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Correction for ‘Adipic acid production from lignin’ by Derek R. Vardon et al., Energy Environ. Sci., 2015, 8, 617–628, https://doi.org/10.1039/C4EE03230F.

The sequence of the promoter used to drive expression of glcDEF operon in the engineered strain MFL185 in the original article was incorrect. As described here, we performed additional experiments that indicate expression of this operon was increased in MFL185, as intended. Ultimately, this error is immaterial with respect to the findings and conclusions reported in the original article.

Pollution from ethylene glycol, and plastics containing this monomer, represent a significant environmental problem. The investigation of its microbial metabolism therefore provides insights into the environmental fate of this pollutant, but also enables its utilization as a carbon source for microbial biotechnology. Here, we reveal the genomic and metabolic basis of ethylene glycol metabolism in Pseudomonas putida KT2440. Although this strain cannot grow on ethylene glycol as sole carbon source, it can be used to generate growth-enhancing reducing equivalents upon co-feeding with acetate. Mutants that utilize ethylene glycol as sole carbon source were isolated through adaptive laboratory evolution. Genomic analysismore » of these mutants revealed a central role of the transcriptional regulator GclR, which represses the glyoxylate carboligase pathway as part of a larger metabolic context of purine and allantoin metabolism. Secondary mutations in a transcriptional regulator encoded by PP_2046 and a porin encoded by PP_2662 further improved growth on ethylene glycol in evolved strains, likely by balancing fluxes through the initial oxidations of ethylene glycol to glyoxylate. With this knowledge we reverse engineered an ethylene glycol utilizing strain and thus, revealed the metabolic and regulatory basis that are essential for efficient ethylene glycol metabolism in P. putida KT2440.« less

Abstract Genes encoding l ‐arabinose transporters in Kluyveromyces marxianus and Pichia guilliermondii were identified by functional complementation of Saccharomyces cerevisiae whose growth on l ‐arabinose was dependent on a functioning l ‐arabinose transporter, or by screening a differential display library, respectively. These transporters also transport d ‐xylose and were designated KmAXT1 (arabinose–xylose transporter) and PgAXT1 , respectively. Transport assays using l ‐arabinose showed that KmAxt1p has K _m 263 m m and V _max 57 n m /mg/min, and PgAxt1p has K _m 0.13 m m and V _max 18 n m /mg/min. Glucose, galactose and xylose significantly inhibit l ‐arabinose transport by bothmore » transporters. Transport assays using d ‐xylose showed that KmAxt1p has K _m 27 m m and V _max 3.8 n m /mg/min, and PgAxt1p has K _m 65 m m and V _max 8.7 n m /mg/min. Neither transporter is capable of recovering growth on glucose or galactose in a S. cerevisiae strain deleted for hexose and galactose transporters. Transport kinetics of S. cerevisiae Gal2p showed K _m 371 m m and V _max 341 n m /mg/min for l ‐arabinose, and K _m 25 m m and V _max 76 n m /mg/min for galactose. Due to the ability of Gal2p and these two newly characterized transporters to transport both l ‐arabinose and d ‐xylose, one scenario for the complete usage of biomass‐derived pentose sugars would require only the low‐affinity, high‐throughput transporter Gal2p and one additional high‐affinity general pentose transporter, rather than dedicated d ‐xylose or l ‐arabinose transporters. Additionally, alignment of these transporters with other characterized pentose transporters provides potential targets for substrate recognition engineering. Accession Nos: KmAXT1 : GZ791039; PgAXT1 : GZ791040 Copyright © 2015 John Wiley & Sons, Ltd.« less