Biochemical Engineering Journal最新文献

{"title":"Limit of hydrogen addition for enhanced methane concentration and production during syngas biomethanation in thermophilic trickle-bed reactor","authors":"Florian Gabler ,&nbsp;George Cheng ,&nbsp;Leticia Pizzul ,&nbsp;Anna Schnürer ,&nbsp;Åke Nordberg","doi":"10.1016/j.bej.2026.110112","DOIUrl":"10.1016/j.bej.2026.110112","url":null,"abstract":"<div><div>Syngas biomethanation is an emerging technology that converts synthesis gas, primarily composed of hydrogen (H₂), carbon monoxide (CO), and carbon dioxide (CO₂), into methane (CH₄) through microbial activity. In this study, the effect of changing syngas composition with increased H₂ shares on CH₄ concentration and production was assessed for 125 days, using a thermophilic trickle-bed reactor (5 L). With the experimental upper limit of 71 % H₂ (14 % CO, 10 % CO₂, 5 % N₂) in the syngas, the maximum CH₄ concentration was 65 %, maintaining high methane evolution rates (4 L/(L_pbv·d)) and high H₂ and CO conversion rates (&gt;95 %). Targeted sulfur supplementation (Na₂S) did not improve H₂ and CO conversion or CH₄ productivity, indicating that sulfur was no limiting factor under digestate-based operation. Reactor performance was instead constrained by system-level factors, including low gas retention time, gas–liquid mass transfer limitations, and inhibition of CO-converting pathways at elevated H₂ partial pressure. 16S rRNA gene sequencing revealed a highly stable microbial community dominated by the hydrogenotrophic methanogen <em>Methanothermobacter</em>. CO conversion occurred via direct methanogenesis and acetate formation, followed by syntrophic acetate oxidation. Overall, increasing H₂ availability enhanced CH₄ production only up to a system-specific threshold, beyond which microbial and transport limitations dominated.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110112"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced bioelectronic scaffolds with electrostimulation for enhanced muscle regeneration","authors":"Xi Yang ,&nbsp;Jianmin Wang ,&nbsp;Liang Zhang ,&nbsp;Fengling Zhuo ,&nbsp;Linyan Ge ,&nbsp;Liuhang Zhang ,&nbsp;Jie Li ,&nbsp;Fei Han ,&nbsp;Guanghui Song ,&nbsp;Xiaozhi Wang","doi":"10.1016/j.bej.2026.110105","DOIUrl":"10.1016/j.bej.2026.110105","url":null,"abstract":"<div><div>Tissue engineering scaffolds are essential for facilitating tissue regeneration, and electrical stimulation has emerged as a powerful complementary strategy to accelerate this process. However, the functionality and performance of current scaffold systems remain suboptimal, limiting their therapeutic potential. In this study, a novel graphene-boron nitride-poly(lactic-co-glycolic acid) (GR-BN-PLGA) scaffold was fabricated using 3D printing technology for the repair of abdominal wall hernias in rats. The scaffold was constructed using two materials with distinct electrical properties, conductive GR-PLGA and insulating BN-PLGA, through a layered printing process. By integrating electrodes and microneedles, the scaffold was designed to establish a centrally directed electric field in the abdominal defect area, enabling effective electrical stimulation therapy. The results demonstrated that the combined application of the scaffold and electrical stimulation significantly upregulated the expression of α-smooth muscle actin, type I collagen, and Cell Proliferation Marker Protein Ki-67, thereby facilitating tissue remodeling. Meanwhile, the lower expression levels of proliferating cell nuclear antigen and connective tissue growth factor effectively suppressed excessive proliferation and fibrosis, aiding in the formation of stable and functional regenerated tissue. The synergistic application of conductive scaffolds and electrical stimulation provides a novel strategy for tissue repair and highlights its tremendous potential in accelerating tissue regeneration and promoting the formation of functional tissues.