Applied Microbiology and Biotechnology最新文献

{"title":"Removal and analysis of foodborne-associated pathogens via peptide functionalized nanoparticles","authors":"Emily Hausen,&nbsp;Sebastian Knorr,&nbsp;Stefan Lyer,&nbsp;Christoph Alexiou,&nbsp;Rainer Tietze,&nbsp;Sonja Lick","doi":"10.1007/s00253-026-13922-x","DOIUrl":"10.1007/s00253-026-13922-x","url":null,"abstract":"<p>Foodborne illnesses still remain a major health issue, as the WHO reported 600 million diseases and 420,000 deaths worldwide in 2010. Most of them were caused by pathogens like <i>Campylobacter</i> spp., <i>Salmonella enterica</i>, <i>Escherichia coli</i>, and <i>Listeria monocytogenes</i>. Due to the short shelf life of fresh meat and dairy products, a rapid detection of pathogens in contaminated food products is essential. Since reference methods for microbial food analysis require time-consuming nonselective and selective culturing procedures, the need for more efficient approaches is given. In this study, we employ superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with the peptide KRQGRVEVLYRASWGTV derived from the salivary protein GP-340, to successfully remove different species of food-related microorganisms (<i>Pseudomonas paracarnis</i>, <i>Campylobacter jejuni</i>, <i>Escherichia coli</i>, <i>Enterococcus faecalis</i>, <i>Salmonella enterica</i>, and <i>Listeria monocytogenes</i>) from pure media and homogenates derived from retail meat products. We discovered differences in extraction efficiencies from pure culture ranging from 18% (<i>C. jejuni</i>) to complete extraction (<i>E. faecalis</i>, <i>L. monocytogenes</i> and <i>P. paracarnis</i>) depending on the organism. It was also shown that <i>L. monocytogenes</i> could successfully be removed from co-culture with a high surplus of non-pathogenic <i>P. paracarnis</i>, and also from food matrices.</p><p>• <i>SPION</i>^<i>Cit</i><i>can be functionalized with a GP-340 derived peptide (SPION</i>^<i>Pep</i><i>)</i></p><p>• <i>SPION</i>^<i>Pep</i><i> can immobilize and remove L. monocytogenes from pure and co-culture with high surplus of non-pathogenic P. paracarnis</i></p><p>• <i>Removal of L. monocytogenes is also possible in complex food matrices</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13922-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148395561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting thioredoxin reductase for anti-tuberculosis drug discovery: the inhibitor OSSL_632214","authors":"Qiyue Jia,&nbsp;Jinghua Shi,&nbsp;Yangxue Ye,&nbsp;Bin Wang,&nbsp;Yu Lu","doi":"10.1007/s00253-026-13949-0","DOIUrl":"10.1007/s00253-026-13949-0","url":null,"abstract":"<p>The persistent prevalence of multidrug-resistant tuberculosis (TB) and extensively drug-resistant TB has progressively undermined the efficacy of TB infection control measures. Thus, developing innovative drugs that act on novel <i>Mycobacterium tuberculosis</i> (Mtb) targets is a strategic priority for global TB control efforts. This research direction offers a robust, evidence-based solution to the urgent, growing challenge of anti-TB drug resistance. Thioredoxin reductase (TrxB2, Rv3913) is an essential enzyme for the in vitro growth and survival of Mtb. At present, no anti-TB lead compounds targeting TrxB2 have been advanced for clinical translation, primarily due to challenges such as off-target drug side effects and insufficient target specificity. We employed a virtual screening approach to screen compounds from small-molecule libraries. We conducted further experiments, including enzyme activity assays and studies using overexpression strains, to verify the therapeutic target and mechanism of action of the hit compound. Using virtual screening, we discovered compound OSSL_632214, which exhibited potent anti-Mtb activity (MIC 3.13–6.25 μg/mL) in vitro and showed no cross-resistance with existing anti-TB drugs. In this study, we report for the first time the potent in vitro anti-Mtb activity of OSSL_632214, which possibly acts by targeting TrxB2 and inducing lipid peroxidation in Mtb. These findings provide a theoretical basis for developing novel anti-TB drugs targeting TrxB2.</p><p>• <i>Development of anti-TB drugs based on the novel target TrxB2</i></p><p>• <i>OSSL_632214 exhibits anti-Mycobacterium tuberculosis activity</i></p><p>• <i>OSSL_632214 exhibits potential for the development of TrxB2-targeted drug</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13620018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148395564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Aspergillus neutral protease II in heat-induced soy sauce sediment formation","authors":"Takayuki Igarashi,&nbsp;Hideo Ikeuchi,&nbsp;Naho Shinohara,&nbsp;Yuichiro Hashiguchi,&nbsp;Yasuko Araki,&nbsp;Kotaro Ito","doi":"10.1007/s00253-026-13923-w","DOIUrl":"10.1007/s00253-026-13923-w","url":null,"abstract":"<p>Soy sauce is produced from fermented soybeans, wheat, and salt by koji