Pub Date : 2025-12-31DOI: 10.1016/j.bej.2025.110064
Hongyuan Sun , Jiaqi Liu , Xuewen Gao , Kuizu Su , Rui Tang , Xinmin Zhan , Zhen-Hu Hu
Dry anaerobic digestion (AD) is a promising technology for pig manure treatment, yet it is challenged by ammonia inhibition. Magnesium salt addition promotes the formation of magnesium ammonium phosphate (MAP), which in-situ captures ammonia nitrogen and mitigates inhibition, while high solids content limits MAP crystallization. This study evaluated the effect of magnesium salt pretreatment of wheat straw on dry AD of pig manure. Four Mg:P molar ratios (1.0:1.0, 1.5:1.0, 2.0:1.0, and 3.0:1.0) were investigated. Adding magnesium salt-pretreated wheat straw under molar ratios of 1.0:1.0 and 1.5:1.0 captured 14.3–14.4 % of ammonia nitrogen and reduced free ammonia by 19.0–19.1 %. Methane production increased by 15.0–19.2 % and substrate degradation by 8.4–8.6 %. Such pretreatment promoted MAP nucleation and growth on the straw surface, facilitating ammonia nitrogen capture. The capture of ammonia nitrogen restored the abundance of acetoclastic methanogens from 7.3 % to 12.5 %, thereby enhancing methane production. These results provide a practical strategy for mitigating ammonia inhibition in dry AD of pig manure.
{"title":"Enhancing dry anaerobic digestion of pig manure via in-situ ammonia capture by adding magnesium salt-pretreated wheat straw","authors":"Hongyuan Sun , Jiaqi Liu , Xuewen Gao , Kuizu Su , Rui Tang , Xinmin Zhan , Zhen-Hu Hu","doi":"10.1016/j.bej.2025.110064","DOIUrl":"10.1016/j.bej.2025.110064","url":null,"abstract":"<div><div>Dry anaerobic digestion (AD) is a promising technology for pig manure treatment, yet it is challenged by ammonia inhibition. Magnesium salt addition promotes the formation of magnesium ammonium phosphate (MAP), which <em>in-situ</em> captures ammonia nitrogen and mitigates inhibition, while high solids content limits MAP crystallization. This study evaluated the effect of magnesium salt pretreatment of wheat straw on dry AD of pig manure. Four Mg:P molar ratios (1.0:1.0, 1.5:1.0, 2.0:1.0, and 3.0:1.0) were investigated. Adding magnesium salt-pretreated wheat straw under molar ratios of 1.0:1.0 and 1.5:1.0 captured 14.3–14.4 % of ammonia nitrogen and reduced free ammonia by 19.0–19.1 %. Methane production increased by 15.0–19.2 % and substrate degradation by 8.4–8.6 %. Such pretreatment promoted MAP nucleation and growth on the straw surface, facilitating ammonia nitrogen capture. The capture of ammonia nitrogen restored the abundance of acetoclastic methanogens from 7.3 % to 12.5 %, thereby enhancing methane production. These results provide a practical strategy for mitigating ammonia inhibition in dry AD of pig manure.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"228 ","pages":"Article 110064"},"PeriodicalIF":3.7,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923128","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}
Pub Date : 2025-12-30DOI: 10.1016/j.bej.2025.110065
Fernanda de Oliveira , Caio de Azevedo Lima , Diana Cláudia Gouveia Alves Pinto , Laura Carmona Ferreira , Tais Maria Bauab , Silvio Silvério da Silva , Valéria Carvalho Santos-Ebinuma
The global rise of antimicrobial resistance highlights the urgent need for alternative bioactive compounds from sustainable sources. Fungal colorants, especially azaphilones, represent promising natural molecules due to their structural diversity, colorant properties, and biological activities. Talaromyces amestolkiae is a well-known source of Monascus-like azaphilone colorants free of mycotoxins, yet its antimicrobial potential and production dynamics remain underexplored. In this study, submerged cultivations were conducted to improve colorant production, isolate novel compounds, and assess antimicrobial activity. The effects of glucose concentration and hydrodynamic conditions, expressed through agitation, aeration, and the volumetric oxygen transfer coefficient (kLa), were investigated. The optimal condition (100 rpm, 1.0 vvm, 10 g·L⁻¹ of glucose) promoted balanced oxygen availability and carbon utilization, resulting in maximum colorant yield. Two novel purple-red azaphilone alkaloids, cis-amestolkin (1) and trans-amestolkin (2), were isolated and characterized by UV–Vis, LC-HRMS, and NMR spectroscopy. These compounds are geometric isomers of nitrogen-containing azaphilones featuring a γ-lactone ring and a unique 4-amino-6-hydroxyhexanoic acid moiety. Antimicrobial assays revealed that T. amestolkiae-derived metabolites exhibit pronounced inhibitory activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella setubal, highlighting their bioactive potential . This work integrates bioprocess improvement with metabolite identification and biological evaluation, underscoring the value of fungal colorants as multifunctional, sustainable agents for industrial and pharmaceutical applications.
