Pub Date : 2025-03-02DOI: 10.1016/j.biortech.2025.132331
Ming Zhu , Liuying Song , Weiquan Li , Yu Qin , Yu-You Li
The feasibility of converting brewery spent grain (BSG) to biomethane in a mesophilic continuously-stirred tank reactor was demonstrated at various hydraulic retention times (HRTs) of 100, 60, 30, and 20 d. As HRT decreased to 30 d, the biogas and CH4 production rates increased to 1.40 ± 0.05 and 0.89 ± 0.03 L/L/d, respectively. However, a shorter HRT of 20 d increased the instability of the system according to the ratio of total volatile fatty acid and total alkalinity (> 0.35). The modified first-order kinetic equation accurately predicted biogas and CH4 production rates and organics degradation efficiencies. As HRT decreased from 100 to 30 d, the ratio of the conversion of organics based on chemical oxygen demand to CH4 decreased from 80.8 ± 1.8 % to 40.8 ± 1.8 %. The results of the energy balance demonstrated the economic feasibility of anaerobic digestion (AD) of BSG. These finding provide valuable insights for industrial-scale AD of BSG.
{"title":"Hydraulic retention times as key parameter governing biomethanation of brewery spent grain and system stability in long-term continuously-feeding anaerobic digestion","authors":"Ming Zhu , Liuying Song , Weiquan Li , Yu Qin , Yu-You Li","doi":"10.1016/j.biortech.2025.132331","DOIUrl":"10.1016/j.biortech.2025.132331","url":null,"abstract":"<div><div>The feasibility of converting brewery spent grain (BSG) to biomethane in a mesophilic continuously-stirred tank reactor was demonstrated at various hydraulic retention times (HRTs) of 100, 60, 30, and 20 d. As HRT decreased to 30 d, the biogas and CH<sub>4</sub> production rates increased to 1.40 ± 0.05 and 0.89 ± 0.03 L/L/d, respectively. However, a shorter HRT of 20 d increased the instability of the system according to the ratio of total volatile fatty acid and total alkalinity (> 0.35). The modified first-order kinetic equation accurately predicted biogas and CH<sub>4</sub> production rates and organics degradation efficiencies. As HRT decreased from 100 to 30 d, the ratio of the conversion of organics based on chemical oxygen demand to CH<sub>4</sub> decreased from 80.8 ± 1.8 % to 40.8 ± 1.8 %. The results of the energy balance demonstrated the economic feasibility of anaerobic digestion (AD) of BSG. These finding provide valuable insights for industrial-scale AD of BSG.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132331"},"PeriodicalIF":9.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547116","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 : 2025-03-02DOI: 10.1016/j.biortech.2025.132329
Jana Schultz, Marvin Scherzinger, Timo Steinbrecher, Asli Isci, Martin Kaltschmitt
This study compares the biogas potential of solid common reed residues after undergoing vapothermal and hydrothermal pre-treatment, accompanied by a compositional and structural biomass characterization. In a pre-test series, a design of experiments approach was used to determine the influence of the initial biomass water content during vapothermal pre-treatment on the biogas yield. In the main test series, common reed was pre-treated hydrothermally (i.e., in liquid water) and vapothermally (i.e., in saturated steam) while varying temperature and residence time. The initial biomass water content significantly impacted the biogas potential, with an optimum at a value of 32 to 46 wt-%FM. In the main test series, unlike the residence time, temperature significantly impacted the subsequent anaerobic digestion. Vapothermal pre-treatment had a narrow temperature optimum while hydrothermal pre-treatment led to a biogas increase in a broader temperature range. The optimum temperature of both methods was 170 °C, where methane potentials increased by 28 % (vapothermal) and 36 % (hydrothermal) compared to the untreated sample. Considering the mass loss occurring during the pre-treatment, this increase was still 18 % for vapothermal pre-treatment, while it diminished the increase to 6 % for hydrothermal pre-treatment. Overall, vapothermal pre-treatment produced a similar amount of biogas under comparable conditions, but was less susceptible to carbon loss, and, according to an estimation of the required process energy, may offer energy savings compared to hydrothermal pre-treatment.
