International Biodeterioration & Biodegradation最新文献

{"title":"Synergistic ultrasound and zero-valent iron pretreatment for enhanced waste activated sludge anaerobic fermentation: Mechanism elucidation, process optimization, and benefit analysis","authors":"Yingte Li ,&nbsp;Dingxun Ma ,&nbsp;Minggang Liu ,&nbsp;Yizhou Tu ,&nbsp;Hongbin Chen ,&nbsp;Xianchun Tang","doi":"10.1016/j.ibiod.2025.106242","DOIUrl":"10.1016/j.ibiod.2025.106242","url":null,"abstract":"<div><div>This study employed synergistic ultrasound and zero-valent iron (ZVI) pretreatment to enhance waste activated sludge (WAS) anaerobic fermentation. Using response surface methodology (RSM) to systematically optimize the ultrasonic power, ultrasound time, and ZVI dosage, aiming to determine the optimal synergistic pretreatment conditions for enhancing subsequent anaerobic fermentation. The results indicated that pretreatment reduced the particle size of WAS, increased fractal dimension and zeta potential absolute value, and resulted in a higher specific surface area, promoting electrostatic repulsion, system stability, and microbial growth. Alpha diversity increased (as reflected by the Chao index), and functional microbiota involved in hydrolysis and acidification, such as Actinomycetota and Bacteroidota, were further enriched. Further confirmation through three-dimensional excitation-emission matrix (3D-EEM) spectroscopy and molecular weight distribution analysis of dissolved organic matter revealed that the synergistic pretreatment significantly enhanced sludge hydrolysis efficiency and released substantial biodegradable components, with a higher biological index (BIX) and lower humification index (HIX). Specific analysis demonstrated that a maximum soluble chemical oxygen demand (SCOD) concentration of 1632.99 mg/L in the pretreated supernatant was achieved at an ultrasonic power of 1.86 W/mL, an ultrasound time of 14.10 min, and a ZVI dosage of 0.38 g/L. Furthermore, the maximum volatile fatty acids (VFAs) production (1722.65 mg COD/L) during the fermentation period was attained at an ultrasonic power of 1.78 W/mL, an ultrasound time of 14.48 min, and a ZVI dosage of 0.38 g/L. Benefit analysis suggests that this optimized process demonstrates promising application potential, offering an efficient and cost-effective strategy for sludge resource recovery.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"207 ","pages":"Article 106242"},"PeriodicalIF":4.1,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental occurrence, ecological risks, and microbial interactions of p-chloro-m-xylenol: An emerging ubiquitous antimicrobial agent","authors":"Hanqing Pan ,&nbsp;Jia Shi ,&nbsp;Dan Xu ,&nbsp;Jingwei Wang ,&nbsp;Qiao Ma","doi":"10.1016/j.ibiod.2025.106229","DOIUrl":"10.1016/j.ibiod.2025.106229","url":null,"abstract":"<div><div><em>p</em>-Chloro-<em>m</em>-xylenol (PCMX), a halogenated phenolic antimicrobial agent, has gained global prominence in disinfectants and personal care products. This review synthesizes current knowledge on PCMX's environmental occurrence, ecological impacts, and microbial transformation mechanisms. Environmental monitoring reveals pervasive contamination (ng/L to mg/L) across wastewater systems and surface waters, with seasonal and regional variability linked to consumption patterns and treatment inefficiencies. Ecotoxicological assessments demonstrate acute toxicity to aquatic organisms and chronic effects, such as developmental abnormalities, endocrine disruption, and neurobehavioral impairments. Emerging evidence highlights PCMX's role in promoting antibiotic resistance gene dissemination via enhanced horizontal gene transfer. Critically, microbial degradation studies identify <em>Rhodococcus</em> species as key degraders, employing pathways involving dechlorination to 2,6-dimethylhydroquinone or hydroxylation to 4-chloro-3,5-dimethylcatechol. Mechanistic insights reveal a flavin-dependent monooxygenase (CxyA) catalyzing initial transformation, though genetic regulation and roles of associated enzymes (e.g., CYP450) require further elucidation. This review establishes PCMX as a nonnegligible emerging contaminant, emphasizing the need for coordinated monitoring strategies, refined ecological risk assessment frameworks, and innovative bioremediation approaches to mitigate its environmental impacts.