Pub Date : 2025-02-25DOI: 10.1016/j.biortech.2025.132226
Xin Zou , Yang Lu , Yang Liu
Aerobic granular sludge (AGS) reactors are promising for treating high ammonia wastewaters, yet the roles of granules and flocs in nitrogen removal under varying carbon to nitrogen (COD/N) ratios remain unclear. This study investigated microbial communities and their contributions to N removal as the COD/N ratio shifted from 6 to 4, and to 2. Results showed granules contributed 53–64 % nitrification capacity at higher COD/N ratios (6 and 4), but flocs contributed more (50–63 %) at a ratio of 2. Granules consistently exhibited higher denitrification capacity (>50 %). Heterotrophic bacteria dominated in both granules and flocs across all ratios. As the COD/N ratio reduced, the relative abundance of anaerobic ammonia oxidation microorganisms (Candidatus Anammoximicrobium) and filamentous bacteria increased in granules, while ammonia oxidizing bacteria (Nitrosomonas) and complex organic degraders increased in flocs. These findings highlight the importance of selectively retaining granules or flocs under varying COD/N ratios to optimize nitrogen removal efficiency.
{"title":"Divergences of granules and flocs microbial communities and contributions to nitrogen removal under varied carbon to nitrogen ratios","authors":"Xin Zou , Yang Lu , Yang Liu","doi":"10.1016/j.biortech.2025.132226","DOIUrl":"10.1016/j.biortech.2025.132226","url":null,"abstract":"<div><div>Aerobic granular sludge (AGS) reactors are promising for treating high ammonia wastewaters, yet the roles of granules and flocs in nitrogen removal under varying carbon to nitrogen (COD/N) ratios remain unclear. This study investigated microbial communities and their contributions to N removal as the COD/N ratio shifted from 6 to 4, and to 2. Results showed granules contributed 53–64 % nitrification capacity at higher COD/N ratios (6 and 4), but flocs contributed more (50–63 %) at a ratio of 2. Granules consistently exhibited higher denitrification capacity (>50 %). Heterotrophic bacteria dominated in both granules and flocs across all ratios. As the COD/N ratio reduced, the relative abundance of anaerobic ammonia oxidation microorganisms (<em>Candidatus Anammoximicrobium</em>) and filamentous bacteria increased in granules, while ammonia oxidizing bacteria (<em>Nitrosomonas</em>) and complex organic degraders increased in flocs. These findings highlight the importance of selectively retaining granules or flocs under varying COD/N ratios to optimize nitrogen removal efficiency.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132226"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132296
Mario Olaya-Rincon , Joaquim Serra-Rada , Cristopher Da Silva , Pol Barcelona , Joan Dosta , Sergi Astals , Mònica Martínez
This study examines the anaerobic biodegradability of six commercial polylactic acid (PLA) products under thermophilic conditions. All products showed similar methane yields of 507 ± 24 L CH4 kg-1 VS, with an estimated biodegradability of 100 %. However, these products showed a slow degradation rate, with an average kinetic constant of 0.008 d-1. Products degradation was monitored by recovering samples from tests after 30, 60 and 90 days. After 30 days, all products showed changes in colour and fragmentation, that were more pronounced after 60 and 90 days. Degradation was also evident by the reduction of the carbonyl index and a decrease in the melting temperature. Nonetheless, differences in crystallinity, thermal properties, thickness and additives did not affect methane yield or degradation rate. Despite being fully biodegradable, biodegradation at full-scale was estimated at < 20 %, limiting the feasibility of anaerobic digestion as an end-of-life management option and highlighting the need for improved waste management strategies.
