BIOTECHNOLOGY LETTERS
·
2026
·Vol. 48
·期 2
·44
·
IF 2.5
Ma Li,Wang Yuyu,Liu Ruiqi,Hu Jingjia,Zheng Xiaobing,Yue Xiaoyang,Liu Guanhua,He Ying,Zhou Liya
Developing stable and easy-to-operate biocatalysts is crucial for their use as industrial catalysts. Here immobilized whole-cell catalysts were used for β-alanine production by immobilizing recombinant Escherichia coli cells (containing hydroaminase) with diatomite. E. coli BL21 (DE3)/pET-30a ( +)-HAMase was genetically engineered for the efficient synthesis of β-alanine from acrylic acid and aqueous ammonia. Using glutaraldehyde as a cross-linking agent, polyethyleneimine (PEI) as a flocculant, and diatomite as the immobilization carrier, optimal immobilization was achieved with 8% (w/v) PEI solution, 5% (w/v) glutaraldehyde, and 100 mg wet cell/mL cell suspension, along with a PEI flocculation time of 2.5 h and glutaraldehyde cross-linking time of 1.5 h. The enzyme activity recovery rate reached 70.72%. Remarkably, the immobilized whole-cell catalysts exhibited excellent stability, retaining over 90% of initial enzyme activity after 12 h incubation at 45 °C and maintaining over 72% enzyme activity after storage for 60 days at 4 °C. Additionally, the immobilized cells demonstrated enhanced reusability, maintaining consistent β-alanine yield even after ten consecutive reaction batches with an average yield of approximately 80%.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2026
·
IF 6.2
Yan Zheng,Heng Hu,Mengying Jiang,Yingying Zhu,Wanmeng Mu
Indigo, one of the oldest dyes still widely used in textiles, food, and pharmaceuticals, requires sustainable microbial production due to the high environmental burden and energy intensity of its chemical synthesis. In this study, indigo biosynthesis was enabled in E. coli MG1655 through heterologous expression and optimization of tryptophanases (TnaAs) and naphthalene dioxygenases (NDOs). To improve strain robustness for production, genes involved in the oxidative stress response were integrated into the chromosome, and gldA was overexpressed to ensure cofactor NADH availability. Furthermore, co-expression of molecular chaperone genes was employed to enhance the soluble expression of NDO. Following these multi-step optimizations, the final engineered strain achieved an indigo titer of 2.38 g/L in shake-flask fermentation. Finally, we demonstrated that fed-batch cultivation in a 5 L bioreactor yielded 6.90 g/L of indigo.
✓ 已验证
DOI
高影响因子
ARCHIVES OF MICROBIOLOGY
·
2026
·Vol. 208
·期 8
·385
·
IF 3.4
Wang Jiahui,Zhu Yuzhang,Liu Tao,Hong Xiangyu,Liu Mi,Zhou Rui,Li Xianke,Jing Mingguo,Yang Lifang
The antibacterial strategy that utilizes ultraviolet-A (UVA)-irradiated natural photosensitizers is promising, being particularly effective against multidrug-resistant pathogens with high bactericidal efficiency and minimal resistance-inducing risk. Rutin is a natural flavonoid with wide availability, low cytotoxicity, and diverse pharmacological activities, making it a promising photosensitizer; however, its UVA-induced photodynamic antibacterial properties remain underexplored. The aim of this study is to systematically evaluate the antibacterial efficacy and mechanism of UVA-Rutin against foodborne Escherichia coli O157:H7 . In the study, Fourier transform infrared spectroscopy and Raman spectroscopy were used to characterize structural alterations in rutin post-UVA irradiation, focusing on functional groups relevant to photodynamic activity. Antibacterial efficacy was assessed via standardized assays including minimum inhibitory concentration (MIC) determination, while biocompatibility was evaluated using MTT cytotoxicity assays. To confirm the antibacterial effects, physiological/structural perturbations of bacteria were measured, including cell membrane integrity, DNA damage, motility, biofilm formation, and extracellular polysaccharide (EPS) production, as well as the generation of intracellular reactive oxygen species (ROS) measured using fluorescent probes. Reverse transcription quantitative polymerase chain reaction was used to analyze key virulence- and quorum sensing-related genes ( luxS , phoP , qseB , qseC ). Results showed that UVA-induced structural changes enhanced the photosensitizing activity of rutin. UVA-Rutin exhibited significant antibacterial activity (low MIC) and good biocompatibility, triggering the generation of massive intracellular ROS, disrupting cell membranes, inducing DNA damage, impairing motility, inhibiting biofilm/EPS production, and downregulating target genes. Collectively, UVA-Rutin exerts potent antibacterial effects via ROS-mediated structural/functional disruption and virulence gene regulation, highlighting its potential as a novel food industry antibacterial agent.
