Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2024.105986
Meng-Wen Peng , Ya-Song Chen , You-Peng Chen , Wan Sun , Meng-Meng Liu , Xun Weng , Shuai Wang , Yu Shen , Hui-Min Fu
The three-dimensional (3D) structure of Anaerobic ammonium oxidation (Anammox) granular sludge (AnGS) is vital for substrate transfer and metabolite excretion, yet its intricacies are not fully understood due to a lack of in situ non-destructive characterization methods. This study employs synchrotron-based X-ray micro-computed tomography to visualize the 3D structure of AnGS at different growth stages. We observed that porosity and pore size increased with granule depth, while larger granules displayed reduced porosity (decreased from 85.3% to 63.1%) and more concentrated pore structures. Medium-sized granules (4.2–5.0 mm) exhibited the highest abundance of Anammox bacteria. Our findings revealed significant correlations among pore structure, specific anammox activity, and microbial community, particularly with Candidatus Jettenia and Norank_f_SJA-28. This study offers a comprehensive understanding of the 3D structure and growth characteristics of AnGS, providing theoretical support for substrate mass transfer and enhancing nitrogen removal efficiency within these systems.
{"title":"Nondestructive three-dimensional structure and growth characteristics of anammox granular sludge","authors":"Meng-Wen Peng , Ya-Song Chen , You-Peng Chen , Wan Sun , Meng-Meng Liu , Xun Weng , Shuai Wang , Yu Shen , Hui-Min Fu","doi":"10.1016/j.ibiod.2024.105986","DOIUrl":"10.1016/j.ibiod.2024.105986","url":null,"abstract":"<div><div>The three-dimensional (3D) structure of Anaerobic ammonium oxidation (Anammox) granular sludge (AnGS) is vital for substrate transfer and metabolite excretion, yet its intricacies are not fully understood due to a lack of in situ non-destructive characterization methods. This study employs synchrotron-based X-ray micro-computed tomography to visualize the 3D structure of AnGS at different growth stages. We observed that porosity and pore size increased with granule depth, while larger granules displayed reduced porosity (decreased from 85.3% to 63.1%) and more concentrated pore structures. Medium-sized granules (4.2–5.0 mm) exhibited the highest abundance of Anammox bacteria. Our findings revealed significant correlations among pore structure, specific anammox activity, and microbial community, particularly with <em>Candidatus Jettenia</em> and <em>Norank_f_SJA-28</em>. This study offers a comprehensive understanding of the 3D structure and growth characteristics of AnGS, providing theoretical support for substrate mass transfer and enhancing nitrogen removal efficiency within these systems.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 105986"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164686","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}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2024.105989
Jiankun Wang , Jin Li , Jin Wu , Yangyang Tang , Zheng Zhang , Yumeng Fu , Xiaoling Wang
In recent years, more and more researchers have revealed the relationship between biofilm growth and the environment from a mechanical perspective, providing us with new insights. In this article, we develop multi-scale agent-based biofilm growth models and simulate biofilm growth dynamics from different size scales and aim to reveal the relationship between biofilm, environment, and internal stress. In the mesoscopic model, the bacterial clusters are treated as particles. The predicted biased growth of biofilm under low nutrient concentration is consistent with the experimental measurement results. Sudden alterations in the nutritional environment can lead to drastic changes in biofilm morphology. In the microscopic model, big particles represent individual cells and small particles represent extracellular polymeric substances (EPSs), which is used to simulate complicated interactions among EPSs and cells in the colloidal biofilm system. Results indicate that the emergence of branching structures can help to reduce internal stress concentration in colonies and have a positive effect on colony expansion. The simulation results of this article not only can deepen our understanding of the interaction between biofilms and environments but also make us learn interactions among different components inside the biofilm.