{"title":"Thermophilic anaerobic biodegradation of commercial polylactic acid products","authors":"Mario Olaya-Rincon , Joaquim Serra-Rada , Cristopher Da Silva , Pol Barcelona , Joan Dosta , Sergi Astals , Mònica Martínez","doi":"10.1016/j.biortech.2025.132296","DOIUrl":"10.1016/j.biortech.2025.132296","url":null,"abstract":"<div><div>This study examines the anaerobic biodegradability of six commercial polylactic acid (PLA) products under thermophilic conditions. All products showed similar methane yields of 507 ± 24 L CH<sub>4</sub> kg<sup>-</sup><sup>1</sup> VS, with an estimated biodegradability of 100 %. However, these products showed a slow degradation rate, with an average kinetic constant of 0.008 d<sup>-</sup><sup>1</sup>. Products degradation was monitored by recovering samples from tests after 30, 60 and 90 days. After 30 days, all products showed changes in colour and fragmentation, that were more pronounced after 60 and 90 days. Degradation was also evident by the reduction of the carbonyl index and a decrease in the melting temperature. Nonetheless, differences in crystallinity, thermal properties, thickness and additives did not affect methane yield or degradation rate. Despite being fully biodegradable, biodegradation at full-scale was estimated at < 20 %, limiting the feasibility of anaerobic digestion as an end-of-life management option and highlighting the need for improved waste management strategies.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132296"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132300
Jian Gao, Jingyu Wu, Yuancai Chen
This study found that bio-Pd0 nanoparticles could launch proton motive force (PMF)-mediated antibiotics efflux pump (AEP) to confer the detoxification capability on Citrobacter freundii, as evidenced by the highest sulfamethoxazole (SMX) specific degradation rate (81.7 μg L−1 mg−1 protein d−1) at high PMF (pH 6). The batch experiment and RT-qPCR results indicated that bio-Pd0 activated the AcrB efflux pump through upregulating the AEP transcriptional regulation factor ramA (2.7–3.1 times), which benefited the intra/extracellular respiration and ATP production/utilization. Path analysis revealed that the prosperity of metabolic activity and extracellular electron output capacity enabled SMX biodegradation, mainly through the electron redistribution and energy optimization with the formate dehydrogenase/hydrogenase based Short-chain (FDH/Hase-S-chain). The upregulation of hypE (2.7–8.6 times) and atpD (1.9–2.3 times) genes encoding the Hase respiratory chain and the F-type ATP synthase, respectively, further supports this mechanism. These novel findings provided a new strategy to improve the biodegradation efficiency of antibiotics wastewater.
{"title":"Promoted sulfamethoxazole extracellular biodegradation in Citrobacter freundii JH@Pd by launching AcrB efflux pump","authors":"Jian Gao, Jingyu Wu, Yuancai Chen","doi":"10.1016/j.biortech.2025.132300","DOIUrl":"10.1016/j.biortech.2025.132300","url":null,"abstract":"<div><div>This study found that bio-Pd<sup>0</sup> nanoparticles could launch proton motive force (PMF)-mediated antibiotics efflux pump (AEP) to confer the detoxification capability on <em>Citrobacter freundii</em>, as evidenced by the highest sulfamethoxazole (SMX) specific degradation rate (81.7 μg L<sup>−1</sup> mg<sup>−1</sup> protein d<sup>−1</sup>) at high PMF (pH 6). The batch experiment and RT-qPCR results indicated that bio-Pd<sup>0</sup> activated the AcrB efflux pump through upregulating the AEP transcriptional regulation factor <em>ramA</em> (2.7–3.1 times), which benefited the intra/extracellular respiration and ATP production/utilization. Path analysis revealed that the prosperity of metabolic activity and extracellular electron output capacity enabled SMX biodegradation, mainly through the electron redistribution and energy optimization with the formate dehydrogenase/hydrogenase based Short-chain (FDH/Hase-S-chain). The upregulation of <em>hypE</em> (2.7–8.6 times) and <em>atpD</em> (1.9–2.3 times) genes encoding the Hase respiratory chain and the F-type ATP synthase, respectively, further supports this mechanism. These novel findings provided a new strategy to improve the biodegradation efficiency of antibiotics wastewater.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"424 ","pages":"Article 132300"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143507511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132303
Wen-Jie Ma, Han-Min Zhang
Sulfur autotrophic denitrification (SAD) process has significant potential in treating low carbon/nitrogen ratio wastewater. However, the presence of zinc ions (Zn2+) adversely affects the denitrification performance. This study investigated the effect of biochar prepared at 300 °C (BC300) and 600 °C (BC600), as well as dosing strategy, on denitrification performance in the SAD process under Zn2+ inhibition. Firstly, BC600 had a higher maximum adsorption capacity for Zn2+ than BC300 in nitrogen-containing wastewater. Surface complexation was mainly adsorption mechanism. BC300 exhibited a greater ability in enhancing denitrification ability than BC600. The strategy of synchronous addition is more effective than pre-adsorption. Firstly, BC300 enhancing humic-like component secretion. BC300 enriched higher abundance of sulfur-oxidizing bacteria. More importantly, BC300 counteracted the negative effect of Zn2+ by enhancing glycan biosynthesis and metabolism, enriching functional genes, and increased the level of quorum sensing. The study presents a sustainable approach for maintaining denitrification performance under environmental stress.
