Biochemical Engineering Journal最新文献_第4页

Impact of stringent stress response and amino acid supplementation on recombinant protein production in Escherichia coli

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-17 DOI: 10.1016/j.bej.2025.109727

Girish H. Rajacharya , Jashwant Kumar , Jaya A. Gupta , Anurag S. Rathore

{"title":"Impact of stringent stress response and amino acid supplementation on recombinant protein production in Escherichia coli","authors":"Girish H. Rajacharya , Jashwant Kumar , Jaya A. Gupta , Anurag S. Rathore","doi":"10.1016/j.bej.2025.109727","DOIUrl":"10.1016/j.bej.2025.109727","url":null,"abstract":"<div><div>The metabolic response of <em>Escherichia coli</em> BL21 DE3 strains upon amino acid supplementation and stringent stress was examined to assess its effects on growth, protein production, metabolic efficiency, and cellular stress. In the absence of amino acids, <em>E. coli</em> prioritized amino acid synthesis, essential for recombinant protein production. Supplementation led to faster growth, higher cell densities, and reduced acetate accumulation, indicating improved metabolic balance. Proteomic analysis revealed notable changes in protein abundance during the early log and post-induction mid-log phases, with supplemented cultures showing enhanced metabolic capacity and reduced stress levels. Gene expression analysis demonstrated that amino acid availability downregulated stress response genes and upregulated genes associated with nutrient uptake and metabolism, boosting growth and productivity. Specifically, genes <em>lldR</em>, <em>ydgR</em>, <em>tppB</em>, and <em>yhhN</em> were upregulated, while <em>adiA</em> and <em>ydeI</em> were downregulated, reflecting better metabolic conditions. Stringent response analysis showed elevated (p)ppGpp levels and increased activities of SpoT and RelA without supplementation, indicative of nutrient stress. Supplementation lowered these stress markers, fostering a favourable metabolic state. The study underscores the importance of amino acid supplementation for optimizing biomass production and recombinant protein yields, offering insights into <em>E. coli</em> physiology and strategies for metabolic engineering.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109727"},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Voltage application and biomass retention increased biogas production in a combined microbial electrolysis cell and anaerobic digestion system treating chicken manure

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-17 DOI: 10.1016/j.bej.2025.109728

Kenan Dalkılıç , Elvin Aghayev , Eda Sinoplu

{"title":"Voltage application and biomass retention increased biogas production in a combined microbial electrolysis cell and anaerobic digestion system treating chicken manure","authors":"Kenan Dalkılıç , Elvin Aghayev , Eda Sinoplu","doi":"10.1016/j.bej.2025.109728","DOIUrl":"10.1016/j.bej.2025.109728","url":null,"abstract":"<div><div>This study investigates the effect of the voltage application and biomass retention on the biogas production performance of a combined microbial electrolysis cell and anaerobic digestion (MEC+AD) reactor operated at different organic loading rates (OLR). The chicken manure (CM) with a content of 6 % VS was fed to the reactors as substrate at various hydraulic retention times (HRT) ranging from 3 to 20 days. It was observed that the conventional anaerobic digestion (AD) reactor collapsed due to the overloading at the HRT of 5 days. On the other hand, due to the voltage application and biomass retention on the electrodes of the combined reactors, (MEC+AD)<sub>C</sub> without a voltage application and (MEC+AD)<sub>0.3</sub> with a voltage application of 0.3 V presented the highest methane production of 1.98 ± 0.19 and 2.37 ± 0.32 L/L<sub>R</sub>/d, respectively. Organic removal rates of the combined reactors were similar to each other; however, in terms of biogas production, (MEC+AD)<sub>0.3</sub> presented superior performance at all sets due to the voltage application and microbial community on the electrodes. <em>Methanosarcina</em> had a dominance of 5 % at the cathode of (MEC+AD)<sub>0.3</sub> at the genus level, which affected the results. The highest methane yield obtained in this study was 373 ± 72 mL CH<sub>4</sub>/g VS at (MEC+AD)<sub>0.3,</sub> which was 30 % higher than that of (MEC+AD)<sub>C</sub> due to the voltage application and the genus <em>Methanosarcina</em> on the cathode.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109728"},"PeriodicalIF":3.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rerouting of phytosterol degradation pathways in targeted high-yield and high-purity 9α-hydroxyandrost-4-ene-3,17-dione microbial biotransformation

