Screening non-conventional yeasts for acid tolerance and engineering Pichia occidentalis for production of muconic acid

• Published in: Nature communications Vol. 14; no. 1; p. 5294
• Main Authors: Pyne, Michael E., Bagley, James A., Narcross, Lauren, Kevvai, Kaspar, Exley, Kealan, Davies, Meghan, Wang, Qingzhao, Whiteway, Malcolm, Martin, Vincent J. J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.08.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/252/318; 631/326/2522; 631/61/212; 631/61/318; Acids; Adipic acid; Batch culture; Batch production; Bioprocessing; Biotechnology; Editing; Fermentation; Genome editing; Genomes; Host selection; Humanities and Social Sciences; Muconic acid; multidisciplinary; Organic acids; Pichia occidentalis; Precursors; Saccharomyces cerevisiae; Science; Science (multidisciplinary); Toolkits; Toxicity; Yeast; Yeasts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41064-5

Saccharomyces cerevisiae is a workhorse of industrial biotechnology owing to the organism’s prominence in alcohol fermentation and the suite of sophisticated genetic tools available to manipulate its metabolism. However, S. cerevisiae is not suited to overproduce many bulk bioproducts, as toxicity constrains production at high titers. Here, we employ a high-throughput assay to screen 108 publicly accessible yeast strains for tolerance to 20 g L −1 adipic acid (AA), a nylon precursor. We identify 15 tolerant yeasts and select Pichia occidentalis for production of cis , cis -muconic acid (CCM), the precursor to AA. By developing a genome editing toolkit for P. occidentalis , we demonstrate fed-batch production of CCM with a maximum titer (38.8 g L −1 ), yield (0.134 g g −1 glucose) and productivity (0.511 g L −1  h −1 ) that surpasses all metrics achieved using S. cerevisiae . This work brings us closer to the industrial bioproduction of AA and underscores the importance of host selection in bioprocessing. Baker’s yeast is a workhorse of industrial biotechnology, but it is not suited to overproduce many bulk bioproducts, especially organic acids. Here, the authors identify Pichia occidentalis as an acid tolerant yeast and engineer it for the production of muconic acid using a newly developed genome editing toolkit.