{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T06:18:10Z","timestamp":1787811490863,"version":"build-2784847793"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T00:00:00Z","timestamp":1787788800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100018774","name":"Bundesministerium f\u00fcr Klimaschutz, Umwelt, Energie, Mobilit\u00e4t, Innovation und Technologie","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100018774","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>\n                    Recycling critical metals from spent lithium-ion batteries (LIB) has attracted significant attention in recent years, driving the search for more sustainable and environmentally friendly recovery methods. Among emerging approaches, indirect bioleaching may be a very promising alternative for recovering valuable metals from spent LIB. In this study, sulfuric acid (H\n                    <jats:sub>2<\/jats:sub>\n                    SO\n                    <jats:sub>4<\/jats:sub>\n                    ) was produced by using a mixed culture containing\n                    <jats:italic>Acidithiobacillus thiooxidans<\/jats:italic>\n                    and\n                    <jats:italic>Acidithiobacillus caldus<\/jats:italic>\n                    , supplemented with elemental sulfur recovered as a waste product from a biogas plant. The biogenic acid was subsequently used for leaching black mass derived from nickel manganese cobalt (NMC)-based lithium-ion batteries (LIB). First, the influence of different concentrations (0.2, 1, and 2 M) of hydrogen peroxide (H\n                    <jats:sub>2<\/jats:sub>\n                    O\n                    <jats:sub>2<\/jats:sub>\n                    ) on metal dissolution was investigated. Subsequently, 2% (v\/v) of rhamnolipids \/ phospholipids was added and the effect on the H\n                    <jats:sub>2<\/jats:sub>\n                    SO\n                    <jats:sub>4<\/jats:sub>\n                    \u2013H\n                    <jats:sub>2<\/jats:sub>\n                    O\n                    <jats:sub>2<\/jats:sub>\n                    system was studied. Finally, the best performing system was scaled up to a 1L reactor, achieving complete recovery of Mn and Li from 10% (w\/v) NMC within 1 h. This result highlights the high potential of microbially produced H\n                    <jats:sub>2<\/jats:sub>\n                    SO\n                    <jats:sub>4<\/jats:sub>\n                    as an effective leaching agent for recovering critical metals from spent LIB, while simultaneously valorizing a secondary sulfur waste stream, aligning with the broader objectives of circular and sustainable resource recovery approaches.\n                  <\/jats:p>","DOI":"10.3389\/fmicb.2026.1921494","type":"journal-article","created":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T05:34:00Z","timestamp":1787808840000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Indirect bioleaching for metal recovery from battery black mass using microbially generated acid from a secondary sulfur resource"],"prefix":"10.3389","volume":"17","author":[{"given":"Lalropuia","family":"Lalropuia","sequence":"first","affiliation":[{"name":"K1-MET GmbH","place":["Linz, Austria"]},{"name":"Department of Agricultural Sciences, Institute of Environmental Biotechnology, BOKU University","place":["Tulln an der Donau, Austria"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karri","family":"Meril\u00e4inen","sequence":"additional","affiliation":[{"name":"Biotechnology and Chemical Engineering, Turku University of Applied Sciences","place":["Turku, Finland"]},{"name":"Department of Science and Technology, Institute of Biotechnology, IMC University of Applied Sciences","place":["Krems, Austria"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wadih Y.","family":"Rassy","sequence":"additional","affiliation":[{"name":"Department of Science and Technology, Institute of Biotechnology, IMC University