{"title":"Purple-red azaphilone alkaloids from Talaromyces amestolkiae showing antimicrobial activity","authors":"Fernanda de Oliveira , Caio de Azevedo Lima , Diana Cláudia Gouveia Alves Pinto , Laura Carmona Ferreira , Tais Maria Bauab , Silvio Silvério da Silva , Valéria Carvalho Santos-Ebinuma","doi":"10.1016/j.bej.2025.110065","DOIUrl":"10.1016/j.bej.2025.110065","url":null,"abstract":"<div><div>The global rise of antimicrobial resistance highlights the urgent need for alternative bioactive compounds from sustainable sources. Fungal colorants, especially azaphilones, represent promising natural molecules due to their structural diversity, colorant properties, and biological activities. <em>Talaromyces amestolkiae</em> is a well-known source of Monascus-like azaphilone colorants free of mycotoxins, yet its antimicrobial potential and production dynamics remain underexplored. In this study, submerged cultivations were conducted to improve colorant production, isolate novel compounds, and assess antimicrobial activity. The effects of glucose concentration and hydrodynamic conditions, expressed through agitation, aeration, and the volumetric oxygen transfer coefficient (k<sub>L</sub>a), were investigated. The optimal condition (100 rpm, 1.0 vvm, 10 g·L⁻¹ of glucose) promoted balanced oxygen availability and carbon utilization, resulting in maximum colorant yield. Two novel purple-red azaphilone alkaloids, <em>cis</em>-amestolkin (1) and <em>trans</em>-amestolkin (2), were isolated and characterized by UV–Vis, LC-HRMS, and NMR spectroscopy. These compounds are geometric isomers of nitrogen-containing azaphilones featuring a γ-lactone ring and a unique 4-amino-6-hydroxyhexanoic acid moiety. Antimicrobial assays revealed that <em>T. amestolkiae-</em>derived metabolites exhibit pronounced inhibitory activity against <em>Pseudomonas aeruginosa</em>, <em>Staphylococcus aureus</em>, and <em>Salmonella setubal</em>, highlighting their bioactive potential . This work integrates bioprocess improvement with metabolite identification and biological evaluation, underscoring the value of fungal colorants as multifunctional, sustainable agents for industrial and pharmaceutical applications.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"228 ","pages":"Article 110065"},"PeriodicalIF":3.7,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923135","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}
Very-high-gravity (VHG) fermentation increases ethanol yield and decreases water use, but it imposes severe osmotic and ethanolic stress on Saccharomyces cerevisiae, which frequently limits overall productivity. In situ ethanol removal through CO2 gas stripping can mitigate this inhibition. However, the optimal timing for stripping onset under different temperature conditions remains not fully characterized. This study examined the effect of stripping initiation timing in VHG fed-batch fermentations at 28, 30, 32, and 34°C. A mechanistic fermentation model based on Monod-type kinetics with ethanol inhibition terms and coupled gas-liquid mass transfer was estimated using differential evolution. Distinct, temperature-specific ethanol concentration thresholds for stripping onset were identified, which maximized ethanol productivity (). Plateau analysis, based on identification of concentration regions where delayed initiation produced negligible changes in , refined these thresholds to within ±0.5 % of the maximum productivity. This resulted in CO2 gas savings equivalent to 1.05 ± 0.06 h per fermentation cycle. Model-based time-varying temperature control optimization predicted an increase in ethanol productivity to 12.32 g L⁻1 h⁻1. The findings provide a simulation and parameter estimation framework for temperature-integrated extractive control strategies to improve ethanol production in high-biomass VHG fermentations.