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-16 DOI: 10.1016/j.bej.2025.109723

Xinxin Chen , Xiaohan Jiang , Bo Zhang , Zhiqiang Liu , Yuguo Zheng

{"title":"Rerouting of phytosterol degradation pathways in targeted high-yield and high-purity 9α-hydroxyandrost-4-ene-3,17-dione microbial biotransformation","authors":"Xinxin Chen , Xiaohan Jiang , Bo Zhang , Zhiqiang Liu , Yuguo Zheng","doi":"10.1016/j.bej.2025.109723","DOIUrl":"10.1016/j.bej.2025.109723","url":null,"abstract":"<div><div>9α-Hydroxyandrost-4-ene-3,17-dione (9-OHAD) is a representative precursor in steroid drug synthesis. However, during the 9-OHAD production from phytosterol in <em>Mycolicibacterium neoaurum</em> (<em>M. neoaurum</em>), the current manufacturing processes suffer from low productivity and purity due to the generation of a variety of by-products. In this study, we genetically modified the phytosterol catabolism <em>in M. neoaurum</em> and achieved 13.4 g/L and 91.1 % molar yield of 9-OHAD with no detectable by-products at a high phytosterol concentration of 20 g/L in shake flask. It was achieved by inactivating <em>Opccr</em>, <em>SalA</em>, <em>TeB</em>, and overexpressing <em>KshA1</em> and <em>ChsH1–2</em> to eliminate the production of 20-hydroxymethyl-9,21-dihydroxy-20-methyl-pregna-4-en-3-one (9-OH-4-HBC), 4-androstene-3,17-dione (4-AD) and 3-oxo-4-pregnene-9-OH-20-carboxylic methyl ester (9-OH-3-OPCM) as well as overcoming the production limitations of 9-OHAD. Notably, when scaled up in a 5 L bioreactor with 45 g/L phytosterol concentration, the modified <em>M. neoaurum</em> achieved 24.5 g/L and 74.5 % molar conversion of 9-OHAD by using soybean oil and (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) as a co-solvent and antifoam agent. Therefore, our findings demonstrate a method to improve the efficiency and purity of 9-OHAD biosynthesis in <em>M. neoaurum</em>.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109723"},"PeriodicalIF":3.7,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of novel adsorbents in methanol removal from ethanol: Citric acid-modified 4A zeolites and Cu@ZIF-7

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-16 DOI: 10.1016/j.bej.2025.109719

Jing Fang, Lingzhi Luo, Wenyan Li, Hao Li

{"title":"Application of novel adsorbents in methanol removal from ethanol: Citric acid-modified 4A zeolites and Cu@ZIF-7","authors":"Jing Fang, Lingzhi Luo, Wenyan Li, Hao Li","doi":"10.1016/j.bej.2025.109719","DOIUrl":"10.1016/j.bej.2025.109719","url":null,"abstract":"<div><div>Ethanol, as an important solvent and basic chemical feedstock, has widespread applications in the pharmaceutical, food, and fine chemical industries, including processes such as absorption, washing, and extraction. However, methanol and water are inevitable by-products in the industrial production of ethanol, whether through biological fermentation or chemical synthesis. Particularly methanol, which is harmful to both health and the environment, is typically present in ethanol products at low concentrations, posing a significant challenge for its effective removal. We designed citric acid-modified 4A zeolites and a bimetallic organic framework Cu@ZIF-7. Under optimal modification conditions, the modified 4A zeolite showed a 39.15 % and 37.21 % increase in selectivity for methanol and water, respectively, compared to the initial 4A zeolite. The yield of qualified products increased by 44.71 %. Furthermore, Cu@ZIF-7 exhibited a methanol adsorption capacity of 1.125 mg·g<sup>−1</sup>, which is 3.42 times that of the initial 4A zeolites. Density Functional Theory (DFT) calculations confirmed that the introduced Cu sites are associated with this enhanced methanol adsorption capacity. Experimental evidence suggests that these adsorbents perform exceptionally in purifying ethanol, particularly in the removal of trace methanol. As a new, environmentally friendly separation method, it holds great potential for obtaining high-purity ethanol.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"220 ","pages":"Article 109719"},"PeriodicalIF":3.7,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of aeration conditions on nitrogen removal performance and N2O emissions in a biofilm CANON reactor