{"title":"Metagenomics deciphers the function of biochar in alleviating zinc ion stress during sulfur autotrophic denitrification process","authors":"Wen-Jie Ma, Han-Min Zhang","doi":"10.1016/j.biortech.2025.132303","DOIUrl":"10.1016/j.biortech.2025.132303","url":null,"abstract":"<div><div>Sulfur autotrophic denitrification (SAD) process has significant potential in treating low carbon/nitrogen ratio wastewater. However, the presence of zinc ions (Zn<sup>2+</sup>) adversely affects the denitrification performance. This study investigated the effect of biochar prepared at 300 °C (BC300) and 600 °C (BC600), as well as dosing strategy, on denitrification performance in the SAD process under Zn<sup>2+</sup> inhibition. Firstly, BC600 had a higher maximum adsorption capacity for Zn<sup>2+</sup> than BC300 in nitrogen-containing wastewater. Surface complexation was mainly adsorption mechanism. BC300 exhibited a greater ability in enhancing denitrification ability than BC600. The strategy of synchronous addition is more effective than pre-adsorption. Firstly, BC300 enhancing humic-like component secretion. BC300 enriched higher abundance of sulfur-oxidizing bacteria. More importantly, BC300 counteracted the negative effect of Zn<sup>2+</sup> by enhancing glycan biosynthesis and metabolism, enriching functional genes, and increased the level of quorum sensing. The study presents a sustainable approach for maintaining denitrification performance under environmental stress.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"424 ","pages":"Article 132303"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
The use of orange peel as a precursor for activated carbon (AC) is a promising way to valorize this waste due to its ease of acquisition and the high elemental carbon content of this raw material. In this study, two different methods for the synthesis of carbon catalysts based on AC from biomass were presented. In these methods, H3PO4 was used as the chemical activator, while Cu (NO3)2 acted as the metal precursor for the active phase of the catalyst. Copper was introduced into the carbon material at different stages of preparation (before and after carbonization). The catalysts were characterized using FTIR, XRD, SEM, EDX and XPS. The textural properties were investigated using N2 sorption at −196 °C. These materials were successfully used in the oxidation of α-pinene and the conversion of this cheap terpene into compounds of great industrial importance (α-pinene oxide, verbenone and verbenol). The results showed that the material prepared by impregnating the already prepared carbon support (AC_5%Cu_impregnation) was more active. For this catalyst, the conversion of α-pinene was 53 mol%, while this value for AC_5%Cu_oven sample was 43 mol%. The selectivity of the α-pinene oxide was 48 mol% for AC_5%Cu_impregnation sample and 39 mol% for AC_5%Cu_oven catalyst. The selectivities of the other products eg. verbenone and verbenol were not significantly different for both catalysts. Considering catalytic activity, it was found that a better method of prepared catalysts for use in the α-pinene oxidation was impregnation of carbonaceous support with a copper salt solution after the carbonization process.
