Enhanced Biosynthesis of Phenolics and Antioxidants by Marine Endophyte Penicillium rubens: Optimization and Bioactivity Evaluation

Enhanced Biosynthesis of Phenolics and Antioxidants by Marine Endophyte Penicillium rubens: Optimization and Bioactivity Evaluation | 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 Enhanced Biosynthesis of Phenolics and Antioxidants by Marine Endophyte Penicillium rubens: Optimization and Bioactivity Evaluation Jeyamanikandan Venkatachalam, Veronica Shalini Jeyadoss, Senthamil Selvi Poongavanam This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8754183/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 14 Apr, 2026 Read the published version in Applied Biochemistry and Biotechnology → Version 1 posted 5 You are reading this latest preprint version Abstract Marine-derived endophytic fungi have long been recognised as valuable sources of therapeutic metabolites. In the present study, the endophyte Penicillium rubens strain PrubVJ was studied for optimised production of bioactive compounds using Response Surface Methodology (RSM). Experimental data predicted that incubation time was identified as the most influential variable, with maximum protein yield (190 mg/L) observed at day 20, antioxidant activity (74%) at 10–15 days and total phenolics (1,724 ± 19 µg GAE g⁻¹ DW) at day 25. The optimal fermentation conditions (25°C, pH 3.6, 4 g/L salinity, 10 days incubation) with a desirability of 0.92, yielding 158 ± 1.325 mg/L protein, 1,798 ± 18 µg GAE g⁻¹ DW phenolics, and 84.9% antioxidant activity were predicted from the RSM model. Experimental validation under these conditions achieved a desirability of 0.92, with 190 mg/L protein, 1,724 µg phenolics, and 74% antioxidant activity, confirming the reliability and robustness of the model. The developed quadratic models exhibited strong statistical reliability with stochastic parameters such as F-value, p-value and other factors such as R 2 , adjusted R 2 and predicted R 2 in all three responses was reported to be above 80%, validating model adequacy. Experimental validation at the predicted optimum achieved a desirability of 0.92, confirming excellent agreement between predicted and observed outcomes. Collectively, these findings establish P. rubens strain PrubVJ as a promising microbial platform, providing a reliable framework for optimising fungal fermentation. This study recommends the optimized strategy for large-scale pharmaceutical bioprocessing of fungal metabolites, to reduce production costs and accelerate the discovery of novel bioactive metabolites with pharmaceutical relevance, particularly for anticancer, antimicrobial, and antioxidant applications. Secondary metabolites Bioprocess optimisation Antioxidant activity Central Composite Design (CCD) Pharmaceutical biotechnology Full Text Cite Share Download PDF Status: Published Journal Publication published 14 Apr, 2026 Read the published version in Applied Biochemistry and Biotechnology → Version 1 posted Reviewers agreed at journal 12 Feb, 2026 Reviewers invited by journal 12 Feb, 2026 Editor invited by journal 09 Feb, 2026 Editor assigned by journal 05 Feb, 2026 First submitted to journal 03 Feb, 2026 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-8754183","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":590542556,"identity":"9ff8b526-6766-4e36-a37a-65eb3bc2083a","order_by":0,"name":"Jeyamanikandan Venkatachalam","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFklEQVRIiWNgGAWjYHCCBAjFzAYkgJgfLFZAihbJBpCYAVG2QbUYHABx8GgBKnj4mKdmm7w5O1vi54Iyuzzj86sTPzwwYJDnFzuAS0uyMc+x24Y7m9kOS884l1xsduPtZgmgwwxnzk7AqgXo8jRpHrbbjBsOszdI87YxJ267cXYDSEuCwW2cWtJ/8/y7bQ/U0vybt60+cfOMs5t/4NMCDNI0Zt6224kbDrMdA9pyOHEDf+82vLbwMzMkS87tu50M1JJmzXPueOKMG7zbLBIMJHD6hY29J/HDm2+3bTecP2Z8m6esOrG//+zmmz8qbOT5pbFrYWDmSWDiQRGRAKuUwK4cDNgPMP5AdesBPKpHwSgYBaNgJAIA77BgKisYafwAAAAASUVORK5CYII=","orcid":"","institution":"Jeppiaar Engineering College","correspondingAuthor":true,"prefix":"","firstName":"Jeyamanikandan","middleName":"","lastName":"Venkatachalam","suffix":""},{"id":590542557,"identity":"fe0646c5-08a4-41a4-b1fb-f0662e155fad","order_by":1,"name":"Veronica Shalini Jeyadoss","email":"","orcid":"","institution":"Jeppiaar Engineering College","correspondingAuthor":false,"prefix":"","firstName":"Veronica","middleName":"Shalini","lastName":"Jeyadoss","suffix":""},{"id":590542558,"identity":"48648cdd-bc9e-43d1-b441-393309e8bb18","order_by":2,"name":"Senthamil Selvi Poongavanam","email":"","orcid":"","institution":"Saveetha Institute of Medical and Technical Sciences (Deemed to be University) - Poonamallee Campus: SIMATS Deemed University","correspondingAuthor":false,"prefix":"","firstName":"Senthamil","middleName":"Selvi","lastName":"Poongavanam","suffix":""}],"badges":[],"createdAt":"2026-02-01 06:47:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8754183/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8754183/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s12010-026-05688-9","type":"published","date":"2026-04-14T15:59:35+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":107350905,"identity":"a2b435c4-adac-449d-8db9-55be84f498f9","added_by":"auto","created_at":"2026-04-20 16:06:45","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1096275,"visible":true,"origin":"","legend":"","description":"","filename":"JeyamaniPlagreduced31.12.20251.