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-13 DOI: 10.1016/j.bej.2025.109724

Kunming Fu , Zirui Li , Huifang Wang , Hui Li , Xueying Su

{"title":"Effects of aeration conditions on nitrogen removal performance and N2O emissions in a biofilm CANON reactor","authors":"Kunming Fu , Zirui Li , Huifang Wang , Hui Li , Xueying Su","doi":"10.1016/j.bej.2025.109724","DOIUrl":"10.1016/j.bej.2025.109724","url":null,"abstract":"<div><div>The complete autotrophic nitrogen removal over nitrite (CANON) process offers significant nitrogen removal benefits, but N<sub>2</sub>O emissions remain a concern. This study used a sequencing batch biofilm reactor (SBBR) to examine how different aeration conditions (aeration rates and strategies) affect N2O emissions during CANON. In the experiment, N<sub>2</sub>O emissions were collected and calculated every 30 min, with nitrogen removal efficiency (NRE) maintained between 81 % and 92 %. The results showed that under continuous aeration conditions, as the aeration rate increased from 1 m<sup>3</sup>·(m<sup>3</sup>·h)<sup>−1</sup> to 8 m<sup>3</sup>·(m<sup>3</sup>·h)<sup>−1</sup>, N<sub>2</sub>O emissions significantly increased from 2.99 mg to 20.23 mg, and the emission proportion increased from 1.53 % to 9.74 %. Under intermittent aeration conditions, when the aeration rate was maintained at 8 m<sup>3</sup>·(m<sup>3</sup>·h)<sup>−1</sup> and the initial aerobic phase was shortened by 30 min, the system rapidly shifted from aerobic to anaerobic conditions, reducing N<sub>2</sub>O emissions from 16.16 mg to 12.69 mg, with the emission proportion dropping from 7.94 % to 6.1 %. At this point, the concentration of NO<sub>2</sub><sup>-</sup>-N decreased from 27.77 mg·L<sup>−1</sup> to 18 mg·L<sup>−1</sup>. The study suggests that the aeration rate influences N<sub>2</sub>O generation by regulating dissolved oxygen (DO) concentration and NO<sub>2</sub><sup>-</sup>-N accumulation, and affects its release through the gas stripping effect. Appropriately shortening the duration of both the aerobic and anaerobic phases can effectively reduce N<sub>2</sub>O emissions.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109724"},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An investigation of kinetics and mass transfer parameters during ultrasound-assisted extraction of fucoidan from the brown seaweed Ecklonia maxima

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-13 DOI: 10.1016/j.bej.2025.109717

Zwonaka Mapholi, George Mbella Teke, Neill Jurgens Goosen

{"title":"An investigation of kinetics and mass transfer parameters during ultrasound-assisted extraction of fucoidan from the brown seaweed Ecklonia maxima","authors":"Zwonaka Mapholi, George Mbella Teke, Neill Jurgens Goosen","doi":"10.1016/j.bej.2025.109717","DOIUrl":"10.1016/j.bej.2025.109717","url":null,"abstract":"<div><div>Fucoidan, a bioactive sulfated polysaccharide from brown seaweed, holds significant industrial potential. This study explores ultrasound-assisted extraction (UAE) using a batch recirculation flow cell for fucoidan extraction. The impacts of ultrasound amplitude (0 – 190 μm), temperature (25 – 85 ℃) and pH (3 – 11) were evaluated on mass transfer parameters – effective diffusivity, mass transfer coefficient, initial extraction rate, and the sulfates equilibrium concentration. These parameters were modelled using Fick’s second law, the mass transfer model and the Peleg model, all of which demonstrated good agreement with experimental data (R<sup>2</sup> > 0.89). UAE (at 190 μm) significantly enhances extraction kinetics, increasing effective diffusivity from 0.863 to 3.46 × 10<sup>−12</sup> m<sup>2</sup>·s<sup>−1</sup> and mass transfer coefficient from 0.451 to 1.84 × 10<sup>−6</sup> m·s<sup>−1</sup> compared to no ultrasound. Higher temperatures and higher amplitudes enhance the mass transfer rates, while pH beyond 5 reduces these rates due to alginates co-extraction, but increased sulfates equilibrium concentration, suggesting benefits for maximising final yields. UAE of fucoidan is an internal diffusion-limited process (Biot numbers > 50).</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109717"},"PeriodicalIF":3.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Amino acid supplementation to achieve enhanced production of a fab fragment in Escherichia coli: rHu ranibizumab as a case study

