Constraint-based mathematical model analysis reveals glycogen and cellulose storage competition during conversion of CO2 to hyaluronic acid in Chlorella vulgaris

Constraint-based mathematical model analysis reveals glycogen and cellulose storage competition during conversion of CO2 to hyaluronic acid in Chlorella vulgaris | 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 Constraint-based mathematical model analysis reveals glycogen and cellulose storage competition during conversion of CO2 to hyaluronic acid in Chlorella vulgaris Pratik Ramchandra Chaudhari, Alisha Zaffar, Muhil Raj Prabhakar, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9064306/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 Hyaluronic acid (HA) is a biopolymer with a wide range of biomedical and industrial applications. Conventionally, it is manufactured from rooster comb and fermentation of Streptococcus zooepidemicus. In this work, we explore hyaluronic acid production under phototrophic conditions using a reduced-scale, constraint-based in silico microalgal model comprising 216 reactions, 144 metabolites, and 318 genes, reconstructing a microalgal system. In model validation, verify stoichiometric consistency, phototrophic conditions, and constraints, and also check for leaks in reaction flux. Single limiter analysis shows the HA production steadily increases with photon from (0.05 to – 0.31 mmol gDW⁻¹ h⁻¹), and CO₂ (0.1 to 1 mmol gDW⁻¹ h⁻¹), uptake, indicating strictly resource-limited biosynthesis. Trade-off analysis between biomass-HA under phototrophic growth, where the wild-type state produced HA = 0.26 mmol gDW⁻¹ h⁻¹ with biomass flux ~ 3.88–4.00 mmol gDW⁻¹ h⁻¹. Enforcing storage allocation activated glycogen and cellulose sinks, diverting carbon away from HA and decreasing HA to ~ 0.15 mmol gDW⁻¹ h⁻¹, along with reduced growth. Pareto and weighted-sum optimization revealed a steep, non-smooth front, indicating discrete switching between growth and HA-dominated metabolic states. Knockout of the competing storage reactions redirected carbon toward HA biosynthesis, recovering HA to ~ 0.26 mmol gDW⁻¹ h⁻¹ without decreasing biomass growth. 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-9064306","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":607767413,"identity":"6d6ffb5b-9a48-45e6-98a3-33071bd7868a","order_by":0,"name":"Pratik Ramchandra Chaudhari","email":"","orcid":"","institution":"National Institute of Technology Rourkela","correspondingAuthor":false,"prefix":"","firstName":"Pratik","middleName":"Ramchandra","lastName":"Chaudhari","suffix":""},{"id":607767414,"identity":"8aeaa814-81f6-4c68-9fb7-f7ba2ab2af4d","order_by":1,"name":"Alisha Zaffar","email":"","orcid":"","institution":"National Institute of Technology Rourkela","correspondingAuthor":false,"prefix":"","firstName":"Alisha","middleName":"","lastName":"Zaffar","suffix":""},{"id":607767415,"identity":"ab122bfb-08c7-48e7-9871-b59569874879","order_by":2,"name":"Muhil Raj Prabhakar","email":"","orcid":"","institution":"National Institute of Technology Rourkela","correspondingAuthor":false,"prefix":"","firstName":"Muhil","middleName":"Raj","lastName":"Prabhakar","suffix":""},{"id":607767416,"identity":"f085b160-d6f8-42e2-8d64-8c2e468778bb","order_by":3,"name":"Balasubramanian Paramasivan","email":"","orcid":"","institution":"National Institute of Technology Rourkela","correspondingAuthor":false,"prefix":"","firstName":"Balasubramanian","middleName":"","lastName":"Paramasivan","suffix":""},{"id":607767417,"identity":"ee8e3529-3cb9-4b2f-a90e-e83ec388ade3","order_by":4,"name":"Bikash Chandra Maharaj","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABB0lEQVRIiWNgGAWjYBACA2Y2BgbGBiBLAsTlsQESjI0HSNGSBtLSgF8LA4oWhsNgEq8Wc3a2xI8/dzBE889ufvbhh8x5u7Xth4G21NhE49Ji2cx2WJr3DEPujDvHjGf28NxO3nYmEajlWFpuAy6HHWZvkGZsY8htuJFgzMAD1GJ2AKiFseEwPi3NP38Ctcy/kf6Z8Q/PuWSz8w8JaWE7JsEL1LLhRo4xMw/PATuzGwRsAfolzZq3TSJ3442cYmYZnuQEsxtAWxLw+MWc/5jxzZ9tNrnzbqRvZnzbY2dvdj794YMPNTY4tUABJFIYGHsYEsEqE/ArRwY/GOyJVzwKRsEoGAUjBQAAXBNirmw84HcAAAAASUVORK5CYII=","orcid":"","institution":"National