CARBOHYDRATE RESEARCH
·
2024
·
IF 2.4
Lin Wang,Yu Pang,Zhongwen Su,Meihua Xin,Mingchun Li,Yangfan Mao
N -(sodium 2-hydroxypropylsulfonate) chitosan (HSCS), N -sulfonate chitosan (SCS) and N -isonicotinic sulfonate chitosan (ISCS) were prepared. The structures of the prepared chitosan derivatives were characterized by nuclear magnetic resonance ( 1 H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy and elemental analysis (EA). Antibacterial and antibiofilm activities of these chitosan derivatives were evaluated in vitro . The minimum inhibitory concentration (MIC) of HSCS and SCS against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) were 0.625 mg/mL and 0.156 mg/mL, respectively. ISCS exhibited MIC values of 0.313 mg/mL and 0.078 mg/mL against E. coli and S. aureus , respectively. ISCS demonstrated superior antibacterial and antibiofilm properties compared to SCS and HSCS. These findings suggest that the incorporation of a pyridine structure into sulfonate chitosan enhances its antibacterial and antibiofilm activities, and the prepared ISCS has a promising application prospect for controlling the reproduction of microorganisms in the field of food packaging.
研究领域:
材料科学
·
微生物学
·
生物技术
·
食品科学
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产品关联
DOI
PubMed
高影响因子
BRAZILIAN JOURNAL OF BIOLOGY
·
2021
·
IF 1.651
Huang Y.,Zhang N.-J.,Zhao Z.
As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.
研究领域:
酶工程
·
工业微生物学
·
生物技术
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DOI
PubMed
高影响因子
Microbial Cell Factories
·
2021
·Vol. 20
·期 1
·1-13
·
IF 5.328
Zhang Yuyang,Chen Hongping,Zhang Yao,Yin Huifang,Zhou Chenyan,Wang Yan
Background Violaceins have attracted much attention as potential targets used in medicines, food additives, insecticides, cosmetics and textiles, but low productivity was the key factor to limit their large-scale applications. This work put forward a direct RBS engineering strategy to engineer the violacein biosynthetic gene cluster cloned from Chromobacterium violaceum ATCC 12,472 to efficiently improve the fermentation titers.Results Through four-rounds of engineering of the native RBSs within the violaceins biosynthetic operon vioABCDE, this work apparently broke through the rate-limiting steps of intermediates conversion, resulting in 2.41-fold improvement of violaceins production compared to the titers of the starting strain Escherichia coli BL21(DE3) (Vio12472). Furthermore, by optimizing the batch-fermentation parameters including temperature, concentration of IPTG inducer and fermentation time, the maximum yield of violaceins from (BCDE)m (tnaA−) reached 3269.7 µM at 2 mM tryptophan in the medium. Interestingly, rather than previous reported low temperature (20 ℃), we for the first time found the RBS engineered Escherichia coli strain (BCDE)m worked better at higher temperature (30 ℃ and 37 ℃), leading to a higher-level production of violaceins.Conclusion sTo our knowledge, this is the first time that a direct RBS engineering strategy is used for the biosynthesis of natural products, having the potential for a greater improvement of the product yields within tryptophan hyperproducers and simultaneously avoiding the costly low temperature cultivation for large-scale industrial production of violaciens. This direct RBS engineering strategy could also be easily and helpfully used in engineering the native RBSs of other larger and value-added natural product biosynthetic gene clusters by widely used site-specific mutagenesis methods represented by inverse PCR or CRISPR-Cas9 techniques to increase their fermentation titers in the future.
研究领域:
合成生物学
·
微生物学
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DOI
PubMed
高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 39
·395602
·
IF 3.551
Hongchao Geng,Ning Jiang,Chenyi Li,Xingqi Zhu,Yan Qiao,Qingyun Cai
A novel visible light-driven photocatalyst (represented as Mn-CdS/ZCISe/CIS/TiO2) for the passivation of E. coli was prepared with TiO2 nanowires as support and using CuInS2 (CIS) and ZnCuInSe (ZCISe) quantum dots (QDs), as well as Mn-doped CdS (Mn-CdS) nanoparticles (NPs) as sensitizers. The use of CIS and ZCISe QDs and Mn-CdS NPs extends the light harvest region to visible light. The photoelectric conversion efficiency was consequently improved, with a photocurrent density of 12.5 mA cm−2, about 60 times that of pure TiO2 nanowires. The germicidal efficiency of the photocatalyst was assessed by passivation of E. coli, 96% bacteria in 50 ml 105 colony forming units (CFU) ml−1 solution were killed within 50 min. Besides the high efficiency, the composite has good stability and satisfactory recycling performance. The antibiotic mechanism was also performed by using photoluminescence and a scavenging agent of different active matter, revealing that the photo-generated holes play a major role in the sterilization process.