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-12 DOI: 10.1016/j.bej.2025.109718

Rucha S. Patil, Drashti P. Trivedi, Anurag S. Rathore

{"title":"Amino acid supplementation to achieve enhanced production of a fab fragment in Escherichia coli: rHu ranibizumab as a case study","authors":"Rucha S. Patil, Drashti P. Trivedi, Anurag S. Rathore","doi":"10.1016/j.bej.2025.109718","DOIUrl":"10.1016/j.bej.2025.109718","url":null,"abstract":"<div><div>Microbial host systems, specifically <em>E. coli</em>-based, are widely used hosts for the production of recombinant proteins and biotherapeutics. Overproduction of heterologous protein often causes excessive consumption of ATPs and other precursors, especially amino acids, and this can disrupt cell metabolism, thereby resulting in reduced cell growth and protein production. In this study, we demonstrate that supplementation of amino acids can reduce metabolic burden and thereby improve the biomass and protein yield. Ranibizumab, a fab fragment biotherapeutic, has been taken as a case study. Plackett-Burman Design of Experiments (DOE) based screening of all 20 amino acids was performed first to identify significant amino acids. Further, to confirm the finding of the screening study, consumption of amino acids was monitored and based on the pattern, the required amino acids were supplemented. This targeted amino acid supplementation resulted in a significant increase in biomass (28 % increase in dry cell weight), protein titre (40 % increase in g protein per g IBs), specific growth rate (by 23 %), and substrate uptake (by 37 %). The results demonstrate that optimal amino acid supplementation enhances process productivity.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109718"},"PeriodicalIF":3.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Engineering of β-carotene hydroxylase for enhanced astaxanthin production in Saccharomyces cerevisiae 对β-胡萝卜素羟化酶进行工程改造，提高酿酒酵母中虾青素的产量

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-12 DOI: 10.1016/j.bej.2025.109722

Jiayan Du , Youtong Bao , Jingyuan Zhu , Xueqing Pang , Depeng Ren , Xinjian Yin , Pingping Zhou

{"title":"Engineering of β-carotene hydroxylase for enhanced astaxanthin production in Saccharomyces cerevisiae","authors":"Jiayan Du , Youtong Bao , Jingyuan Zhu , Xueqing Pang , Depeng Ren , Xinjian Yin , Pingping Zhou","doi":"10.1016/j.bej.2025.109722","DOIUrl":"10.1016/j.bej.2025.109722","url":null,"abstract":"<div><div>Astaxanthin, a potent antioxidant widely applied in health supplements, cosmetics, and animal feed, faces production challenges in microbial synthesis due to inefficient β-carotene hydroxylase activity. This study identified rate-limiting enzymes and demonstrated that the expressing phytoene desaturase BtCrtI from <em>Blakeslea trispora</em> in <em>Saccharomyces cerevisiae</em> increased β-carotene production 2.8-fold compared to XdCrtI from <em>Xanthophyllomyces dendrorhous</em>. Integrating of XdCrtYB, BtCrtI, CrtE03M, and tHMG1 achieved 208.7 mg/L β-carotene. However, introducing β-carotene ketolase and β-carotene hydroxylase into this strain unexpectedly increased lycopene accumulation, likely due to feedback inhibition by the product and enzyme imbalance. To address this, we utilized a moderate β-carotene producer YJYast-02 for astaxanthin production. Truncating the N-terminal 39 amino acids of β-carotene hydroxylase from <em>Haematococcus pluvialis</em> improved astaxanthin titer by 37.7 %. Rational engineering of the hydrophobicity of the substrate-binding pocket in β-carotene hydroxylase, specifically through mutations such as N183A, C191A and T213A, further increased astaxanthin titer by 15.8 %, 30.5 %, 36.8 %, respectively. The final engineered strain, YJYast-03(t5t39<sup>T213A</sup>), expressing t5OBKTM30 and t39OcrtZM1<sup>T213A</sup>, achieved 26.0 mg/L (3.6 mg/g DCW) astaxanthin. This work pioneers the use of molecular docking for engineering β-carotene hydroxylase, offering potential to significantly enhance catalytic activity and optimize astaxanthin biosynthesis in yeast.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109722"},"PeriodicalIF":3.7,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Short-circuited microbial fuel cell enhanced denitrification in pyrite packed-bed bioreactor

