{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T16:57:24Z","timestamp":1790528244246,"version":"4.1.0"},"posted":{"date-parts":[[2026,9,24]]},"group-title":"Microbiology","reference-count":41,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T00:00:00Z","timestamp":1790208000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"NIH-NIGMS","award":["P20 GM103446"],"award-info":[{"award-number":["P20 GM103446"]}]},{"name":"NIH-NIGMS","award":["P20 GM139760"],"award-info":[{"award-number":["P20 GM139760"]}]},{"name":"NIH-NIGMS","award":["S10 OD025165"],"award-info":[{"award-number":["S10 OD025165"]}]},{"name":"State of Delaware"},{"name":"University of Delaware Graduate College Interdisciplinary Frontiers Graduate and Postdoctoral Fellows Program"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,9,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Pyrogenic black carbon, such as biochar and wildfire char, possesses a reversible electron storage capacity (ESC), allowing it to serve as an electron donor or acceptor for microorganisms. However, not all the ESC is bioavailable, and the proportion available varies by culture. We hypothesized microbes capable of producing soluble redox mediators could access the ESC in biochar interior and thus utilize a higher percentage of the ESC than organisms without a mediator. To test this hypothesis, we grew wild-type\n                  <jats:italic>Shewanella oneidensis<\/jats:italic>\n                  (MR-1) and \u0394\n                  <jats:italic>bfe<\/jats:italic>\n                  MR-1, a mutant incapable of exporting flavins, on air-oxidized wood biochar. Cell counts and redox titration show that both strains of MR-1 grew to similar cell densities and accessed comparable amounts of biochar\u2019s ESC (\u223c19%). The addition of exogenous flavin mononucleotide (FMN) yielded no measurable increase in final cell density, due to the strong adsorption of FMN to biochar. SEM images show attachment of MR-1 and \u0394\n                  <jats:italic>bfe<\/jats:italic>\n                  to biochar surfaces and the presence of nanowires. This study demonstrates MR-1 can utilize biochar\u2019s ESC for growth, through direct physical contact without the involvement of flavins. Understanding how microbes metabolize biochar provides insight into the impacts and biogeochemical roles of pyrogenic carbon.\n                <\/jats:p>","DOI":"10.64898\/2026.09.21.753187","type":"posted-content","created":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T17:45:16Z","timestamp":1790271916000},"source":"Crossref","is-referenced-by-count":0,"title":["<i>Shewanella oneidensis<\/i>\n                  grows on biochar as an electron acceptor via direct contact without flavins"],"prefix":"10.64898","author":[{"given":"Ankit","family":"Singh","sequence":"first","affiliation":[{"name":"Department of Civil, Construction, and Environmental Engineering, University of Delaware, Newark, DE 19716, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0302-3588","authenticated-orcid":false,"given":"Jessica L.","family":"Keffer","sequence":"additional","affiliation":[{"name":"Department of Earth Sciences, University of Delaware, Newark, DE 19716, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiwon","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Civil, Construction, and Environmental Engineering, University of Delaware, Newark, DE 19716, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pei C.","family":"Chiu","sequence":"additional","affiliation":[{"name":"Department of Civil, Construction, and Environmental Engineering, University of Delaware, Newark, DE 19716, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1810-4994","authenticated-orcid":false,"given":"Clara S.","family":"Chan","sequence":"additional","affiliation":[{"name":"Department of Earth Sciences, University of Delaware, Newark, DE 19716, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026092709300538000_2026.09.21.753187v1.1","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2180-5-41"},{"key":"2026092709300538000_2026.09.21.753187v1.2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01615-16"},{"key":"2026092709300538000_2026.09.21.753187v1.3","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M109.043455"},{"key":"2026092709300538000_2026.09.21.753187v1.4","first-page":"481","article-title":"The prokaryotes: a handbook on the biology of bacteria","volume":"7","year":"2006","journal-title":"Proteobacteria Delta Epsil Subclasses Deep Rooted Bact"},{"key":"2026092709300538000_2026.09.21.753187v1.5","doi-asserted-by":"publisher","DOI":"10.1038\/srep05019"},{"key":"2026092709300538000_2026.09.21.753187v1.