Extrapolation of design strategies for lignocellulosic biomass conversion to the challenge of plastic waste.

The goal of cost-effective production of fuels and chemicals from biomass has been a substantial driver of the development of the field of metabolic engineering. The resulting design principles and procedures provide a guide for the development of cost-effective methods for degradation, and possibly even valorization, of plastic wastes. Here, we highlight these parallels, using the creative work of Lonnie O'Neal (Neal) Ingram in enabling production of fuels and chemicals from lignocellulosic biomass, with a focus on ethanol production as an exemplar process.

Survey of nonconventional yeasts for lipid and hydrocarbon biotechnology.

Nonconventional yeasts have an untapped potential to expand biotechnology and enable process development necessary for a circular economy. They are especially convenient for the field of lipid and hydrocarbon biotechnology because they offer faster growth than plants and easier scalability than microalgae and exhibit increased tolerance relative to some bacteria. The ability of industrial organisms to import and metabolically transform lipids and hydrocarbons is crucial in such applications. Here, we assessed the ability of 14 yeasts to utilize 18 model lipids and hydrocarbons from six functional groups and three carbon chain lengths. The studied strains covered 12 genera from nine families. Nine nonconventional yeasts performed better than Saccharomyces cerevisiae, the most common industrial yeast. Rhodotorula toruloides, Candida maltosa, Scheffersomyces stipitis, and Yarrowia lipolytica were observed to grow significantly better and on more types of lipids and lipid molecules than other strains. They were all able to utilize mid- to long-chain fatty acids, fatty alcohols, alkanes, alkenes, and dicarboxylic acids, including 28 previously unreported substrates across the four yeasts. Interestingly, a phylogenetic analysis showed a short evolutionary distance between the R. toruloides, C. maltosa, and S. stipitis, even though R. toruloides is classified under a different phylum. This work provides valuable insight into the lipid substrate range of nonconventional yeasts that can inform species selection decisions and viability of lipid feedstocks.