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110105"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced anticancer activity through bidirectional fermentation of Epimedium brevicornum Maxim. with Morchella esculenta","authors":"Chengchuan Che ,&nbsp;Lijun Sheng ,&nbsp;Pingping Ding ,&nbsp;Qi Liu ,&nbsp;Huimin Zhao ,&nbsp;Wenyu Han ,&nbsp;Yunli Guo ,&nbsp;Cuijuan Gao ,&nbsp;Carol Sze Ki Lin ,&nbsp;Xinxin Liang","doi":"10.1016/j.bej.2026.110103","DOIUrl":"10.1016/j.bej.2026.110103","url":null,"abstract":"<div><div><em>Epimedium brevicornum</em> Maxim. (EB), a traditional Chinese herbal medicine, exhibits notable anticancer and anti-aging activities attributed primarily to flavonoids such as epimedin C and icariin. However, its effective application is limited by low extraction efficiency and incomplete mechanistic understanding. Bidirectional fermentation is an effective microbial bioconversion strategy to enrich bioactive constituents or generate novel metabolites. Herein, the medicinal fungus <em>Morchella esculenta</em> (ME) was used to conduct bidirectional fermentation of EB. Compared with single-fermentation EB extract, the ME/EB extract had 2.39-fold and 1.44-fold greater epimedin C and icariin content, respectively. The ME/EB extract exhibited significant antiproliferative activity against cancer cells, with IC₅₀ values of 215 μg/mL for human cervical cancer HeLa cells and 235 μg/mL for non-small-cell lung cancer A549 cells. Moreover, the ME/EB extract induced cell-cycle arrest at G1/G0 phase in HeLa cells and S phase in A549 cells, while markedly suppressing cell migration and invasion. The ME/EB extract also down-regulated Bcl-2 protein expression and up-regulated Bax, PI3K, and Akt protein expression, thereby promoting cancer cell apoptosis. Therefore, bidirectional fermentation significantly enhanced EB anticancer activity, potentially through modulation of the PI3K/Akt signalling pathway. Overall, ME-mediated bidirectional fermentation of EB shows promise as a novel strategy for developing anticancer agents.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110103"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovatively engineered biowaste-derived CaO–Fe/activated carbon and ce/sepiolite composite catalysts for microwave-intensified biodiesel production from waste cooking oil","authors":"Hiba A. Abdulkareem ,&nbsp;Mohammed T. Yassen ,&nbsp;Nooralhuda N. Ahmed ,&nbsp;Malak. B.Ahmed ,&nbsp;Saba A. Gheni ,&nbsp;Mudheher M. Ali ,&nbsp;Farah T. Al-Sudani ,&nbsp;Ataallah K. Tahah","doi":"10.1016/j.bej.2026.110097","DOIUrl":"10.1016/j.bej.2026.110097","url":null,"abstract":"<div><div>The development of low-cost and sustainable catalytic systems is essential for advancing biodiesel production from waste lipids. This study presents two novel heterogeneous catalysts derived entirely from natural and biowaste resources: (i) CaO–Fe supported on activated carbon produced from eggshells and date palm fronds (CaO–Fe/AC), and (ii) cerium-modified activated sepiolite (Ce/AS). The catalysts were synthesized via incipient wetness impregnation followed by thermal activation and comprehensively characterized using BET, SEM, XRD, FTIR, TGA, and ICP-OES analyses. The CaO–Fe/AC catalyst exhibited strong basicity and high surface area favorable for transesterification, while the Ce/AS catalyst provided bifunctional acid–base properties enabling the direct conversion of high–free fatty acid (FFA) waste cooking oil (WCO) through simultaneous esterification and transesterification. Process intensification using microwave irradiation significantly reduced reaction time and energy consumption. Under optimized conditions (methanol-to-oil ratio of 9:1, catalyst loading of 0.3 wt%, and 100 % microwave power), biodiesel conversions of 97 % for CaO–Fe/AC and 99 % for Ce/AS were achieved within 6 min. The produced biodiesel met ASTM D6751 and EN 14214 specifications. The combination of microwave-assisted heating and biowaste-derived composite catalysts offers a rapid, energy-efficient, and environmentally sustainable route for biodiesel production, supporting circular economy strategies and scalable renewable fuel technologies.