{"title":"Mechanical modeling of biofilm morphology variation induced by changes in environments and internal stress","authors":"Jiankun Wang , Jin Li , Jin Wu , Yangyang Tang , Zheng Zhang , Yumeng Fu , Xiaoling Wang","doi":"10.1016/j.ibiod.2024.105989","DOIUrl":"10.1016/j.ibiod.2024.105989","url":null,"abstract":"<div><div>In recent years, more and more researchers have revealed the relationship between biofilm growth and the environment from a mechanical perspective, providing us with new insights. In this article, we develop multi-scale agent-based biofilm growth models and simulate biofilm growth dynamics from different size scales and aim to reveal the relationship between biofilm, environment, and internal stress. In the mesoscopic model, the bacterial clusters are treated as particles. The predicted biased growth of biofilm under low nutrient concentration is consistent with the experimental measurement results. Sudden alterations in the nutritional environment can lead to drastic changes in biofilm morphology. In the microscopic model, big particles represent individual cells and small particles represent extracellular polymeric substances (EPSs), which is used to simulate complicated interactions among EPSs and cells in the colloidal biofilm system. Results indicate that the emergence of branching structures can help to reduce internal stress concentration in colonies and have a positive effect on colony expansion. The simulation results of this article not only can deepen our understanding of the interaction between biofilms and environments but also make us learn interactions among different components inside the biofilm.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 105989"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164688","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}
Antibiotics significantly impact the anaerobic fermentation of waste activated sludge (WAS). However, only a few studies have been conducted on the influence of ofloxacin (OFL) on the production of short-chain fatty acids (SCFAs) and its underlying mechanisms during WAS anaerobic fermentation. This study aimed to elucidate the impact of OFL on SCFA production from alkaline-pretreated WAS fermentation. The results showed that the addition of 10 mg OFL/kg SS led to a peak concentration of 2931.85 mg COD/L, resulting in a 1.1-fold increase in SCFA production compared to the control group. Further exploration revealed that OFL simultaneously promoted WAS solubilization, hydrolysis and acidification. Additionally, a low concentration of OFL increased the abundance of hydrolytic acidifying bacteria but decreased the abundance of SCFA-consuming bacteria. Metagenomic analysis revealed an enhanced abundance (103.76–134.56%) of critical genes related to extracellular hydrolysis (i.e., malZ, bglX, and degP), membrane transport (i.e., msmX, gtsA, and gltI), substrate metabolism (i.e., glk, glnA, and gdhA), and SCFAs biosynthesis (i.e., ackA and fabG) in the presence of low OFL concentration. These findings broadened our understanding regarding the influence exerted by OFL on WAS anaerobic fermentation.
{"title":"Metagenomic analysis elucidates the dose-dependent impact of ofloxacin on sludge anaerobic fermentation for short-chain fatty acid production","authors":"Jinghua Lv, Shujia Zhang, Siqi He, Tianyu Shi, Yuge Liang, Yunbei Li, Kaili Ma","doi":"10.1016/j.ibiod.2025.106013","DOIUrl":"10.1016/j.ibiod.2025.106013","url":null,"abstract":"<div><div>Antibiotics significantly impact the anaerobic fermentation of waste activated sludge (WAS). However, only a few studies have been conducted on the influence of ofloxacin (OFL) on the production of short-chain fatty acids (SCFAs) and its underlying mechanisms during WAS anaerobic fermentation. This study aimed to elucidate the impact of OFL on SCFA production from alkaline-pretreated WAS fermentation. The results showed that the addition of 10 mg OFL/kg SS led to a peak concentration of 2931.85 mg COD/L, resulting in a 1.1-fold increase in SCFA production compared to the control group. Further exploration revealed that OFL simultaneously promoted WAS solubilization, hydrolysis and acidification. Additionally, a low concentration of OFL increased the abundance of hydrolytic acidifying bacteria but decreased the abundance of SCFA-consuming bacteria. Metagenomic analysis revealed an enhanced abundance (103.76–134.56%) of critical genes related to extracellular hydrolysis (i.e., <em>malZ</em>, <em>bglX</em>, and <em>degP</em>), membrane transport (i.e., <em>msmX</em>, <em>gtsA</em>, and <em>gltI</em>), substrate metabolism (i.e., <em>glk</em>, <em>glnA</em>, and <em>gdhA</em>), and SCFAs biosynthesis (i.e., <em>ackA</em> and <em>fabG</em>) in the presence of low OFL concentration. These findings broadened our understanding regarding the influence exerted by OFL on WAS anaerobic fermentation.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 106013"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165386","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}
To date, the focus of microbially induced corrosion (MIC) studies has largely been on marine environments. In this study, biocorrosion of steel enrichment cultures from a freshwater corrosion site was investigated under sulfate reducing conditions. Biomass and metabolic processes were monitored by measuring the time-dependent biophysicochemical parameters and with Fe0 (steel) as the sole electron source, or with H2 as control. Although yields and sulfate reduction rates were higher with H2 due to its greater bioavailability, the yield coefficients indicated that bacterial growth with Fe0 was equally efficient. Upon imaging of the steel surface by SEM, patches of cells embedded in an iron sulfide matrix on top of larger carbonate and phosphate minerals were observed. Cell number determination indicated that the cells on the steel surface constituted only a minor proportion (<4%) of the total counts. The 16S rRNA gene sequencing revealed the enrichment of sulfate reducers next to acetogens, indicating a syntrophic relationship. In compliance with biophysicochemical analysis and estimated yield coefficients, metaproteomics indicated no major differences in the pathways of energy metabolism between treatments with H2 and Fe0. Highly abundant proteins namely periplasmic hydrogenases and c-cytochromes associated with H2-mediated electron transfer coupled to dissimilatory sulfate reduction indicated this mechanism to be dominant (except for a few putative outer membrane proteins identified with Fe0). In conclusion, using a multiphasic approach including metaproteomics to elucidate metabolic pathways improved the overall understanding of microbial processes associated with freshwater MIC.