研究领域:
微生物学
·
材料科学
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环境科学
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Yimin Li,Wenjie Yuan,Jiaoqi Gao,Chao Fan,Wenzhong Wu,Fengwu Bai
In this study, the optimum induction and reaction conditions, and fermentation process of producing Ala-Gln by E. coli Origami 2 overexpressing α-amino acid ester acyltransferase (OPA) were investigated. Besides, the Ala-Gln synthesis by OPA achieved the maximum molar yield of 94.7% and productivity of 1.89 g/L/min due to the extremely high enzyme activity. On this basis, repeated-cycle batch fermentation to produce Ala-Gln indicated that OPA could maintain high Ala-Gln yields and enzyme stabilities after several cell recycling. Consequently, the cost-efficient and environmentally friendly approach for Ala-Gln production by recycling OPA makes a great contribution to further industrial-scale applications.
研究领域:
生物技术
·
生化工程
·
微生物学
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DOI
PubMed
高影响因子
Microbial Cell Factories
·
2025
·Vol. 24
·期 1
·1-11
·
IF 4.9
Liu Wen,Guo Jing,Lu Wei,Cheng Tao,Li Yiting,Xian Mo,Zhang Rubing
Background L -5-Methyltetrahydrofolate (5-MTHF) is the sole biologically active form of folate present in human blood and serves as an essential nutritional supplement. While microbial biosynthesis of 5-MTHF offers a sustainable alternative to chemical synthesis, its low yield limits industrial potential. Results In this study, strategies for improving the methyl supply combined with engineering the tetrahydrofolate (THF) synthetic pathway were employed in E. coli to increase 5-MTHF production. First, a new exogenous C1 pathway was introduced to improve the intracellular methyl supply through acetyl-CoA breakdown. High expression of key rate-limiting genes folE , folP and purU enhanced metabolic flux of THF pathway, resulting in a 5-MTHF titer of 1.075 mg/L during shake-flask fermentation. A subsequent increase in 5-MTHF production was achieved by knocking out the metE gene, which is involved in the consumption of 5-MTHF. The best engineered strain, M3012, produced 8.2 mg/L 5-MTHF in a 5 L bioreactor via fed-batch fermentation, which presented the highest 5-MTHF titer to date. Conclusion We successfully engineered E. coli by introducing a novel exogenous C1 metabolic pathway to augment the methyl donor pool essential for the biosynthesis of 5-MTHF. Further metabolic optimizations, including the enhancement of the THF precursor flux and the elimination of competing degradation pathways, developed a recombinant strain with significantly increased yield, which paves the way for industrial production of 5-MTHF.
研究领域:
生物化学
·
微生物学
·
营养学
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产品关联
DOI
PubMed
高影响因子
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
·
2013
·
IF 3.389
Ting Wu,Mengying He,Xixi Zang,Ying Zhou,Tianfu Qiu,Siyi Pan,Xiaoyun Xu
Flavonoids exhibit a broad range of biological activities including antibacterial activity. However, the mechanism of their antibacterial activity has not been fully investigated. The antibacterial activity and membrane interaction of 11 flavonoids (including 2 polymethoxyflavones and 4 isoflavonoids) against Escherichia coli were examined in this study. The antibacterial capacity was determined as flavonoids > polymethoxyflavones > isoflavonoids. Using fluorescence, it was observed that the 5 flavonoids rigidified the liposomal membrane, while the polymethoxyflavones and isoflavonoids increased membrane fluidity. There was a significant positive correlation between antibacterial capacity and membrane rigidification effect of the flavonoids. A quantitative structure–activity relationship (QSAR) study demonstrated that the activity of the flavonoid compounds can be related to molecular hydrophobicity (CLogP) and charges on C atom at position3 (C3). The QSAR model could be used to predict the antibacterial activity of flavonoids which could lead to natural compounds having important use in food and medical industry.
