Biochemical Engineering Journal最新文献

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

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

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

The complete autotrophic nitrogen removal over nitrite (CANON) process offers significant nitrogen removal benefits, but N₂O 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, N₂O 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 m³·(m³·h)⁻¹ to 8 m³·(m³·h)⁻¹, N₂O 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 m³·(m³·h)⁻¹ and the initial aerobic phase was shortened by 30 min, the system rapidly shifted from aerobic to anaerobic conditions, reducing N₂O 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 NO₂^--N decreased from 27.77 mg·L⁻¹ to 18 mg·L⁻¹. The study suggests that the aeration rate influences N₂O generation by regulating dissolved oxygen (DO) concentration and NO₂^--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 N₂O emissions.

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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 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

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

Zwonaka Mapholi, George Mbella Teke, Neill Jurgens Goosen

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 (R² > 0.89). UAE (at 190 μm) significantly enhances extraction kinetics, increasing effective diffusivity from 0.863 to 3.46 × 10⁻¹² m²·s⁻¹ and mass transfer coefficient from 0.451 to 1.84 × 10⁻⁶ m·s⁻¹ 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).

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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 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

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

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

Microbial host systems, specifically E. coli-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.

{"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 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

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

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 Blakeslea trispora in Saccharomyces cerevisiae increased β-carotene production 2.8-fold compared to XdCrtI from Xanthophyllomyces dendrorhous. 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 Haematococcus pluvialis 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^T213A), expressing t5OBKTM30 and t39OcrtZM1^T213A, 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.

虾青素是一种有效的抗氧化剂，被广泛应用于保健品、化妆品和动物饲料中，但由于β-胡萝卜素羟化酶活性低，在微生物合成过程中面临生产挑战。这项研究确定了限速酶，并证明在酿酒酵母中表达来自三孢鳢（Blakeslea trispora）的植物烯去饱和酶 BtCrtI 可使β-胡萝卜素产量比来自黄绿酵母菌（Xanthophyllomyces dendrorhous）的 XdCrtI 提高 2.8 倍。整合 XdCrtYB、BtCrtI、CrtE03M 和 tHMG1 可获得 208.7 mg/L β-胡萝卜素。然而，在该菌株中引入 β-胡萝卜素酮化酶和β-胡萝卜素羟化酶后，番茄红素的积累意外增加，这可能是由于产物的反馈抑制作用和酶的不平衡造成的。为了解决这个问题，我们利用中等β-胡萝卜素产量的YJYast-02来生产虾青素。截断血球藻β-胡萝卜素羟化酶 N 端 39 个氨基酸可使虾青素滴度提高 37.7%。通过对 β-胡萝卜素羟化酶底物结合袋的疏水性进行合理工程改造，特别是通过 N183A、C191A 和 T213A 等突变，虾青素滴度分别提高了 15.8%、30.5% 和 36.8%。表达 t5OBKTM30 和 t39OcrtZM1T213A 的最终工程菌株 YJYast-03(t5t39T213A)的虾青素含量为 26.0 mg/L（3.6 mg/g DCW）。这项工作开创性地将分子对接用于β-胡萝卜素羟化酶的工程化，为显著提高催化活性和优化酵母中虾青素的生物合成提供了可能。

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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 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

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

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 Phycisphaerae (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.

{"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 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

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

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 Flavobacterium, promoting the production of polysaccharides in EPS, while the dominant genus in the dissolved starch system was Kouleothrix, 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.

{"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

An Ag+-assisted high-speed countercurrent chromatography and column chromatography for effective separating sciadonic acid from Torreya grandis oils

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

Pub Date : 2025-03-10 DOI: 10.1016/j.bej.2025.109716

Meng Xianghe , Wang Shuyi , Lu Yuanchao , Nie Xiaohua , Ye Qin

Sciadonic acid (△5,11,14–20:3, SCA) is a rare versatile non-methylene-interrupted polyunsaturated fatty acid. To prepare high purity SCA from Torreya oils with 8.04 % purity, Ag⁺-assisted high-speed countercurrent chromatography (HSCCC) combined with urea complexation (UC) or argentation column chromatography (CC) was investigated. Results showed that n-hexane: acetonitrile (1:1, v/v) was suitable mobile phase for HSCCC, and SCA with purity of 23.74 % and recovery of 61.74 % (SCA purity>20 %) were obtained. When the Ag⁺ addition was 0.50 %, one round of Ag⁺-HSCCC resulted in a recovery of SCA up to 95.38 % with purity around 21 %. It was believed that the enhanced performance originated from the reversible complexes between Ag⁺ and CC in SCA through π-s * and d-π* bonds. Starting with low purity SCA of 8.04 %, HSCCC (23.74 %), UC (62.67 %), or Ag⁺-CC (60.41^%) alone failed to produce SCA with high-purity (>90 %). However, Ag⁺-HSCCC combined with Ag⁺-UC or Ag⁺-CC yielded SCA with purities of 76.21 % and 97.74 %, and overall recovery of 21.38 % and 19.31 %, respectively. Thus, Ag⁺-HSCCC was an efficient method for the pre-enrichment of SCA, which could effectively facilitate coupling with UC, Ag⁺-CC or other PUFA purification techniques, resulted in significant improved purification performances.