✓ 已验证
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Li Fu,Qingmei Chen,Suqi Deng,Li Jia
An economical and label-free fluorescent sensor was developed for the selective detection of Escherichia coli ( E. coli ) based on the competitive reduction of Cu 2+ in CuFe 2 O 4 magnetic particles (MPs) by E. coli and o -phenylenediamine (OPD). Cu 2+ in CuFe 2 O 4 MPs can oxidize OPD to generate 2,3-diaminophenazine (OPDox) with fluorescent property. The presence of E. coli can weaken the oxidative ability of CuFe 2 O 4 MPs toward OPD owing to the copper reductase activity of NADH dehydrogenase-2 (NDH-2) in E. coli . NDH-2 can reduce Cu 2+ to Cu + , thereby inhibiting the OPD oxidation and resulting in the decrease of the fluorescence of the system. Under the optimum conditions, the fluorescent sensor exhibited a wide linear response to E. coli in the concentration range of 10 3 – 10 6 cfu mL −1 , and the detection limit was calculated to be 5.8 × 10 2 cfu mL −1 . Furthermore, the feasibility of the sensor was verified by successful detection of E. coli in popsicle and swimming pool water samples. More importantly, the sensor utilized the magnetic property of CuFe 2 O 4 MPs to realize the phase separation, thus averting the interference of other impurities in the sample matrix.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL IMMUNOPHARMACOLOGY
·
2022
·
IF 5.714
Shiyuan Feng,Yihao Zhang,Shaodong Fu,Zhi Li,Jinqiu Zhang,Yuanyuan Xu,Xiangan Han,Jinfeng Miao
Mastitis affects animal welfare and causes economic losses in the dairy industry. It is caused mainly by bacterial pathogens, among which Escherichia coli ( E. coli ) is one of the prominent causative agents. To treat bovine mastitis, antibiotics were widely used. However, their extensive and uncontrolled use has led to the emergence of multi-antibiotic-resistant strains. Indeed, a superbug of E. coli was successfully isolated from a mastitis-suffering cow and found resistant to at least 10 antibiotics. Therefore, the development of a universal therapeutic agent used as a replacement for the antibiotic is an immediate need in the dairy industry. To do so, we examined whether chlorogenic acid (CGA), a natural and herbal extract, could be a perfect alternative in mastitis treatment. In this study, we observed that the combination of CGA and antibiotic had an additive or synergistic effect; CGA fought against the superbug by directly targeting bacterial cell wall and membrane; CGA can significantly alleviate the mastitis caused by the superbug E. coli via its antimicrobial, antioxidant and anti-inflammatory activities. Collectively, these data indicated that CGA had a true potential to replace antibiotics during mastitis treatment.
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 413
·期 27
·6813-6821
·
IF 4.157
Ma Liang,Zhu Yindi,Chen Xueming,Fang Raohao,Chen Yuru,Xu Xia,Huang Guozheng,Liu Zi,Liu Xiang
Nano-magnetite with superparamagnetism could be coated by some organic compounds or by nano Au or Pt via surface modifications with multi-step reactions for the applications of isolating histidine-tagged (His-tagged) proteins. Introducing active sites of binding histidine onto the surface of nano-magnetite was the ultimate task. However, multi-step treatments might result in departure of the coatings from the surface of the nano-magnetite, which led to loss of active sites. In this work, we reported a convenient and efficient way of treating nano-magnetites and applied them in isolating His-tagged proteins. Carboxylates were introduced on the surface of home-made nano-magnetite directly via ultrasonic mixing with sodium bitartrate rather than complicated surface modifications, which was proved by thermogravimetric analyses. Ni 2+ was, therefore, caught by the carboxylates of the coating via the coordinate interaction, demonstrated by X-ray photoelectron spectra. The coated magnetic nanoparticles with the bonded Ni 2+ were successfully employed to selectively bind and separate recombinant His-tagged proteins directly from the mixture of Escherichia coli cell lysate, and showed wonderful affinity for His-tagged proteins with the saturated adsorption amount being 556 mg g −1 . Additionally, such functionalized nano-magnetite manifested the excellent recyclability in isolating His-tagged proteins. Graphical abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Qing Ning,Dali Wang,Jiahui An,Qi Ding,Zhiyi Huang,Yue Zou,Fan Wu,Jing You