of Applied Sciences","place":["Krems, Austria"]},{"name":"Faculty of Technical Chemistry, TU Wien","place":["Vienna, Austria"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eva","family":"Pakostova","sequence":"additional","affiliation":[{"name":"School of Natural Sciences, Laurentian University","place":["Sudbury, ON, Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Georg M.","family":"Guebitz","sequence":"additional","affiliation":[{"name":"Department of Agricultural Sciences, Institute of Environmental Biotechnology, BOKU University","place":["Tulln an der Donau, Austria"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,27]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"329","DOI":"10.1007\/s12010-008-8285-1","article-title":"Characterization of rhamnolipid produced by Pseudomonas aeruginosa isolate Bs20.","volume":"157","author":"Abdel-Mawgoud","year":"2009","journal-title":"Appl. Biochem. Biotechnol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"127891","DOI":"10.1016\/j.jenvman.2025.127891","article-title":"Towards a circular economy in lithium ion battery recycling by integrating microbial processes with electrowinning and precipitation for sustainable metal recovery.","volume":"395","author":"Baniasadi","year":"2025","journal-title":"J. Environ. Manage"},{"key":"B3","doi-asserted-by":"publisher","first-page":"504","DOI":"10.1016\/j.jhazmat.2018.08.024","article-title":"Application of indirect non-contact bioleaching for extracting metals from waste lithium-ion batteries.","volume":"360","author":"Boxall","year":"2018","journal-title":"J. Hazard. Mater"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1016\/j.jiec.2026.06.016","article-title":"Evaluation of biosurfactant-based ion flotation process for metal separation and selective recovery from battery recycling process waters.","author":"Chakankar","year":"2026","journal-title":"J. Ind. Eng. Chem."},{"key":"B5","doi-asserted-by":"publisher","first-page":"101763","DOI":"10.1016\/j.cocis.2023.101763","article-title":"Emerging application of biosurfactants in metal extraction Irina.","volume":"68","author":"Chernyshova","year":"2023","journal-title":"Curr. Opin. Colloid Interface Sci."},{"key":"B6","doi-asserted-by":"publisher","first-page":"16","DOI":"10.1080\/15320383.2014.907239","article-title":"Metal removal from contaminated soils through bioleaching with oxidizing bacteria and rhamnolipid biosurfactants.","volume":"24","author":"Diaz","year":"2015","journal-title":"Soil Sediment Contam"},{"key":"B7","doi-asserted-by":"publisher","first-page":"107740","DOI":"10.1016\/j.est.2023.107740","article-title":"Is shifting from Li-ion NMC to LFP in EVs beneficial for second-life storages in electricity markets?","volume":"68","author":"Fallah","year":"2023","journal-title":"J. Energy Storage"},{"key":"B8","doi-asserted-by":"publisher","first-page":"100792","DOI":"10.1016\/j.jwpe.2019.100792","article-title":"Mn(II) removal from water using emulsion liquid membrane composed of chelating agents and biosurfactant produced in loco.","volume":"29","author":"Ferreira","year":"2019","journal-title":"J. Water Process Eng."},{"key":"B9","doi-asserted-by":"publisher","first-page":"161450","DOI":"10.1016\/j.cej.2025.161450","article-title":"Efficient bioleaching of Li from waste lithium\u2013iron phosphate batteries by acidophilic bacterial consortium: Enrichment condition, Li recovery, and brief carbon footprint analysis.","volume":"509","author":"Gu","year":"2025","journal-title":"Chem. Eng. J."