{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,28]],"date-time":"2026-10-28T09:24:26Z","timestamp":1793179466399,"version":"4.5.0"},"reference-count":42,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T00:00:00Z","timestamp":1747872000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Council of Thailand (NRCT)","award":["N42A660930"],"award-info":[{"award-number":["N42A660930"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Plants"],"abstract":"<jats:p>Euglena gracilis is a metabolically versatile microalga capable of thriving under photoautotrophic (light, no ethanol), mixotrophic (light with 1% v\/v ethanol), and heterotrophic (dark with 1% v\/v ethanol) conditions. Here, we applied untargeted LC-MS metabolomics (Agilent 1290 LC, 6545XT QTOF-MS; Agilent Technologies, Santa Clara, California, USA) to investigate its trophic-mode-dependent metabolic adaptations and assess its biotechnological potential. Metabolites were separated on a C18 column and analyzed in both positive and negative ion modes. Multivariate analyses (PCA and sPLS-DA) revealed clear and reproducible metabolic separations among growth modes (p &lt; 0.001). Photoautotrophic cultures were enriched in phenolic acids, flavonoids, and lipid classes associated with oxidative stress protection. Mixotrophy induced a broader spectrum of upregulated metabolite classes, including saccharolipids, macrolactams, and triterpenoids, reflecting a hybrid metabolism combining photosynthesis and ethanol utilization. Heterotrophic cultures showed elevated levels of polyamines and amino acids (e.g., putrescine, proline), indicative of redox regulation and stress adaptation in dark, ethanol-rich conditions. Class-level comparisons identified distinct and shared metabolite categories, with photoautotrophy favoring antioxidant biosynthesis and mixotrophy supporting metabolic diversity. These findings provide metabolite-level insights into the extraordinary plasticity of E. gracilis and offer a framework for optimizing cultivation strategies to enhance the targeted production of high-value bioproducts.<\/jats:p>","DOI":"10.3390\/plants14111580","type":"journal-article","created":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T12:15:43Z","timestamp":1747916143000},"page":"1580","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Metabolomic Insights into the Adaptations and Biotechnological Potential of Euglena gracilis Under Different Trophic Conditions"],"prefix":"10.3390","volume":"14","author":[{"given":"Sahutchai","family":"Inwongwan","sequence":"first","affiliation":[{"name":"Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sutthiphat","family":"Sriwari","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1866-3641","authenticated-orcid":false,"given":"Chayakorn","family":"Pumas","sequence":"additional","affiliation":[{"name":"Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1002\/(SICI)1097-0290(19970120)53:2<185::AID-BIT8>3.0.CO;2-K","article-title":"Production of antioxidant vitamins, beta-carotene, vitamin C, and vitamin E, by two-step culture of Euglena gracilis Z","volume":"53","author":"Takeyama","year":"1997","journal-title":"Biotechnol. 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