非常高重力（VHG）发酵提高了乙醇产量，减少了水的使用，但它对酿酒酵母施加了严重的渗透和乙醇压力，这往往限制了总体生产力。通过CO2气提原位去除乙醇可以减轻这种抑制作用。然而，在不同温度条件下，汽提开始的最佳时机尚未完全确定。本研究考察了在28、30、32和34℃条件下VHG补料分批发酵中剥离起始时间的影响。利用微分演化方法估计了一个基于monod型动力学、乙醇抑制项和气液耦合传质的机制发酵模型。确定了不同的温度特异性乙醇浓度阈值，以最大化乙醇生产率（PCE）。平台分析，基于识别延迟起始产生可忽略不计的PCE变化的浓度区域，将这些阈值细化到最大生产力的±0.5%以内。这导致二氧化碳气体节省相当于1.05±0.06小时每个发酵周期。基于模型的时变温度控制优化预测乙醇产量将增加到12.32 g L - 1 h - 1。研究结果为温度集成萃取控制策略提供了模拟和参数估计框架，以提高高生物量VHG发酵的乙醇产量。
{"title":"Model-based optimization of stripping onset in Saccharomyces cerevisiae very-high-gravity ethanol fermentations","authors":"I.I.K. Veloso , V.T. Mazziero , D.A. Lemos , A.J.G. Cruz , M.O. Cerri , A.C. Badino","doi":"10.1016/j.bej.2025.110057","DOIUrl":"10.1016/j.bej.2025.110057","url":null,"abstract":"<div><div>Very-high-gravity (VHG) fermentation increases ethanol yield and decreases water use, but it imposes severe osmotic and ethanolic stress on <em>Saccharomyces cerevisiae</em>, which frequently limits overall productivity. In situ ethanol removal through CO<sub>2</sub> gas stripping can mitigate this inhibition. However, the optimal timing for stripping onset under different temperature conditions remains not fully characterized. This study examined the effect of stripping initiation timing in VHG fed-batch fermentations at 28, 30, 32, and 34°C. A mechanistic fermentation model based on Monod-type kinetics with ethanol inhibition terms and coupled gas-liquid mass transfer was estimated using differential evolution. Distinct, temperature-specific ethanol concentration thresholds for stripping onset were identified, which maximized ethanol productivity (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>CE</mi></mrow></msub></math></span>). Plateau analysis, based on identification of concentration regions where delayed initiation produced negligible changes in <span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>CE</mi></mrow></msub></math></span>, refined these thresholds to within ±0.5 % of the maximum productivity. This resulted in CO<sub>2</sub> gas savings equivalent to 1.05 ± 0.06 h per fermentation cycle. Model-based time-varying temperature control optimization predicted an increase in ethanol productivity to 12.32 g L⁻<sup>1</sup> h⁻<sup>1</sup>. The findings provide a simulation and parameter estimation framework for temperature-integrated extractive control strategies to improve ethanol production in high-biomass VHG fermentations.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110057"},"PeriodicalIF":3.7,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880162","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}
Pub Date : 2025-12-22DOI: 10.1016/j.bej.2025.110054
Zhiwei Zhu , Yahui Li , Junyong He , Yulian Li , Peidong Hong , Chao Xie , Zijian Wu , Jiandong Lu , Dandan Yang , Lingtao Kong
This study developed an iron-carbon enhanced constructed wetland-microbial fuel cell (ICCW-MFC) to treat real rural greywater with high COD/TN ratios (13.1–16.0). The ICCW-MFC significantly improved pollutant removal, especially under extended hydraulic retention time (HRT), increasing removal efficiencies by 19.4 % (COD), 16.5 % (TN), 20.7 % (NH₄⁺-N), and 13.6 % (TP). The ICCW-MFC consistently produced higher quality effluent, with average reductions of 5.1 % (COD), 4.5 % (TN), 7.3 % (NH₄⁺-N), and 5.5 % (TP) compared to the control. Bioenergy recovery was substantially boosted, with a 2.8-fold higher current density and an 8-fold greater maximum power density compared to a conventional CW-MFC (lab control). Microbial diversity increased significantly (P < 0.001) at the anode, enriching electroactive genera (e.g., Geobacter) and forming a synergistic degradation network. PCA identified HRT as the dominant operational factor, while 3D-EEM confirmed effective degradation of tryptophan-like organics. The ICCW-M demonstrates promise for decentralized greywater treatment with concurrent energy recovery.