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"207 ","pages":"Article 106229"},"PeriodicalIF":4.1,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Waste-to-resource: Enhanced production of cellulases and lichenase from lignocellulosic biomass via mutated Bacillus subtilis","authors":"Junaid Ahmad Raza,&nbsp;Aqsa Aslam,&nbsp;Sibtain Ahmed,&nbsp;Hina Andaleeb,&nbsp;Sheikh Muhammad Yahya Waseem","doi":"10.1016/j.ibiod.2025.106227","DOIUrl":"10.1016/j.ibiod.2025.106227","url":null,"abstract":"<div><div>Microbial enzymes such as cellulases and lichenase hold great importance in industrial and biotechnological sectors. This study demonstrates the successful enhancement of cellulase and lichenase production in <em>Bacillus subtilis</em> through strain improvement and process optimization. By using ethyl methanesulfonate (EMS) for bacterial mutagenesis followed by comprehensive screening, a mutant strain was obtained that exhibited superior enzymatic performance compared to the wild-type strain. Subsequent optimization studies utilizing low-cost lignocellulosic substrates revealed wheat straw and barley flour as the most effective agricultural wastes for cellulase and Lichenase production under ideal fermentation conditions (pH 7.0, 35 °C, 72 h incubation). For both enzymes, optimal production was reached when cultivated with sucrose and tryptone as the primary carbon and nitrogen source. Detailed kinetic characterization of the enzymes produced by the mutant strain showed that there is an increase in enzyme substrate binding affinity as well as rate of catalysis in endoglucanase, exoglucanase, β-glucosidase, and lichenase. The mutant enzymes exhibited remarkable thermostability and pH stability, retaining nearly 80 % of their initial activity over a 4-h period. These findings provide both fundamental insights into the enhancement of enzymes through chemical mutagenesis and practical solutions for industrial enzyme production. The demonstrated approach combines strain improvement with sustainable utilization, offering a viable pathway to reduce production cost and maintain high yields. This work particularly highlights the potential of agricultural residues in biotechnological applications and establishes a framework for future strain development efforts targeting hydrolytic enzyme production.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"207 ","pages":"Article 106227"},"PeriodicalIF":4.1,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Triclosan-induced shifts in aryl sulfatase activity: Implications in aquatic sediments","authors":"Priya Varghese ,&nbsp;Kundan Kumar ,&nbsp;Saurav Kumar ,&nbsp;S.P. Shukla ,&nbsp;Sutanu Karmakar ,&nbsp;Pritam Sarkar ,&nbsp;Puja Rani Basak","doi":"10.1016/j.ibiod.2025.106247","DOIUrl":"10.1016/j.ibiod.2025.106247","url":null,"abstract":"<div><div>The effects of triclosan (TCS), a widely distributed broad-spectrum antimicrobial agent, on aryl sulfatase (ARS) activity in aquatic sediments were systematically investigated. Sediment samples from Versova Creek, Mumbai, were exposed to TCS concentrations of 0, 3, and 6 mg/kg over 28 days in a microcosm set-up. ARS activity increased in a concentration-dependent manner, rising by 37 % at 3 mg/kg and 20 % at 6 mg/kg on the final day (51.66 ± 1.36 and 45.18 ± 0.15 PNP g/hr, respectively) relative to the initial control value (37.65 ± 0.64 PNP g/hr). This activity was positively correlated with sulfur availability, demonstrating enhanced sulfur cycling under TCS exposure. Metagenomic analysis identified <em>Pseudomonas, Corynebacterium, and Aeromonas</em> species as dominant ARS producers, with microbial diversity impacted by TCS concentration. At lower concentrations, TCS stimulated ARS-producing bacteria, which may have implications for bioremediation, while higher concentrations inhibited heterotrophic bacterial growth. The findings highlighted the role of TCS in altering sediment microbial dynamics and biogeochemistry, indicating its potential impact on sediment nutrient cycles and microbial functions essential for ecosystem stability. These alterations underscore the importance of further research into pollutant-driven shifts in microbial and nutrient cycling, which could contribute towards the development of sustainable environmental management strategies, including effective bioremediation approaches.