molds (<i>Aspergillus oryzae</i> and <i>Aspergillus sojae</i>) together with salt-tolerant lactic acid bacteria and yeast. Pasteurization, an essential production step, causes protein insolubilization and produces heat-induced sediment that must be removed because it impairs product appearance. Although koji mold–derived proteins have been suggested to contribute to sediment formation, the underlying mechanisms remain unclear. In this study, we aimed to identify the key protein responsible for heat-induced sediment formation. Pasteurizing soy sauce in the presence of a metal chelator prevented sediment formation, and sediment reappeared upon reintroduction of divalent metal ions, indicating that heat-induced aggregation requires metal ion availability. This dependence is consistent with the involvement of neutral protease II (NpII, also known as DeuA or NptB), a thermostable zinc metalloprotease. Soy sauce brewed with <i>A. oryzae</i> and <i>A. sojae</i> strains deficient in NpII showed no sediment formation. Furthermore, in soy sauce brewed with the NpII-disruptant strains, the addition of a non-thermostable protease preparation after pasteurization restored sediment formation, demonstrating that partial proteolysis occurring only after heat treatment is crucial for sediment generation. Proteomic analysis revealed that &gt; 98% of the proteins in heat-induced sediment originated from koji molds and exhibited highly similar profiles across species and strains. To the best of our knowledge, this is the first study to demonstrate that improvement of koji mold strains can prevent detectable heat-induced sediment formation in soy sauce brewing, contributing to more sustainable manufacturing by eliminating the sediment removal process.</p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13923-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cysteine-S-conjugate β-lyase: a green catalyst for the production of flavor-active mercaptoketones","authors":"Yi-Chi Huang,&nbsp;Hao-Kai Li,&nbsp;Yu-Lun Lin,&nbsp;Hsi Ho,&nbsp;Tze-Chia Lin,&nbsp;Hong-Ting Victor Lin","doi":"10.1007/s00253-026-13927-6","DOIUrl":"10.1007/s00253-026-13927-6","url":null,"abstract":"<p>Sulfur-containing aroma compounds, which are key determinants of the sensory profile and consumer acceptance of many foods, have received limited research attention regarding the liberation of these thiol aromas via exogenous enzymes. In this study, we characterized and successfully overexpressed an active cysteine-<i>S</i>-conjugate β-lyase (MetC) from the marine bacterium <i>Shewanella putrefaciens</i>, and we also established its optimal catalytic conditions. Kinetic analysis demonstrated effective activity of the enzyme toward natural substrates and aroma mercaptoketone precursors. Size-exclusion chromatography indicated a tetrameric structure for MetC. For most substrates, the apparent catalytic efficiency (<span>({V}_{text{m}text{a}text{x}})</span>/<span>({K}_{text{m}})</span>)_app was calculated from the initial slopes of the velocity-concentration curves, which was used to evaluate catalytic efficiency due to solubility limits. Notably, only Cys-4MP-one reached saturation and conformed to sigmoidal model, indicating a unique cooperative behavior. These findings provide a quantitative basis for comparing the substrate specificity and catalytic effectiveness of MetC toward diverse precursors. The practical application of the enzyme was validated through preparative enzymatic conversion of cysteine-4-mercapto-4-methylpentan-2-one to 4-mercapto-4-methylpentan-2-one, with a 48.5% conversion achieved from its cysteine-conjugated precursor. Our findings demonstrate that <i>S. putrefaciens</i> MetC functions effectively as a biocatalyst for aroma thiol mercaptoketone production. Additionally, this research provides perspectives on the enzymatic production of sulfur-containing aroma compounds for applications in the fragrance and food industries.</p><p>• <i>Eco-friendly enzymatic bioconversion produced aroma mercaptoketone.</i></p><p>• <i>Cysteine-S-conjugate β-lyase from Shewanella putrefaciens exhibited sigmoidal kinetics toward Cys-4MP-one, while other substrates followed linear kinetics.</i></p><p>• <i>A conversion of 48.5% was achieved for 4MMP during the preparative-scale biotransformation.