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110097"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetically encoded FRET-based sensor for intracellular heparin monitoring in real time","authors":"Sana Masroor,&nbsp;Neha Soleja,&nbsp;Mohamad Aman Jairajpuri,&nbsp;Mohd Mohsin","doi":"10.1016/j.bej.2026.110099","DOIUrl":"10.1016/j.bej.2026.110099","url":null,"abstract":"<div><div>Heparin is an indispensable anticoagulant commonly administered during surgical interventions that require extracorporeal blood circulation, including cardiopulmonary bypass surgery. However, heparin overdose frequently leads to potentially fatal bleeding complications. Hence, precise monitoring of heparin levels is critical to avoid risks such as heparin-induced thrombocytopenia (HIT) and hemorrhage. Recently, Various detection tools have been designed for heparin, but these have complex procedures, low sensitivity, and do not perform real-time monitoring of heparin. Therefore, we have designed a highly effective genetically encoded fluorescence resonance energy transfer (FRET)-based <u>Hep</u>arin <u>Sen</u>sor (HepSen) to perform real-time monitoring of heparin with high spatio-temporal resolution. HepSen was developed by incorporating heparin-binding protein, platelet factor 4 (PF4) protein, between ECFP and Venus at N- and C-terminus, respectively. This novel nanosensor exhibits high stability at physiological pH levels and remains unaffected by the addition of biologically significant metal ions. Furthermore, two mutant variants, C12G and R20A, were also designed; nevertheless, wild-type HepSen showed the highest binding affinity with <em>K</em>_d of 2.73 × 10⁻⁷ M and a broad detection range of 1 nM-50 µM. HepSen exhibited robust expression in <em>Escherichia coli</em> (<em>E. coli</em>), <em>Saccharomyces cerevisiae</em> (<em>S. cerevisiae</em>), and human embryonic kidney (HEK-293T) cells, facilitating real-time monitoring of heparin with a well-defined saturation curve, thereby demonstrating its intracellular sensing capability across diverse biological systems.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110099"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced expression and purification strategy for β2-microglobulin in Escherichia coli","authors":"Boram Kim ,&nbsp;Junwoo Hwang ,&nbsp;Dong-Hyun Seo ,&nbsp;Sun Taek Kim ,&nbsp;Ji-Hun Kim ,&nbsp;Kyoung-Seok Ryu","doi":"10.1016/j.bej.2026.110100","DOIUrl":"10.1016/j.bej.2026.110100","url":null,"abstract":"<div><div>β2-microglobulin (β2m) is a biomarker for various renal diseases and forms the major histocompatibility complex class I (MHC-I) with the heavy chain. The presenting antigenic peptide on the MHC-I is critical for the cytotoxic T-cell mediated immune responses, and thus extensive efforts have been paid to the <em>in vitro</em> reconstitution of the MHC-I through co-refolding of the heavy chain and β2m. Although β2m that contains a single disulfide bond is highly stable, it is typically expressed as an insoluble form in <em>Escherichia coli</em> (<em>E. coli</em>). In this study, native β2m was prepared via soluble expression in the <em>E. coli</em> SHuffle T7 Express strain, achieving a yield of 30–40 mg per liter of Luria-Bertani (LB) medium, more than 10-fold higher than that obtained through periplasmic expression. The refolding of the heavy chain with the purified β2m successfully produced the cognate peptide-loaded MHC-I (pMHC-I). The SHuffle T7 system offers a straightforward approach for producing functional β2m for future researches in immunology and structural biology.