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8754183/v1_covered_421999ef-b6a4-47aa-9ba1-23ca95fcbbbb.pdf"}],"financialInterests":"","formattedTitle":"Enhanced Biosynthesis of Phenolics and Antioxidants by Marine Endophyte Penicillium rubens: Optimization and Bioactivity Evaluation","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"applied-biochemistry-and-biotechnology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"abab","sideBox":"Learn more about [Applied Biochemistry and Biotechnology](https://www.springer.com/journal/12010)","snPcode":"12010","submissionUrl":"https://submission.nature.com/new-submission/12010/3","title":"Applied Biochemistry and Biotechnology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Secondary metabolites, Bioprocess optimisation, Antioxidant activity, Central Composite Design (CCD), Pharmaceutical biotechnology","lastPublishedDoi":"10.21203/rs.3.rs-8754183/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8754183/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMarine-derived endophytic fungi have long been recognised as valuable sources of therapeutic metabolites. In the present study, the endophyte \u003cem\u003ePenicillium rubens\u003c/em\u003e strain PrubVJ was studied for optimised production of bioactive compounds using Response Surface Methodology (RSM). Experimental data predicted that incubation time was identified as the most influential variable, with maximum protein yield (190 mg/L) observed at day 20, antioxidant activity (74%) at 10\u0026ndash;15 days and total phenolics (1,724\u0026thinsp;\u0026plusmn;\u0026thinsp;19 \u0026micro;g GAE g⁻\u0026sup1; DW) at day 25. The optimal fermentation conditions (25\u0026deg;C, pH 3.6, 4 g/L salinity, 10 days incubation) with a desirability of 0.92, yielding 158\u0026thinsp;\u0026plusmn;\u0026thinsp;1.325 mg/L protein, 1,798\u0026thinsp;\u0026plusmn;\u0026thinsp;18 \u0026micro;g GAE g⁻\u0026sup1; DW phenolics, and 84.9% antioxidant activity were predicted from the RSM model. Experimental validation under these conditions achieved a desirability of 0.92, with 190 mg/L protein, 1,724 \u0026micro;g phenolics, and 74% antioxidant activity, confirming the reliability and robustness of the model. The developed quadratic models exhibited strong statistical reliability with stochastic parameters such as F-value, p-value and other factors such as R\u003csup\u003e2\u003c/sup\u003e, adjusted R\u003csup\u003e2\u003c/sup\u003e and predicted R\u003csup\u003e2\u003c/sup\u003e in all three responses was reported to be above 80%, validating model adequacy. Experimental validation at the predicted optimum achieved a desirability of 0.92, confirming excellent agreement between predicted and observed outcomes. Collectively, these findings establish \u003cem\u003eP. rubens\u003c/em\u003e strain PrubVJ as a promising microbial platform, providing a reliable framework for optimising fungal fermentation. This study recommends the optimized strategy for large-scale pharmaceutical bioprocessing of fungal metabolites, to reduce production costs and accelerate the discovery of novel bioactive metabolites with pharmaceutical relevance, particularly for anticancer, antimicrobial, and antioxidant applications.\u003c/p\u003e","manuscriptTitle":"Enhanced Biosynthesis of Phenolics and Antioxidants by Marine Endophyte Penicillium rubens: Optimization and Bioactivity Evaluation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-18 10:10:14","doi":"10.21203/rs.3.rs-8754183/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-02-13T04:21:33+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-12T23:30:52+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Applied Biochemistry and Biotechnology","date":"2026-02-10T01:56:54+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-06T00:21:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"Applied Biochemistry and Biotechnology","date":"2026-02-03T12:36:40+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"applied-biochemistry-and-biotechnology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"abab","sideBox":"Learn more about [Applied Biochemistry and Biotechnology](https://www.springer.com/journal/12010)","snPcode":"12010","submissionUrl":"https://submission.nature.com/new-submission/12010/3","title":"Applied Biochemistry and Biotechnology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"bc629847-75c2-42c2-b342-f76d5e62e5f5","owner":[],"postedDate":"February 18th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-04-20T16:04:10+00:00","versionOfRecord":{"articleIdentity":"rs-8754183","link":"https://doi.org/10.1007/s12010-026-05688-9","journal":{"identity":"applied-biochemistry-and-biotechnology","isVorOnly":false,"title":"Applied Biochemistry and Biotechnology"},"publishedOn":"2026-04-14 15:59:35","publishedOnDateReadable":"April 14th, 2026"},"versionCreatedAt":"2026-02-18 10:10:14","video":"","vorDoi":"10.1007/s12010-026-05688-9","vorDoiUrl":"https://doi.org/10.1007/s12010-026-05688-9","workflowStages":[]},"version":"v1","identity":"rs-8754183","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8754183","identity":"rs-8754183","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}