Adaptation during propagation improves Clostridium autoethanogenum tolerance towards benzene, toluene and xylenes during gas fermentation. (December 2020)

• Record Type: Journal Article
• Authors: Piatek, Pawel; Olsson, Lisbeth; Nygård, Yvonne
• Is Part Of: Bioresource technology reports. Volume 12(2020)
• Publication Date: 2020-12
• Subjects: Inhibitor tolerance -- Clostridium autoethanogenum -- Short-term adaptation -- Propagation -- Syngas fermentation; Biomass energy -- Periodicals; Biotransformation (Metabolism) -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Waste products as fuel -- Periodicals; Waste products as fuel; Organic wastes; Factory and trade waste; Biotransformation (Metabolism); Biomass energy; Agricultural wastes; Periodicals; Electronic journals; 662.88
• DOI: 10.1016/j.biteb.2020.100564
• Languages: English
• ISSNs: 2589-014X

Abstract

Abstract: Benzene, toluene and xylenes (BTX) are a group of compounds detected in many crude syngas mixtures. However, BTX have been identified to negatively affect microorganisms, including acetogenic species that are capable of fermenting syngas into valuable biocommodities. In order to overcome BTX inhibitory effects, we describe stepwise adaptation in Clostridium autoethanogenum that leads to tolerance to up to 0.5 mM benzene, 0.21 mM toluene and 0.07 mM xylenes. This is equivalent to eightfold of that which is found in a wood gasification plant syngas stream. Fully adapted cultures matched growth, acetate and ethanol product concentrations, and CO consumption compared to the control. The results demonstrate an efficient route towards producing a highly tolerant, industrially relevant acetogenic strain. Graphical abstract: Unlabelled Image Highlights: BTX inhibition can be overcome through stepwise adaptation techniques. Clostridium autoethanogenum can be adapted to tolerate high amounts of BTX. Adaptation enabled ethanol and acetate production at equal yield as in fermentation without BTX.