{"title":"Study of carbon-supported copper catalysts from orange peels − Preparation, characterization, and application in α-pinene oxidation","authors":"Adrianna Kamińska , Joanna Sreńscek-Nazzal , Jarosław Serafin , Agnieszka Kałamaga , Karolina Kiełbasa , Agnieszka Wróblewska","doi":"10.1016/j.biortech.2025.132305","DOIUrl":"10.1016/j.biortech.2025.132305","url":null,"abstract":"<div><div>The use of orange peel as a precursor for activated carbon (AC) is a promising way to valorize this waste due to its ease of acquisition and the high elemental carbon content of this raw material. In this study, two different methods for the synthesis of carbon catalysts based on AC from biomass were presented. In these methods, H<sub>3</sub>PO<sub>4</sub> was used as the chemical activator, while Cu (NO<sub>3</sub>)<sub>2</sub> acted as the metal precursor for the active phase of the catalyst. Copper was introduced into the carbon material at different stages of preparation (before and after carbonization). The catalysts were characterized using FTIR, XRD, SEM, EDX and XPS. The textural properties were investigated using N<sub>2</sub> sorption at −196 °C. These materials were successfully used in the oxidation of α-pinene and the conversion of this cheap terpene into compounds of great industrial importance (α-pinene oxide, verbenone and verbenol). The results showed that the material prepared by impregnating the already prepared carbon support (AC_5%Cu_impregnation) was more active. For this catalyst, the conversion of α-pinene was 53 mol%, while this value for AC_5%Cu_oven sample was 43 mol%. The selectivity of the α-pinene oxide was 48 mol% for AC_5%Cu_impregnation sample and 39 mol% for AC_5%Cu_oven catalyst. The selectivities of the other products eg. verbenone and verbenol were not significantly different for both catalysts. Considering catalytic activity, it was found that a better method of prepared catalysts for use in the α-pinene oxidation was impregnation of carbonaceous support with a copper salt solution after the carbonization process.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"424 ","pages":"Article 132305"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132304
M.Carolina Espinosa-Arzate , Edgardo I. Valenzuela , Sonia Arriaga , Adalberto Noyola , Francisco J. Cervantes
Bioreactors supplied with sulfate and Fe(III) oxides (hematite and goethite), as electron acceptors, were tested for their capacity to remove dissolved methane from a digestate from a methanogenic reactor treating synthetic wastewater. Negligible removal of dissolved methane occurred when no electron acceptor was provided. However, when hematite and goethite were supplied, methane removal rates of 6.7 and 3.7 g CH4/m3-day, respectively, were achieved coupled to the reduction of both minerals. Simultaneous supply of sulfate and hematite supported the highest removal rate observed (9.1 g CH4/m3-day) coupled to the reduction of both electron acceptors. Taxonomic characterization based on 16S rRNA gene sequencing revealed Methanobacterium and Methanolinea as the microorganisms potentially involved in the removal of dissolved methane. This treatment concept could contribute to prevent the emission of dissolved methane from digested effluents, which ultimately may attenuate global warming associated with greenhouse gases emissions from wastewater treatment plants.
{"title":"Removal of dissolved methane from digested effluent by anaerobic methane oxidation linked to ferric oxides and sulfate reduction","authors":"M.Carolina Espinosa-Arzate , Edgardo I. Valenzuela , Sonia Arriaga , Adalberto Noyola , Francisco J. Cervantes","doi":"10.1016/j.biortech.2025.132304","DOIUrl":"10.1016/j.biortech.2025.132304","url":null,"abstract":"<div><div>Bioreactors supplied with sulfate and Fe(III) oxides (hematite and goethite), as electron acceptors, were tested for their capacity to remove dissolved methane from a digestate from a methanogenic reactor treating synthetic wastewater. Negligible removal of dissolved methane occurred when no electron acceptor was provided. However, when hematite and goethite were supplied, methane removal rates of 6.7 and 3.7 g CH<sub>4</sub>/m<sup>3</sup>-day, respectively, were achieved coupled to the reduction of both minerals. Simultaneous supply of sulfate and hematite supported the highest removal rate observed (9.1 g CH<sub>4</sub>/m<sup>3</sup>-day) coupled to the reduction of both electron acceptors. Taxonomic characterization based on 16S rRNA gene sequencing revealed <em>Methanobacterium</em> and <em>Methanolinea</em> as the microorganisms potentially involved in the removal of dissolved methane. This treatment concept could contribute to prevent the emission of dissolved methane from digested effluents, which ultimately may attenuate global warming associated with greenhouse gases emissions from wastewater treatment plants.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"424 ","pages":"Article 132304"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132306
Zhichao Chen , Ling Ma , Weiwei Liu , Changgeng Li , Meng Yuan , Zichen Yu , Lanxiao Li , Xiaoguang Fan , Qingyang Xu
l-tyrosine (l-tyr) is a valuable aromatic amino acid that can be produced via microbial fermentation, providing a sustainable alternative to costly and polluting chemical synthesis. However, industrial production is limited by poor strain performance and inefficient resource utilization. In this study, a high-performance Escherichia coli strain was engineered to address key fermentation bottlenecks for efficient l-tyr synthesis from high-purity glucose syrup. Initially, a “rapid channel” for l-tyr biosynthesis was established by overexpressing aroGfbr and tyrAfbr genes, introducing the pyridoxal 5’-phosphate synthesis pathway, and strengthening tyrosine efflux. Precursor pools of phosphoenolpyruvate and erythrose-4-phosphate were enriched using modular metabolic engineering and dynamic regulation strategies. Co-metabolism of glucose, maltose, and isomaltose was achieved by integrating Bacillus subtilis-derived membrane permease and maltose-6’-phosphate glucosidase, alongside Bifidobacterium adolescentis-derived oligo-1,6-glucosidase, and by employing a suboptimal glucose supplementation feeding strategy. To overcome oxygen limitation, Vitreoscilla hemoglobin was localized to the periplasm via the twin-arginine translocation pathway. Systematic fermentation optimization further improved strain performance, achieving an l-tyr titer, yield, and productivity of 109.2 g/L, 0.292 g/g, and 2.18 g/L/h, respectively—the highest reported to date. This research demonstrates a promising strategy for enhancing l-tyrosine biosynthesis, providing a scalable approach for industrial production and broader applications in microbial metabolic engineering.