{"title":"Influence of vapothermal and hydrothermal pre-treatment on anaerobic degradability of lignocellulosic biomass.","authors":"Jana Schultz, Marvin Scherzinger, Timo Steinbrecher, Asli Isci, Martin Kaltschmitt","doi":"10.1016/j.biortech.2025.132329","DOIUrl":"https://doi.org/10.1016/j.biortech.2025.132329","url":null,"abstract":"<p><p>This study compares the biogas potential of solid common reed residues after undergoing vapothermal and hydrothermal pre-treatment, accompanied by a compositional and structural biomass characterization. In a pre-test series, a design of experiments approach was used to determine the influence of the initial biomass water content during vapothermal pre-treatment on the biogas yield. In the main test series, common reed was pre-treated hydrothermally (i.e., in liquid water) and vapothermally (i.e., in saturated steam) while varying temperature and residence time. The initial biomass water content significantly impacted the biogas potential, with an optimum at a value of 32 to 46 wt-%<sub>FM</sub>. In the main test series, unlike the residence time, temperature significantly impacted the subsequent anaerobic digestion. Vapothermal pre-treatment had a narrow temperature optimum while hydrothermal pre-treatment led to a biogas increase in a broader temperature range. The optimum temperature of both methods was 170 °C, where methane potentials increased by 28 % (vapothermal) and 36 % (hydrothermal) compared to the untreated sample. Considering the mass loss occurring during the pre-treatment, this increase was still 18 % for vapothermal pre-treatment, while it diminished the increase to 6 % for hydrothermal pre-treatment. Overall, vapothermal pre-treatment produced a similar amount of biogas under comparable conditions, but was less susceptible to carbon loss, and, according to an estimation of the required process energy, may offer energy savings compared to hydrothermal pre-treatment.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"132329"},"PeriodicalIF":9.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555513","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 : 2025-03-02DOI: 10.1016/j.biortech.2025.132328
Zifang Chi , Wenjing Li , Pengdong Zhang , Huai Li
Selenate (Se(VI)) and nitrate as co-contamination pose significant threats to both environment and human health. This study intends to examine the effects of the addition of Se(VI) on nitrogen removal in iron/manganese ore and wood based two-stage vertical flow constructed wetlands (B-CWs and C-CWs), as well as the feasibility of simultaneous removal. The results indicated that low Se(VI) concentration (0.5 mg/L) caused acute inhibition for nitrogen removal. Increasing nitrate concentration and prolonging HRT resulted in simultaneous and efficient removal of Se(VI) and nitrogen in B-CWs and C-CWs, with C-CWs having a higher total selenium removal. However, nitrogen removal was inhibited when further increasing Se(VI) concentration (1 mg/L) in C-CWs, but Se(VI) removal remained efficient. High concentrations of Se(VI) (5 mg/L) had a long-term inhibition for Se(VI) and nitrogen removal, which was not recoverable. Se(0) was the main reduction end product, accompanied by some Se(IV) production. High abundance of denitrifying/Se(VI)-reducing bacteria coupled with iron/manganese cycling pumps promoted efficient Se(VI) bioreduction.
