초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>Triterpenes (especially triterpene acids) are some of the major physiologically active components of <I>Ganoderma lucidum.</I> However, submerged fermentation techniques for triterpenes have not been optimized for commercial use, and the total triterpene yield is still very low. The aim of this work was to develop a two‐stage pH‐control strategy integrated with the use of an ether extract from the medicinal insect, <I>Catharsius molossus</I> (EECM), as a stimulus for enhanced <I>G. lucidum</I> triterpene acid production.</P><P><B>RESULTS</B></P><P>Triterpene acid production of 302.76 mg L<SUP>−1</SUP> was obtained in <I>G. lucidum</I> cultured with the EECM; this production was higher by 60% than that of the control cultures not fed the EECM. Based on the EECM feeding method, a new two‐stage pH‐control strategy was integrated, resulting in triterpene acid yields of 361.47 mg L<SUP>−1</SUP>. Subsequent studies optimized the interaction between EECM feeding and two‐stage pH‐control strategies, which resulted in an optimal EECM concentration of 185.89 mg L<SUP>−1</SUP> and optimal pH values of 5.07 in the first 72 h incubation and 4.37 after 72 h, with a maximum triterpene acid concentration of 449.37 mg L<SUP>−1</SUP>. This represented a 137% increase compared with that of the control cultures. Furthermore, when a 150 L fermenter was used under these conditions, a triterpene acid concentration of 431.83 mg L<SUP>−1</SUP> was achieved.</P><P><B>CONCLUSIONS</B></P><P>The enhanced production of triterpene acid in submerged cultures of <I>G. lucidum</I> was achieved using an EECM feeding stimulus integrated with a two‐stage pH‐control strategy at large scale. © 2016 Society of Chemical Industry</P>