Biodegradation最新文献

{"title":"Green treatments for polyaromatic hydrocarbons in e-wastes","authors":"Bandita Dutta,&nbsp;Debarati Chatterjee,&nbsp;Arina Guha,&nbsp;Rina Rani Ray","doi":"10.1007/s10532-025-10140-6","DOIUrl":"10.1007/s10532-025-10140-6","url":null,"abstract":"<div><p>Rapid elevation of global population along with increased urbanization and industrialization afflict the water resources leading to the blooming of wastewater. Two or more aromatic rings fused with organic compound Polycyclic Aromatic Hydrocarbons (PAHs) emerged worldwide through anthropogenic processes, mainly due to the incomplete combustion of organic fuels. In accordance with the United States Environmental Protection Agency (USEPA), there are 16 PAHs that are deemed as primary pollutants. These are toxic to the living organisms due to their pervasive existence, rebelliousness, potential for bioaccumulation and carcinogenic venture. Several methods including fixation, incineration and oxidation are put forward to remove PAHs. Occasionally some fictional toxic products are produced by the incomplete removal of PAHs. Bioremediation is one of the ecological techniques to remove the PAHs. Microbial biodegradation is considered as an effective and inexpensive technique to remove PAHs along with other hydrocarbons and xenobiotic compounds and are accomplished by few PAHs degrading bacteria including <i>Haemophilus</i> spp., <i>Mycobacterium</i> spp., <i>Paenibacillus</i> spp., <i>Pseudomonas aeruginosa</i>, <i>P. fluorescens</i>, <i>Rhodococcus</i> spp. along with few biosurfactant-producing microbes. The novel biochemical events involved in hydrocarbon catabolism are microbial physical adaptation, their acquisition and uptake. The bioremediation efficacy can be further ameliorated through genetic modification of the microbes. This chapter will focus on the eco-friendly treatment for the PAHs remediation in in situ and ex situ. This chapter will explore the remediation of the PAH by-products through the multi-process conjunctional treatment processes under the green therapy.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of enhancement of chlorophenol bioremediation using synergistic effects between zero-valent iron and microorganisms","authors":"Hao Liu,&nbsp;Deli Wu,&nbsp;Weishi Wang","doi":"10.1007/s10532-025-10133-5","DOIUrl":"10.1007/s10532-025-10133-5","url":null,"abstract":"<div><p>Chlorophenols (CPs) are a class of synthetic organic chemicals that are widely distributed in soil and groundwater, posing significant risks to human health and the environment due to persistence, acute toxicity, and potential carcinogenicity. Zero-valent iron (ZVI) has emerged as a promising remediation technique for CPs, but its efficacy is often hindered by surface passivation, non-target competition, and limited mobility in the subsurface. While CPs are inherently biodegradable, their high toxicity and the lack of functional enzymes in indigenous microbial systems restrict the effectiveness of bioremediation. Recently, a hybrid system integrating ZVI with microbial degradation draws increasingly research interests, paving out a new path for sustainable degradation of CPs. These systems leverage the synergistic interactions between ZVI and microorganisms to enhance CP biodegradation. This review provides a comprehensive analysis of the advancement. Key topics include the enhancement of electron transfer, alterations to microbial communities, mitigation of toxicity, and the interplay between other processes. Operation modes, ZVI dosage, and interactions with naturally occurring iron minerals, are also discussed in the context of applications in soil and groundwater remediation. Despite research efforts and successful implementations, critical knowledge gaps remain, particularly in regard to the characterization of microbial processes in natural systems, highlighting the need for future research.