{"title":"Hydraulic retention time (HRT) extension and nitrate addition mitigate Se(VI) inhibition and enhance selenium removal in constructed wetlands: Potential role of nitrate and Fe/Mn pumps","authors":"Zifang Chi , Wenjing Li , Pengdong Zhang , Huai Li","doi":"10.1016/j.biortech.2025.132328","DOIUrl":"10.1016/j.biortech.2025.132328","url":null,"abstract":"<div><div>Selenate (Se(VI)) and nitrate as co-contamination pose significant threats to both environment and human health. This study intends to examine the effects of the addition of Se(VI) on nitrogen removal in iron/manganese ore and wood based two-stage vertical flow constructed wetlands (B-CWs and C-CWs), as well as the feasibility of simultaneous removal. The results indicated that low Se(VI) concentration (0.5 mg/L) caused acute inhibition for nitrogen removal. Increasing nitrate concentration and prolonging HRT resulted in simultaneous and efficient removal of Se(VI) and nitrogen in B-CWs and C-CWs, with C-CWs having a higher total selenium removal. However, nitrogen removal was inhibited when further increasing Se(VI) concentration (1 mg/L) in C-CWs, but Se(VI) removal remained efficient. High concentrations of Se(VI) (5 mg/L) had a long-term inhibition for Se(VI) and nitrogen removal, which was not recoverable. Se(0) was the main reduction end product, accompanied by some Se(IV) production. High abundance of denitrifying/Se(VI)-reducing bacteria coupled with iron/manganese cycling pumps promoted efficient Se(VI) bioreduction.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132328"},"PeriodicalIF":9.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547117","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 : 2025-03-02DOI: 10.1016/j.biortech.2025.132330
Zhengyang Lu , Yanwen Shen , Xiaohong Guan
Anoxygenic phototrophs oxidize both organic and inorganic electron donors for phototrophic fixation of CO2 without O2 generation, playing important roles in global carbon cycles. However, it remains unknown whether and how they can fix CO2 using zero-valent iron (ZVI) as solid-phase electron donor. This study investigated the feasibility of Fe0-driven CO2 fixation by the model bacteria Rhodopseudomonas palustris using nano- (nZVI) and micron-ZVI (mZVI). The results showed that ZVI could empower photoautotrophic and photoheterotrophic growth of R. palustris through iron biocorrosion, with CO2 fixation increased by up to 15%. The ZVI-driven CO2 fixation was attributed to H2-mediated extracellular electron uptake (EEU) and Fe(II) oxidation. The genes encoding EEU-associated pathways were up-regulated in the presence of ZVI, indicating that ZVI promoted CO2 fixation through direct transfer. However, ZVI cannot enable dark CO2 fixation. These findings highlighted the potential of ZVI as a solid electron donor for enhanced microbial CO2 fixation.
{"title":"Zero-valent iron as an alternative electron donor for extracellular electron uptake linked to CO2 fixation in Rhodopseudomonas palustris","authors":"Zhengyang Lu , Yanwen Shen , Xiaohong Guan","doi":"10.1016/j.biortech.2025.132330","DOIUrl":"10.1016/j.biortech.2025.132330","url":null,"abstract":"<div><div>Anoxygenic phototrophs oxidize both organic and inorganic electron donors for phototrophic fixation of CO<sub>2</sub> without O<sub>2</sub> generation, playing important roles in global carbon cycles. However, it remains unknown whether and how they can fix CO<sub>2</sub> using zero-valent iron (ZVI) as solid-phase electron donor. This study investigated the feasibility of Fe<sup>0</sup>-driven CO<sub>2</sub> fixation by the model bacteria <em>Rhodopseudomonas palustris</em> using nano- (nZVI) and micron-ZVI (mZVI). The results showed that ZVI could empower photoautotrophic and photoheterotrophic growth of <em>R. palustris</em> through iron biocorrosion, with CO<sub>2</sub> fixation increased by up to 15%. The ZVI-driven CO<sub>2</sub> fixation was attributed to H<sub>2</sub>-mediated extracellular electron uptake (EEU) and Fe(II) oxidation. The genes encoding EEU-associated pathways were up-regulated in the presence of ZVI, indicating that ZVI promoted CO<sub>2</sub> fixation through direct transfer. However, ZVI cannot enable dark CO<sub>2</sub> fixation. These findings highlighted the potential of ZVI as a solid electron donor for enhanced microbial CO<sub>2</sub> fixation.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132330"},"PeriodicalIF":9.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143547118","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 : 2025-03-02DOI: 10.1016/j.biortech.2025.132332
Sungman Lee , Seongbong Heo , Jihea Lee , Heejong Son , Jinhua Wang , Young Mo Kim
This study investigated how the biodegradation rate constant (kbio) of 11 micropollutants (MPs) responded to changes in the concentrations of growth substrates and microbial activities while considering the predominant microbial degraders of MPs. Metformin, losartan, valsartan, and cimetidine (group A) were biodegraded predominantly by nitrifiers. MPs of group A showed a positive correlation with kbio and nitrifying activity, while a negative correlation was observed with the initial concentration of ammonium, possibly due to competitive inhibition. Atenolol, caffeine, and naproxen (group B) were biodegraded predominantly by heterotrophs, with kbio remaining stable despite changes in organic matter concentration or heterotrophic activity. Olmesartan, candesartan, diclofenac, and sulfamethoxazole (group C) showed low kbio regardless of growth substrate concentration and microbial activity, which could be attributed to their chemical structures. These findings suggest that the kbio of MPs in WWTPs could respond differently to growth substrate concentration and microbial activity depending on their predominant degraders.