研究领域:
微生物学
·
药理学
·
生物化学
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DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Xiaoting Hong,Yumei Zhou,Zhuoliang Ye,Haifeng Zhuang,Wanpeng Liu,K.S. Hui,Zhi Zeng,Xianhuan Qiu
Ag 3 PO 4 /TiO 2 nanocomposite was fabricated by an in situ precipitation method and then blended into poly(vinylidene fluoride) (PVDF) casting solution to prepare the ultrafiltration membrane via wet phase inversion technique. The water flux and bovine serum albumin (BSA) rejection rate of membrane were investigated; meanwhile, the ultrafiltration membrane morphologies and structural properties were analyzed using scanning electron microscope (SEM) and X-ray diffraction. Compared with the control membrane, the permeate performance of blended membranes was improved while possessing a steady BSA retention due to enhanced hydrophilicity. Mechanical tests revealed that the modified membranes exhibited a larger tensile strength and breakage elongation. SEM images and the halo zone testing were employed to assess the antibacterial performances of the nanocomposite membranes against Escherichia coli. The antibacterial tests confirmed that the modified membranes showed an effective antibacterial property against E. coli.
研究领域:
材料科学
·
环境工程
·
膜技术
·
纳米复合材料
·
水处理
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DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 106
·期 23
·7805-7817
·
IF 5.56
Fu Linglong,Sun Mengning,Wen Weizhang,Dong Na,Li Defa
Abstract Small ubiquitin-like modifier (SUMO) tag is widely used to promote soluble expression of exogenous proteins, which can then be cleaved by ubiquitin-like protease 1 (Ulp1) to obtain interested protein. But the application of Ulp1 in large-scale recombinant protein production is limited by complicated purification procedures and high cost. In this study, we describe an efficient and simple method of extracellular production of Ulp1 403-621 using a leaky Escherichia coli BL21(DE3), engineered by deleting the peptidoglycan-associated outer membrane lipoprotein ( pal ) gene. Ulp1 403-621 was successfully leaked into extracellular supernatant by the BL21(DE3)-Δ pal strain after IPTG induction. The addition of 1% glycine increased the extracellular production of Ulp1 403-621 approximately four fold. Moreover, extracellular Ulp1 403-621 without purification had high activities for cleaving SUMO fusion proteins, and antimicrobial peptide pBD2 obtained after cleavage can inhibit the growth of Staphylococcus aureus . The specific activity of extracellular Ulp1 403-621 containing 1 mM EDTA and 8 mM DTT reached 2.0 × 10 6 U/L. Another commonly used protease, human rhinovirus 3C protease, was also successfully secreted by leaky E. coli strains. In conclusion, extracellular production of tool enzymes is an attractive way for producing large-scale active recombinant proteins at a lower cost for pharmaceutical, industrial, and biotechnological applications. Key points
• First report of extracellular production of Ulp1
403-621
in leaky Escherichia coli BL21(DE3) strain.
• One percent glycine addition into cultivation medium increased the extracellular production of Ulp1
403-621
approximately four fold.
• The specific activity of extracellular Ulp1
403-621
produced in this study reached 2.0 × 10
6
U/L.
研究领域:
生物技术
·
微生物学
·
蛋白质工程
·
药学
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DOI
PubMed
高影响因子
ACS Synthetic Biology
·
2021
·
IF 5.11
Guangbao Zhang,Xiaohui Yang,Zhenhua Zhao,Tao Xu,Xiaoqiang Jia
Polycyclic aromatic hydrocarbons (PAHs) are highly toxic and persistent organic pollutions that can accumulate in the environment. In this study, an aromatic ring cleavage module, a salicylic acid synthesis module, and a catechol metabolism module were respectively constructed in three Escherichia coli BL21 strains. Subsequently, the engineered strains were cocultured as an artificial consortium for the biodegradation of phenanthrene, a typical PHA. Single factor experiments and response surface methodology were used to identify the optimal degradation conditions, including an inoculation interval of 6 h, inoculation ratio of 1:1:1, and IPTG concentration of 2 mM. Under these conditions, the 7-day degradation ratio of 100 mg/L phenanthrene reached 72.67%. Moreover, the engineered Escherichia coli BL21 strains showed good phenanthrene degradation ability at substrate concentrations 10 mg/L up to 500 mg/L. Enzyme activity assays combined with gas chromatography–mass spectrometry measurements confirmed that the three engineered strains behaved as a synergistic consortium in the phenanthrene degradation process. Based on the analysis of the key metabolites, the engineered bacteria were supplemented at 7-day intervals in batches so that each engineered strain maintained its optimal degradation ability. The 21-day degradation ratio finally reached 90.66%, which was much higher than what was observed with simultaneous inoculation. These findings suggest that the three engineered strains with separate modules constructed in this study offer an attractive solution for removing PAHs from the environment.