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-11 DOI: 10.1016/j.bej.2025.109720

Xuexi Fang, Xinhua Tang, Shiyang Zhang, Jialong Xiao, Xingyuan Li

{"title":"Short-circuited microbial fuel cell enhanced denitrification in pyrite packed-bed bioreactor","authors":"Xuexi Fang, Xinhua Tang, Shiyang Zhang, Jialong Xiao, Xingyuan Li","doi":"10.1016/j.bej.2025.109720","DOIUrl":"10.1016/j.bej.2025.109720","url":null,"abstract":"<div><div>Pyrite autotrophic denitrification (PAD) faces challenges in electron utilization efficiency for treating low C/N wastewater. Here, we proposed a short-circuited microbial fuel cell (SMFC) integrated with a pyrite-packed bioreactor to overcome these limitations. Unlike conventional MFCs requiring external circuits, the SMFC employed an internal short-circuited design (direct anode-cathode connection via titanium wires), eliminating external power supply while enabling spontaneous electron transfer from the anode to the cathode. This configuration enhanced total nitrogen (TN) removal by 7.93 % compared to standalone PAD, with effluent NO₂⁻-N stably below 1 mg/L. High-throughput sequencing revealed that <em>Phycisphaerae</em> (27 % abundance on the cathode) was a key genus, utilizing bioelectrons from the SMFC to drive complete nitrite reduction via dissimilatory Onr genes. The SMFC-PAD system achieved a 28.4 % increase in electron utilization efficiency by optimizing electron flux between pyrite oxidation (anode) and denitrification (cathode), overcoming intermediate accumulation of nitrite in traditional PAD. This work demonstrated a cost-effective strategy for denitrification by leveraging spatial electron regulation and microbial-electrochemical synergies.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109720"},"PeriodicalIF":3.7,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of slowly biodegradable organic matter morphology on sludge floc characteristics and microbial colony development

IF 3.7 3区生物学

Biochemical Engineering Journal Pub Date : 2025-03-11 DOI: 10.1016/j.bej.2025.109721

Yunya Gao, Chundi Gao, Jiamin Zhou, Zhuoni Chen, Xinyan Hu, Yongzhen Peng

{"title":"Influence of slowly biodegradable organic matter morphology on sludge floc characteristics and microbial colony development","authors":"Yunya Gao, Chundi Gao, Jiamin Zhou, Zhuoni Chen, Xinyan Hu, Yongzhen Peng","doi":"10.1016/j.bej.2025.109721","DOIUrl":"10.1016/j.bej.2025.109721","url":null,"abstract":"<div><div>Slowly biodegradable organic matters play an important role in sewage treatment because of their complex structure and slow degradation. This study compared the sludge floc characteristics and microbial colony growth of different substrate forms, namely particulate (particulate starch) and dissolved (dissolved starch) slowly biodegradable organic matters, in different operational modes of a sequencing batch reactor (SBR). Results showed that dissolved starch promoted sludge floc granulation and maintained good sedimentation performance during the whole operational period, while particulate starch accumulated extracellular starch in full aerobic operation mode and the total polysaccharide content increased significantly, causing non-filamentous bulking. High-throughput sequencing results confirmed the effects of varying sludge characteristics when supplied with different starch forms, on the functional microbial community. The dominant genus in the particulate starch system was <em>Flavobacterium</em>, promoting the production of polysaccharides in EPS, while the dominant genus in the dissolved starch system was <em>Kouleothrix</em>, which plays an adsorption bridging role in sludge with larger particle sizes and maintains a good sludge sedimentation performance. PICRUSt2 analysis showed that microbes in the particulate starch system exhibited high activity in terms of nitrogen, carbon and amino acid metabolism. Here, we demonstrate a theoretical basis for the use of particulate organic matter in sewage treatment systems, providing a novel perspective on the relationship between the morphology of slowly biodegradable organic matters and sludge bulking.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109721"},"PeriodicalIF":3.7,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143600666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0