{"title":"Aerobic biodegradation of micropollutants by nitrifiers and heterotrophs: Changes in biodegradation rate constant depending on levels of growth substrates and microbial activities","authors":"Sungman Lee , Seongbong Heo , Jihea Lee , Heejong Son , Jinhua Wang , Young Mo Kim","doi":"10.1016/j.biortech.2025.132332","DOIUrl":"10.1016/j.biortech.2025.132332","url":null,"abstract":"<div><div>This study investigated how the biodegradation rate constant (<em>k</em><sub>bio</sub>) of 11 micropollutants (MPs) responded to changes in the concentrations of growth substrates and microbial activities while considering the predominant microbial degraders of MPs. Metformin, losartan, valsartan, and cimetidine (group A) were biodegraded predominantly by nitrifiers. MPs of group A showed a positive correlation with <em>k</em><sub>bio</sub> and nitrifying activity, while a negative correlation was observed with the initial concentration of ammonium, possibly due to competitive inhibition. Atenolol, caffeine, and naproxen (group B) were biodegraded predominantly by heterotrophs, with <em>k</em><sub>bio</sub> remaining stable despite changes in organic matter concentration or heterotrophic activity. Olmesartan, candesartan, diclofenac, and sulfamethoxazole (group C) showed low <em>k</em><sub>bio</sub> regardless of growth substrate concentration and microbial activity, which could be attributed to their chemical structures. These findings suggest that the <em>k</em><sub>bio</sub> of MPs in WWTPs could respond differently to growth substrate concentration and microbial activity depending on their predominant degraders.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132332"},"PeriodicalIF":9.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555512","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 : 2025-03-01DOI: 10.1016/j.biortech.2025.132320
Soheil Valizadeh , Yasin Khani , Behzad Valizadeh , Jeong-Chul Kim , Kanghee Cho , Young-Kwon Park
Widespread reliance on fossil fuels and their increasing costs have necessitated the search for viable alternatives. This study details a reliable method for generating jet fuel-range aromatic hydrocarbons (C8-C16) via catalytic pyrolysis of woody biomass. To do this, HZSM-5 was modified using NaOH (N-HZSM-5) and HCl (H-HZSM-5) and utilized in the pyrolysis of three types of sawdust (S1, S2, and S3). In S1 pyrolysis, HZSM-5 increased C8-C16 aromatics’ selectivity despite a lower bio-oil yield compared to the Non-C test. Among sawdust samples, S2 pyrolysis produced the highest C8-C16 aromatics (44.2%) due to its compositional and thermal characteristics. The use of N-HZSM-5 in S2 pyrolysis maximized the yield of bio-oil (46.9 wt%) and the selectivity for C8-C16 aromatics (49.3 %). N-HZSM-5 exhibited stable performance over three cycles, with minimal decline in C8-C16 aromatics. This study proposes a sustainable and feasible method for the generation of biojet fuel from lignocellulosic biomass.