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13927-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perfusion development and its potential for cell therapy manufacturing with adherent cells","authors":"Samuel Lukas Schneider,&nbsp;Vivian Ott,&nbsp;Regine Eibl","doi":"10.1007/s00253-026-13939-2","DOIUrl":"10.1007/s00253-026-13939-2","url":null,"abstract":"<p>Perfusion processing has established itself as a powerful intensification strategy for biopharmaceutical production processes of recombinant proteins. However, in the relatively young field of cell therapeutics manufacturing, this tool has been overlooked so far and with rising approvals, this field is in dire need of scalable and efficient production processes. In this regard, perfusion operation mode and related cell retention devices can be used to support upstream and downstream processing by automating operations, reducing contamination risk and ensuring stable cell quality. In this review, the history of cell retention technologies developed for suspension cell processing is laid out alongside the perfusion-based process intensification strategies they made possible. It is summarized how these technologies could be used to intensify the upstream processing of therapeutic adherent cells and to what degree perfusion processing of these demanding cells is already described in literature. Additionally, the applicability of cell retention devices for harvesting and downstream processing of therapeutic cells, which mainly consists of cell washing and formulation steps, is elaborated. In conclusion, through the implementation of scalable, single-use, good manufacturing practices compliant cultivation systems and cell retention devices, it should be possible substantially to accelerate the development of therapeutic adherent cell manufacturing strategies.</p><p>• <i>Perfusion can automate medium exchanges in therapeutic adherent cell manufacturing</i></p><p>• <i> Perfusion technologies from suspension cell processing can be translated to adherent cell manufacturing</i></p><p>• <i>Scalable single-use perfusion systems are needed for the production of cell therapies</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13454009/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148374337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial degradation of aromatic ester pollutants in agro-ecosystems: implications for bioremediation","authors":"Prashant S. Phale,&nbsp;Sandesh E. Papade,&nbsp;Venkatesh M. Ghodke,&nbsp;Braja Kishor Saha,&nbsp;Tushar Dhamale","doi":"10.1007/s00253-026-13916-9","DOIUrl":"10.1007/s00253-026-13916-9","url":null,"abstract":"<p>Agricultural fields are increasingly contaminated with aromatic ester compounds originating from insecticides, herbicides, plastic mulching films, adjuvants and stabilizers used in agrochemicals. Many of these esters are persistent and bioaccumulate in the food chain, posing serious risks to non-target biota, including crops and humans. Among various remediation strategies available, bioremediation represents a cost-effective, sustainable, and eco-friendly approach for the clean-up of these contaminants. This review describes types of aromatic ester (aromatic-acid and aromatic-alcohol esters) pollutants and their bacterial degradation. The recent advances in understanding genetic, metabolic, evolutionary aspects of bacteria and synthetic biology approaches that aid in degradation of these xenobiotics are discussed. Additionally, it provides insights into the assistive eco-physiological traits of aromatic ester-degrading bacteria, which collectively enhance in situ degradation and offer promising avenues for sustainable agricultural practices and restoration of contaminated agro-ecosystems.</p><p>• <i>Aromatic esters are persistent, bioaccumulative and toxic to diverse biota</i></p><p>• <i>Biodegradation is an efficient strategy for mitigation of aromatic ester–contaminated sites</i></p><p>• <i>Integrating eco-physiological traits with synthetic biology enhances remediation</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13594046/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148366673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing reproducibility in mixing time determination of stirred tank reactors via automated analysis and standardized inter-laboratory trials","authors":"Isabelle Barth,&nbsp;Jürgen Fitschen,&nbsp;Christian Sieblist,&nbsp;Ute Husemann,&nbsp;Dominic Kues,&nbsp;Christoph Neubrand,&nbsp;Christoph Bouvier,&nbsp;Cedric Schirmer,&nbsp;Bernd Tscheschke,&nbsp;Igor Vassilev,&nbsp;Percy Kampeis","doi":"10.1007/s00253-026-13941-8","DOIUrl":"10.1007/s00253-026-13941-8","url":null,"abstract":"<p>Determining the mixing time in a mixing apparatus enables the evaluation of mixing quality and, therefore, represents a valuable tool for characterizing unit operations in process engineering. Mixing is highly relevant in both upstream processes (e.g., bioreactors) and downstream processes (e.g., blending tanks in diafiltration) in biotechnology and pharmaceutics. The aim of combining a colorimetric method with video capture and automated image analysis is to provide a robust, standardized methodology for determining mixing times in transparent bioreactors, such as laboratory-scale glass bioreactors and single-use bioreactors. A Python-based tool for video analysis was developed for this purpose. The Python script provides different mixing indices that enable the evaluation of both global and local mixing times under varying stirring speeds and aeration rates. This approach offers deep insights into the mixing process and enables the identification of heterogeneities. A round-robin study involving members of the DECHEMA Working Group “Single-Use Technologies for Bio-Based Applications” is currently being conducted to enhance the analysis and ensure reproducibility across different laboratories, thereby providing a robust basis for validating computational-fluid dynamics simulations. Initial reproducibility issues were identified and addressed in the standard operating procedure, demonstrating that a framework for automated analysis and improved standardization has been established.