{"title":"An Ag+-assisted high-speed countercurrent chromatography and column chromatography for effective separating sciadonic acid from Torreya grandis oils","authors":"Meng Xianghe , Wang Shuyi , Lu Yuanchao , Nie Xiaohua , Ye Qin","doi":"10.1016/j.bej.2025.109716","DOIUrl":"10.1016/j.bej.2025.109716","url":null,"abstract":"<div><div>Sciadonic acid (△5,11,14–20:3, SCA) is a rare versatile non-methylene-interrupted polyunsaturated fatty acid. To prepare high purity SCA from <em>Torreya</em> oils with 8.04 % purity, Ag<sup>+</sup>-assisted high-speed countercurrent chromatography (HSCCC) combined with urea complexation (UC) or argentation column chromatography (CC) was investigated. Results showed that <em>n</em>-hexane: acetonitrile (1:1, v/v) was suitable mobile phase for HSCCC, and SCA with purity of 23.74 % and recovery of 61.74 % (SCA purity>20 %) were obtained. When the Ag<sup>+</sup> addition was 0.50 %, one round of Ag<sup>+</sup>-HSCCC resulted in a recovery of SCA up to 95.38 % with purity around 21 %. It was believed that the enhanced performance originated from the reversible complexes between Ag<sup>+</sup> and C<img>C in SCA through π-s * and d-π* bonds. Starting with low purity SCA of 8.04 %, HSCCC (23.74 %), UC (62.67 %), or Ag<sup>+</sup>-CC (60.41<sup>%</sup>) alone failed to produce SCA with high-purity (>90 %). However, Ag<sup>+</sup>-HSCCC combined with Ag<sup>+</sup>-UC or Ag<sup>+</sup>-CC yielded SCA with purities of 76.21 % and 97.74 %, and overall recovery of 21.38 % and 19.31 %, respectively. Thus, Ag<sup>+</sup>-HSCCC was an efficient method for the pre-enrichment of SCA, which could effectively facilitate coupling with UC, Ag<sup>+</sup>-CC or other PUFA purification techniques, resulted in significant improved purification performances.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109716"},"PeriodicalIF":3.7,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593354","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

Biodegradation characteristics of acetaminophen by Delftia sp. PY-12: Performance, degradative kinetics, and pathway

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

Pub Date : 2025-03-08 DOI: 10.1016/j.bej.2025.109707

Yanxue Pei , Muchen Yin , Yanan Cui , Fan Yang , Xueying Bian , Jun Li , Yaodong Wu

Acetaminophen (APAP) is widely used for its antipyretic properties and is commonly found in wastewater, potentially threatening aquatic ecosystems. Microbial degradation has been proven effective in removing APAP. However, strains capable of efficiently degrading APAP are rare, and the research on the biodegradation kinetics of APAP is insufficient. In this study, a novel APAP-degrading strain, identified as Delftia sp. PY-12 by morphological characterization and 16S rRNA gene sequencing, was isolated from activated sludge. Experimental conditions were optimized using the Box-Behnken response surface design, revealing that PY-12 degraded 100 mg/L APAP under pH 7.11, 30℃, and 163 rpm within 24 h, outperforming most other strains. Comparative analysis of substrate inhibition models shows that the Aiba and Tiesser were most suitable for the substrate inhibition characteristics of PY-12. The models indicate that PY-12 can still degrade APAP even at concentrations of 446.919 mg/L and 554.215 mg/L. Through potential enzyme activity measurements, the degradation pathway of APAP by PY-12 was determined. APAP is first converted by amidohydrolase into 4-aminophenol (4-AP) and then converted by deaminase into hydroquinone (HQ), which is further converted by hydroquinone 1,2-dioxygenase to form 4-hydroxymuconic semialdehyde, ultimately entering the TCA cycle. This study revealed the potential application value of PY-12 in APAP degradation, which could be a strong candidate strain for microbial bioremediation of APAP pollution in environmental remediation.