{"title":"New insights in the metabolic functions of freshwater sulfate reducing communities during steel corrosion by biophysicochemical, 16S rRNA gene sequence and metaproteomic analysis","authors":"Lipi Raghunatha Reddy , Carolin Egerter , Nico Jehmlich , Annika Fiskal , Lissa Helmholz , Sandro Castronovo , Peter Schweyen , Sven-Erik Wulf , Thomas Ternes , Arne Wick , Jutta Meier","doi":"10.1016/j.ibiod.2024.105995","DOIUrl":"10.1016/j.ibiod.2024.105995","url":null,"abstract":"<div><div>To date, the focus of microbially induced corrosion (MIC) studies has largely been on marine environments. In this study, biocorrosion of steel enrichment cultures from a freshwater corrosion site was investigated under sulfate reducing conditions. Biomass and metabolic processes were monitored by measuring the time-dependent biophysicochemical parameters and with Fe<sup>0</sup> (steel) as the sole electron source, or with H<sub>2</sub> as control. Although yields and sulfate reduction rates were higher with H<sub>2</sub> due to its greater bioavailability, the yield coefficients indicated that bacterial growth with Fe<sup>0</sup> was equally efficient. Upon imaging of the steel surface by SEM, patches of cells embedded in an iron sulfide matrix on top of larger carbonate and phosphate minerals were observed. Cell number determination indicated that the cells on the steel surface constituted only a minor proportion (<4%) of the total counts. The 16S rRNA gene sequencing revealed the enrichment of sulfate reducers next to acetogens, indicating a syntrophic relationship. In compliance with biophysicochemical analysis and estimated yield coefficients, metaproteomics indicated no major differences in the pathways of energy metabolism between treatments with H<sub>2</sub> and Fe<sup>0</sup>. Highly abundant proteins namely periplasmic hydrogenases and c-cytochromes associated with H<sub>2</sub>-mediated electron transfer coupled to dissimilatory sulfate reduction indicated this mechanism to be dominant (except for a few putative outer membrane proteins identified with Fe<sup>0</sup>). In conclusion, using a multiphasic approach including metaproteomics to elucidate metabolic pathways improved the overall understanding of microbial processes associated with freshwater MIC.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 105995"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2025.106012
Ji-Dong Gu
As academic publication becomes increasingly more competitive for both authors and also the publishers, quality of a manuscript is the most critical element for acceptance through the intensive reviewing process. Manuscripts are increasing in number, but fewer are distinguished from the enormous large pool of them. It is logical for authors to ask what is needed or missing in a manuscript for a good quality to be judged by professional peers? Very briefly, the reproducibility of the results is the basic element and foundation stone for science, and, more importantly, the soul of a manuscript, more than often, is missing. Because of this, I would like to discuss contents of a manuscript in this communication as my focal point in a hope to assist authors to improve manuscript quality and submission success rate.