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"207 ","pages":"Article 106247"},"PeriodicalIF":4.1,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of microbial biofilms against chloramphenicol stress by AHL-driven quorum sensing","authors":"Jia Zhou ,&nbsp;Weilong Xu ,&nbsp;Zhanbo Xu ,&nbsp;Sihan Liu ,&nbsp;Yifan Liu ,&nbsp;Leizhen Zhao ,&nbsp;Shuai Zhao ,&nbsp;Jianhang Qu ,&nbsp;Bingjie Ni","doi":"10.1016/j.ibiod.2025.106241","DOIUrl":"10.1016/j.ibiod.2025.106241","url":null,"abstract":"<div><div>Quorum sensing (QS) is a promising strategy to positively regulate the physiochemical properties of microbiota and consequently enhance the performance of biofilm reactor, however, its role in strengthening microbial biofilms against chloramphenicol (CAP) stress has not yet been fully elucidated. In this study, an N-acyl homoserine lactones (AHLs)-mediated QS signaling molecule, N-hexanoyl-L-homoserine lactone (C6-HSL), was supplemented into a biological contact oxidation reactor (BCOR) to evaluate its effect on reactor performance and microbial community under CAP shock conditions. When the influent CAP concentration increased from 20 to 50 mg/L, the addition of 0.1 μM C6-HSL enhanced the CAP removal efficiency from 84 % to 94 % in the BCOR. Meanwhile, the C6-HSL supplementation markedly stimulated the secretion of extracellular polymeric substances (EPS), particularly leading to a twofold increase in polysaccharide (PS) content, which played a vital role in maintaining biofilm stability and improving tolerance to CAP stress. Metagenomic analysis further revealed that C6-HSL supplementation enriched <em>Sphingopyxis</em>, <em>Hydrogenophaga, Sphingobium,</em> the major CAP-degrading genera harboring the <em>capO</em> gene edcoding CAP oxidoreductase, and upregulated QS-related functional genes involved in microbial communication. These findings demonstrate that QS regulation can effectively reinforce pollutant removal under antibiotic stress, offering a potential strategy for engineering robust microbial consortia in antibiotic-contaminated wastewater treatment systems.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"207 ","pages":"Article 106241"},"PeriodicalIF":4.1,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of the decay degree of Pinus sylvestris L. sapwood by fungi on the feeding of termites Reticulitermes flavipes (Kollar, 1837) in compulsion test","authors":"Adam Krajewski,&nbsp;Michał Drożdżek,&nbsp;Piotr Witomski","doi":"10.1016/j.ibiod.2025.106169","DOIUrl":"10.1016/j.ibiod.2025.106169","url":null,"abstract":"<div><div>The rot of <em>Pinus sylvestris</em> L. sapwood caused by <em>Coniophora puteana</em> (Schumach.) P. Karst. and <em>Trametes versicolor</em> (L.) Lloyd was conducted at various times. The content of holocellulose, cellulose and lignin in control blocks and decayed blocks was determined. Subsequently control blocks after brown rot and white rot were exposed for four weeks to feeding on termites <em>Reticulitermes flavipes</em> (Kollar, 1837) (Isoptera: Rhinotermitidae) in cocompulsion tests according to ASTM D 3345-08 (2017) procedure. Weight mass losses of wood caused by fungi were calculated, termite eating and jointly for both degradation factors in all experimental variants. The visual method of assessing the grade of wood damage recommended in ASTM D 3345-08 (2017) turned out to be unreliable. The correlation between the losses of wood after decomposition by fungi and the losses of holocellulose, cellulose and lignin as well as the coefficient of determination was calculated. Termites destroyed wood more quickly and to a greater extent if it was partially decayed by fungus than wood without any rot. The degradation of wood by termites increases with the decomposition state of wood by fungi and the loss of holocellulose and especially hemicellulose.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"206 ","pages":"Article 106169"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144919954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacillus subtilis and Halomonas meridiana isolated from saline sandy soils mediate the biodegradation of polyvinyl chloride (PVC) microplastics","authors":"Ayesha Alam ,&nbsp;Shafeeq Rahman ,&nbsp;Labeeb Ali ,&nbsp;Mohammednoor Altarawneh","doi":"10.1016/j.ibiod.2025.106220","DOIUrl":"10.1016/j.ibiod.2025.106220","url":null,"abstract":"<div><div>Microplastics are notorious class of environmental pollutants that are added to the environment by the slow degradation of plastic infrastructure commonly used everywhere. Microplastics are small particles that tend to flow through the xylem vessels of plant roots and bioaccumulate in the plant tissues. Saline sandy soil in the United Arab Emirates (UAE) is colonized by beneficial bacterial strains that exhibit plastic degradation properties. This area is of great interest for new insights; however, very little is known about microplastic-degrading microorganisms, particularly in the Middle Eastern region of the world. To fill this gap, bacterial strains isolated from hypersaline soil offer a promising and sustainable approach to mitigate