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enzymatic degradation of PET by hydrolase from Brucella intermedia IITR130 and its genomic insights","authors":"Pallavi Srivastava,&nbsp;Saurabh Singh,&nbsp;Mohini Soni,&nbsp;J. Venkatesh Pratap,&nbsp;Srikrishna Subramanian,&nbsp;Natesan Manickam","doi":"10.1007/s10532-025-10141-5","DOIUrl":"10.1007/s10532-025-10141-5","url":null,"abstract":"<div><p>Plastic pollution, particularly from polyethylene terephthalate (PET), has become a significant environmental concern, necessitating innovative and sustainable degradation strategies. The present study provides valuable perspectives on the genomic and functional characteristics of <i>Brucella intermedia</i> IITR130, a bacterium capable of degrading PET. Hybrid genome sequencing of IITR130 resulted in identification of two chromosomes combining 4.59 Mbp size. Genomic annotation revealed occurrence of key enzymes involved in the PET sheet biodegradation pathway, including hydrolases, ring hydroxylating dioxygenases, protocatechuate 3,4 dioxygenases, genes for metabolism of several other natural and synthetic plastic. A hydrolase gene Hy1 of 24 kDa, was identified, expressed, and characterized, demonstrating an optimal catalytic activity at 37 °C and pH 8.5. Scanning electron microscopy (SEM) and fourier-transform infrared spectroscopy (FTIR) confirmed substantial degradation of PET surfaces treated with Hy1 protein, resulted in surface erosion, crack formation, and functional group modifications in the range 2150–2550 cm⁻¹ and 2950–3350 cm⁻¹ suggestive of O=C=O stretching and O–H stretching respectively. Monomethyl terephthalate (MMT) and terephthalic acid (TPA) were identified as PET degradation metabolites formed by strain IITR130. Fluorescence quenching showed higher substrate affinity for bis(2-hydroxyethyl) terephthalate (BHET) (K_d = 148.2) than terephthalic acid (TPA) (K_d = 674). Moreover, phylogenetic analysis of Hy1 protein revealed that Hy1 containing conserved catalytic triad (Ser¹⁰⁸, His¹⁸⁸, Asp¹⁵⁵) belonging to the family III of hydrolase enzyme sharing a clade with PET degrading hydrolase PETase from <i>Ideonella sakaiensis.</i> These results demonstrate the potential of <i>B. intermedia</i> IITR130 as an efficient biocatalyst for PET biodegradation which could be exploited appropriately for plastic waste management.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biodegradation assessment tests of biopolymers in standardised water: different sources of variability","authors":"David Gutiérrez-Rial,&nbsp;Iria Villar,&nbsp;Pilar Feijóo,&nbsp;Benedicto Soto,&nbsp;Josefina Garrido,&nbsp;Salustiano Mato","doi":"10.1007/s10532-025-10143-3","DOIUrl":"10.1007/s10532-025-10143-3","url":null,"abstract":"<div><p>This study assessed the ultimate biodegradation degree of two resins, polyhydroxybutyrate and polylactic acid (PHB and PLA), and three commercial biobased bags (BMAT, BGREEN, and BBEIGE) through the measurement of oxygen consumption in closed respirometers. Activated sludge from a wastewater treatment plant (WWTP) was used as the inoculum, cellulose was used as the reference material, and five trials were conducted with two different devices under identical conditions, with a 28-day incubation period. The results revealed statistically significant differences in the biochemical oxygen demand (BOD) measurements for cellulose, PHB, and PLA between the two devices and within the same devices across different trials. The degree of biodegradation (D_t), calculated as the percentage of theoretical oxygen demand (ThOD), varied depending on the device and trial. For cellulose, D_t ranged from 61 to 93%; for PLA, the maximum Dt was 6%; and for PHB, D_t oscillated between 16 and 72%. These findings highlight the critical importance of carefully selecting the testing equipment, as it significantly influences biodegradation results, in addition to the already known interlaboratory variability caused by the inoculum.