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110100"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A combination of domain fusion and homologous site transplantation improves the performance of Bst DNA polymerase in denaturation bubble-mediated strand exchange amplification","authors":"Quanling Dong ,&nbsp;Qiming Chen ,&nbsp;Keren Shang ,&nbsp;Zhengrong Lu ,&nbsp;Yuanlong Hu ,&nbsp;Zhanmin Liu","doi":"10.1016/j.bej.2026.110104","DOIUrl":"10.1016/j.bej.2026.110104","url":null,"abstract":"<div><div>Bst DNA polymerase has been widely used in isothermal nucleic-acid amplification platforms for pathogen detection and molecular diagnostics. Improving the catalytic efficiency and operational robustness of Bst DNA polymerase through protein engineering is therefore of substantial interest. In this study, we combined domain fusion with the introduction of a homologous site transplantation in the large fragment of Bst DNA polymerase (BstLF). Specifically, the double-stranded DNA-binding domain Sso7d was fused to BstLF via a flexible linker, while the F496H mutation was introduced. The resulting mutant, Sso7d-BstLF(F496H), demonstrated improved catalytic efficiency in isothermal amplification techniques of denaturation bubble-mediated strand exchange amplification (SEA). Compared with the wild-type, Sso7d-BstLF(F496H) reduced the SEA amplification time by approximately 50 %. In addition, the engineered polymerase retained robust amplification activity at 71°C and showed improved tolerance to pH fluctuations and to common inhibitory components (NaCl, EDTA, urea, ethanol, and SDS). Molecular docking and mutation energy calculations suggested that improved performance might be associated with additional hydrogen bonds between the R group and DNA, consistent with increased protein-DNA affinity. Molecular dynamics simulations further indicated that F496H preserves global structural stability while reducing local flexibility, providing a plausible structural basis for the observed activity enhancement. Collectively, these findings identify Sso7d–BstLF(F496H) as a promising polymerase for improved isothermal amplification–based molecular diagnostics.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110104"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen removal performance and low-temperature impact of hybrid membrane aerated biofilms reactor (H-MABR)","authors":"Youzhao Wang ,&nbsp;Jie Han ,&nbsp;Mingdong Chang ,&nbsp;Yongguang Ma ,&nbsp;Xiaoyan Dang ,&nbsp;Shumin He ,&nbsp;Zhipeng Wang ,&nbsp;Rongxiao Zhang ,&nbsp;Junnan Liu ,&nbsp;Jinxiang Wang ,&nbsp;Lin Zhai ,&nbsp;Junting Wang ,&nbsp;Zhenning Lv ,&nbsp;Tong Zhu","doi":"10.1016/j.bej.2026.110102","DOIUrl":"10.1016/j.bej.2026.110102","url":null,"abstract":"<div><div>Declining microbial activity under low-temperature conditions poses a persistent challenge for biological wastewater treatment. Conventional Membrane Aerated Biofilm Reactor (C-MABR) has the advantages of high mass transfer efficiency, stable treatment effect and low aeration energy consumption. However, treatment capacity of C-MABR is significantly compromised under low-temperature conditions. In this work, a novel hybrid membrane aerated biofilm reactor (H-MABR) was developed by integrating biomass carriers with membrane aeration to enhance system robustness in cold conditions. Performance, process optimization, and microbial community characteristics of H‑MABR were systematically evaluated at <span><math><mrow><mn>10</mn><mo>∼</mo><mn>12</mn><mtext>℃</mtext></mrow></math></span>. The results indicated that under approximately 200 mg/L of COD, approximately 50 mg/L of <span><math><mrow><msubsup><mrow><mtext>NH</mtext></mrow><mrow><mn>4</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>−</mo><mtext>N</mtext></mrow></math></span> and 12 h of HRT, COD removal loading rates averaged 0.244 kg/(m³∙d), <span><math><mrow><msubsup><mrow><mtext>NH</mtext></mrow><mrow><mn>4</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>−</mo><mtext>N</mtext></mrow></math></span> removal loading rates averaged 0.051 kg N/(m³∙d) and TN removal loading rates averaged 0.038 kg N/(m³∙d), respectively. Using response surface methodology (RSM), optimal operating window for pollutant removal was identified as followed: temperature <span><math><mrow><mn>10</mn><mo>∼</mo><mn>12</mn><mtext>℃</mtext></mrow></math></span>, pH 7.5, C/N ratio 3.71, and aeration pressure 0.02 MPa. Microbial community analysis demonstrated that exposure to low temperature markedly reshaped the community structure in H‑MABR, indicating a strong linkage between temperature and functional microbial community. Overall, this study elucidated impact of low-temperature operation on H‑MABR performance and microbial ecology and provided practical insights to guide the design and operation for wastewater treatment in cold environments.