{"title":"What is missing in a manuscript?","authors":"Ji-Dong Gu","doi":"10.1016/j.ibiod.2025.106012","DOIUrl":"10.1016/j.ibiod.2025.106012","url":null,"abstract":"<div><div>As academic publication becomes increasingly more competitive for both authors and also the publishers, quality of a manuscript is the most critical element for acceptance through the intensive reviewing process. Manuscripts are increasing in number, but fewer are distinguished from the enormous large pool of them. It is logical for authors to ask what is needed or missing in a manuscript for a good quality to be judged by professional peers? Very briefly, the reproducibility of the results is the basic element and foundation stone for science, and, more importantly, the soul of a manuscript, more than often, is missing. Because of this, I would like to discuss contents of a manuscript in this communication as my focal point in a hope to assist authors to improve manuscript quality and submission success rate.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 106012"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376526","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}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2024.105996
Qingyun Li , Shaohui Yan , Zhengfeng Jiang , Liang Xian , Jianjia Du , Haibo Liu , Youyan Liu
Cyanide and phenol are highly toxic chemicals that exert severe inhibitory effects on microorganisms, posing significant challenges for their removal by biological methods in coexistent systems. In this study, we successfully isolated a bacterial strain named JF101, identified as Alcaligenes faecalis, which was capable of degrading both cyanide and phenol. The interactions between cyanide and phenol during biodegradation were investigated. It was found that the presence of 100 mg/L cyanide significantly enhanced the degradation of phenol, leading to the complete degradation of 1000 mg/L phenol within 86 h. In contrast, only 21.9% of phenol was degraded in the absence of cyanide. Additionally, the presence of phenol had minimal impact on cyanide degradation; a concentration of 100 mg/L cyanide could be rapidly and completely degraded within 40 min even in the presence of up to 1000 mg/L phenol. Five empirical kinetic models of Haldane, Aiba, Edward, Yano, and Webb were employed to describe the degradation processes of phenol and cyanide in both single-substrate and dual-substrate systems. The putative degrading enzymes, degradation products, and pathways associated with the co-degradation of cyanide and phenol were systematically analyzed. The formamide and NH4+-N produced from the rapid degradation of cyanide served as nitrogen sources, facilitating the resumed growth of strain JF101 and enhancing phenol degradation.
{"title":"Co-biodegradation of cyanide and phenol by Alcaligenes faecalis JF101: Investigating interaction effects","authors":"Qingyun Li , Shaohui Yan , Zhengfeng Jiang , Liang Xian , Jianjia Du , Haibo Liu , Youyan Liu","doi":"10.1016/j.ibiod.2024.105996","DOIUrl":"10.1016/j.ibiod.2024.105996","url":null,"abstract":"<div><div>Cyanide and phenol are highly toxic chemicals that exert severe inhibitory effects on microorganisms, posing significant challenges for their removal by biological methods in coexistent systems. In this study, we successfully isolated a bacterial strain named JF101, identified as <em>Alcaligenes faecalis</em>, which was capable of degrading both cyanide and phenol. The interactions between cyanide and phenol during biodegradation were investigated. It was found that the presence of 100 mg/L cyanide significantly enhanced the degradation of phenol, leading to the complete degradation of 1000 mg/L phenol within 86 h. In contrast, only 21.9% of phenol was degraded in the absence of cyanide. Additionally, the presence of phenol had minimal impact on cyanide degradation; a concentration of 100 mg/L cyanide could be rapidly and completely degraded within 40 min even in the presence of up to 1000 mg/L phenol. Five empirical kinetic models of Haldane, Aiba, Edward, Yano, and Webb were employed to describe the degradation processes of phenol and cyanide in both single-substrate and dual-substrate systems. The putative degrading enzymes, degradation products, and pathways associated with the co-degradation of cyanide and phenol were systematically analyzed. The formamide and NH<sub>4</sub><sup>+</sup>-N produced from the rapid degradation of cyanide served as nitrogen sources, facilitating the resumed growth of strain JF101 and enhancing phenol degradation.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 105996"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143164795","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}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2025.106002
Meimei Wan, Peiyang Zheng, Yang Liu, Ying Lei, Yuanyuan Dong, Zhiqiang Cai
Heterotrophic nitrification-aerobic denitrification bacteria have attracted more and more attention due to their high tolerance to ammonia nitrogen, efficient nitrogen removal capacity, and strong pH adaptability. This experiment studied the optimal conditions for the degradation of ammonia nitrogen by the heterotrophic nitrification-aerobic denitrification strain Alcaligenes sp. TD-94. Based on gene identification results, the metabolic pathway of TD-94 for degrading ammonia nitrogen was inferred. The key enzyme pyruvic oxime dioxygenase (POD) in the heterotrophic nitrification process was purified, and its catalytic properties were studied. The results showed that the denitrification performance of Alcaligenes sp. TD-94 was optimal when the carbon source was sodium acetate, the C/N ratio was 10, the pH was 7.0, the inoculation amount was 10%, and the temperature was 28–37 °C. The pathway of strain TD-94 is NH4+ - NH2OH - NO2− - NO - N2O - N2. In the experiment, POD was successfully expressed at 28 °C. After purification, it remained stably expressed, and enzymatic reaction verification showed good nitrite generation. The protein structure of POD was predicted, and it was highly similar to the known aldolase structure in the PBD database, and the predicted amino acid sequence of POD from positions 32 to 210 was detected as the aldolase domain.