Toxicological effects of nanoplastics have been demonstrated in a variety of organisms, yet their impacts on bacteria, especially on the antibiotic resistance evolution remain under explored. Herein, we report individual and combined effects of nano-polystyrene (nano-PS) and erythromycin (ERY) on growth and resistance mutations of Escherichia coli . The toxicity of nano-PS was dependent on size and functional modifications, with 30 nm and amino-modified PS (PS-NH 2 , 200 nm) showing the greatest toxicity. Adsorption of nano-PS onto bacterial surface and the subsequent increase of intracellular ROS or the probable mechanical damage were considered as the primary toxic mechanisms. Furthermore, nano-PS increased the bacterial resistance mutations, which was due to the oxidative damage to DNA and the SOS response. In addition, PS-NH 2 presented synergistic effects with ERY while non-modified PS had no impact, although both of them showed adsorption capacity to ERY. This was likely because the positively charged PS-NH 2 acted as a carrier of ERY and enhanced the interactions between ERY and the bacteria. Our findings raised the concerns about the risk of nanoplastics in accelerating the bacterial resistance evolution, and highlighted the necessity of including combined effects of nanoplastics and co-contaminants in risk assessment.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Hongwei Luo,Chenyang Liu,Ying Cheng,Yifeng Zeng,Dongqin He,Xiangliang Pan
The biggest problem with Fe/PMS (peroxymonosulfate) system is the slow generation rate of SO 4 − due to inefficient Fe 3+ /Fe 2+ cycle and the low decomposition efficiency of PMS . Here, we report the Fe 3+ -enhanced decomposition of PMS by a two-dimensional transition metal dichalcogenide WS 2 for pollutant degradation and E. coli disinfection. Experimental results showed that the removal rates of six representative pollutants were all above 90% under various pH conditions. Over a wide range of pH values (2–9), the removal rate of carbamazepine (CBZ) in PMS/WS 2 /Fe 3+ system almost reached 100% within 10 min, and E. coli could be inactivated by 97.3% within 1 min. WS 2 in the system accelerated the Fe 3+ /Fe 2+ cycle and participated in the activation of PMS. Electron paramagnetic resonance (EPR) measurements and scavenging experiments demonstrated that the SO 4 − and HO radicals were the main active oxidative species. The degradation pathway of CBZ was revealed based on its intermediates as determined by liquid chromatograph-mass spectrometer (LC-MS). The presence of common anions such as Cl − and HCO 3 − in PMS/WS 2 /Fe 3+ system noticeably affected the CBZ degradation. The characterization results verified the structural stability and the reusability of WS 2 . These research findings suggest that the combination of Fe 3+ and WS 2 is a promising method for PMS activation to remove organic pollutants and inactivate pathogenic bacteria during the process of wastewater treatment .
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Huifang Yin,Hongping Chen,Meng Yan,Zhikun Li,Rongdi Yang,Yanjiao Li,Yanfang Wang,Jianyi Guan,Huili Mao,Yan Wang,Yuyang Zhang
Blue indigo dye, an important natural colorant, is used for textiles and food additives worldwide, while another red isomer, indirubin, is the major active ingredient of a traditional Chinese medicine named “Danggui Longhui Wan” for treating various diseases including granulocytic leukemia, cancer, and Alzheimer’s disease. In this work, we constructed a new and highly efficient indigoid production system by optimizing a novel terpenoid cyclase, XiaI, from the xiamycin biosynthetic pathway. Through introducing the flavin-reducing enzyme Fre, tryptophan-lysing and -importing enzymes TnaA and TnaB, and H2O2-degrading enzyme KatE and optimizing the fermentation parameters including temperature, the concentration of isopropyl-β-d-thiogalactopyranoside, and feeding of the l-tryptophan precursor, the final maximum productivity of indigoids by the recombinant strain Escherichia coli BL21(DE3) (XiaI-Fre-TnaAB-KatE) was apparently improved to 101.9 mg/L, an approximately 60-fold improvement to that of the starting strain E. coli BL21(DE3) (XiaI) (1.7 mg/L). In addition, when the fermentation system was enlarged to 1 L in the flask (feeding with 5 mM tryptophan and 10 mM 2-hydroxyindole), the indigoid productivity further increased to 276.7 mg/L at 48 h, including an indigo productivity of 26.0 mg/L and an indirubin productivity of 250.7 mg/L, which has been the highest productivity of indirubin so far. This work provided a basis for the commercial production of bio-indigo and the clinical drug indirubin in the future.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2020
