in the food filamentous fungus <i> Aspergillus oryzae </i>using the added rice husk cultivation model}, volume={42}, url={https://vjs.ac.vn/index.php/vjbio/article/view/14985}, DOI={10.15625/2615-9023/v42n2.14985}, abstractNote={&lt;p&gt;&lt;em&gt;Aspergillus oryzae&lt;/em&gt;, a safe filamentous fungus, is widely used in food and enzyme production. In this study, we examined a cultivation model using rice husks as carrier to assess the capacity of recombinant protein production in &lt;em&gt;A. oryzae&lt;/em&gt;. The model was first tested with the &lt;em&gt;A. oryzae&lt;/em&gt; strain expressing the &lt;em&gt;DsRed&lt;/em&gt; reporter gene. Expression of &lt;em&gt;DsRed &lt;/em&gt;was easily detected by the pink color of the fungal mycelium on culture media and under a fluorescence microscope. The model was then evaluated with the &lt;em&gt;phyA&lt;/em&gt; gene encoding a phytase from the fungus &lt;em&gt;Aspergillus fumigatus&lt;/em&gt;. The &lt;em&gt;phyA&lt;/em&gt; expression cassette regulated by the &lt;em&gt;amyB&lt;/em&gt; promoter was permanently integrated into the genome of &lt;em&gt;A. oryzae&lt;/em&gt; via &lt;em&gt;Agrobacterium tumefaciens&lt;/em&gt;-mediated transformation with the &lt;em&gt;pyrG &lt;/em&gt;nutritional marker. Results showed that &lt;em&gt;A. oryzae&lt;/em&gt; transgenic strains carrying 2−3 copies of the &lt;em&gt;phyA&lt;/em&gt; gene in their genomes exhibited a significant increase in phytase activity on agar medium supplemented with phytate. With rice husks added, these transgenic strains could secrete the recombinant phytase into the culture and phytase activity of the crude enzyme solution increased by 4.3 times compared to the unstransgenic &lt;em&gt;A. oryzae&lt;/em&gt;. The established cultivation model and the transgenic approach in this study represent a potential for being used in production of secreted recombinant enzymes for animal feeds.&lt;/p&gt;&lt;p&gt;&lt;em&gt; &lt;/em&gt;&lt;/p&gt;}, number={2}, journal={Academia Journal of Biology}, author={Dung, Thai Hanh and Tuan, Tran Van}, year={2020}, month={Jun.} }