</p><p>• <i>Mixing-time experiments conducted at different aeration rates and stirring speeds</i></p><p>• <i>Automated video analysis for determining mixing times on both global and local scales</i></p><p>• <i>Identification of heterogeneities through visualization of local mixing times</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13941-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148359172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibiting biofilm growth on ammonium salt-functionalized or fluorinated voice prostheses silicone","authors":"Sławomir Okła,&nbsp;Szczepan Kaliniak,&nbsp;Jakub Spałek,&nbsp;Katarzyna Piotrowska,&nbsp;Dawid Łysik,&nbsp;Piotr Deptuła,&nbsp;Konrad Żochowski,&nbsp;Michał Dutkiewicz,&nbsp;Joanna Mystkowska,&nbsp;Urszula Wnorowska,&nbsp;Robert Bucki,&nbsp;Bonita Durnaś,&nbsp;Monika Madej,&nbsp;Hieronim Maciejewski,&nbsp;Stanisław Góźdź","doi":"10.1007/s00253-026-13904-z","DOIUrl":"10.1007/s00253-026-13904-z","url":null,"abstract":"<div><p>Voice prostheses (VPs) are largely limited by their relatively short functional lifespans, mainly due to colonization by heterogeneous fungal-bacterial biofilms. This biofilm-mediated degradation is a major contributor to VP failure and is associated with clinically significant complications such as impaired phonation, leakage through the tracheoesophageal fistula, and an increased risk of pneumonia. We performed a series of in vitro experiments to assess the antimicrobial and physicochemical properties of VPs constructed from quaternary ammonium salt–functionalized or fluorinated silicone. Biofilm development on each prosthesis was quantified by measuring crystal violet–stained biomass, and surface coverage was visualized using scanning electron microscopy. Furthermore, biofilm morphology and material adhesion characteristics were examined by atomic force microscopy. To evaluate cytocompatibility, fibroblasts were exposed to extracts obtained after 24 h incubation of each material in culture medium. This was followed by analysis of cell area, circularity index, haemolytic activity and cytokine secretion. Mechanical testing was performed to determine the physiochemical performance of the tested silicone materials. Crystal violet staining demonstrated substantial biofilm accumulation on VPs retrieved from patients after three months of use. In contrast, the modified silicone materials exhibited markedly reduced biofilm coverage. All tested materials supported normal fibroblast proliferation and showed minimal hemolytic activity, although they differed in their capacity to induce cytokine expression. Incorporation of ammonium salt-functionalised or fluorinated silicone in VP design may substantially reduce surface biofilm formation. Thereby, improving device longevity and decreasing the risk of use-related complications.</p>\u0000<div><div><div><table><tbody><tr><td><p><b>Key points</b></p><p>• <i>Fluorinated and quaternary ammonium salt–modified silicones exhibit significant biofilm resistance.</i></p><p>• <i>The modified materials demonstrate established biocompatibility with human cells.</i></p><p>• <i>These findings suggest the potential for developing new, extended-lifespan voice prostheses.</i></p></td></tr></tbody></table></div></div></div></div>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13904-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148359142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative production of recombinant capripoxvirus in Vero cells using microcarrier- and macrocarrier-based dynamic cell culture systems under serum-free conditions","authors":"Zhanat Amanova,&nbsp;Zhanna Sametova,&nbsp;Olga Chervyakova,&nbsp;Sholpan Turyskeldy,&nbsp;Alina Kurmasheva,&nbsp;Ruslan Abitayev,&nbsp;Abdurakhman Ussembay,&nbsp;Zhanat Kondibayeva,&nbsp;Dariya Toktyrova,&nbsp;Dana Mazbayeva,&nbsp;Kuandyk Zhugunissov,&nbsp;Yerbol Bulatov","doi":"10.1007/s00253-026-13934-7","DOIUrl":"10.1007/s00253-026-13934-7","url":null,"abstract":"<p>Brucellosis remains one of the most significant zoonotic diseases worldwide, and the absence of licensed human vaccines highlights the need for novel vaccine platforms and reproducible laboratory-scale manufacturing strategies. In the present study, the replication efficiency of a recombinant capripoxvirus expressing a Brucella antigen was evaluated