PHYSICAL BIOLOGY
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2022
·Vol. 19
·期 4
·046004
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IF 2.959
Yue Yang,Caijuan Yue,Chi Zhang,Junhua Yuan
Polymers are important components of the complex fluid environment for microorganisms. The mechanical effects on bacterial motile behavior due to the viscous or viscoelastic properties of polymers were extensively studied, whereas possible chemical effects on bacterial motility through bacterial chemoreception of the polymers were unclear. Here we studied the chemotactic response of Escherichia coli to polymeric solutions by combining the bead assay and FRET measurements. We found that the wild-type E. coli strain exhibited an attractant response to widely used polymers such as Ficoll 400, polyethylene glycol (PEG) 20000 and polyvinyl pyrrolidone (PVP) 360000, and the response amplitude from chemoreception was much larger than that from the load-dependence of motor switching due to viscosity change. The chemotactic response depended on the type of receptors and the chain length of the polymers. Our findings here provided important new ingredients for further studies of bacterial motile behavior in complex fluids.
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METABOLIC ENGINEERING
·
2016
·
IF 8.201
Yanfen Bai,Hua Yin,Huiping Bi,Yibin Zhuang,Tao Liu,Yanhe Ma
Gastrodin, a phenolic glycoside , is the key ingredient of Gastrodia elata , a notable herbal plant that has been used to treat various conditions in oriental countries for centuries. Gastrodin is extensively used clinically for its sedative, hypnotic, anticonvulsive and neuroprotective properties in China. Gastrodin is usually produced by plant extraction or chemical synthesis, which has many disadvantages. Herein, we report unprecedented microbial synthesis of gastrodin via an artificial pathway. A Nocardia carboxylic acid reductase , endogenous alcohol dehydrogenases and a Rhodiola glycosyltransferase UGT73B6 transformed 4-hydroxybenzoic acid, an intermediate of ubiquinone biosynthesis , into gastrodin in Escherichia coli. Pathway genes were overexpressed to enhance metabolic flux toward precursor 4-hydroxybenzyl alcohol. Furthermore, the catalytic properties of the UGT73B6 toward phenolic alcohols were improved through directed evolution. The finally engineered strain produced 545 mg l −1 gastrodin in 48 h. This work creates a new route to produce gastrodin, instead of plant extractions and chemical synthesis.
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BIOTECHNOLOGY LETTERS
·
2015
·Vol. 38
·期 4
·619-627
·
IF 1.591
Zhuang Yibin,Jiang Jingjie,Bi Huiping,Yin Hua,Liu Shaowei,Liu Tao
Objectives To produce rosmarinic acid analogues in the recombinant Escherichia coli BLRA1, harboring a 4-coumarate: CoA ligase from Arabidopsis thaliana (At4CL) and a rosmarinic acid synthase from Coleus blumei (CbRAS). Results Incubation of the recombinant E. coli strain BLRA1 with exogenously supplied phenyllactic acid (PL) and analogues as acceptor substrates, and coumaric acid and analogues as donor substrates led to production of 18 compounds, including 13 unnatural RA analogues. Conclusion This work demonstrates the viability of synthesizing a broad range of rosmarinic acid analogues in E. coli , and sheds new light on the substrate specificity of CbRAS.