{"title":"Iron-carbon enhanced CW-MFC for treating high COD/TN rural greywater: Performance and microbial synergy in bioenergy recovery","authors":"Zhiwei Zhu , Yahui Li , Junyong He , Yulian Li , Peidong Hong , Chao Xie , Zijian Wu , Jiandong Lu , Dandan Yang , Lingtao Kong","doi":"10.1016/j.bej.2025.110054","DOIUrl":"10.1016/j.bej.2025.110054","url":null,"abstract":"<div><div>This study developed an iron-carbon enhanced constructed wetland-microbial fuel cell (ICCW-MFC) to treat real rural greywater with high COD/TN ratios (13.1–16.0). The ICCW-MFC significantly improved pollutant removal, especially under extended hydraulic retention time (HRT), increasing removal efficiencies by 19.4 % (COD), 16.5 % (TN), 20.7 % (NH₄⁺-N), and 13.6 % (TP). The ICCW-MFC consistently produced higher quality effluent, with average reductions of 5.1 % (COD), 4.5 % (TN), 7.3 % (NH₄⁺-N), and 5.5 % (TP) compared to the control. Bioenergy recovery was substantially boosted, with a 2.8-fold higher current density and an 8-fold greater maximum power density compared to a conventional CW-MFC (lab control). Microbial diversity increased significantly (P < 0.001) at the anode, enriching electroactive genera (e.g., <em>Geobacter</em>) and forming a synergistic degradation network. PCA identified HRT as the dominant operational factor, while 3D-EEM confirmed effective degradation of tryptophan-like organics. The ICCW-M demonstrates promise for decentralized greywater treatment with concurrent energy recovery.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110054"},"PeriodicalIF":3.7,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836648","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}
Pub Date : 2025-12-20DOI: 10.1016/j.bej.2025.110053
Irnia Nurika , Eka Nur Shabrina , Nurul Azizah , Sri Suhartini , Guy C. Barker , Timothy D.H. Bugg
This study assesses the facultative anaerobe Comamonas testosteroni as a mild, chemical-free pre-treatment for valorising oil palm empty fruit bunches (OPEFB) into biomethane and lignin-derived aromatics. Incubation with 2 % (v/v) C. testosteroni for 7 days at 30 °C, reduced lignin to 15.67 % (33.42 % removal), while retaining high cellulose (53.48–56.19 %) and hemicellulose (up to 16.21 %). Pre-treated OPEFB showed 20 % weight loss (vs 8 % in controls) and a 51 % rise in total soluble phenols, evidencing active lignin depolymerisation. GC–MS of liquor and solids qualitatively confirmed lignin breakdown and identified representative low-molecular-weight products (e.g., phenol, betulin, acetic acid and benzoxazole), supporting co-product potential. In biochemical methane potential tests, the pre-treated residue achieved a specific methane potential of 0.173 m³ CH4 kg⁻¹ VS, an 85 % increase over the abiotic residue and higher than non-treated OPEFB. Kinetic fitting with Transference, Modified Gompertz and Logistic models yielded good agreement (R2 up to 0.92), with Modified Gompertz best capturing cumulative methane production and the shortest lag phases. A simple energy check indicates a favourable margin: the incremental methane (ΔSMP ≈ 0.08 m³ CH₄ kg⁻¹ VS) equates ∼0.8 kWh kg⁻¹ VS, whereas estimated mixing for pre-treatment is ∼0.017–0.034 kWh kg⁻¹ VS. Overall C. testosteroni pre-treatment enables dual valorisation (biomethane plus aromatics) under mesophilic conditions, offering a practical route for integrated OPEFB biorefineries.
{"title":"Bioconversion kinetics and valorisation of oil palm empty fruit bunches for biomethane production and lignin derived compounds","authors":"Irnia Nurika , Eka Nur Shabrina , Nurul Azizah , Sri Suhartini , Guy C. Barker , Timothy D.H. Bugg","doi":"10.1016/j.bej.2025.110053","DOIUrl":"10.1016/j.bej.2025.110053","url":null,"abstract":"<div><div>This study assesses the facultative anaerobe <em>Comamonas testosteroni</em> as a mild, chemical-free pre-treatment for valorising oil palm empty fruit bunches (OPEFB) into biomethane and lignin-derived aromatics. Incubation with 2 % (v/v) <em>C. testosteroni</em> for 7 days at 30 °C, reduced lignin to 15.67 % (33.42 % removal), while retaining high cellulose (53.48–56.19 %) and hemicellulose (up to 16.21 %). Pre-treated OPEFB showed 20 % weight loss (vs 8 % in controls) and a 51 % rise in total soluble phenols, evidencing active lignin depolymerisation. GC–MS of liquor and solids qualitatively confirmed lignin breakdown and identified representative low-molecular-weight products (e.g., phenol, betulin, acetic acid and benzoxazole), supporting co-product potential. In biochemical methane potential tests, the pre-treated residue achieved a specific methane potential of 0.173 m³ CH<sub>4</sub> kg⁻¹ VS, an 85 % increase over the abiotic residue and higher than non-treated OPEFB. Kinetic fitting with Transference, Modified Gompertz and Logistic models yielded good agreement (R<sup>2</sup> up to 0.92), with Modified Gompertz best capturing cumulative methane production and the shortest lag phases. A simple energy check indicates a favourable margin: the incremental methane (ΔSMP ≈ 0.08 m³ CH₄ kg⁻¹ VS) equates ∼0.8 kWh kg⁻¹ VS, whereas estimated mixing for pre-treatment is ∼0.017–0.034 kWh kg⁻¹ VS. Overall <em>C. testosteroni</em> pre-treatment enables dual valorisation (biomethane plus aromatics) under mesophilic conditions, offering a practical route for integrated OPEFB biorefineries.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110053"},"PeriodicalIF":3.7,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836647","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}
Pub Date : 2025-12-16DOI: 10.1016/j.bej.2025.110052
Santhana Krishnan , Araya Thongsai , Pongsak (Lek) Noophan , Muhammad Ahmar Siddiqui , Yee-Shian Wong , Jaeho Bae , Sumate Chaiprapat
This study presents a novel hybrid membrane treatment train that integrates an anaerobic membrane bioreactor (AnMBR) with a fluidized bed membrane bioreactor enriched with partial nitritation and anammox (FMBRPN/A) for the treatment of industrial wastewater. The system was evaluated in terms of pollutant removal performance, microbial community structure, and energy efficiency, and benchmarked against a conventional full-scale aerobic/anoxic activated sludge system with an integrated constructed wetland (ASN/DN+Wetland). The AnMBR+FMBRPN/A achieved high removal efficiencies for COD (91.1 %) and total nitrogen (70.1 %), matching the performance of the conventional system while operating under low-carbon effluent conditions. Strategic aeration of FMBRPN/A enabled spatial separation of partial nitritation and anammox zones, promoting syntrophic coexistence of ammonium-oxidizing (AOB), nitrite-oxidizing (NOB), denitrifying (DN), and anammox (AMX) microbes in direct contact with the membrane surface, contrasted with microbial dynamics in traditional systems. The AnMBR+FMBRPN/A process had better energy performance, with 26.6 % reduction in electricity consumption (0.55 vs. 0.74 kWh/m3) and added benefits in biomethane recovery and reduced greenhouse gas emissions. These findings point to the potential of hybrid membrane bioreactors to transform industrial nitrogen management towards more efficient and sustainable solutions.