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10532-025-10143-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic behaviour of petroleum based oily wastewater treatment in a hybrid moving bed biofilm reactor","authors":"P. Sanghamitra,&nbsp;Debabrata Mazumder,&nbsp;Somnath Mukherjee","doi":"10.1007/s10532-025-10142-4","DOIUrl":"10.1007/s10532-025-10142-4","url":null,"abstract":"<div><p>Performance of a laboratory scale moving bed hybrid bioreactor (<i>MBHBR</i>) was assessed in the present study under batch operation with varying concentration of oil and grease in wastewater sample in the range of 62–370 mg/L. Oily wastewater was fed in the MBHBR with polypropylene carriers in the temperature range of 18.5–25.7 °C and the pH range of 7.28–8.24. The study showed a maximum oil removal of 85.4% for an initial oil concentration of 275 mg/L under a contact time of 20 h. Monod’s kinetic theory has been applied to the results as obtained in the batch experimental study considering the contribution of both suspended and attached biomass. Various kinetic parameters were estimated as Maximum specific substrate utilisation rate, k = 0.32/d, Half saturation constant, Ks = 209 mg/L, Yield coefficient, Y = 0.728 mg/mg and Endogenous decay constant, k_d = 0.016/d. No major inhibition was observed during treatment of synthetic oily wastewater for the concentration range of 62–275 mg/L. The removal efficiency of oil was observed to be better in presence of attached biomass than suspended growth environment. The present study will be useful for the design of hybrid bio-reactors and for development of mathematical models under similar experimental condition.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achromobacter xylosoxidans and Stutzerimonas stutzeri from the phyllosphere of Eichhornia crassipes (water hyacinth) degrade chlorpyrifos as consortia","authors":"Sheeba Hoda,&nbsp;Kamal Krishan Aggarwal","doi":"10.1007/s10532-025-10139-z","DOIUrl":"10.1007/s10532-025-10139-z","url":null,"abstract":"<div><p>Organophosphates (OPs) constitute a significant proportion of pesticides currently used worldwide in agriculture. Widespread and repeated application of these insecticides contaminates the soil and water, posing significant non-target toxicity risks to other organisms within the ecosystem. Acute pesticide exposure causes toxicity to insects, plants, animals, and humans, and thus emphasizes the need for sustainable management. Bacterial degradation of pesticides has been considered as a preferred strategy. In the present study, the phyllosphere of water hyacinth (<i>Eichhornia crassipes</i>) was explored for the chlorpyrifos degrading bacteria using Culture-independent and culture-dependent methods. Culture-independent study revealed 44,514 operational taxonomic units (OTUs) that were classified into 16 phyla and 330 genera, with dominating genera such as <i>Acinetobacter, Paenibacillus, Pseudomonas, Sphingobacterium, and Achromobacter</i>. Culture-dependent method yielded <i>Achromobacter xylosoxidans and Stutzerimonas stutzeri</i> as chlorpyrifos tolerant and degraders. These isolated strains exhibited enhanced growth as a consortium with chlorpyrifos as the only carbon source. The consortia effectively degrade 98% of chlorpyrifos within seven days, indicating its potential for pesticide degradation. Proteomics analysis revealed upregulation of key enzymes implicated in chlorpyrifos degradation, such as phosphodiesterase, metallo-beta-lactamases and oxidoreductase. The down-regulation of stress-response proteins suggests an adaptive tolerance to the pesticide. This study justifies the potential of consortia of isolated strains in the degradation of chlorpyrifos and may be developed into a promising and eco-friendly approach for remediating chlorpyrifos-contaminated environments.