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bioRxiv · 10.1101/2025.02.08.637243

Flavoaffinins, elusive cellulose-binding natural products from an anaerobic bacterium

Kountz, D. J.·Yu, R.·Lee, J. H.·Maloney, K. N.·Balskus, E. P.
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Abstract

Cellulose is the most abundant polymer on earth. Many anaerobic cellulose-degrading bacteria produce uncharacterized yellow-orange, cellulose-binding pigments known as yellow affinity substances (here referred to as flavoaffinins) that are associated with cellulose degradation. Here, we isolate and structurally characterize the flavoaffinins from Clostridium (Hungateiclostridium) thermocellum, a key workhorse for the industrial conversion of cellulosic feedstocks to ethanol. Flavoaffinins represent an unprecedented structural juxtaposition of an aryl polyene chain with a hydroxy-diene {gamma}-lactone. We also shed light on their biosynthesis using stable-isotope feeding experiments. This effort lays the groundwork for understanding the biological function(s) of the flavoaffinins and expands the limited number of natural products isolated from obligately anaerobic microbes.

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Kountz, D. J., Yu, R., Lee, J. H., Maloney, K. N., Balskus, E. P.. 2025-02-08. Flavoaffinins, elusive cellulose-binding natural products from an anaerobic bacterium. https://doi.org/10.1101/2025.02.08.637243

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