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Microorganisms
·
2022
·Vol. 10
·期 3
·628
·
IF 4.926
Guosi Li,Fucheng Zhu,Peipei Wei,Hailong Xue,Naidong Chen,Baowei Lu,Hui Deng,Cunwu Chen,Xinjian Yin
Hyperoside (quercetin 3-O-galactoside) exhibits many biological functions, along with higher bioactivities than quercetin. In this study, three UDP-dependent glycosyltransferases (UGTs) were screened for efficient hyperoside synthesis from quercetin. The highest hyperoside production of 58.5 mg·L−1was obtained in a recombinantEscherichia colico-expressing UGT fromPetunia hybrida(PhUGT) and UDP-glucose epimerase (GalE, a key enzyme catalyzing the conversion of UDP-glucose to UDP-galactose) fromE. coli. When additional enzymes (phosphoglucomutase (Pgm) and UDP-glucose pyrophosphorylase (GalU)) were introduced into the recombinantE. coli, the increased flux toward UDP-glucose synthesis led to enhanced UDP-galactose-derived hyperoside synthesis. The efficiency of the recombinant strain was further improved by increasing the copy number of the PhUGT, which is a limiting step in the bioconversion. Through the optimization of the fermentation conditions, the production of hyperoside increased from 245.6 to 411.2 mg·L−1. The production was also conducted using a substrate-fed batch fermentation, and the maximal hyperoside production was 831.6 mg·L−1, with a molar conversion ratio of 90.2% and a specific productivity of 27.7 mg·L−1·h−1after 30 h of fermentation. The efficient hyperoside synthesis pathway described here can be used widely for the glycosylation of other flavonoids and bioactive substances.Keywords:hyperoside;quercetin;UDP-dependent glycosyltransferase;UDP-glucose;metabolic engineering
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Scientific Reports
·
2014
·Vol. 4
·期 1
·1-8
·
IF 5.078
Bai Yanfen,Bi Huiping,Zhuang Yibin,Liu Chang,Cai Tao,Liu Xiaonan,Zhang Xueli,Liu Tao,Ma Yanhe
Salidroside (1) is the most important bioactive component of Rhodiola (also called as “Tibetan Ginseng”), which is a valuable medicinal herb exhibiting several adaptogenic properties. Due to the inefficiency of plant extraction and chemical synthesis, the supply of salidroside (1) is currently limited. Herein, we achieved unprecedented biosynthesis of salidroside (1) from glucose in a microorganism. First, the pyruvate decarboxylase ARO10 and endogenous alcohol dehydrogenases were recruited to convert 4-hydroxyphenylpyruvate (2), an intermediate of L -tyrosine pathway, to tyrosol (3) in Escherichia coli . Subsequently, tyrosol production was improved by overexpressing the pathway genes and by eliminating competing pathways and feedback inhibition. Finally, by introducing Rhodiola -derived glycosyltransferase UGT73B6 into the above-mentioned recombinant strain, salidroside (1) was produced with a titer of 56.9 mg/L. Interestingly, the Rhodiola -derived glycosyltransferase, UGT73B6, also catalyzed the attachment of glucose to the phenol position of tyrosol (3) to form icariside D2 (4), which was not reported in any previous literatures.
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Frontiers in Veterinary Science
·
2023
·
IF 3.2
Tong Yin-Chao,Zhang Yi-Ning,Li Peng-Cheng,Cao Ya-Li,Ding Dong-Zhao,Yang Yang,Lin Qing-Yi,Gao Yi-Nuo,Sun Shao-Qiang,Fan Yun-Peng,Liu Ying-Qiu,Qing Su-Zhu,Ma Wu-Ren,Zhang Wei-Min
Background: The development of antimicrobial resistance in the opportunistic pathogen Escherichia coli has become a global public health concern. Due to daily close contact, dogs kept as pets share the same E. coli with their owners. Therefore, the detection of antimicrobial resistance in canine E. coli is important, as the results could provide guidance for the future use of antibiotics. This study aimed to detect the prevalence of antibiotic-resistance of canine origin E. coli in Shaanxi province and to explore the inhibition effect of magnolol combined with cefquinome on MDR E. coli, so as to provide evidence for the use of antibiotics.Methods: Canine fecal samples were collected from animal hospitals. The E. coli isolates were separated and purified using various indicator media and polymerase chain reaction (PCR). Drug-resistance genes [aacC2, ant(3')-I, aph(3')-II, aac(6')-Ib-cr, aac(3')-IIe, blaKPC, blaIMP−4, blaOXA, blaCMY, blaTEM−1, blaSHV, blaCTX−M−1, blaCTX−M−9, Qnra, Qnrb, Qnrs, TetA, TetB, TetM, Ermb] were also detected by PCR. The minimum inhibitory concentration (MIC) was determined for 10 antibiotics using