},{"key":"B10","doi-asserted-by":"publisher","first-page":"144303","DOI":"10.1016\/j.chemosphere.2025.144303","article-title":"Magnetic field-assisted bioleaching of cathode materials from spent li-ion batteries using acidithiobacillus ferrooxidans.","volume":"376","author":"Hong","year":"2025","journal-title":"Chemosphere"},{"key":"B11","doi-asserted-by":"publisher","first-page":"426","DOI":"10.1016\/j.hydromet.2017.02.010","article-title":"Current collectors as reducing agent to dissolve active materials of positive electrodes from li-ion battery wastes.","volume":"169","author":"Jouli\u00e9","year":"2017","journal-title":"Hydrometallurgy"},{"key":"B12","doi-asserted-by":"publisher","first-page":"163714","DOI":"10.1016\/j.cej.2025.163714","article-title":"Sustainable recovery of critical metals from spent lithium-ion batteries through gluconic acid-based bioleaching: Techno-economic analysis, life cycle assessment and process optimization.","volume":"516","author":"Khan","year":"2025","journal-title":"Chem. Eng. J."},{"key":"B13","doi-asserted-by":"publisher","first-page":"122012","DOI":"10.1016\/j.jenvman.2024.122012","article-title":"Enhanced bioleaching of spent li-ion batteries using A. ferrooxidans by application of external magnetic field.","volume":"367","author":"Kim","year":"2024","journal-title":"J. Environ. Manage"},{"key":"B14","doi-asserted-by":"publisher","first-page":"277","DOI":"10.3390\/min16030277","article-title":"Microbial bioleaching of critical metals from spent lithium-ion batteries: A biohydrometallurgical approach.","volume":"16","author":"Kiskira","year":"2026","journal-title":"Minerals"},{"key":"B15","doi-asserted-by":"publisher","first-page":"182","DOI":"10.1016\/j.wasman.2022.03.025","article-title":"Optimized biogenic sulfuric acid production and application in the treatment of waste incineration residues.","volume":"144","author":"Kremser","year":"2022","journal-title":"Waste. Manag"},{"key":"B16","doi-asserted-by":"publisher","first-page":"106124","DOI":"10.1016\/j.hydromet.2023.106124","article-title":"Pharmaceutical blister waste recycling using biogenic sulfuric acid: Effect of sulfur source and blister material on bioleaching efficiency.","volume":"221","author":"Kremser","year":"2023","journal-title":"Hydrometallurgy"},{"key":"B17","doi-asserted-by":"publisher","first-page":"1347072","DOI":"10.3389\/fmicb.2024.1347072","article-title":"Metal recovery from spent lithium-ion batteries via two-step bioleaching using adapted chemolithotrophs from an acidic mine pit lake.","volume":"15","author":"Lalropuia","year":"2024","journal-title":"Front. Microbiol"},{"key":"B18","doi-asserted-by":"publisher","first-page":"258","DOI":"10.1007\/s11270-019-4319-2","article-title":"Removal of heavy metals using rhamnolipid biosurfactant on manganese nodules.","volume":"230","author":"Lee","year":"2019","journal-title":"Water Air Soil Pollut."},{"key":"B19","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1016\/S0304-386X(02)00167-6","article-title":"Reductive leaching of cathodic active materials from lithium ion battery wastes.","volume":"68","author":"Lee","year":"2003","journal-title":"Hydrometallurgy"},{"key":"B20","doi-asserted-by":"publisher","first-page":"106494","DOI":"10.1016\/j.hydromet.2025.106494","article-title":"Hydrometallurgical process of spent lithium-ion battery recycling Part. 1 Chemical leaching of valuable metals from cathode active materials: Review and case study.","volume":"235","author":"Lee","year":"2025","journal-title":"Hydrometallurgy"},{"key":"B21","doi-asserted-by":"publisher","first-page":"10229","DOI":"10.1021\/acssuschemeng.4c02941","article-title":"Economic feasibility evaluation of bioleaching-based tungsten recycling of semiconductor industry waste.","volume":"12","author":"Lee","year":"2024","journal-title":"ACS Sustain. Chem. Eng."},{"key":"B22","doi-asserted-by":"publisher","first-page":"381","DOI":"10.1007\/s10098-023-02640-x","article-title":"Life cycle environmental impacts of pyrometallurgical and hydrometallurgical recovery processes for spent lithium-ion batteries: Present and future perspectives.","volume":"26","author":"Liu","year":"2024","journal-title":"Clean Technol. Environ. Policy"},{"key":"B23","doi-asserted-by":"publisher","first-page":"gad361","DOI":"10.1093\/pnasnexus\/pgad361","article-title":"Estimating the environmental impacts of global lithium-ion battery supply chain: A temporal, geographical, and technological