DOE researchers show microbes can turn hazardous biomass pretreatment waste into valuable chemicals for plastics and other products

Researchers supported The study examined spent liquor left after aqueous ammonia pretreatment of poplar wood. That leftover liquid contains hazardous compounds that must be treated before disposal. Researchers identified main phenolics including phenol, p-hydroxybenzamide and p-hydroxybenzoic acid, and evaluated how metal additives used in pretreatment affected phenolic formation. An engineered strain of the bacterium Novosphingobium aromaticivorans was tested to convert the phenolics into 2-pyrone-4,6-dicarboxylic acid, or PDC, which the DOE summary describes as a building block of nylon and other plastics. The scientists also tested microbial conversion of the phenolics into chemicals for plastics, adhesives and medicines. Biotransformation of p-hydroxybenzamide to PDC was possible in the presence of p-hydroxybenzoic acid but not when p-hydroxybenzamide was the sole phenolic substrate. Phenol present was not transformed to PDC and did not inhibit PDC production. The summary said this is the first report on making PDC from phenolic amide using N. aromaticivorans. Funding came through the Great Lakes Bioenergy Research Center. The work was published in ChemSusChem