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.scitotenv.2016.09.006"},{"key":"2026092709300538000_2026.09.21.753187v1.7","doi-asserted-by":"publisher","DOI":"10.1021\/acs.est.5c05709"},{"key":"2026092709300538000_2026.09.21.753187v1.8","doi-asserted-by":"publisher","DOI":"10.1038\/s41561-018-0159-8"},{"key":"2026092709300538000_2026.09.21.753187v1.9","unstructured":"Fortune Business Insights. Biochar Market Size, Share, Growth, Trends, Forecast, 2034. 24 Aug. 2026. https:\/\/www.fortunebusinessinsights.com\/industry-reports\/biochar-market-100750 (9 Sept. 2026, date last accessed)."},{"key":"2026092709300538000_2026.09.21.753187v1.10","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0604517103"},{"key":"2026092709300538000_2026.09.21.753187v1.11","doi-asserted-by":"publisher","DOI":"10.1021\/acs.jpcb.6b03851"},{"key":"2026092709300538000_2026.09.21.753187v1.12","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00090-10"},{"key":"2026092709300538000_2026.09.21.753187v1.13","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1011699107"},{"key":"2026092709300538000_2026.09.21.753187v1.14","doi-asserted-by":"publisher","DOI":"10.1021\/ez5002209"},{"key":"2026092709300538000_2026.09.21.753187v1.15","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00553-12"},{"key":"2026092709300538000_2026.09.21.753187v1.16","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00553-12"},{"key":"2026092709300538000_2026.09.21.753187v1.17","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2015.00609"},{"key":"2026092709300538000_2026.09.21.753187v1.18","doi-asserted-by":"publisher","DOI":"10.1021\/acs.est.6c04532"},{"key":"2026092709300538000_2026.09.21.753187v1.19","doi-asserted-by":"publisher","DOI":"10.1007\/s10533-025-01221-y"},{"key":"2026092709300538000_2026.09.21.753187v1.20","doi-asserted-by":"publisher","DOI":"10.1088\/1748-9326\/acff7a"},{"key":"2026092709300538000_2026.09.21.753187v1.21","doi-asserted-by":"publisher","DOI":"10.1002\/wer.70164"},{"key":"2026092709300538000_2026.09.21.753187v1.22","doi-asserted-by":"publisher","DOI":"10.1385\/1-59259-266-X:1"},{"key":"2026092709300538000_2026.09.21.753187v1.23","doi-asserted-by":"publisher","DOI":"10.1126\/science.240.4857.1319"},{"key":"2026092709300538000_2026.09.21.753187v1.24","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.66.5.2248-2251.2000"},{"key":"2026092709300538000_2026.09.21.753187v1.25","doi-asserted-by":"publisher","DOI":"10.1038\/srep05628"},{"key":"2026092709300538000_2026.09.21.753187v1.26","doi-asserted-by":"publisher","DOI":"10.1038\/srep31920"},{"key":"2026092709300538000_2026.09.21.753187v1.27","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1410551111"},{"key":"2026092709300538000_2026.09.21.753187v1.28","doi-asserted-by":"publisher","DOI":"10.1007\/s44246-024-00119-y"},{"key":"2026092709300538000_2026.09.21.753187v1.29","doi-asserted-by":"publisher","DOI":"10.1021\/acs.estlett.5b00354"},{"key":"2026092709300538000_2026.09.21.753187v1.30","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1718810115"},{"key":"2026092709300538000_2026.09.21.753187v1.31","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2021.727709"},{"key":"2026092709300538000_2026.09.21.753187v1.32","doi-asserted-by":"publisher","DOI":"10.1038\/nbt1102-1093"},{"key":"2026092709300538000_2026.09.21.753187v1.33","doi-asserted-by":"publisher","DOI":"10.1128\/aem.01313-22"},{"key":"2026092709300538000_2026.09.21.753187v1.34","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01387-07"},{"key":"2026092709300538000_2026.09.21.753187v1.35","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01387-07"},{"key":"2026092709300538000_2026.09.21.753187v1.36","doi-asserted-by":"publisher","DOI":"10.1021\/acs.est.3c05830"},{"key":"2026092709300538000_2026.09.21.753187v1.37","doi-asserted-by":"publisher","DOI":"10.1016\/j.chemosphere.2018.10.080"},{"key":"2026092709300538000_2026.09.21.753187v1.38","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhazmat.2023.131953"},{"key":"2026092709300538000_2026.09.21.753187v1.39","doi-asserted-by":"publisher","DOI":"10.1021\/sb500331x"},{"key":"2026092709300538000_2026.09.21.753187v1.40","doi-asserted-by":"publisher","DOI":"10.1016\/j.scitotenv.2022.157560"},{"key":"2026092709300538000_2026.09.21.753187v1.41","doi-asserted-by":"publisher","DOI":"10.1080\/01490451.2015.1062060"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.09.21.753187","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T16:30:13Z","timestamp":1790526613000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.09.21.753187"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,24]]},"references-count":41,"URL":"https:\/\/doi.org\/10.64898\/2026.09.21.753187","relation":{},"subject":[],"published":{"date-parts":[[2026,9,24]]},"subtype":"preprint"}}