{"title":"Biodegradation characteristics of acetaminophen by Delftia sp. PY-12: Performance, degradative kinetics, and pathway","authors":"Yanxue Pei , Muchen Yin , Yanan Cui , Fan Yang , Xueying Bian , Jun Li , Yaodong Wu","doi":"10.1016/j.bej.2025.109707","DOIUrl":"10.1016/j.bej.2025.109707","url":null,"abstract":"<div><div>Acetaminophen (APAP) is widely used for its antipyretic properties and is commonly found in wastewater, potentially threatening aquatic ecosystems. Microbial degradation has been proven effective in removing APAP. However, strains capable of efficiently degrading APAP are rare, and the research on the biodegradation kinetics of APAP is insufficient. In this study, a novel APAP-degrading strain, identified as <em>Delftia sp</em>. PY-12 by morphological characterization and 16S rRNA gene sequencing, was isolated from activated sludge. Experimental conditions were optimized using the Box-Behnken response surface design, revealing that PY-12 degraded 100 mg/L APAP under pH 7.11, 30℃, and 163 rpm within 24 h, outperforming most other strains. Comparative analysis of substrate inhibition models shows that the Aiba and Tiesser were most suitable for the substrate inhibition characteristics of PY-12. The models indicate that PY-12 can still degrade APAP even at concentrations of 446.919 mg/L and 554.215 mg/L. Through potential enzyme activity measurements, the degradation pathway of APAP by PY-12 was determined. APAP is first converted by amidohydrolase into 4-aminophenol (4-AP) and then converted by deaminase into hydroquinone (HQ), which is further converted by hydroquinone 1,2-dioxygenase to form 4-hydroxymuconic semialdehyde, ultimately entering the TCA cycle. This study revealed the potential application value of PY-12 in APAP degradation, which could be a strong candidate strain for microbial bioremediation of APAP pollution in environmental remediation.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109707"},"PeriodicalIF":3.7,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619898","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

Energy-guided accumulated mutation strategy achieves a highly efficient polyethylene terephthalate-degrading enzyme

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

Pub Date : 2025-03-08 DOI: 10.1016/j.bej.2025.109708

Zhi Wang , Jiaxing Zhang , Shengping You , Rongxin Su , Wei Qi

The extensive application of polyethylene terephthalate (PET) has led to severe environmental pollution. Enzymatic degradation provides a sustainable solution for PET recycling, but the limited hydrolytic activity of current PET hydrolases hinders its practical application. Here, we designed an Energy-Guided Accumulated Mutation Strategy (EGAMS) for the rational design of PET enzyme PHL7. By applying multiple rounds of evolution to enhance the degradation activity and thermostability of PHL7, we achieved the excellent PET degradation enzyme FlashPETase (PHL7^{E148K/T158P/S184E/H185Y}) with 238.8 % PET degradation activity of PHL7 and 82.93 °C melting temperature. FlashPETase completely degrades PET at 72 °C with an enzyme loading of 1.5 mg_enzyme g_PET⁻¹, without any substrate pretreatment or additional processing. As for PET substrates with high crystallinity, FlashPETase still performs well. Furthermore, molecular simulations revealed the structural mechanisms of FlashPETase’s enhanced activity and stability. In summary, the EGAMS protocol and the variants discussed in this work advance the fields of PET degradation and enzyme engineering, offering valuable insights for future research.

{"title":"Energy-guided accumulated mutation strategy achieves a highly efficient polyethylene terephthalate-degrading enzyme","authors":"Zhi Wang , Jiaxing Zhang , Shengping You , Rongxin Su , Wei Qi","doi":"10.1016/j.bej.2025.109708","DOIUrl":"10.1016/j.bej.2025.109708","url":null,"abstract":"<div><div>The extensive application of polyethylene terephthalate (PET) has led to severe environmental pollution. Enzymatic degradation provides a sustainable solution for PET recycling, but the limited hydrolytic activity of current PET hydrolases hinders its practical application. Here, we designed an Energy-Guided Accumulated Mutation Strategy (EGAMS) for the rational design of PET enzyme PHL7. By applying multiple rounds of evolution to enhance the degradation activity and thermostability of PHL7, we achieved the excellent PET degradation enzyme FlashPETase (PHL7<sup>E148K/T158P/S184E/H185Y</sup>) with 238.8 % PET degradation activity of PHL7 and 82.93 °C melting temperature. FlashPETase completely degrades PET at 72 °C with an enzyme loading of 1.5 mg<sub>enzyme</sub> g<sub>PET</sub><sup>−1</sup>, without any substrate pretreatment or additional processing. As for PET substrates with high crystallinity, FlashPETase still performs well. Furthermore, molecular simulations revealed the structural mechanisms of FlashPETase’s enhanced activity and stability. In summary, the EGAMS protocol and the variants discussed in this work advance the fields of PET degradation and enzyme engineering, offering valuable insights for future research.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109708"},"PeriodicalIF":3.7,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642164","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

