Valorization of milling byproducts and ergot-sclerotia-contaminated rye via clostridial ABE fermentation

Bibliographic Details
Title: Valorization of milling byproducts and ergot-sclerotia-contaminated rye via clostridial ABE fermentation
Authors: Holger Edelmann, Nils Thieme, Armin Ehrenreich, Vladimir Zverlov, Wolfgang Liebl
Source: Biotechnology for Biofuels and Bioproducts, Vol 17, Iss 1, Pp 1-13 (2024)
Publisher Information: BMC, 2024.
Publication Year: 2024
Collection: LCC:Biotechnology
LCC:Fuel
Subject Terms: ABE fermentation, Butanol, Clostridia, Milling byproducts, Ergot sclerotia, Biotechnology, TP248.13-248.65, Fuel, TP315-360
More Details: Abstract Background Acetone–butanol–ethanol (ABE) fermentation by solventogenic clostridia can be harnessed to produce CO2 emission neutral bio-based 1-butanol, a valuable compound with a broad range of applications, e.g., in industrial production, as a solvent and as a fuel additive or replacement. However, the relatively low butanol titers and high feedstock costs prevent bio-butanol production on an industrial scale. Agricultural side-stream materials, like milling byproducts, are starch-rich, low-cost and produced all year round. They could be suitable substrates for bio-butanol production by ABE fermentation. Results The milling byproducts wheat red dog (WRD), rye second flour (RSF), wheat bran (WB), rye bran (RB) and ergot sclerotia-containing rye waste stream (ER) were found to contain between ~ 30 and ~ 85% glucan, most of which was starch based. WRD, RSF and ER had the highest glucan content, while the brans contained significant xylan concentrations. Four strains selected from the collection of solventogenic clostridia available in our group produced > 6 g/L butanol on the majority of these substrates, with Clostridium beijerinckii NCIMB 8052 showing the best ABE production performance when regarding all tested substrates. Toxic ergot sclerotia-containing waste material was found to be a suited substrate for ABE fermentation. Strain NCIMB 8052 exhibited butanol titers of up to 9 g/L on substrate mixtures of WRD plus ER and the highest butanol yield per used sugars. Finally, a semi-continuous ABE fermentation of C. beijerinckii NCIMB 8052 on WRD plus ER could be maintained for 96 h. The volumetric ABE productivity during the continuous phase of fermentation was ~ 0.41 g L−1 h−1 and a total of 37.7 g ABE was produced out of 168.2 g substrate. Conclusions Based on their carbohydrate composition, WRD, RSF and ER were the milling byproducts best suited as substrates for bio-butanol production by clostridial ABE fermentation. Importantly, also ergot sclerotia-containing waste materials can be used as substrates, which can help to reduce process costs. The semi-continuous fermentation showed that clostridial ABE fermentation on milling byproducts may represent a suitable avenue for commercial butanol production after further process and/or strain optimization.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2731-3654
Relation: https://doaj.org/toc/2731-3654
DOI: 10.1186/s13068-024-02590-6
Access URL: https://doaj.org/article/fc47d46715074051a3636d09bea70593
Accession Number: edsdoj.fc47d46715074051a3636d09bea70593
Database: Directory of Open Access Journals
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More Details
ISSN:27313654
DOI:10.1186/s13068-024-02590-6
Published in:Biotechnology for Biofuels and Bioproducts
Language:English