BioChem - DOS

Xylose induces cellulase production in Thermoascus aurantiacus

Biotechnology for biofuels

Schuerg, Timo; Prahl, Jan-Philip; Gabriel, Raphael; Harth, Simon; Tachea, Firehiwot; Chen, Chyi-Shin; Miller, Matthew; Masson, Fabrice; He, Qian; Brown, Sarah; Mirshiaghi, Mona; Liang, Ling; Tom, Lauren M.; Tanjore, Deepti; Sun, Ning; Pray, Todd R.; Singer, Steven W.

<P><B>Background</B></P><P>Lignocellulosic biomass is an important resource for renewable production of biofuels and bioproducts. Enzymes that deconstruct this biomass are critical for the viability of biomass-based biofuel production processes. Current commercial enzyme mixtures have limited thermotolerance. Thermophilic fungi may provide enzyme mixtures with greater thermal stability leading to more robust processes. Understanding the induction of biomass-deconstructing enzymes in thermophilic fungi will provide the foundation for strategies to construct hyper-production strains.</P><P><B>Results</B></P><P>Induction of cellulases using xylan was demonstrated during cultivation of the thermophilic fungus <I>Thermoascus aurantiacus</I>. Simulated fed-batch conditions with xylose induced comparable levels of cellulases. These fed-batch conditions were adapted to produce enzymes in 2 and 19 L bioreactors using xylose and xylose-rich hydrolysate from dilute acid pretreatment of corn stover. Enzymes from <I>T. aurantiacus</I> that were produced in the xylose-fed bioreactor demonstrated comparable performance in the saccharification of deacetylated, dilute acid-pretreated corn stover when compared to a commercial enzyme mixture at 50&nbsp;°C. The <I>T. aurantiacus</I> enzymes retained this activity at of 60&nbsp;°C while the commercial enzyme mixture was largely inactivated.</P><P><B>Conclusions</B></P><P>Xylose induces both cellulase and xylanase production in <I>T. aurantiacus</I> and was used to produce enzymes at up to the 19 L bioreactor scale. The demonstration of induction by xylose-rich hydrolysate and saccharification of deacetylated, dilute acid-pretreated corn stover suggests a scenario to couple biomass pretreatment with onsite enzyme production in a biorefinery. This work further demonstrates the potential for <I>T. aurantiacus</I> as a thermophilic platform for cellulase development.</P>

2017

BioMed Central

cc-by

1754-6834

10

pp.271

10.1186/s13068-017-0965-z

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART90097924

https://biotechnologyforbiofuels.biomedcentral.com/track/pdf/10.1186/s13068-017-0965-z

Thermoascus aurantiacus; Xylose; Cellulases; Corn stover; Bioprocess; Thermophile; Filamentous fungi