{"title":"Systems metabolic engineering and process optimization for efficient l-tyrosine production from high-purity glucose syrup in Escherichia coli","authors":"Zhichao Chen , Ling Ma , Weiwei Liu , Changgeng Li , Meng Yuan , Zichen Yu , Lanxiao Li , Xiaoguang Fan , Qingyang Xu","doi":"10.1016/j.biortech.2025.132306","DOIUrl":"10.1016/j.biortech.2025.132306","url":null,"abstract":"<div><div><span>l</span>-tyrosine (<span>l</span>-tyr) is a valuable aromatic amino acid that can be produced via microbial fermentation, providing a sustainable alternative to costly and polluting chemical synthesis. However, industrial production is limited by poor strain performance and inefficient resource utilization. In this study, a high-performance <em>Escherichia coli</em> strain was engineered to address key fermentation bottlenecks for efficient <span>l</span>-tyr synthesis from high-purity glucose syrup. Initially, a “rapid channel” for <span>l</span>-tyr biosynthesis was established by overexpressing <em>aroG<sup>fbr</sup></em> and <em>tyrA<sup>fbr</sup></em> genes, introducing the pyridoxal 5’-phosphate synthesis pathway, and strengthening tyrosine efflux. Precursor pools of phosphoenolpyruvate and erythrose-4-phosphate were enriched using modular metabolic engineering and dynamic regulation strategies. Co-metabolism of glucose, maltose, and isomaltose was achieved by integrating <em>Bacillus subtilis</em>-derived membrane permease and maltose-6’-phosphate glucosidase, alongside <em>Bifidobacterium adolescentis</em>-derived oligo-1,6-glucosidase, and by employing a suboptimal glucose supplementation feeding strategy. To overcome oxygen limitation, <em>Vitreoscilla</em> hemoglobin was localized to the periplasm via the twin-arginine translocation pathway. Systematic fermentation optimization further improved strain performance, achieving an <span>l</span>-tyr titer, yield, and productivity of 109.2 g/L, 0.292 g/g, and 2.18 g/L/h, respectively—the highest reported to date. This research demonstrates a promising strategy for enhancing <span>l</span>-tyrosine biosynthesis, providing a scalable approach for industrial production and broader applications in microbial metabolic engineering.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132306"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132302
Ling Qin , Shoujie He , Jin Hou , Guangjian Li , Yunzi Feng , Mouming Zhao , Mingtao Huang
Succinic acid (SA) is a valuable chemical with broad applications; however, its high concentrations can inhibit yeast cells, reducing fermentation efficiency. In this study, adaptive laboratory evolution was used to enhance yeast tolerance to SA, resulting in several strains capable of growing in medium with 40 g/L SA. Subsequently, whole genome sequencing of the evolved strains was conducted to identify beneficial genetic adaptations. A total of eleven gene mutations were identified across three independent evolutionary lineages, six of which are associated with cell wall functionality and contribute to SA tolerance. Specifically, the deletion of MNN4 impairs mannose side chains and significantly increases resistance to SA. Additionally, the GAS1E267K mutation modifies the surfaces of the electrostatic molecular potential and reduces substrate interaction distances, effectively remodeling the β-1,3-glucan chains in the cell wall. These findings highlight the essential role of the cell wall in enhancing yeast tolerance to SA.
