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Metabolically engineered Caldicellulosiruptor bescii as a platform for producing acetone and hydrogen from lignocellulose
Author(s) -
Straub Christopher T.,
Bing Ryan G.,
Otten Jonathan K.,
Keller Lisa M.,
Zeldes Benjamin M.,
Adams Michael W. W.,
Kelly Robert M.
Publication year - 2020
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.27529
Subject(s) - fermentation , acetone , clostridium thermocellum , chemistry , thermophile , metabolic engineering , lignocellulosic biomass , alcohol dehydrogenase , biochemistry , biohydrogen , ethanol , food science , cellulose , hydrogen production , enzyme , cellulase , catalysis
The production of volatile industrial chemicals utilizing metabolically engineered extreme thermophiles offers the potential for processes with simultaneous fermentation and product separation. An excellent target chemical for such a process is acetone ( T b = 56°C), ideally produced from lignocellulosic biomass. Caldicellulosiruptor bescii ( T opt 78°C), an extremely thermophilic fermentative bacterium naturally capable of deconstructing and fermenting lignocellulose, was metabolically engineered to produce acetone. When the acetone pathway construct was integrated into a parent strain containing the bifunctional alcohol dehydrogenase from Clostridium thermocellum , acetone was produced at 9.1 mM (0.53 g/L), in addition to minimal ethanol 3.3 mM (0.15 g/L), along with net acetate consumption. This demonstrates that C. bescii can be engineered with balanced pathways in which renewable carbohydrate sources are converted to useful metabolites, primarily acetone and H 2 , without net production of its native fermentation products, acetate and lactate.