Isolation and identification of oleogenic yeasts from milk and dairy products and optimisation of single-cell oil production conditions

Isolation and identification of oleogenic yeasts from milk and dairy products and optimisation of single-cell oil production conditions | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Isolation and identification of oleogenic yeasts from milk and dairy products and optimisation of single-cell oil production conditions Latife DALGIÇ, Gülden BAŞYİĞİT KILIÇ This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8818227/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract In this study, 112 strains isolated from milk, yoghurt, cheese, butter, ayran, clotted cream, and whey were identified as oleaginous. Twelve isolates with high dry biomass yields (0.4–0.7 g) were selected for single cell oil (SCO) production, and the fatty acid profiles of the produced lipids were determined. The genetic characterisation of isolates A2-1, A2-3, and Y20-6 selected based on dry biomass yield, lipid content, and unsaturated fatty acid composition, was performed. SCO production was carried out using strain A2-1, isolated from a yoghurt sample, which exhibited high biomass yield, SCO content, and total unsaturated fatty acid content. This strain was selected from among three isolates identified as Clavispora lusitaniae , and biochar derived from walnut shells was added to the production medium. Optimal conditions for dry biomass yield, lipid content, and fatty acid composition of SCO were achieved using biochar concentrations of 5–10 g/L and of 96–144 hour incubation. The optimal biochar concentration and incubation time for maximising SCO yield were 9.40 g/L and 127.2 h, respectively. Under these conditions, the dry biomass yield was 1.42 g, the lipid content was 2.12%, and the total unsaturated fatty acid content was 55.46% in the produced SCO. Moreover, γ-linolenic acid (C18:3, n-6) and arachidonic acid (C20:4, n-6) (ARA) were detected in the SCOs produced under optimal conditions. Oleogenic yeast Single cell oil Walnut shell biochar Dairy products and waste Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8818227","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":595161448,"identity":"1444b2f8-55a4-4de6-a930-f38b73f5ea53","order_by":0,"name":"Latife DALGIÇ","email":"","orcid":"","institution":"Mehmet Akif Ersoy University","correspondingAuthor":false,"prefix":"","firstName":"Latife","middleName":"","lastName":"DALGIÇ","suffix":""},{"id":595161449,"identity":"e081219a-51dd-4adc-9475-7ded415c15bf","order_by":1,"name":"Gülden BAŞYİĞİT KILIÇ","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABDElEQVRIiWNgGAWjYDACHsbGAwkMNgwMEmBuAg97A4yNW0sDUEsaRNkBoBaeA2C2AR4tIIUMh+FaGAhqkfc53HDgQc35aH7p7sTHH2rSZHgYmA/e5mH4k49Li+HZRqDDjt3OnTnn7GaDA8dyeHgY2JKteRgMLBtwaekH+iWx4Xbuhhu52yQOsFXw2DPwmEkDteB0GVTLudz9N3K3/zjwrwJoC/83vFrkeRtBWg7kbpDI3cZwsA3kMB42vFoMeA6C/JKcO+NG7maJs31pPDzMbMaWcwyMcdvSk/7w4Y8au9z+GbkbP1R8S7bnYW9+eONNhRxuWw5gCDGDxXFpANrSgFtuFIyCUTAKRgEEAADDUlqMzBJXIwAAAABJRU5ErkJggg==","orcid":"","institution":"Mehmet Akif Ersoy University","correspondingAuthor":true,"prefix":"","firstName":"Gülden","middleName":"BAŞYİĞİT","lastName":"KILIÇ","suffix":""}],"badges":[],"createdAt":"2026-02-07 22:38:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8818227/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8818227/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108122330,"identity":"64585e42-7e0a-4e0b-9b5c-f1735f630264","added_by":"auto","created_at":"2026-04-29 14:41:11","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":589537,"visible":true,"origin":"","legend":"","description":"","filename":"Isolationandidentificationofoleogenicyeasts.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8818227/v1_covered_7c3221b1-ea44-46f4-9d8d-129f1ff82ca4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Isolation and identification of oleogenic yeasts from milk and dairy products and optimisation of single-cell oil production conditions","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Oleogenic yeast, Single cell, oil Walnut, shell biochar, Dairy products and waste","lastPublishedDoi":"10.21203/rs.3.rs-8818227/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8818227/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this study, 112 strains isolated from milk, yoghurt, cheese, butter, ayran, clotted cream, and whey were identified as oleaginous. Twelve isolates with high dry biomass yields (0.4\u0026ndash;0.7 g) were selected for single cell oil (SCO) production, and the fatty acid profiles of the produced lipids were determined. The genetic characterisation of isolates A2-1, A2-3, and Y20-6 selected based on dry biomass yield, lipid content, and unsaturated fatty acid composition, was performed. SCO production was carried out using strain A2-1, isolated from a yoghurt sample, which exhibited high biomass yield, SCO content, and total unsaturated fatty acid content. This strain was selected from among three isolates identified as \u003cem\u003eClavispora lusitaniae\u003c/em\u003e, and biochar derived from walnut shells was added to the production medium. Optimal conditions for dry biomass yield, lipid content, and fatty acid composition of SCO were achieved using biochar concentrations of 5\u0026ndash;10 g/L and of 96\u0026ndash;144 hour incubation. The optimal biochar concentration and incubation time for maximising SCO yield were 9.40 g/L and 127.2 h, respectively. Under these conditions, the dry biomass yield was 1.42 g, the lipid content was 2.12%, and the total unsaturated fatty acid content was 55.46% in the produced SCO. 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