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144073927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The performance of hybrid materials for the biodegradation of dichloromethane using Pseudomonas aeruginosa, coconut shell, rice husk, and metal organic framework","authors":"Anju Mangotra","doi":"10.1007/s10532-025-10137-1","DOIUrl":"10.1007/s10532-025-10137-1","url":null,"abstract":"<div><p>The industrial effluents containing volatile organic compounds manipulate the purity of the environment. Dichloromethane emerges as the toxic malodor that causes carcinogenicity, mutagenicity and teratogenicity. The aim of the present study was to find out the potency of hybrid materials for the removal of dichloromethane using raw rice husk, coconut shell, metal organic framework and <i>Pseudomonas aeruginosa</i>. The identification of bacteria was done by biochemical methods and 16SrRNA test. The characterization of adsorbents was done using sophisticated fourier transform infrared, field emission scanning electron microscopy and x-ray diffraction technique. The particle size of adsorbents was calculated using the Scherrer equation. The analysis of the final concentration of dichloromethane in hybrid materials was done by gas chromatography-flame ionization detector. The removal percentage obtained using Pse + RRH, Pse + CSAC, Pse + MOF (UiO-66(Zr), Pse + RRH + CSAC, Pse + RRH + CSAC + MOF (UiO-66)(Zr) was 96.87%, 99.80%, 97.63%, 97.35%, 98.08%, respectively with 50 mg/L of dichloromethane concentration. On the other hand, the removal percentage obtained using Pse + RRH, Pse + CSAC, Pse + MOF (UiO-66(Zr), Pse + RRH + CSAC, Pse + RRH + CSAC + MOF (UiO-66)(Zr) was 96.5%, 99.5,% 96.5%, 97.0%, 98.09, with 200 mg/L of dichloromethane concentration. The removal percentage obtained using alone <i>Pseudomonas aeruginosa</i> with 50 mg/L and 200 mg/L of dichloromethane was 93.78% and 92.33% respectively. The maximum removal percentage was achieved by a hybrid material using <i>Pseudomonas aeruginosa</i> and coconut shell.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pharmaceutical micropollutants removal and N2O production by nitrification process in SBR and SBBR: a review","authors":"J. Leiva-González,&nbsp;L. Hernández-Vélez,&nbsp;J. Quezada-Cáceres,&nbsp;J. Pagés-Diaz,&nbsp;C. Huiliñir","doi":"10.1007/s10532-025-10130-8","DOIUrl":"10.1007/s10532-025-10130-8","url":null,"abstract":"<div><p>Pharmaceutical micropollutants (PMPs) can cause significant environmental risks, with trace levels of exposure harming humans and wildlife. Biotransformation is a high-potential and low-cost way to remove PMPs, where ammonia-oxidizing microorganisms (AOM) are essential for eliminating pharmaceutical micropollutants. On the other hand, AOM are associated with nitrous oxide (N₂O) emission generation in nitrifying. In this sense, micropollutants can inhibit the activity of AOB, reducing the ammonia oxidation rate and increasing N₂O emissions. To mitigate these challenges, systems that allow satisfactory performance of the metabolism of AOB and NOB, such as the Sequencing Batch Reactor (SBR) and Sequencing Batch Biofilm Reactor (SBBR), are essential. However, no systematic review of the advances or gaps in this field has been published, mainly focused on SBR or SBBR. Thus, this work reviews recent advances regarding PMP biotransformation and N₂O production by AOM, emphasizing SBR and SBBR systems. Besides, we compare the removal performances of various micropollutants in biological processes. The biotransformation of emerging pollutants was also presented to explore the metabolic pathways of N₂O production and the critical factors that influence N₂O emissions in biological processes. Controlling DO levels, intermittent aeration, and maintaining low ammonium concentrations can help mitigate N₂O emissions. The simultaneous removal of PMPs and N₂O emissions was also analyzed; however, there is still limited research regarding the effect of PMPs on N₂O emission production in the nitrification process using SBR or SBBR. However, SBBRs may provide a more stable platform for both PMP removal and minimized emissions, mainly when biofilm characteristics and intermittent aeration are well managed. Thus, this review gives a complete vision of the advances of SBR and SBBR to remove PMPs and minimize the N₂O, as well as the future directions that research needs to address to improve the PMPs biotransformation and N₂O minimization.