perspective.","volume":"2","author":"Llamas-Orozco","year":"2023","journal-title":"PNAS Nexus"},{"key":"B24","doi-asserted-by":"publisher","first-page":"1550","DOI":"10.1038\/s41467-020-15355-0","article-title":"A reflection on lithium-ion battery cathode chemistry.","volume":"11","author":"Manthiram","year":"2020","journal-title":"Nat. Commun"},{"key":"B25","doi-asserted-by":"publisher","first-page":"2613","DOI":"10.1007\/s11837-016-2032-9","article-title":"Comparision of different reductants in leaching of spent lithium ion batteries.","volume":"68","author":"Meshram","year":"2016","journal-title":"JOM"},{"key":"B26","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1016\/j.wasman.2015.05.027","article-title":"Recovery of valuable metals from cathodic active material of spent lithium ion batteries: Leaching and kinetic aspects.","volume":"45","author":"Meshram","year":"2015","journal-title":"Waste. Manag"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1016\/j.hydromet.2026.106811","article-title":"Unraveling the synergistic mechanism of H2SO4\/H2O2 system enabled by a dynamic dosing strategy for sustainable recycling of spent li-ion batteries.","volume":"244","author":"Miao","year":"2026","journal-title":"Hydrometallurgy"},{"key":"B28","doi-asserted-by":"publisher","first-page":"126253","DOI":"10.1016\/j.jhazmat.2021.126253","article-title":"Biosurfactant is a powerful tool for the bioremediation of heavy metals from contaminated soils.","volume":"418","author":"Mishra","year":"2021","journal-title":"J. Hazard. Mater"},{"key":"B29","doi-asserted-by":"publisher","first-page":"1099","DOI":"10.1039\/d4ya00049h","article-title":"Mechanisms underlying the acid leaching process for LiNi0.6Co0.2Mn0.2O2 with and without H2O2.","volume":"3","author":"Mukai","year":"2024","journal-title":"Energy Adv."},{"key":"B30","doi-asserted-by":"publisher","first-page":"111","DOI":"10.1016\/s0304-3894(01)00224-2","article-title":"Heavy metal removal from sediments by biosurfactants.","volume":"85","author":"Mulligan","year":"2001","journal-title":"J. Hazard. Mater"},{"key":"B31","doi-asserted-by":"publisher","first-page":"111","DOI":"10.1007\/s40033-020-00221-6","article-title":"Leaching of Co, Mn and Ni using H2O2 in sulfuric acid medium from mobile phone LIBs.","volume":"101","author":"Nadimi","year":"2020","journal-title":"J. Inst. Eng. Ser. D"},{"key":"B32","doi-asserted-by":"publisher","first-page":"fnw083","DOI":"10.1093\/femsle\/fnw083","article-title":"Solid and liquid media for isolating and cultivating acidophilic and acid-tolerant sulfate-reducing bacteria.","volume":"363","author":"\u0147ancucheo","year":"2016","journal-title":"FEMS Microbiol. Lett"},{"key":"B33","doi-asserted-by":"publisher","first-page":"e37447","DOI":"10.1016\/j.heliyon.2024.e37447","article-title":"Improvement of Li and Mn bioleaching from spent lithium-ion batteries, using step-wise addition of biogenic sulfuric acid by acidithiobacillus thiooxidans.","volume":"10","author":"Naseri","year":"2024","journal-title":"Heliyon"},{"key":"B34","doi-asserted-by":"publisher","first-page":"001475","DOI":"10.1099\/mic.0.001475","article-title":"A novel closed-loop biotechnology for recovery of cobalt from a lithium-ion battery active cathode material.","volume":"170","author":"Pakostova","year":"2024","journal-title":"Microbiology"},{"key":"B35","doi-asserted-by":"publisher","first-page":"1069","DOI":"10.1002\/jctb.7609","article-title":"Small-scale and scale-up bioleaching of Li, Co, Ni and Mn from spent lithium-ion batteries.","volume":"99","author":"Panda","year":"2024","journal-title":"J. Chem. Technol. Biotechnol."},{"key":"B36","doi-asserted-by":"publisher","first-page":"116305","DOI":"10.1016\/j.seppur.2019.116305","article-title":"Lithium ion battery active material dissolution kinetics in Fe(II)\/Fe(III) catalyzed Cu-H2SO4 leaching system.","volume":"236","author":"Porvali","year":"2020","journal-title":"Sep. Purif. Technol."