{"title":"Ammonia nitrogen degrading characteristics by the novel strain Alcaligenes sp. TD-94 and regulation mechanism of POD gene","authors":"Meimei Wan, Peiyang Zheng, Yang Liu, Ying Lei, Yuanyuan Dong, Zhiqiang Cai","doi":"10.1016/j.ibiod.2025.106002","DOIUrl":"10.1016/j.ibiod.2025.106002","url":null,"abstract":"<div><div>Heterotrophic nitrification-aerobic denitrification bacteria have attracted more and more attention due to their high tolerance to ammonia nitrogen, efficient nitrogen removal capacity, and strong pH adaptability. This experiment studied the optimal conditions for the degradation of ammonia nitrogen by the heterotrophic nitrification-aerobic denitrification strain <em>Alcaligenes</em> sp. TD-94. Based on gene identification results, the metabolic pathway of TD-94 for degrading ammonia nitrogen was inferred. The key enzyme pyruvic oxime dioxygenase (<em>POD</em>) in the heterotrophic nitrification process was purified, and its catalytic properties were studied. The results showed that the denitrification performance of <em>Alcaligenes</em> sp. TD-94 was optimal when the carbon source was sodium acetate, the C/N ratio was 10, the pH was 7.0, the inoculation amount was 10%, and the temperature was 28–37 °C. The pathway of strain TD-94 is NH<sub>4</sub><sup>+</sup> - NH<sub>2</sub>OH - NO<sub>2</sub><sup>−</sup> - NO - N<sub>2</sub>O - N<sub>2</sub>. In the experiment, <em>POD</em> was successfully expressed at 28 °C. After purification, it remained stably expressed, and enzymatic reaction verification showed good nitrite generation. The protein structure of <em>POD</em> was predicted, and it was highly similar to the known aldolase structure in the PBD database, and the predicted amino acid sequence of POD from positions 32 to 210 was detected as the aldolase domain.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 106002"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165382","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}
Pseudomonas moorei KB4 belongs to the paracetamol-degrading strains. This strain was immobilized on a biodegradable carrier – a cellulose sponge from Luffa cylindrica. The study aimed to determine the impact of the immobilization process on the metabolic activity of the strain, including the biodegradation process of paracetamol. The research that was conducted showed significant differences in the level of transcription of selected genes, as well as in the metabolic profile and the composition of total fatty acids. However, the immobilization process did not significantly affect the degradation of paracetamol. This indicates a lack of limitation in the availability of the substrate, which is not very toxic to the tested strain. However, immobilization causes greater strain resistance to the appearance of the toxic 4-aminophenol. After immobilization, it is possible to decompose higher concentrations of paracetamol, which, under normal conditions, leads to the accumulation of 4-aminophenol, inhibiting the free strain's growth. Differences in the degradation of this drug by free and immobilized cells, depending on the number of doses, were observed. After analyzing the enzymes and intermediates of the paracetamol degradation pathway, differences were shown between the metabolism of this compound by the free and immobilized strain. It was shown that, 3-methyl-3-vinyl-cyclohexanon was a characteristic intermediate identified only during paracetamol degradation by the free strain of KB4. Moreover, no deaminase and hydroquinone 1,2-dioxygenase were active in the system with immobilized KB4. The resulting hydroquinone ring was probably not cleaved in the immobilized system. Hence, decomposition probably proceeds by catechol cleavage.