本研究提出了一种新型的混合膜处理系统，该系统将厌氧膜生物反应器（AnMBR）与富部分硝化和厌氧氨氧化的流化床膜生物反应器（FMBRPN/ a）集成在一起，用于工业废水的处理。该系统在污染物去除性能、微生物群落结构和能源效率方面进行了评估，并与传统的全规模好氧/缺氧活性污泥系统（ASN/DN+湿地）进行了基准测试。在低碳出水条件下，AnMBR+FMBRPN/A对COD（91.1 %）和总氮（70.1 %）的去除率达到了常规系统的水平。与传统系统的微生物动力学相比，FMBRPN/A的策略曝气使部分硝化和厌氧氨氧化区在空间上分离，促进氨氧化（AOB）、亚硝酸盐氧化（NOB）、反硝化（DN）和厌氧氨氧化（AMX）微生物与膜表面直接接触的共生共存。AnMBR+FMBRPN/A工艺具有更好的能源性能，可减少26.6% %的用电量（0.55 vs. 0.74 kWh/m3），并增加了生物甲烷回收和减少温室气体排放的效益。这些发现表明，混合膜生物反应器有潜力将工业氮管理转变为更有效和可持续的解决方案。
{"title":"Comparative evaluation of a hybrid membrane treatment train versus full-scale aerobic/anoxic activated sludge system: C-N removal performances, syntrophic microbial dynamics, and energy savings","authors":"Santhana Krishnan , Araya Thongsai , Pongsak (Lek) Noophan , Muhammad Ahmar Siddiqui , Yee-Shian Wong , Jaeho Bae , Sumate Chaiprapat","doi":"10.1016/j.bej.2025.110052","DOIUrl":"10.1016/j.bej.2025.110052","url":null,"abstract":"<div><div>This study presents a novel hybrid membrane treatment train that integrates an anaerobic membrane bioreactor (AnMBR) with a fluidized bed membrane bioreactor enriched with partial nitritation and anammox (FMBR<sup>PN/A</sup>) for the treatment of industrial wastewater. The system was evaluated in terms of pollutant removal performance, microbial community structure, and energy efficiency, and benchmarked against a conventional full-scale aerobic/anoxic activated sludge system with an integrated constructed wetland (AS<sup>N/DN</sup>+Wetland). The AnMBR+FMBR<sup>PN/A</sup> achieved high removal efficiencies for COD (91.1 %) and total nitrogen (70.1 %), matching the performance of the conventional system while operating under low-carbon effluent conditions. Strategic aeration of FMBR<sup>PN/A</sup> enabled spatial separation of partial nitritation and anammox zones, promoting syntrophic coexistence of ammonium-oxidizing (AOB), nitrite-oxidizing (NOB), denitrifying (DN), and anammox (AMX) microbes in direct contact with the membrane surface, contrasted with microbial dynamics in traditional systems. The AnMBR+FMBR<sup>PN/A</sup> process had better energy performance, with 26.6 % reduction in electricity consumption (0.55 vs. 0.74 kWh/m<sup>3</sup>) and added benefits in biomethane recovery and reduced greenhouse gas emissions. These findings point to the potential of hybrid membrane bioreactors to transform industrial nitrogen management towards more efficient and sustainable solutions.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110052"},"PeriodicalIF":3.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786983","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}
Pub Date : 2025-12-15DOI: 10.1016/j.bej.2025.110028
Ao Wang , Peng-fei Yu , Ding Wang , Hai-wen Sun , Bo-mei Hu , Xing-guan Ma , Shi-gang Tu
Lowering water content and pollutant concentration in sludge is key for sludge reduction and resource reuse. However, the waste liquid generated during this process is highly concentrated, imposing additional environmental burdens. To address this issue, an Algae-bacteria granular sludge (ABGS) system was constructed. This study compared and analyzed pollutant removal performance and microbial interactions within the ABGS when treating both sludge high-temperature fermentation Liquid (HFL) and mechanical dewatering filtrate (MDF). The results showed: The ABGS achieved high removal efficiencies for Total Organic Carbon (950 and 800 mg/L), Total Nitrogen (230 and 130 mg/L), and Phosphorus (65 and 3 mg/L) in both the HFL and the MDF, with rates reaching 93.35 %, 98.07 %, 96.35 % for HFL and 98.18 %, 86.12 %, 89.81 % for MDF, respectively. Both actual wastewater enhanced extracellular polymeric substances (295.56, 315.81 mg/g VSS), integrity coefficient, granular size, and MLVSS/MLSS ratio (than 0.75), improved granular strength of the ABGS.A high-concentration environment of carbon, nitrogen, and phosphorus may activate algal-bacterial cometabolic networks. Microalgae release dissolved oxygen via photosynthesis, enhancing the activity of nitrifying bacteria (Pararhodobacter). Functional complementarity occurs between polyphosphate accumulating organisms such as Paracoccaceae and denitrifiers like Thauera. Through quorum sensing, key metabolic genes (pst, pts, nir, nor) are regulated, establishing a coupled system integrating photosynthetic oxygen supply with simultaneous nitrogen and phosphorus removal.
