Consolidated bioprocessing of untreated switchgrass to hydrogen by the extreme thermophile Caldicellulosiruptor saccharolyticus DSM 8903

• Published in: Bioresource technology Vol. 139; pp. 272 - 279
• Main Authors: Talluri, Suvarna, Raj, Subramanian Mohan, Christopher, Lew Paul
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2013; Elsevier
• Subjects: Anaerobiosis - drug effects; Biological and medical sciences; Bioprocessing; Biotechnology; Biotechnology - methods; Caldicellulosiruptor saccharolyticus DSM 8903; Carbon - metabolism; Carbon Dioxide - metabolism; Cellulose - metabolism; Consolidated bioprocessing; Consolidation; Distributed memory; Extreme thermophiles; Fermentation; Fundamental and applied biological sciences. Psychology; Glucose; Glucose - pharmacology; Gram-Positive Bacteria - drug effects; Gram-Positive Bacteria - growth & development; Gram-Positive Bacteria - metabolism; Gram-Positive Bacteria - ultrastructure; Hydrogen; Hydrogen - metabolism; Lignocellulose; Panicum - drug effects; Panicum - metabolism; Polymers - pharmacology; Pretreatment; Saccharification; Temperature; Time Factors; Untreated switchgrass; Untreated switchgrass; Hydrogen; Consolidated bioprocessing; Caldicellulosiruptor saccharolyticus DSM 8903; Extreme thermophiles; Monocotyledones; Thermophily; Panicum virgatum; Gramineae; Angiospermae; Herbaceous plant; Spermatophyta; Biological treatment
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.04.005

•Caldicellulosiruptor saccharolyticus fermented untreated switchgrass and MCC to H2.•The extreme thermophile produced the maximum theoretical yield of 4mol H2/mol glucose.•Pretreatment, enzyme production, hydrolysis, fermentation were combined in one step.•C. saccharolyticus DSM 8903 is a promising candidate for consolidated bioprocessing.•Potential for cost savings from capital and operating expenditures could exceed 50%. The abilities of the extreme thermophilic bacterium Caldicellulosiruptor saccharolyticus DSM 8903 to ferment switchgrass (SWG), microcrystalline cellulose (MCC) and glucose to hydrogen (H2) in one-step were examined. Hydrogen production from glucose reached the theoretical maximum for dark fermentation of 4mol H2/mol glucose. The H2 yield on MCC and SWG after 6days of fermentation was 23.2mmol H2/L or 9.4mmol H2/g MCC and 14.3mmol H2/L or 11.2mmol H2/g SWG, respectively. The rate of H2 formation however was higher on MCC (0.7mmol/Lh) than SWG (0.1mmol/Lh). C. saccharolyticus DSM 8903 was able to produce H2 directly from mechanically-comminuted SWG without any physicochemical or biological pretreatment. Combining four processing steps (pretreatment, enzyme production, saccharification and fermentation) into a single biorefinery operation makes C. saccharolyticus DSM 8903 a promising candidate for consolidated bioprocessing (CBP) of lignocellulosic biomass.