{"title":"Enhanced generation of jet fuel-range aromatic hydrocarbons through catalytic pyrolysis of woody biomass by simple chemical treatment on ZSM-5 catalyst","authors":"Soheil Valizadeh , Yasin Khani , Behzad Valizadeh , Jeong-Chul Kim , Kanghee Cho , Young-Kwon Park","doi":"10.1016/j.biortech.2025.132320","DOIUrl":"10.1016/j.biortech.2025.132320","url":null,"abstract":"<div><div>Widespread reliance on fossil fuels and their increasing costs have necessitated the search for viable alternatives. This study details a reliable method for generating jet fuel-range aromatic hydrocarbons (C<sub>8</sub>-C<sub>16</sub>) via catalytic pyrolysis of woody biomass. To do this, HZSM-5 was modified using NaOH (N-HZSM-5) and HCl (H-HZSM-5) and utilized in the pyrolysis of three types of sawdust (S1, S2, and S3). In S1 pyrolysis, HZSM-5 increased C<sub>8</sub>-C<sub>16</sub> aromatics’ selectivity despite a lower bio-oil yield compared to the Non-C test. Among sawdust samples, S2 pyrolysis produced the highest C<sub>8</sub>-C<sub>16</sub> aromatics (44.2%) due to its compositional and thermal characteristics. The use of N-HZSM-5 in S2 pyrolysis maximized the yield of bio-oil (46.9 wt%) and the selectivity for C<sub>8</sub>-C<sub>16</sub> aromatics (49.3 %). N-HZSM-5 exhibited stable performance over three cycles, with minimal decline in C<sub>8</sub>-C<sub>16</sub> aromatics. This study proposes a sustainable and feasible method for the generation of biojet fuel from lignocellulosic biomass.</div><div>Abbreviations: RJF, Renewable jet fuel; LAS, Lewis acid sites; BAS, Brønsted Lowry acid sites; S1, Sawdust 1; S2, Sawdust 2; S3, Sawdust 3; HZSM-5 (80), HZSM-5 (SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub>: 80); N-HZSM-5, NaOH-treated HZSM-5 (80); H-HZSM-5, HCl-treated HZSM-5 (80); XRF, X-ray Fluorescence; XRD, X-ray diffraction (XRD); NH<sub>3</sub>-TPD, Ammonia temperature-programmed desorption; FT-IR, Pyridine Fourier transform infrared; NMR, Solid-state nuclear magnetic resonance; MAS, Magic angle spinning; FE-SEM, Field emission scanning electron microscopy; HR-TEM, High-resolution transmission electron microscopy; S<sub>BET</sub>, BET surface area; V<sub>Total</sub>, Total pore volume; S<sub>Meso</sub>, Mesopores’ surface area; V<sub>Meso</sub>, Mesopores’ pore volume; S<sub>Micro</sub>, Micropores’ surface area; V<sub>Micro</sub>, Micropores’ pore volume; H<sup>+</sup>, Proton; Non-C, Non-Catalytic.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132320"},"PeriodicalIF":9.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539641","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 : 2025-03-01DOI: 10.1016/j.biortech.2025.132321
Zahra Nemati, Mohammad Hossein Kianmehr, Akbar Arabhosseini, Ali Abdulkhani, Wolfgang Stelte
Sugarcane bagasse pith (SBP), a byproduct of sugar production, is often discarded or burned as waste, despite its potential as a biofuel feedstock. This study explores ozone pretreatment as a processing step to enhance the physicochemical and pelletizing properties of SBP for biofuel production. Ozone pretreatment, conducted in a fixed-bed reactor, selectively reduced lignin content and improved the biomass's binding properties, promoting stronger interparticle adhesion during pelletization. Key variables, including moisture content, die temperature, pressure, and ozonation time, were optimized using Response Surface Methodology (RSM) with Central Composite Design (CCD), leading to improved pellet density and mechanical strength. Thermogravimetric analysis revealed enhanced thermal stability and combustion efficiency in ozone-treated SBP pellets. These findings demonstrate that ozone pretreatment is a promising, sustainable approach to valorize SBP and optimize biomass pellet production.