{"title":"Effects of high-temperature fermentation liquid and mechanically dewatering liquid on algal-bacterial granular sludge: Granular characteristics, pollutant removal and algal-bacterial structure","authors":"Ao Wang , Peng-fei Yu , Ding Wang , Hai-wen Sun , Bo-mei Hu , Xing-guan Ma , Shi-gang Tu","doi":"10.1016/j.bej.2025.110028","DOIUrl":"10.1016/j.bej.2025.110028","url":null,"abstract":"<div><div>Lowering water content and pollutant concentration in sludge is key for sludge reduction and resource reuse. However, the waste liquid generated during this process is highly concentrated, imposing additional environmental burdens. To address this issue, an Algae-bacteria granular sludge (ABGS) system was constructed. This study compared and analyzed pollutant removal performance and microbial interactions within the ABGS when treating both sludge high-temperature fermentation Liquid (HFL) and mechanical dewatering filtrate (MDF). The results showed: The ABGS achieved high removal efficiencies for Total Organic Carbon (950 and 800 mg/L), Total Nitrogen (230 and 130 mg/L), and Phosphorus (65 and 3 mg/L) in both the HFL and the MDF, with rates reaching 93.35 %, 98.07 %, 96.35 % for HFL and 98.18 %, 86.12 %, 89.81 % for MDF, respectively. Both actual wastewater enhanced extracellular polymeric substances (295.56, 315.81 mg/g VSS), integrity coefficient, granular size, and MLVSS/MLSS ratio (than 0.75), improved granular strength of the ABGS.A high-concentration environment of carbon, nitrogen, and phosphorus may activate algal-bacterial cometabolic networks. Microalgae release dissolved oxygen via photosynthesis, enhancing the activity of nitrifying bacteria (<em>Pararhodobacter</em>). Functional complementarity occurs between polyphosphate accumulating organisms such as <em>Paracoccaceae</em> and denitrifiers like <em>Thauera</em>. Through quorum sensing, key metabolic genes (pst, pts, nir, nor) are regulated, establishing a coupled system integrating photosynthetic oxygen supply with simultaneous nitrogen and phosphorus removal.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110028"},"PeriodicalIF":3.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786989","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}
Pub Date : 2025-12-15DOI: 10.1016/j.bej.2025.110048
Zhigang Li , Nanxun Lu , Ruifang Li , Wei Liu , Chang Li , Zhonghua Zhang , Tianyou Yang
The insufficient supply of ATP limited cAMP synthesis during fermentations using Arthrobacter sp. CCTCC 2013431. cAMP fermentations with/without hexametaphosphate addition were conducted in a 7 L bioreactor and the underlying mechanism for enhanced cAMP biosynthesis under hexametaphosphate addition condition was investigated. Due to the addition of 2 g/L-broth sodium hexametaphosphate at 24 h, cAMP content reached 3.64 g/L, with an increment of 33.82 % when compared with control. The transcriptome analysis results revealed that 227 genes were up-regulated and 265 genes were down-regulated significantly in response to hexametaphosphate addition. For glycometabolism, the transcription levels of key enzymes genes involved with cAMP synthesis were enhanced significantly, and for energy metabolism, the transcription levels of genes associated with electron transport chain and polyphosphate kinase gene were increased significantly by which sufficient carbon skeleton and ATP were provided for cAMP biosynthesis. In addition, transcription levels of most reductase genes were up regulated significantly suggesting that intracellular antioxidant capacity was improved effectively by hexametaphosphate. Finally, activities of key enzymes together with intracellular contents of ROS, MDA and key metabolites were detected and the results were in accordance to those of transcriptome analysis. It could be concluded that hexametaphosphate relieved severe oxidative stress, strengthened energy metabolism and redistributed the carbon flux among different pathways resulting in enhanced cAMP synthesis and decreased byproduct generation.