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal of high concentrations of zinc, cadmium, and nickel heavy metals by Bacillus and Comamonas through microbially induced carbonate precipitation","authors":"Adharsh Rajasekar,&nbsp;Cailin Zhao,&nbsp;Suowei Wu,&nbsp;Raphinos Tackmore Murava,&nbsp;Eyram Norgbey,&nbsp;Armstrong Ighodalo Omoregie,&nbsp;Charles K. S. Moy","doi":"10.1007/s10532-025-10131-7","DOIUrl":"10.1007/s10532-025-10131-7","url":null,"abstract":"<div><p>Heavy metal pollution in urban freshwater, driven by anthropogenic activities, poses significant risks to aquatic ecosystems and human health due to its toxicity and persistence. Recently, urease-producing bacteria have gained attention for their ability to remove heavy metals through microbial-induced carbonate precipitation (MICP). In this study, eight urease-producing bacteria were exposed to individual solutions of zinc (Zn²⁺), cadmium (Cd²⁺), and nickel (Ni²⁺) at concentrations ranging from 0 to 6 mM to assess their resistance. Three strains—<i>Bacillus subtilis</i> HMZC1 (B2), <i>Bacillus sp.</i> HMZCSW (B6), and <i>Comamonas sp.</i> HMZC (B11)—survived at 4 mM and 6 mM, while most others could not tolerate 4 mM. Their urea-degrading ability was tested at different pH levels, identifying an optimal pH of 7 for MICP. Heavy metal carbonate precipitation experiments at 4 mM and 6 mM revealed that all three strains achieved &gt; 93% removal of Zn²⁺, Ni²⁺, and Cd²⁺ within 72 h. <i>Comamonas sp.</i> HMZC exhibited the highest efficiency, achieving &gt; 95% removal of certain heavy metals at 6 mM. Statistical analysis using one-way ANOVA revealed significant differences (p &lt; 0.05) in heavy metal removal efficiencies among the strains for certain treatment conditions (Cd²⁺ and Zn²⁺ at 4 mM), although not all comparisons reached statistical significance. Scanning Electron Microscopy and X-ray Diffraction confirmed the morphology and composition of the precipitated heavy metal carbonates. Our findings demonstrate that urease-producing bacteria can effectively immobilize multiple heavy metals, highlighting the MICP process as a practical and sustainable biological approach for ecological restoration and wastewater treatment.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10532-025-10131-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological and transcriptomic response of enriched anammox culture upon elevated hydrazine exposure","authors":"Tugba Sari,&nbsp;Kozet Yapsakli,&nbsp;Deniz Akgul,&nbsp;Bulent Mertoglu","doi":"10.1007/s10532-025-10132-6","DOIUrl":"10.1007/s10532-025-10132-6","url":null,"abstract":"<div><p>Anammox has emerged as a cost-effective and eco-friendly biological treatment technology for high-strength wastewater, and hydrazine (N₂H₄) is a unique intermediate in the anammox metabolism. This study presents the first investigation into the genetic responses of anammox bacteria to elevated N₂H₄ concentrations, offering critical insights into their potential for sustainable environmental applications. In this scope, anammox cultures were exposed to high levels of N₂H₄ (up to 3 g/L) over a short-term period to evaluate their nitrogen treatment capacity and transcriptional responses. The results indicated that anammox activity continued at N₂H₄ concentrations of 1.88 g/L or less. However, acute N₂H₄ exposure significantly downregulated key genes, such as acetyl-CoA synthase beta and delta subunits, hydrazine synthase, hydrazine dehydrogenase, and hydroxylamine oxidoreductase, except for AAA family ATPase. Overall, high exogenous N₂H₄ concentrations severely constrained the metabolism and survival of anammox bacteria at a molecular level. Understanding the genetic responses of anammox bacteria to elevated N₂H₄ concentrations is crucial for optimizing their application in further anammox-based technologies. Future studies should focus on improving the resilience of anammox bacteria to high N₂H₄ concentrations, thereby broadening their applicability in engineered wastewater treatment and biotechnological processes while maintaining system stability and efficiency.</p></div>","PeriodicalId":486,"journal":{"name":"Biodegradation","volume":"36 3","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10532-025-10132-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}