{"title":"Luffa cylindrica-based immobilization: Effects on metabolic activity and paracetamol degradation by Pseudomonas moorei KB4","authors":"Urszula Guzik , Anna Dzionek , Agnieszka Nowak , Ariel Marchlewicz , Katarzyna Hupert-Kocurek , Daria Szada , Teofil Jesionowski , Jacek Borgulat , Łukasz Jałowiecki , Grażyna Płaza , Danuta Wojcieszyńska","doi":"10.1016/j.ibiod.2025.106007","DOIUrl":"10.1016/j.ibiod.2025.106007","url":null,"abstract":"<div><div><em>Pseudomonas moorei</em> KB4 belongs to the paracetamol-degrading strains. This strain was immobilized on a biodegradable carrier – a cellulose sponge from <em>Luffa cylindrica</em>. The study aimed to determine the impact of the immobilization process on the metabolic activity of the strain, including the biodegradation process of paracetamol. The research that was conducted showed significant differences in the level of transcription of selected genes, as well as in the metabolic profile and the composition of total fatty acids. However, the immobilization process did not significantly affect the degradation of paracetamol. This indicates a lack of limitation in the availability of the substrate, which is not very toxic to the tested strain. However, immobilization causes greater strain resistance to the appearance of the toxic 4-aminophenol. After immobilization, it is possible to decompose higher concentrations of paracetamol, which, under normal conditions, leads to the accumulation of 4-aminophenol, inhibiting the free strain's growth. Differences in the degradation of this drug by free and immobilized cells, depending on the number of doses, were observed. After analyzing the enzymes and intermediates of the paracetamol degradation pathway, differences were shown between the metabolism of this compound by the free and immobilized strain. It was shown that, 3-methyl-3-vinyl-cyclohexanon was a characteristic intermediate identified only during paracetamol degradation by the free strain of KB4. Moreover, no deaminase and hydroquinone 1,2-dioxygenase were active in the system with immobilized KB4. The resulting hydroquinone ring was probably not cleaved in the immobilized system. Hence, decomposition probably proceeds by catechol cleavage.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 106007"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165384","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}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2024.105988
Haikun Zhang , Lisa Voskuhl , Mohamed Hassoun , Verena S. Brauer , Astrid Dannehl , Yassin M. Kaspareit , Hermann J. Heipieper , Rainer U. Meckenstock
Microbially mediated redox processes of sulfur compounds are closely related to the occurrence of iron oxides in natural ecosystems. However, so far, no pure culture has been reported to couple sulfur oxidation to iron reduction under neutral or alkaline conditions. Here, we report on a pure culture of a sulfur-oxidizing and iron-reducing bacterium (strain CB1MN) and demonstrate that hydrogen can be used as an electron donor supporting the growth of strain CB1MN with ferrihydrite as electron acceptor. The reduction of ferrihydrite by CB1MN produced dissolved Fe(II) and secondary minerals, which was confirmed by Raman analysis. In addition, strain CB1MN can also utilize a few organic carbon and electron sources such as glucose, pyruvate, acetate, and succinate for maintaining growth and metabolic activity with sulfite as electron acceptor. Genomic analysis showed that a membrane-bound Hyd-4-type hydrogenase and a cytoplasmic F420-non-reducing hydrogenase should be responsible for the hydrogen oxidation. Furthermore, a large number of genes encoding type IV pili and flagella were suspected to be involved in electron transport. Our results imply that the sulfur- and iron-utilizing chemoautotrophs not only use sulfur compounds for energy conservation, but hydrogen and organic carbon sources can be electron donors.