研究领域:
环境生物学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
3 Biotech
·
2018
·Vol. 8
·期 7
·1-9
·
IF 1.497
Huang Jian-Feng,Zhang Bo,Shen Zhen-Yang,Liu Zhi-Qiang,Zheng Yu-Guo
O -succinyl- l -homoserine (OSH) is a promising platform chemical for the production of C4 chemicals with huge market potential which can be produced by fermentation from glucose. To construct a strain capable of producing OSH with high yield, the metJ (encodes transcriptional repressor) and metI (encodes a subunit of dl -methionine transporter) were deleted in Escherichia coli W3110 to obtain a strain E. coli ∆JI. Then, overexpression of metL (encodes bifunctional aspartate kinase/homoserine dehydrogenase II) and inactivation of metB (encodes cystathionine γ-synthase) were implemented in one step, and the OSH titer of the resulting strain E. coli ∆JIB * Trc metL was dramatically increased to 7.30 g/L. The feedback regulation was further relieved by progressively overexpressing metA fbr (encodes homoserine O -succinyltransferase), yjeH (encodes l -methionine exporter), and thrA fbr (encodes bifunctional aspartate kinase/homoserine dehydrogenase I) to increase the metabolic flux from aspartate to OSH. The 100% rationally designed strain E. coli ∆JIB * Trc metL /pTrc- metA fbr -Trc- thrA fbr - yjeH produced 9.31 g/L OSH from 20 g/L glucose (0.466 g/g glucose) in batch fermentation, which represents the highest OSH yield from glucose reported to date. The culture profiles of the newly constructed strains were recorded to investigate their productive properties. The effects of l -methionine addition on the fermentation process of the optimal strain were also studied. Our results demonstrate that tuning the expression level of metL , inactivation of metB , and attenuation of feedback resistance of the crucial enzymes in the biosynthetic pathway are the key factors that impact the OSH production in E. coli .
研究领域:
生物技术
·
微生物学
·
代谢工程
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DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2021
·
IF 5.876
Yang Bai,Gongzhe Nie,Yi He,Chao Li,Xianbo Wang,Liqun Ye
Background The Fenton-like reaction is a highly potential advanced oxidation process. The photo-Fenton-like reaction formed by the combination of photocatalytic advanced oxidation process, which combines their advantages, breaks the original Fenton-like reaction rate bottleneck. Methods In this study, an ultra-thin MOF (Cu-TCPP(BA)-MOF) with porphyrin as the ligand and copper as the metal node was synthesized via a simple one-pot method for the first time. Significant Findings It activates Peroxymonosulfate (PMS) under visible light to degrade 10 mg/L Rhodamine B which can be completely degraded within 40 min. The pseudo-first-order rate constant of RhB is 0.9011 min −1 , being 5 folds larger than this for CuO as catalysts. ESR analysis shows that Cu-TCPP(BA)-MOF/PMS/vis system produces a large amount of non-radical 1 O 2 . Also under visible light, with E. coli concentration of 10 7 cfu/mL, it can be completely inactivated within 50 min. Dilution spreading plate method and Fluorescence spectroscopy confirmed the complete death of bacteria. In terms of mechanism, the ultra-thin MOF provides a large number of Cu 2+ active sites. Under visible light, the cycle between Cu 2+ and Cu + is accelerated and the pathways that produce reactive oxygen species (ROS) is changed, thereby improving the performance of contaminant treatment and sterilization.
研究领域:
环境科学
·
材料科学
·
生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）