Impact of temperature switching on nitrogen removal and effluent S/N ratio via sulfur autotrophic denitrification

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal

Pub Date : 2025-03-06 DOI: 10.1016/j.bej.2025.109703

Xiaoyan Dang , Xu Li , Chaoyue Zhao , Yanping Zhang , Xiaolong Gao , Shumin He , Jie Han , Yaonan Zhu , Youzhao Wang , Tong Zhu

Seasonal temperature alternation severely affects the biological denitrification of high nitrogen concentrations in industrial wastewater. This study used sulfur-based filled particles for the sulfur autotrophic denitrification technique, and evaluated the performance of the sulfur autotrophic denitrification (SAD) reactor for the removal of high concentrations of NO₃^--N by simulating seasonal shifts and switching between 10℃ and 30℃ for 275 days. By precisely adjusting influent nitrate-nitrogen and Hydraulic Retention Times (HRTs), studies revealed enhanced nitrogen removal loading (NRL) at 30℃. Growth of sulfur autotrophs and electron transfer were inhibited at 10℃, and metabolites and biological residues supplied organic matter to heterotrophic denitrifying bacteria, resulting in lower sulfate production and significantly lower S/N ratios than at 30℃. Response surface optimization indicated optimal conditions: 83 % denitrification rate at 27.94℃, 18.7 h HRT, and 135.79 mg/L influent concentration, aligning closely with experimental findings. Thiobacillus and Thermomonas were more abundant at 30℃. And higher correlation of microorganisms between the two samples at high and low temperatures under high-concentration influent conditions. Additionally, the application of the SAD system is economically feasible because its raw materials are low-cost sulfur-based materials. This study aims to demonstrate the advantages of temperature in sulfur autotrophic denitrification, enhance the understanding of its mechanism, and provide a basis for wastewater treatment applications.

{"title":"Impact of temperature switching on nitrogen removal and effluent S/N ratio via sulfur autotrophic denitrification","authors":"Xiaoyan Dang , Xu Li , Chaoyue Zhao , Yanping Zhang , Xiaolong Gao , Shumin He , Jie Han , Yaonan Zhu , Youzhao Wang , Tong Zhu","doi":"10.1016/j.bej.2025.109703","DOIUrl":"10.1016/j.bej.2025.109703","url":null,"abstract":"<div><div>Seasonal temperature alternation severely affects the biological denitrification of high nitrogen concentrations in industrial wastewater. This study used sulfur-based filled particles for the sulfur autotrophic denitrification technique, and evaluated the performance of the sulfur autotrophic denitrification (SAD) reactor for the removal of high concentrations of NO<sub>3</sub><sup>-</sup>-N by simulating seasonal shifts and switching between 10℃ and 30℃ for 275 days. By precisely adjusting influent nitrate-nitrogen and Hydraulic Retention Times <strong>(</strong>HRTs<strong>)</strong>, studies revealed enhanced nitrogen removal loading (NRL) at 30℃. Growth of sulfur autotrophs and electron transfer were inhibited at 10℃, and metabolites and biological residues supplied organic matter to heterotrophic denitrifying bacteria, resulting in lower sulfate production and significantly lower S/N ratios than at 30℃. Response surface optimization indicated optimal conditions: 83 % denitrification rate at 27.94℃, 18.7 h HRT, and 135.79 mg/L influent concentration, aligning closely with experimental findings. <em>Thiobacillus</em> and <em>Thermomonas</em> were more abundant at 30℃. And higher correlation of microorganisms between the two samples at high and low temperatures under high-concentration influent conditions. Additionally, the application of the SAD system is economically feasible because its raw materials are low-cost sulfur-based materials. This study aims to demonstrate the advantages of temperature in sulfur autotrophic denitrification, enhance the understanding of its mechanism, and provide a basis for wastewater treatment applications.</div></div>","PeriodicalId":8766,"journal":{"name":"Biochemical Engineering Journal","volume":"219 ","pages":"Article 109703"},"PeriodicalIF":3.7,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593352","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