{"title":"Adaptive laboratory evolution induces cell wall alterations for succinic acid tolerance in Saccharomyces cerevisiae","authors":"Ling Qin , Shoujie He , Jin Hou , Guangjian Li , Yunzi Feng , Mouming Zhao , Mingtao Huang","doi":"10.1016/j.biortech.2025.132302","DOIUrl":"10.1016/j.biortech.2025.132302","url":null,"abstract":"<div><div>Succinic acid (SA) is a valuable chemical with broad applications; however, its high concentrations can inhibit yeast cells, reducing fermentation efficiency. In this study, adaptive laboratory evolution was used to enhance yeast tolerance to SA, resulting in several strains capable of growing in medium with 40 g/L SA. Subsequently, whole genome sequencing of the evolved strains was conducted to identify beneficial genetic adaptations. A total of eleven gene mutations were identified across three independent evolutionary lineages, six of which are associated with cell wall functionality and contribute to SA tolerance. Specifically, the deletion of <em>MNN4</em> impairs mannose side chains and significantly increases resistance to SA. Additionally, the GAS1<sup>E267K</sup> mutation modifies the surfaces of the electrostatic molecular potential and reduces substrate interaction distances, effectively remodeling the β-1,3-glucan chains in the cell wall. These findings highlight the essential role of the cell wall in enhancing yeast tolerance to SA.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132302"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132268
Nia Z. Petrova, Tünde N. Tóth, Prateek Shetty, Gergely Maróti, Szilvia Z. Tóth
{"title":"Corrigendum to “Enhancing biophotovoltaic efficiency: Study on a highly productive green algal strain Parachlorella kessleri MACC-38” [Bioresour.= Technol. 394 (2024) 130206]","authors":"Nia Z. Petrova, Tünde N. Tóth, Prateek Shetty, Gergely Maróti, Szilvia Z. Tóth","doi":"10.1016/j.biortech.2025.132268","DOIUrl":"10.1016/j.biortech.2025.132268","url":null,"abstract":"","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"424 ","pages":"Article 132268"},"PeriodicalIF":9.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-02-25DOI: 10.1016/j.biortech.2025.132292
Yi-Tong Yao , Xiao Zhang , Chen-Yu Wang , Yu-He Zhang , Da-Wei Li, Wei-Dong Yang, Hong-Ye Li, Li-Gong Zou
Crypthecodinium cohnii, a protist renowned for its high docosahexaenoic acid (DHA) production, has an unclear mechanism for converting docosapentaenoic acid (DPA) into DHA. This study employed transcriptomic analysis to investigate the effect of excessive oxygen limitation (EOL) on DHA biosynthesis, uncovering a novel oxygen-dependent pathway. The use of intermittent oxygen limitation (IOL) strategy significantly boosted DHA production. Five △4-fatty acid desaturase (FAD4) genes were identified, with CcFAD4_52534 exhibiting the highest catalytic efficiency and dual-functionality, converting eicosapentaenoic acid (EPA) to DPA, and subsequently to DHA. This study integrates transcriptomic insights, the discovery of the bifunctional CcFAD4_52534 enzyme, and the optimized IOL strategy, offering transformative potential for sustainable and high-yield DHA production through tailored genetic engineering in C. cohnii. This approach bridges ecological understanding with industrial innovation.
隐翅虫（Crypthecodinium cohnii）是一种以生产大量二十二碳六烯酸（DHA）而闻名的原生动物，但其将二十二碳五烯酸（DPA）转化为 DHA 的机制尚不清楚。本研究利用转录组分析来研究过度氧限制（EOL）对 DHA 生物合成的影响，发现了一种新的氧气依赖途径。使用间歇性氧限制（IOL）策略显著提高了DHA的产量。研究发现了五个△4-脂肪酸去饱和酶（FAD4）基因，其中CcFAD4_52534具有最高的催化效率和双重功能，可将二十碳五烯酸（EPA）转化为DPA，进而转化为DHA。这项研究综合了转录组学的见解、双功能 CcFAD4_52534 酶的发现以及优化的 IOL 策略，通过对 C. cohnii 进行量身定制的基因工程，为可持续高产 DHA 生产提供了变革性的潜力。这种方法是生态理解与工业创新的桥梁。
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