{"title":"The chemolithoautotrophic bacterium CB1MN can utilize hydrogen and sulfur as electron donors with ferric iron as electron acceptor","authors":"Haikun Zhang , Lisa Voskuhl , Mohamed Hassoun , Verena S. Brauer , Astrid Dannehl , Yassin M. Kaspareit , Hermann J. Heipieper , Rainer U. Meckenstock","doi":"10.1016/j.ibiod.2024.105988","DOIUrl":"10.1016/j.ibiod.2024.105988","url":null,"abstract":"<div><div>Microbially mediated redox processes of sulfur compounds are closely related to the occurrence of iron oxides in natural ecosystems. However, so far, no pure culture has been reported to couple sulfur oxidation to iron reduction under neutral or alkaline conditions. Here, we report on a pure culture of a sulfur-oxidizing and iron-reducing bacterium (strain CB1MN) and demonstrate that hydrogen can be used as an electron donor supporting the growth of strain CB1MN with ferrihydrite as electron acceptor. The reduction of ferrihydrite by CB1MN produced dissolved Fe(II) and secondary minerals, which was confirmed by Raman analysis. In addition, strain CB1MN can also utilize a few organic carbon and electron sources such as glucose, pyruvate, acetate, and succinate for maintaining growth and metabolic activity with sulfite as electron acceptor. Genomic analysis showed that a membrane-bound Hyd-4-type hydrogenase and a cytoplasmic F420-non-reducing hydrogenase should be responsible for the hydrogen oxidation. Furthermore, a large number of genes encoding type IV pili and flagella were suspected to be involved in electron transport. Our results imply that the sulfur- and iron-utilizing chemoautotrophs not only use sulfur compounds for energy conservation, but hydrogen and organic carbon sources can be electron donors.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 105988"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.ibiod.2025.106004
Yinyan Chen , Zhijia Fang , Yongbin Li , Qi Deng , Lijun Sun , Jianmeng Liao , Ravi Gooneratne
As an important toxic pollutant, lead (Pb2+) seriously threatens the environment and human well-being. Microbes and microbial extracellular polymeric substances (EPS) are highly effective at removing heavy metals from solutions. Herein, a Pb2+-tolerant strain, Staphylococcus epidermidis G257 was isolated from Guangxi of China. The strain showed strong resistance to Pb2+ and great Pb2+ adsorbability. The biosorption processes of S. epidermidis G257 and its EPS were characterized using microscopical techniques, ICP-MS, zeta potential measurement, XRD, FTIR, 3D-EEM, and XPS spectroscopy. Results showed that S. epidermidis G257 were effective in adsorbing Pb2+, with a biosorption efficiency of 81%. The biosorption process of Pb2+ was described well by the pseudo-second-order model with an adsorption capacity of 53.52 mg/g. Microscopical analyses showed that Pb2+ was adsorbed on the S. epidermidis surface by forming EPS precipitates. The variations in zeta potential indicated an electrostatic attraction in the Pb2+ adsorption process. Moreover, FTIR, 3D-EEM and XPS analyses revealed that the functional groups participating in Pb2+ adsorption were primarily carbonyl, carboxyl and amino groups of proteins in the EPS, which greatly facilitated Pb2+ adsorption by forming EPS-metal complexes. Therefore, this study unveiled that S. epidermidis G257 can be utilized as a potential biosorbent for eliminating Pb2+ from polluted environment.
{"title":"Characteristic study of Pb2+ binding to extracellular polymeric substances from Staphylococcus epidermidis G257","authors":"Yinyan Chen , Zhijia Fang , Yongbin Li , Qi Deng , Lijun Sun , Jianmeng Liao , Ravi Gooneratne","doi":"10.1016/j.ibiod.2025.106004","DOIUrl":"10.1016/j.ibiod.2025.106004","url":null,"abstract":"<div><div>As an important toxic pollutant, lead (Pb<sup>2+</sup>) seriously threatens the environment and human well-being. Microbes and microbial extracellular polymeric substances (EPS) are highly effective at removing heavy metals from solutions. Herein, a Pb<sup>2+</sup>-tolerant strain, <em>Staphylococcus epidermidis</em> G257 was isolated from Guangxi of China. The strain showed strong resistance to Pb<sup>2+</sup> and great Pb<sup>2+</sup> adsorbability. The biosorption processes of <em>S. epidermidis</em> G257 and its EPS were characterized using microscopical techniques, ICP-MS, zeta potential measurement, XRD, FTIR, 3D-EEM, and XPS spectroscopy. Results showed that <em>S. epidermidis</em> G257 were effective in adsorbing Pb<sup>2+</sup>, with a biosorption efficiency of 81%. The biosorption process of Pb<sup>2+</sup> was described well by the pseudo-second-order model with an adsorption capacity of 53.52 mg/g. Microscopical analyses showed that Pb<sup>2+</sup> was adsorbed on the <em>S. epidermidis</em> surface by forming EPS precipitates. The variations in zeta potential indicated an electrostatic attraction in the Pb<sup>2+</sup> adsorption process. Moreover, FTIR, 3D-EEM and XPS analyses revealed that the functional groups participating in Pb<sup>2+</sup> adsorption were primarily carbonyl, carboxyl and amino groups of proteins in the EPS, which greatly facilitated Pb<sup>2+</sup> adsorption by forming EPS-metal complexes. Therefore, this study unveiled that <em>S. epidermidis</em> G257 can be utilized as a potential biosorbent for eliminating Pb<sup>2+</sup> from polluted environment.</div></div>","PeriodicalId":13643,"journal":{"name":"International Biodeterioration & Biodegradation","volume":"198 ","pages":"Article 106004"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143165459","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}
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