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"229 ","pages":"Article 110102"},"PeriodicalIF":3.7,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel multi-directional modular mixing system for bringing new insight to microalgae production in panel photobioreactors","authors":"Barış Erdoğan ,&nbsp;S. Furkan Demi̇rden ,&nbsp;Deniz Senyay-Oncel ,&nbsp;Suphi S. Oncel","doi":"10.1016/j.bej.2026.110074","DOIUrl":"10.1016/j.bej.2026.110074","url":null,"abstract":"<div><div>A novel system was designed herein to enhance the mixing efficiency of conventional panel photobioreactors (PBRs). Initially, design optimization was conducted using three-dimensional computational modeling. For this, CFD simulations performed using the Shear Stress Transport model of different mixing configurations. These are single vertical shaft (1B), single turbine on each lateral shafts (2B) and single turbines in all directions (3B), respectively. Rushton and marine type impellers are used in these simulations for comprehensive evaluation. Here, <em>Chlamydomonas reinhardtii</em> CC-124 was used as model microalgae. In both simulations and validation studies Rushton turbine gives better results (36.81 ± 0.23 mg.L⁻¹) when compared with marine impeller (16.42 ± 0.67 mg.L⁻¹) in terms of highest total chlorophyll amount reached. Among the different configurations with Rushton impeller, the 1B and 3B configurations come forward. Although, 3B reached higher average shear stress value (3.63 Pa) than 1B, this configuration was able to reach higher microalgae concentration in a short time during the 13-day culture period when evaluated in terms of biomass. This result indicates that 3B configuration which creates highest magnitude multidirectional flow vectors provides a consistent homogeneous mixing for better biomass production in PBR. Based on these results, it can be said that this modular mixing system design is a promising contribution for panel PBRs and new microalgae production systems.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"228 ","pages":"Article 110074"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Configuration and optimization of in-situ microbial protein production via bio-electrochemical system","authors":"Yilin Jiang ,&nbsp;Hangyu Sun ,&nbsp;Shimin Wu ,&nbsp;Xiangjie Xiao ,&nbsp;Yanping Liu ,&nbsp;Ziyi Yang","doi":"10.1016/j.bej.2026.110081","DOIUrl":"10.1016/j.bej.2026.110081","url":null,"abstract":"<div><div>Upcycling of nitrogen for producing microbial protein (MP) is a promising method to support the development of circular economy. In this study, <em>in-situ</em> MP production system was upgraded based on microbial electrolytic cell (MEC). Firstly, ammonia-tolerant electroactive microorganisms were enriched on the bio-anode electrode at 1500 mg N/L. Secondly, to enhance the NH₄⁺ -N migration efficiency, ion concentration in the cathode chamber of 20 mmol K₂HPO₄ + 20 mmol Na₂HPO₄, pH in the cathode chamber of 7.0 and applied voltage of 0.6 V was selected. Thirdly, <em>in-situ</em> MP production system showed the feasibility, with MP production of 1.82 g/L. Finally, voltage of 1.0 V, NH₄⁺-N concentration of 1 g N/L in anode chamber and 20°C were selected as the optimal operational conditions. And MP production of 2.19 g/L was obtained, with 30.47 % of nitrogen stored in MP. Essential amino acids of MP produced in this study was about 42 %, belonging to the high-quality proteins. <em>In-situ</em> protein production system showed the promising MP synthesis capacity, which could be used as a sustainable solution for nitrogen upcycling.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"228 ","pages":"Article 110081"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}