{"title":"Insight into the enhanced cAMP synthesis using Arthrobacter sp. CCTCC 2013431 under polyphosphate addition condition based on physiological and transcriptome analyses","authors":"Zhigang Li , Nanxun Lu , Ruifang Li , Wei Liu , Chang Li , Zhonghua Zhang , Tianyou Yang","doi":"10.1016/j.bej.2025.110048","DOIUrl":"10.1016/j.bej.2025.110048","url":null,"abstract":"<div><div>The insufficient supply of ATP limited cAMP synthesis during fermentations using <em>Arthrobacter</em> sp. CCTCC 2013431. cAMP fermentations with/without hexametaphosphate addition were conducted in a 7 L bioreactor and the underlying mechanism for enhanced cAMP biosynthesis under hexametaphosphate addition condition was investigated. Due to the addition of 2 g/<span>L</span>-broth sodium hexametaphosphate at 24 h, cAMP content reached 3.64 g/L, with an increment of 33.82 % when compared with control. The transcriptome analysis results revealed that 227 genes were up-regulated and 265 genes were down-regulated significantly in response to hexametaphosphate addition. For glycometabolism, the transcription levels of key enzymes genes involved with cAMP synthesis were enhanced significantly, and for energy metabolism, the transcription levels of genes associated with electron transport chain and polyphosphate kinase gene were increased significantly by which sufficient carbon skeleton and ATP were provided for cAMP biosynthesis. In addition, transcription levels of most reductase genes were up regulated significantly suggesting that intracellular antioxidant capacity was improved effectively by hexametaphosphate. Finally, activities of key enzymes together with intracellular contents of ROS, MDA and key metabolites were detected and the results were in accordance to those of transcriptome analysis. It could be concluded that hexametaphosphate relieved severe oxidative stress, strengthened energy metabolism and redistributed the carbon flux among different pathways resulting in enhanced cAMP synthesis and decreased byproduct generation.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110048"},"PeriodicalIF":3.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786988","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}
Pub Date : 2025-12-15DOI: 10.1016/j.bej.2025.110051
Wentao Xu , Shasha Liu , Mei Sun , Shijie Sun , Jiao Wang , Zhiming Bian , Qingyun Zhang , Changsheng Peng
Sludge densification is a promising technology to enhance nutrient removal in existing municipal wastewater treatment plants (WWTPs). In this study, the graded-device hydrocyclone was installed into activated sludge system to assist sludge densification and disclose its microbial response mechanism. Higher nutrient removal (94.2 % for COD, 97.2 % for NH4+-N, 82.3 % for TN, 92.4 % for TP, respectively) were achieved in R2 reactor incorporating hydrocyclone, and these effluent indicators met the wastewater first class A discharge standards of China (GB18918–2002). The hydraulic shear forces of hydrocyclone promoted the sludge transformation from loose flocs to dense particles (average size of 292 μm), sludge settleability (relative hydrophobicity of 79.1 %, SVI30 of 60 mL/g), and the secretion of extracellular polymeric substances (EPS of 98.89 mg/g-SS, protein/polysaccharide ratio of 1.78). Ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria and polyphosphate-accumulating organisms were effectively enriched. These functional bacteria actively participated in membrane transport, signal transduction, carbon metabolism, nitrogen metabolism, phosphonate and phosphinate metabolism, providing the core driving force for long-term stable nutrient removal. These findings provided feasibility and mechanism support for hydrocyclone in enhancing nutrient removal, with a view to achieving cost reduction and efficiency benefits via sludge densification in industrial applications at full-scale WWTPs within the environmental field.
