J.P. Bacik, L. Jarboe
Volume 68, Issue 9, Pages 700-708
Publication year: 2016

The anhydrosugar levoglucosan (1,6‐anhydro‐β‐D‐glucopyranose) and other structurally related sugars such as cellobiosan represent a vastly untapped resource for cellulose‐based production of chemicals and fuels. These carbohydrates exhibit a cyclic 1,6‐anhydro ring structure in addition to the canonical pyranose ring of six‐membered carbohydrates containing five carbons and one oxygen atom (Figure 1). Anhydrosugars are produced naturally through biomass burning. It has been estimated that approximately 9 billion tons of biomass are burned every year 1. While carbon dioxide is obviously the most abundant component of the combustion product, other compounds, such as anhydrosugars, are also present. One study concluded that anhydrosugars accounted for 2.4% (by mass) of the organic carbon in wildfire smoke 2 and it has been estimated that burning of extratropical forest material produces almost three times as much levoglucosan as burning of grasslands or agricultural residues 1. These estimates suggest that approximately 10 – 100 million tons of anhydrosugars are produced from biomass every year. Other anhydrosugars, such as cellobiosan, mannosan, galactosan, levogalactosan, and levomannosan have not been as extensively characterized in wildfire smoke, but have been detected in a variety of aerosol and soil samples 36. Aerosolized anhydrosugars can be degraded via radical activity 78 but can also be transported to the soil by rainwater 9. Once deposited into the soil, the anhydrosugars are subject to microbial utilization 10. This cycle of anhydrosugar production by biomass burning, transport from the atmosphere to the soil via rainwater and microbial consumption is an undercharacterized component of the global carbon cycle.