Institute of Technology Rourkela","correspondingAuthor":true,"prefix":"","firstName":"Bikash","middleName":"Chandra","lastName":"Maharaj","suffix":""}],"badges":[],"createdAt":"2026-03-08 12:54:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9064306/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9064306/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":105035400,"identity":"61178b81-bb1b-4a4f-9139-6c230f84f813","added_by":"auto","created_at":"2026-03-20 07:26:01","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1226837,"visible":true,"origin":"","legend":"","description":"","filename":"FBAManuscript20250308updated.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9064306/v1_covered_7e16e9ea-9717-41c8-becd-a489b27752ee.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Constraint-based mathematical model analysis reveals glycogen and cellulose storage competition during conversion of CO2 to hyaluronic acid in Chlorella vulgaris","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":"","lastPublishedDoi":"10.21203/rs.3.rs-9064306/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9064306/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHyaluronic acid (HA) is a biopolymer with a wide range of biomedical and industrial applications. Conventionally, it is manufactured from rooster comb and fermentation of \u003cem\u003eStreptococcus zooepidemicus.\u003c/em\u003e In this work, we explore hyaluronic acid production under phototrophic conditions using a reduced-scale, constraint-based in silico microalgal model comprising 216 reactions, 144 metabolites, and 318 genes, reconstructing a microalgal system. In model validation, verify stoichiometric consistency, phototrophic conditions, and constraints, and also check for leaks in reaction flux. Single limiter analysis shows the HA production steadily increases with photon from (0.05 to \u0026ndash; 0.31 mmol gDW⁻\u0026sup1; h⁻\u0026sup1;), and CO₂ (0.1 to 1 mmol gDW⁻\u0026sup1; h⁻\u0026sup1;), uptake, indicating strictly resource-limited biosynthesis. Trade-off analysis between biomass-HA under phototrophic growth, where the wild-type state produced HA\u0026thinsp;=\u0026thinsp;0.26 mmol gDW⁻\u0026sup1; h⁻\u0026sup1; with biomass flux\u0026thinsp;~\u0026thinsp;3.88\u0026ndash;4.00 mmol gDW⁻\u0026sup1; h⁻\u0026sup1;. Enforcing storage allocation activated glycogen and cellulose sinks, diverting carbon away from HA and decreasing HA to ~\u0026thinsp;0.15 mmol gDW⁻\u0026sup1; h⁻\u0026sup1;, along with reduced growth. Pareto and weighted-sum optimization revealed a steep, non-smooth front, indicating discrete switching between growth and HA-dominated metabolic states. Knockout of the competing storage reactions redirected carbon toward HA biosynthesis, recovering HA to ~\u0026thinsp;0.26 mmol gDW⁻\u0026sup1; h⁻\u0026sup1; without decreasing biomass growth.\u003c/p\u003e","manuscriptTitle":"Constraint-based mathematical model analysis reveals glycogen and cellulose storage competition during conversion of CO2 to hyaluronic acid in Chlorella vulgaris","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-19 06:49:49","doi":"10.21203/rs.3.rs-9064306/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","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}}],"origin":"","ownerIdentity":"2c18d273-9665-49b8-84dc-037faa3b2177","owner":[],"postedDate":"March 19th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-19T23:38:41+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-19 06:49:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9064306","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9064306","identity":"rs-9064306","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}