{"title":"Hydrocyclone-enhanced nutrient removal and sludge densification in activated sludge system: Insights into microbial response","authors":"Wentao Xu , Shasha Liu , Mei Sun , Shijie Sun , Jiao Wang , Zhiming Bian , Qingyun Zhang , Changsheng Peng","doi":"10.1016/j.bej.2025.110051","DOIUrl":"10.1016/j.bej.2025.110051","url":null,"abstract":"<div><div>Sludge densification is a promising technology to enhance nutrient removal in existing municipal wastewater treatment plants (WWTPs). In this study, the graded-device hydrocyclone was installed into activated sludge system to assist sludge densification and disclose its microbial response mechanism. Higher nutrient removal (94.2 % for COD, 97.2 % for NH<sub>4</sub><sup>+</sup>-N, 82.3 % for TN, 92.4 % for TP, respectively) were achieved in R2 reactor incorporating hydrocyclone, and these effluent indicators met the wastewater first class A discharge standards of China (GB18918–2002). The hydraulic shear forces of hydrocyclone promoted the sludge transformation from loose flocs to dense particles (average size of 292 μm), sludge settleability (relative hydrophobicity of 79.1 %, SVI<sub>30</sub> of 60 mL/g), and the secretion of extracellular polymeric substances (EPS of 98.89 mg/g-SS, protein/polysaccharide ratio of 1.78). Ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria and polyphosphate-accumulating organisms were effectively enriched. These functional bacteria actively participated in membrane transport, signal transduction, carbon metabolism, nitrogen metabolism, phosphonate and phosphinate metabolism, providing the core driving force for long-term stable nutrient removal. These findings provided feasibility and mechanism support for hydrocyclone in enhancing nutrient removal, with a view to achieving cost reduction and efficiency benefits via sludge densification in industrial applications at full-scale WWTPs within the environmental field.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110051"},"PeriodicalIF":3.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786991","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}
Pub Date : 2025-12-14DOI: 10.1016/j.bej.2025.110050
Chenyang Huang , Wanning Gao , Mengting Chang , Xing Zhang , Junhua Tao , Yamei Lin , Lei Lin
Metal-organic frameworks (MOFs) have been widely explored as carriers for enzyme immobilization. However, conventional embedding and adsorption methods often suffer from limitations such as weak binding or enzyme leaching. In this study, we presented an enhanced immobilization strategy leveraging the chelation between histidine residues and nickel ions on Ni-based MOF, and we further validated the mechanism of enzyme immobilization through a histidine alkylation substitution strategy. This approach ensured strong enzyme anchoring on the MOF surface while providing superior protection to the enzyme, especially for the fragile glycoenzymes. Molecular dynamics (MD) simulations confirmed that not only the enzyme attachment was a rapid process, but also the structural integrity and catalytic activity of PmHS2 were preserved upon immobilization. The corresponding Enzyme-MOF system demonstrated remarkable stability, retaining 80.65 % activity after 7 recycling cycles and 80.95 % activity after 40 days of storage. These results confirmed that histidine-Ni²⁺ coordination is a highly effective strategy for improving enzyme immobilization performance.
金属有机骨架作为固定化酶的载体已被广泛探索。然而，传统的包埋和吸附方法往往受到弱结合或酶浸等限制。在本研究中，我们提出了一种利用组氨酸残基与镍离子在ni基MOF上螯合的强化固定化策略，并通过组氨酸烷基化取代策略进一步验证了酶固定化机制。这种方法确保了酶在MOF表面的强锚定，同时为酶提供了优越的保护，特别是对脆弱的糖酶。分子动力学（MD）模拟证实了PmHS2不仅是一个快速的酶附着过程，而且在固定后保持了PmHS2的结构完整性和催化活性。相应的酶- mof体系表现出显著的稳定性，在7次循环后保持80.65 %的活性，在储存40天后保持80.95 %的活性。这些结果证实了组氨酸- ni 2 +配合是提高酶固定化性能的一种非常有效的策略。
{"title":"Leveraging histidine-nickel coordination for stable enzyme immobilization on metal-organic frameworks","authors":"Chenyang Huang , Wanning Gao , Mengting Chang , Xing Zhang , Junhua Tao , Yamei Lin , Lei Lin","doi":"10.1016/j.bej.2025.110050","DOIUrl":"10.1016/j.bej.2025.110050","url":null,"abstract":"<div><div>Metal-organic frameworks (MOFs) have been widely explored as carriers for enzyme immobilization. However, conventional embedding and adsorption methods often suffer from limitations such as weak binding or enzyme leaching. In this study, we presented an enhanced immobilization strategy leveraging the chelation between histidine residues and nickel ions on Ni-based MOF, and we further validated the mechanism of enzyme immobilization through a histidine alkylation substitution strategy. This approach ensured strong enzyme anchoring on the MOF surface while providing superior protection to the enzyme, especially for the fragile glycoenzymes. Molecular dynamics (MD) simulations confirmed that not only the enzyme attachment was a rapid process, but also the structural integrity and catalytic activity of PmHS2 were preserved upon immobilization. The corresponding Enzyme-MOF system demonstrated remarkable stability, retaining 80.65 % activity after 7 recycling cycles and 80.95 % activity after 40 days of storage. These results confirmed that histidine-Ni²⁺ coordination is a highly effective strategy for improving enzyme immobilization performance.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"227 ","pages":"Article 110050"},"PeriodicalIF":3.7,"publicationDate":"2025-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786990","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}
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