·
IF 0.593
Yan Qiao,Hongchao Geng,Ning Jiang,Xingqi Zhu,Chenyi Li,Qingyun Cai
Upconversion nanoparticles, Yb,Tm,Fe-doped NaYF4 nanoparticles, are synthesized and modified with polymyxin B for the selective detection of Gram-negative bacteria. Polymyxin B, a cyclic cationic antimicrobial peptide which can specifically bind to the lipopolysaccharides of cell wall of Gram-negative bacteria, such as Escherichia coli, is used to target and bind Gram-negative bacteria. The bacteria are then quantified by measuring the fluorescence intensity of the upconversion nanoparticle–bacteria complexes at 801 nm under 980 nm excitation. A limit of detection of 36 CFU/mL is achieved in the detection of Escherichia coli, and Escherichia coli in soybean milk is successfully detected. The limited autofluorescence and photobleaching properties of the upconversion nanoparticles make the proposed method useful for in vivo fluorescence imaging of Gram-negative bacteria.
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 187
·期 1
·1-10
·
IF 5.479
Zhang Xuzhi,Wang Xiaochun,Yang Qianqian,Jiang Xiaoyu,Li Yang,Zhao Jun,Qu Keming
A method is described to determine viable populations of Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). The method employs aptamer-magnetic separation combined with resistivity based detection. The bacteria were separated by means of aptamer-functionalized magnetic beads. They were then quantified by measuring their growth kinetics through time-dependent conductivity changes of culture media. The time-course of growth was logged by real-time and contactless measurements that yielded starting concentrations from the duration of lag intervals prior to the log phase of growth. In pure water samples, the linear ranges for measuring E. coli and S. aureus cells are 2.5 × 10 3 –2.5 × 10 8 CFU·mL −1 and 4.1 × 10 3 –4.1 × 10 8 CFU·mL −1 , respectively. In spiked tap water samples, the lower limits of detection are 2.3 × 10 4 CFU·mL −1 and 4.0 × 10 3 CFU·mL −1 for E. coli and S. aureus , with recoveries of 87.0–108.7% and 92.5–105.0%, respectively. The relative standard deviation of these measurements (10.0%) is below that of plate counting method (13.9%). The presence of micro/nanoparticles such as magnetic beads or selenium nanoparticles in the culture media does not interfere, unlike in case of automatted optical density monitoring. The E. coli and S. aureus cells captured on the aptamer-functionalized magnetic beads can be directly tested for their susceptibility to antibiotics. The process of magnetic separation and determination of load burden requires neither bulky, sophisticated equipment nor expensive reagents.
Aptamer-functionalized magnetic beads are used to selectively capture and separate E. coli and S. aureus cells in aqueous samples. They are directly transferred to a multichannel conductometric sensor for the quantification of viable bacteria via automated monitoring of their growth kinetics.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2019
·Vol. 48
·期 12
·7960-7969
·
IF 1.676
Huang Yanyan,Wu Zunyi,Zhao Guangying,Dou Wenchao
In this study, we used gold nanoparticles (AuNPs) modified screen-printed carbon electrodes (SPCE) with a large area working electrode for the detection of Escherichia coli O157:H7 ( E. coli O157:H7) in a direct method by antigen–antibody specificity binding. We compared four SPCE with different working electrode diameters (2 mm, 2.5 mm, 3 mm and 3.5 mm) to choose the optimum one. After electrodepositing chloroauric acid (HAuCl 4 ) on SPCE, a working electrode diameter of 3.5 mm SPCE show the maximum signal. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electrochemical sensor. With the combination of large area working electrode and the great property of AuNPs, this immunoassay plays an ideal detection range from 1.19 × 10 3 CFU mL −1 to 1.19 × 10 9 CFU mL −1 and the limit of detection is 5.94 × 10 2 CFU mL −1 (equivalent to 3.5 CFU) at a signal-to-noise ratio of 3. The immunoassay showed the acceptable specificity, reproducibility, and stability for detection of E. coli O157:H7. These results indicate that this immunoassay has a promising application in the food safety industry.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）