{"title":"Ozone pretreatment and process optimization to improve fuel pellet production from sugarcane bagasse pith.","authors":"Zahra Nemati, Mohammad Hossein Kianmehr, Akbar Arabhosseini, Ali Abdulkhani, Wolfgang Stelte","doi":"10.1016/j.biortech.2025.132321","DOIUrl":"https://doi.org/10.1016/j.biortech.2025.132321","url":null,"abstract":"<p><p>Sugarcane bagasse pith (SBP), a byproduct of sugar production, is often discarded or burned as waste, despite its potential as a biofuel feedstock. This study explores ozone pretreatment as a processing step to enhance the physicochemical and pelletizing properties of SBP for biofuel production. Ozone pretreatment, conducted in a fixed-bed reactor, selectively reduced lignin content and improved the biomass's binding properties, promoting stronger interparticle adhesion during pelletization. Key variables, including moisture content, die temperature, pressure, and ozonation time, were optimized using Response Surface Methodology (RSM) with Central Composite Design (CCD), leading to improved pellet density and mechanical strength. Thermogravimetric analysis revealed enhanced thermal stability and combustion efficiency in ozone-treated SBP pellets. These findings demonstrate that ozone pretreatment is a promising, sustainable approach to valorize SBP and optimize biomass pellet production.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"132321"},"PeriodicalIF":9.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539642","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}
Rational metabolic engineering has numerous applications in the optimization of microorganisms for the production of valuable compounds at the laboratory-scale. However, the existing strategies and tools are far from sufficient for engineering of industrial strains due to their specificity. The aim of this project was to implement novel strategies to enhance industrial l-phenylalanine (l-PHE) production and yield, including the regulation of key gene expressions, modifications of global transcription factors, creation of NADPH-independent pentose phosphate pathway and pyruvate-oxaloacetate-phosphoenolpyruvate cycle. The project also involved the identification and engineering of novel byproduct pathways and the development of a tyrosine-nonauxotrophic strain. Through comprehensive rational engineering, an industrial l-PHE producer, designated PHE17, achieved the highest production (103.15 g/L) and yield (0.229 g/g) of l-PHE reported thus far. This study also represents the first report on the iterative engineering of industrial l-PHE producers, thereby offering great significance for the engineering of other aromatic animo acids-producing strains.
{"title":"Rational metabolic engineering of Escherichia coli for the industrial-scale production of l-phenylalanine.","authors":"Minliang Chen, Chao Han, Peng Zhou, Run Shi, Zhiwei Xing, Qianqian Chen, Gou-An Xie, Rufei Xie, Wei Tan, Hengyu Liang","doi":"10.1016/j.biortech.2025.132325","DOIUrl":"https://doi.org/10.1016/j.biortech.2025.132325","url":null,"abstract":"<p><p>Rational metabolic engineering has numerous applications in the optimization of microorganisms for the production of valuable compounds at the laboratory-scale. However, the existing strategies and tools are far from sufficient for engineering of industrial strains due to their specificity. The aim of this project was to implement novel strategies to enhance industrial l-phenylalanine (l-PHE) production and yield, including the regulation of key gene expressions, modifications of global transcription factors, creation of NADPH-independent pentose phosphate pathway and pyruvate-oxaloacetate-phosphoenolpyruvate cycle. The project also involved the identification and engineering of novel byproduct pathways and the development of a tyrosine-nonauxotrophic strain. Through comprehensive rational engineering, an industrial l-PHE producer, designated PHE17, achieved the highest production (103.15 g/L) and yield (0.229 g/g) of l-PHE reported thus far. This study also represents the first report on the iterative engineering of industrial l-PHE producers, thereby offering great significance for the engineering of other aromatic animo acids-producing strains.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"132325"},"PeriodicalIF":9.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539643","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 : 2025-02-28DOI: 10.1016/j.biortech.2025.132324
Kejing Zhang, Jianxin Chen, Long Zou, Congcan Shi, Xinyue Li, Yuhan Shi, Mengnan Liu, Ying Duan, Qingwei Wang, Chunlian Ding, Yan Shi
Microbial electrosynthesis of CO2 is a sustainable carbon neutral technology. Although known for its diverse and efficient extracellular electron transfer (EET) characteristics, the bacteria of Shewanella genus have never been reported for use in electrosynthesis of multi-carbon chemicals. Herein, the electricity-powered conversion of CO2 to acetate was achieved under ammonium regulation for the first time in the model strain (Shewanella oneidensis MR-1), due to the activation of its intrinsic reductive glycine pathway. A high electron flux from cathode into MR-1 was achieved through the unique electron uptake pathway mediated by endogenous iron release, biomineralization of iron oxide, and inherent EET pathways. Consequently, MR-1 delivered an acetate production rate of 78.6 ± 4.2mmol m-2 d-1, significantly surpassing those of previously reported electro-autotrophic acetogens under similar operating conditions. Our findings not only provide a novel platform for one-carbon biorefinery, but also prompt recognition to the complexity of EET and CO2 fixation.