microplastic pollution in the form of granular biofertilizer and liquid cell suspension in soil and soilless crop production systems. The following study entails the relative potential of <em>Bacillus subtilis</em> and <em>Halomonas meridiana,</em> identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS), to mineralize plastics by forming biofilms. The study indicated the plastic biodegradation efficiency of the bacterial strains ranged from as low as 6.42 ± 5.73 % and as high as 16.95 ± 3.37 % in liquid and solid culture media, with an average of 10 % loss of polymer weight. The bacterial strains exhibited a strong ability of biofilms (optical density ≥0.3–0.5) and enzymatic activity (enzymatic units ≥0.006–0.01), confirmed by optical density spectrophotometric absorbances. Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM-EDS) and Fourier Transform Infrared Spectroscopy (FTIR-S) revealed the formation of minerals, oxidation, increased O/C ratios, and significant variation in the surface anatomy of plastic particles co-cultured with bacteria. The complete absence of the C-Cl peak as a result of FTIR and the highest O/C of (0.600) as a result of SEM-EDS suggested the high degradation efficiency of <em>B. subtilis</em> as compared to <em>H. meridiana.</em> These outcomes confirm the incidence of plastic degradation efficiency and biofilm formation ability of <em>B. subtilis</em> and <em>H. meridiana</em> in both the solid and liquid matrix, signifying their dual application as granular biofertilizer as well as cell suspension to minimize the traces of plastic particles in the agricultural production systems purifying the tropic level of the food chain.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"206 ","pages":"Article 106220"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal carbonization of sewage sludge: Effects of hydrothermal temperature and time on biochar properties and migration and transformation of heavy metals","authors":"Siyao Hou,&nbsp;Han Wang,&nbsp;Jiameng Sun,&nbsp;Jing Liu,&nbsp;Manxu Bai,&nbsp;Wanli Zhang,&nbsp;Wanli Xing,&nbsp;Rundong Li","doi":"10.1016/j.ibiod.2025.106216","DOIUrl":"10.1016/j.ibiod.2025.106216","url":null,"abstract":"<div><div>This study investigated effects of hydrothermal temperature and time on hydrothermal carbonization (HTC) of sewage sludge (SS) in terms of biochar properties, migration and transformation of heavy metals (HMs). The surface functional groups of biochar were greatly affected by hydrothermal temperature and the stretching vibration peak intensities of hydroxyl, carboxyl and aliphatic compound declined with the increased temperature. HMs concentrations in hydrothermal liquid were sorted in the order: Mn &gt; Zn &gt; Cr &gt; Ni &gt; Pb &gt; Cu and those in biochar were Mn &gt; Zn &gt; Cu &gt; Cr &gt; Pb &gt; Ni. HMs concentrations in biochar were much higher than those in hydrothermal liquid, indicating the significant enrichment of HMs in biochar. The enhanced hydrothermal temperature further actuated HMs enrichment in biochar to higher concentrations, but prolonging reaction time only led to slight fluctuations. The bioavailability of HMs in biochar was sorted in the order: Mn &gt; Zn &gt; Ni &gt; Cu &gt; Pb and Cr. More HMs in biochar existed in residual and oxidizable fractions of low bioavailability, indicating HTC treatment reduced the ecological risk of HMs. The hydrothermal temperature was the key factor affecting migration and transformation of HMs. Driven by high hydrothermal temperature, Zn, Ni and Mn elements in biochar transformed from water soluble, acid soluble and reducible fractions to oxidizable or residual fraction. The bioavailability of Cu element in biochar first enhanced then declined with the increasing hydrothermal temperature, but Pb and Cr elements were not sensitive to reaction condition change.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"206 ","pages":"Article 106216"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized deep eutectic solvent cocktail assisted sequential pretreatment to enhance enzymatic hydrolysis of Arachis hypogaea L biomass","authors":"Vidhyadevi Udayakumar,&nbsp;Brinda Lakshmi Anguraj","doi":"10.1016/j.ibiod.2025.106207","DOIUrl":"10.1016/j.ibiod.2025.106207","url":null,"abstract":"<div><div>Roadblock in lignocellulose degradation via enzymatic hydrolysis is critical concern to be addressed to improve the biofuel circular economy. Sequential pretreatments followed by enzymatic hydrolysis leverages high sugar yields from lignocellulose biomass (LCB) through lignin removal and enhanced enzyme adsorption, outperforming single