in Vero cells cultured under serum-free conditions using two 3D carrier-based cultivation systems. Vero cells were cultivated in serum-free medium either on Cytodex 1 microcarriers in a 500-mL reusable spinner flask operated in repeated-batch mode or on BioNOC II® macrocarriers in single-use 500-mL BelloCell™ 500AP vessels integrated into the BelloStage™-3000 system and operated according to the Tide Motion principle with medium recirculation. Cells were infected with recombinant <i>SPPV(TKΔ)-OMP16</i> at a multiplicity of infection of 0.1, and total cell yield, metabolic parameters, and virus production were subsequently monitored throughout cultivation. The microcarrier and macrocarrier systems achieved maximum total cell yields of 7.0 × 10⁸ and 3.1 × 10⁹ cells, respectively. Peak virus titers reached 5.75 log₁₀ TCID₅₀/mL at 120 h post-infection in the microcarrier system and 7.25 log₁₀ TCID₅₀/mL at 168 h post-infection in the macrocarrier system, corresponding to a 1.5 log₁₀ increase in virus titer (<i>p</i> &lt; 0.01). After normalization to the working culture volume, the macrocarrier system exhibited 4.4-fold higher volumetric cell productivity. In addition, virus productivity normalized to the total number of cells present at the time of infection was approximately sevenfold higher than that observed in the microcarrier system.</p><p>These findings demonstrate that the macrocarrier-based dynamic cultivation system enables superior total cell yield and enhanced recombinant virus production under serum-free laboratory-scale conditions.</p><p>• <i>BioNOC II® macrocarriers increased volumetric cell productivity by 4.4-fold compared with Cytodex 1.</i></p><p>• <i>BioNOC II® macrocarriers increased peak virus titers by 1.5 log₁₀ TCID₅₀/mL.</i></p><p>• <i>Cell-specific viral productivity was approximately sevenfold higher in the macrocarrier-based bioreactor system.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13934-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148343810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ammonium and nitrate fluxes drive metabolic functional shifts in tap water biofilms","authors":"Binessi Edouard Ifon,&nbsp;Wei Zhang,&nbsp;Zhongbo Zhou,&nbsp;Okugbe Ebiotubo Ohore,&nbsp;Yeyuan Xiao","doi":"10.1007/s00253-026-13905-y","DOIUrl":"10.1007/s00253-026-13905-y","url":null,"abstract":"<p>Nitrogen availability critically influences biofilm development in drinking water distribution systems (DWDSs), yet the distinct impacts of ammonium (NH₄⁺) and nitrate (NO₃⁻) on biofilm and pathogen risks remain unclear. Using bench-scale annular reactors simulating DWDSs, we investigated how ammonium depletion/supplementation (AD/AS) and nitrate depletion/supplementation (ND/NS) regulate biofilm profiles over 28 days. Water chemistry analyses and functional annotation (KEGG, FAPROTAX) revealed that AS and NS increased total nitrogen retention (AS: 2.046–2.261 mg/L; NS: 10.625–11.800 mg/L) and biofilm prokaryotic cell abundance. AS enriched biosynthesis and virulence pathways (e.g., amino acid transport, energy production), while AD activated stress-response mechanisms (e.g., DNA repair, carbohydrate metabolism). NS favored Gram-negative bacteria, stress-tolerant taxa, and pathogenic genera (e.g., <i>Acinetobacter</i>, <i>Mycobacterium</i>), whereas ND upregulated organic nitrogen scavenging. Nitrogen supplementation preferentially enriched genera including WHO-listed critical-risk pathogens, which correlated strongly with inorganic nitrogen levels (Mantel r &gt; 0.5, <i>P</i> &lt; <i>0.05</i>). In contrast, genera including high/medium-risk pathogens exhibited increased relative abundance under depletion via organic nutrient reliance. These findings demonstrate that NH₄⁺ and NO₃⁻ differentially regulate biofilm pathogenicity: NH₄⁺ drives growth and virulence, while NO₃⁻ enhances structural resilience and redox flexibility. The study advocates targeted nitrogen management in DWDS to monitor and mitigate biofilm-associated health risks and for optimizing microbial stability.</p><p>• <i>Nitrogen species (NH₄⁺ and NO₃⁻) enrichment and availability elevated biofilm cell density and altered functional groups and metabolic processes, revealing strong coupling between nutrient availability and microbial proliferation in DWDSs.</i></p><p>• <i>Ammonium enrichment drove virulence- and metabolism-related functions, whereas nitrate promoted oxidative resilience and biofilm matrix stability.</i></p><p>• <i>Nitrogen limitation activated stress-adaptive and organic nitrogen scavenging pathways, reshaping community composition toward stress-tolerant, opportunistic taxa.</i></p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":"110 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2026-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00253-026-13905-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148350404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}