},{"key":"B37","doi-asserted-by":"publisher","first-page":"1","DOI":"10.4172\/2090-4541.1000248","article-title":"A review on the biosurfactants: Properties, types and its applications.","volume":"8","author":"Roy","year":"2018","journal-title":"J. Fundamentals Renew. Energy Appl."},{"key":"B38","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1007\/s43938-023-00023-8","article-title":"The ion flotation of copper, nickel, and cobalt using the biosurfactant surfactin.","volume":"3","author":"Schlebusch","year":"2023","journal-title":"Discov. Chem. Eng."},{"key":"B39","doi-asserted-by":"publisher","first-page":"116918","DOI":"10.1016\/j.seppur.2020.116918","article-title":"Heavy metal removal effectiveness, flow direction and speciation variations in the sludge during the biosurfactant-enhanced electrokinetic remediation.","volume":"246","author":"Tang","year":"2020","journal-title":"Sep. Purif. Technol."},{"key":"B40","doi-asserted-by":"publisher","first-page":"115748","DOI":"10.1016\/j.wasman.2026.115748","article-title":"Biogas-derived sulfur enhances microbial sulfuric acid production.","volume":"224","author":"V\u00e4limets","year":"2026","journal-title":"Waste Manag"},{"key":"B41","doi-asserted-by":"publisher","first-page":"7529","DOI":"10.1007\/s00253-013-4954-2","article-title":"Progress in bioleaching: Fundamentals and mechanisms of bacterial metal sulfide oxidation\u2013part A.","volume":"97","author":"Vera","year":"2013","journal-title":"Appl. Microbiol. Biotechnol"},{"key":"B42","doi-asserted-by":"publisher","first-page":"9662","DOI":"10.1021\/acssuschemeng.3c01238","article-title":"Recycling of lithium-ion batteries: Effect of hydrogen peroxide and a dosing method on the leaching of LCO, NMC oxides, and industrial black mass.","volume":"11","author":"Vieceli","year":"2023","journal-title":"ACS Sustain. Chem. Eng."},{"key":"B43","doi-asserted-by":"publisher","first-page":"85303","DOI":"10.1039\/c6ra16801a","article-title":"Recovery of cobalt from spent lithium ion batteries using sulfuric acid leaching followed by solid-liquid separation and solvent extraction.","volume":"6","author":"Wang","year":"2016","journal-title":"RSC Adv."},{"key":"B44","doi-asserted-by":"publisher","first-page":"6163","DOI":"10.1016\/j.biortech.2009.06.086","article-title":"Bioleaching mechanism of Co and Li from spent lithium-ion battery by the mixed culture of acidophilic sulfur-oxidizing and iron-oxidizing bacteria.","volume":"100","author":"Xin","year":"2009","journal-title":"Bioresour. Technol"},{"key":"B45","doi-asserted-by":"publisher","first-page":"9156","DOI":"10.1039\/d3gc03144f","article-title":"A closed-loop process for high-value regeneration of spent LiFePO4 cathodes after selective aluminium precipitation.","volume":"25","author":"Yan","year":"2023","journal-title":"Green Chem."},{"key":"B46","doi-asserted-by":"publisher","first-page":"105846","DOI":"10.1016\/j.jece.2021.105846","article-title":"Removal of Pb, Zn, Ni and Cr from industrial sludge by biodegradable washing agents: Caboxyethylthiosuccinic acid and itaconic-acrylic acid.","volume":"9","author":"Yang","year":"2021","journal-title":"J. Environ. Chem. Eng."},{"key":"B47","doi-asserted-by":"publisher","first-page":"38","DOI":"10.3390\/batteries10010038","article-title":"A review of lithium-ion battery recycling: Technologies, sustainability, and open issues.","volume":"10","author":"Zanoletti","year":"2024","journal-title":"Batteries"}],"container-title":["Frontiers in Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2026.1921494\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T05:34:01Z","timestamp":1787808841000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmicb.2026.1921494\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,27]]},"references-count":47,"alternative-id":["10.3389\/fmicb.2026.1921494"],"URL":"https:\/\/doi.org\/10.3389\/fmicb.2026.1921494","relation":{},"ISSN":["1664-302X"],"issn-type":[{"value":"1664-302X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,27]]},"article-number":"1921494"}}