pretreatment methods. However, the biofuel sector continues the search for alternative greenness pretreatment techniques that combine versatile, cost effective, and environmental sustainability. This study introduces an innovative, eco-friendly synergistic pretreatment method utilising a deep eutectic solvent (DES) mixture of choline chloride, tannic acid, and glucose (ChCl: TA: Glu), together with optimized microwave irradiation (MWI) and ultrasonication, to enhance enzyme hydrolysis of groundnut shell (GNS) into fermentable sugars. Meanwhile, crucial parameters influencing ternary DES treatment - pH 6.2, temperature 65 °C, time 4.2 h and biomass loading 12 % - were predicted by Response Surface Methodology (RSM) to enhance LCB hydrolysis before microwave and ultrasonic processing. MWI power and ultrasonic frequency were optimized via the One Variable At a Time (OVAT) approach, finding 300W and 50Hz as optimal for sequential treatment to minimize energy consumption and complexity. Under optimized configurations, this sequential DES-based treatment accomplished significant delignification and hemicellulose removal, resulting in the liberation of 92.89 % cellulose and improved enzymatic saccharification. RSM optimization shown substantial enhancements in sugar release, with cellulose and glucose yield escalating by 5.7 times and 17.22 times (248 mg), respectively from 1 % pretreated sample and yielded bioethanol 12.4g/100g of raw biomass. Structural transformations in GNS were validated by FTIR,XRD, SEM, TEM, DLS, EDAZ, and TGA studies.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"206 ","pages":"Article 106207"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145099522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sessile culture as a strategy to enhance the production of emulsifying exopolysaccharides by Glutamicibacter sp. XHA18","authors":"Luis Herrera-Candelario ,&nbsp;Susana De la Rosa-García ,&nbsp;Eugenia Zarza ,&nbsp;Karina Guillen-Navarro ,&nbsp;Mayra A. Alvarez-Lemus ,&nbsp;Sergio Gómez-Cornelio","doi":"10.1016/j.ibiod.2025.106213","DOIUrl":"10.1016/j.ibiod.2025.106213","url":null,"abstract":"<div><div>Pristine environments harbor diverse microbial communities with unique and underexplored metabolic capabilities, including the production of exopolysaccharides (EPS) with bioemulsifying properties. These polymers have increasing biotechnological relevance in food, pharmaceutical, and environmental sectors. This study evaluated the effect of two contrasting growth modes—sessile and planktonic—on the production and stability of an emulsifying EPS synthesized by the halotolerant strain <em>Glutamicibacter</em> sp. XHA18, isolated from a pristine cenote in the Yucatan Peninsula, Mexico. Emulsifying activity and 24-h stability were assessed using the emulsification index (EI₂₄), while physicochemical parameters such as carbon and nitrogen sources, pH, agitation, and salinity were optimized in both culture systems. EPS extraction and purification protocols were designed to recovery both high- and low-molecular-weight fractions. The purified EPS was characterized by FTIR, UV–Vis spectroscopy, SEM-EDS, and zeta potential analysis. Sessile cultivation promoted earlier and higher emulsifying activity (EI₂₄ = 62.09 % at 24 h), whereas planktonic culture required 96 h to reach comparable levels (EI₂₄ = 60.09 %). In both systems, dextrose and alkaline pH significantly enhanced EPS production, whereas high salinity impaired its emulsifying performance. EPS yield was higher under sessile conditions (2.8 g/L) than in planktonic culture (1.8 g/L). FTIR and zeta potential analysis confirmed the polysaccharidic nature and negative surface charge of the EPS, supporting its ability to form stable emulsions with various hydrophobic substrates, even under salinity levels of 5–10 %. Toxicity assays with <em>Artemia salina</em> and <em>Cucumis sativus</em> confirmed the low toxicity of the EPS, with only minor effects at elevated concentration. Genomic analysis revealed that strain XHA18 belongs to the genus <em>Glutamicibacter</em> but differs in G + C content and metabolic features from known species, suggesting it may represent a novel taxon. Overall, this study provides new insights into the biosynthesis and functional stability of bioemulsifying EPS under sessile conditions and highlights <em>Glutamicibacter</em> sp. XHA18 as a promising biotechnological resource for industrial and environmental applications.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"206 ","pages":"Article 106213"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}