Abstract
BackgroundResistance to deconstruction is a major limitation to the use of lignocellulosic biomass as a substrate for the production of fuels and chemicals. Consolidated bioprocessing (CBP), the use of microbes for the simultaneous hydrolysis of lignocellulose into soluble sugars and fermentation of the resulting sugars to products of interest, is a potential solution to this obstacle. The pretreatment of plant biomass, however, releases compounds that are inhibitory to the growth of microbes used for CBP.ResultsHeterologous expression of the Thermoanaerobacter pseudethanolicus 39E bdhA gene, that encodes an alcohol dehydrogenase, in Clostridium thermocellum significantly increased resistance to furan derivatives at concentrations found in acid-pretreated biomass. The mechanism of detoxification of hydroxymethylfurfural was shown to be primarily reduction using NADPH as the cofactor. In addition, we report the construction of new expression vectors for homologous and heterologous expression in C. thermocellum. These vectors use regulatory signals from both C. bescii (the S-layer promoter) and C. thermocellum (the enolase promoter) shown to efficiently drive expression of the BdhA enzyme.ConclusionsToxic compounds present in lignocellulose hydrolysates that inhibit cell growth and product formation are obstacles to the commercialization of fuels and chemicals from biomass. Expression of genes that reduce the effect of these inhibitors, such as furan derivatives, will serve to enable commercial processes using plant biomass for the production of fuels and chemicals.
Highlights
ResultsHeterologous expression of the Thermoanaerobacter pseudethanolicus 39E bdhA gene, that encodes an alco‐ hol dehydrogenase, in Clostridium thermocellum significantly increased resistance to furan derivatives at concentra‐ tions found in acid-pretreated biomass
Resistance to deconstruction is a major limitation to the use of lignocellulosic biomass as a substrate for the production of fuels and chemicals
We recently demonstrated that heterologous expression of this heatstable butanol dehydrogenase (BdhA) enzyme increased resistance of engineered C. bescii strains to both furfural and HMF [9]
Summary
Heterologous expression of the Thermoanaerobacter pseudethanolicus 39E bdhA gene, that encodes an alco‐ hol dehydrogenase, in Clostridium thermocellum significantly increased resistance to furan derivatives at concentra‐ tions found in acid-pretreated biomass. The mechanism of detoxification of hydroxymethylfurfural was shown to be primarily reduction using NADPH as the cofactor. We report the construction of new expression vectors for homologous and heterologous expression in C. thermocellum. These vectors use regulatory signals from both C. bescii (the S-layer promoter) and C. thermocellum (the enolase promoter) shown to efficiently drive expression of the BdhA enzyme
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