{"title":"Electricity-powered cryptic CO<sub>2</sub> fixation pathway in heterotrophic Shewanella oneidensis for acetate synthesis.","authors":"Kejing Zhang, Jianxin Chen, Long Zou, Congcan Shi, Xinyue Li, Yuhan Shi, Mengnan Liu, Ying Duan, Qingwei Wang, Chunlian Ding, Yan Shi","doi":"10.1016/j.biortech.2025.132324","DOIUrl":"https://doi.org/10.1016/j.biortech.2025.132324","url":null,"abstract":"<p><p>Microbial electrosynthesis of CO<sub>2</sub> is a sustainable carbon neutral technology. Although known for its diverse and efficient extracellular electron transfer (EET) characteristics, the bacteria of Shewanella genus have never been reported for use in electrosynthesis of multi-carbon chemicals. Herein, the electricity-powered conversion of CO<sub>2</sub> to acetate was achieved under ammonium regulation for the first time in the model strain (Shewanella oneidensis MR-1), due to the activation of its intrinsic reductive glycine pathway. A high electron flux from cathode into MR-1 was achieved through the unique electron uptake pathway mediated by endogenous iron release, biomineralization of iron oxide, and inherent EET pathways. Consequently, MR-1 delivered an acetate production rate of 78.6 ± 4.2mmol m<sup>-2</sup> d<sup>-1</sup>, significantly surpassing those of previously reported electro-autotrophic acetogens under similar operating conditions. Our findings not only provide a novel platform for one-carbon biorefinery, but also prompt recognition to the complexity of EET and CO<sub>2</sub> fixation.</p>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":" ","pages":"132324"},"PeriodicalIF":9.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536239","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 : 2025-02-28DOI: 10.1016/j.biortech.2025.132323
Xue Bai , Mario Jr Rebosura , Paul D. Jensen
Alkaline pre-treatment enhances the biological accessibility and methane recovery of lignocellulosic feedstocks during anaerobic digestion. This study investigates the impact of potassium hydroxide (KOH) pre-treatment on paunch (2.5 and 12 g per 100 g paunch TS for 24 hr at 22 °C) using biochemical methane potential tests and 5 L bench-scale CSTR bioreactors. BMP tests showed significant improvements in hydrolysis kinetics and methane yield. Continuous experiments validated these findings, with volatile solids destruction increasing from 33 % for raw paunch to 61 % for 12 % KOH pre-treated paunch. Methane yield was consistently enhanced with an increase of up to 150 % compared to raw paunch. Microbial analysis revealed a shift in dominant methanogens from Methanosaeta to Methanobacterium, in response to KOH pre-treatment. While the results highlight the potential of KOH pre-treatment to improve both degradability and methane recovery, challenges related to process stability were identified, emphasizing the need for further investigation to optimise operational conditions for full-scale applications.
{"title":"Enhanced anaerobic digestion of lignocellulosic paunch waste using potassium hydroxide pre-treatment","authors":"Xue Bai , Mario Jr Rebosura , Paul D. Jensen","doi":"10.1016/j.biortech.2025.132323","DOIUrl":"10.1016/j.biortech.2025.132323","url":null,"abstract":"<div><div>Alkaline pre-treatment enhances the biological accessibility and methane recovery of lignocellulosic feedstocks during anaerobic digestion. This study investigates the impact of potassium hydroxide (KOH) pre-treatment on paunch (2.5 and 12 g per 100 g paunch TS for 24 hr at 22 °C) using biochemical methane potential tests and 5 L bench-scale CSTR bioreactors. BMP tests showed significant improvements in hydrolysis kinetics and methane yield. Continuous experiments validated these findings, with volatile solids destruction increasing from 33 % for raw paunch to 61 % for 12 % KOH pre-treated paunch. Methane yield was consistently enhanced with an increase of up to 150 % compared to raw paunch. Microbial analysis revealed a shift in dominant methanogens from <em>Methanosaeta</em> to <em>Methanobacterium,</em> in response to KOH pre-treatment. While the results highlight the potential of KOH pre-treatment to improve both degradability and methane recovery, challenges related to process stability were identified, emphasizing the need for further investigation to optimise operational conditions for full-scale applications.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"425 ","pages":"Article 132323"},"PeriodicalIF":9.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536242","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}
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