{"title":"Efficient utilization of xylose requires CO2 fixation in Synechococcus elongatus PCC 7942","authors":"","doi":"10.1016/j.ymben.2024.09.010","DOIUrl":null,"url":null,"abstract":"<div><div>Cyanobacteria show great promise as autotrophic hosts for the renewable biosynthesis of useful chemicals from CO<sub>2</sub> and light. While they can efficiently fix CO<sub>2</sub>, cyanobacteria are generally outperformed by heterotrophic production hosts in terms of productivity and titer. Photomixotrophy, or co-utilization of sugars and CO<sub>2</sub> as carbon feedstocks, has been implemented in cyanobacteria to greatly improve productivity and titers of several chemical products. We introduced xylose photomixotrophy to a 2,3-butanediol producing strain of <em>Synechococcus elongatus</em> PCC 7942 and characterized the effect of gene knockouts, changing pathway expression levels, and changing growth conditions on chemical production. Interestingly, 2,3-butanediol production was almost completely inhibited in the absence of added CO<sub>2</sub>. Untargeted metabolomics implied that RuBisCO was a significant bottleneck, especially at ambient CO<sub>2</sub> levels, restricting the supply of lower glycolysis metabolites needed for 2,3-butanediol production. The dependence of the strain on elevated CO<sub>2</sub> levels suggests some practical limitations on how xylose photomixotrophy can be efficiently carried out in <em>S. elongatus</em>.</div></div>","PeriodicalId":18483,"journal":{"name":"Metabolic engineering","volume":null,"pages":null},"PeriodicalIF":6.8000,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1096717624001277/pdfft?md5=d948f70faeea495436d780992a7c5a88&pid=1-s2.0-S1096717624001277-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metabolic engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1096717624001277","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Cyanobacteria show great promise as autotrophic hosts for the renewable biosynthesis of useful chemicals from CO2 and light. While they can efficiently fix CO2, cyanobacteria are generally outperformed by heterotrophic production hosts in terms of productivity and titer. Photomixotrophy, or co-utilization of sugars and CO2 as carbon feedstocks, has been implemented in cyanobacteria to greatly improve productivity and titers of several chemical products. We introduced xylose photomixotrophy to a 2,3-butanediol producing strain of Synechococcus elongatus PCC 7942 and characterized the effect of gene knockouts, changing pathway expression levels, and changing growth conditions on chemical production. Interestingly, 2,3-butanediol production was almost completely inhibited in the absence of added CO2. Untargeted metabolomics implied that RuBisCO was a significant bottleneck, especially at ambient CO2 levels, restricting the supply of lower glycolysis metabolites needed for 2,3-butanediol production. The dependence of the strain on elevated CO2 levels suggests some practical limitations on how xylose photomixotrophy can be efficiently carried out in S. elongatus.
期刊介绍:
Metabolic Engineering (MBE) is a journal that focuses on publishing original research papers on the directed modulation of metabolic pathways for metabolite overproduction or the enhancement of cellular properties. It welcomes papers that describe the engineering of native pathways and the synthesis of heterologous pathways to convert microorganisms into microbial cell factories. The journal covers experimental, computational, and modeling approaches for understanding metabolic pathways and manipulating them through genetic, media, or environmental means. Effective exploration of metabolic pathways necessitates the use of molecular biology and biochemistry methods, as well as engineering techniques for modeling and data analysis. MBE serves as a platform for interdisciplinary research in fields such as biochemistry, molecular biology, applied microbiology, cellular physiology, cellular nutrition in health and disease, and biochemical engineering. The journal publishes various types of papers, including original research papers and review papers. It is indexed and abstracted in databases such as Scopus, Embase, EMBiology, Current Contents - Life Sciences and Clinical Medicine, Science Citation Index, PubMed/Medline, CAS and Biotechnology Citation Index.