the broth-microdilution method. Synergistic activity of magnolol and cefquinome against multidrug-resistant (MDR) E. coli strains was investigated using checkerboard assays, time-kill curves, and drug-resistance curves.Results: A total of 101 E. coli strains were isolated from 158 fecal samples collected from animal hospitals. MIC determinations showed that 75.25% (76/101) of the E. coli strains were MDR. A total of 22 drug-resistance genes were detected among the 101 strains. The blaTEM−1gene exhibited the highest detection rate (89.77%). The TetA and Sul gene also exhibited high detection rate (66.34 and 53.47%, respectively). Carbapenem-resistant E. coli strains were found in Shangluo and Yan'an. Additionally, in MDR E. coli initially resistant to cefquinome, magnolol increased the susceptibility to cefquinome, with an FICI (Fractional Inhibitory Concentration Index) between 0.125 and 0.5, indicating stable synergy. Furthermore, magnolol enhanced the killing effect of cefquinome against MDR E. coli. Resistance of MDR E. coli to cefquinome decreased markedly after treatment with magnolol for 15 generations.Conclusion: Our study indicates that antibiotic-resistance E. coli has been found in domestic dogs. After treatment with magnolol extracted from the Chinese herb Houpo (Magnolia officinalis), the sensitivity of MDR E. coli to cefquinome was enhanced, indicating that magnolol reverses the resistance of MDR E. coli. The results of this study thus provide reference for the control of E. coli resistance.
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Food Analytical Methods
·
2018
·Vol. 11
·期 8
·2280-2286
·
IF 2.245
Yang Xiaozhan,Feng Luqiao,Qin Xiang
The food-borne diseases triggered by Escherichia coli O157: H7 ( E. coli O157: H7) have become a life-threatening problem for tens of thousands of people around the world in the past few decades. Therefore, a rapid, simple, and user-friendly biosensing label to monitor E. coli O157: H7 has become necessary and important. In this work, carboxyl functionalized graphene quantum dots (cf-GQDs) as fluorescent labels for optical imaging and sensing in E. coli O157: H7 have been firstly proposed and evaluated. E. coli O157: H7 antibody is successfully covalently conjugated to water-soluble cf-GQDs via a cross-linking reaction, and then cf-GQDs immunofluorescence probe is achieved. The probe can effectively recognize E. coli O157: H7 and generate strong fluorescent signal. The experimental result shows that the blocking agent can obviously improve the specificity of the bioprobe for E. coli O157: H7 with the minimum detection limit of 100 cfu/mL. This novel detection method could be as a useful tool to detect E. coli O157: H7 in food, water, and environment.
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ACS Synthetic Biology
·
2026
·
IF 4.5
Yanqiao Xue,Moshi Liu,Jun Tang,Tao Liu
Trigonelline, a naturally occurring pyridine alkaloid found in fenugreek (Trigonella foenum-graecum) seeds and other legumes, exerts diverse pharmacological effects, including anti-inflammatory and neuroprotective effects. Currently, it is predominantly produced through plant extraction and chemical synthesis. Here, we report trigonelline production from a de novo pathway in Escherichia coli for the first time. Identification and expression of the nicotinate N-methyltransferase Aco_009_01073 resulted in an initial trigonelline titer of 13.59 mg/L. Trigonelline titers were subsequently improved through systematic pathway engineering. Supply of the key precursor nicotinate was increased via heterologous expression of sdt1 (encoding NMN/NaMN 5′-nucleotidase) and urh1 (encoding nicotinate riboside hydrolase) from Saccharomyces cerevisiae and overexpression of nadB (encoding aspartate oxidase) and nadA (encoding quinolinate synthase). Nicotinate consumption was reduced by deleting pncB (encoding nicotinate phosphoribosyltransferase). In addition, the NadB–NadA module was assembled into an enzyme complex, the Sdt1–Urh1 module was constructed as a fusion protein, and the quinolinate phosphoribosyltransferase gene nadC was overexpressed. These modifications collectively enhanced trigonelline yield of 29.95 mg/L in shake-flask cultures. Fed-batch fermentation in a 5 L bioreactor led to a final trigonelline yield of 128.38 mg/L. Overall, this study reports the successful engineering of a microbial platform for trigonelline biosynthesis and provides a general framework for nicotinate-based N-methyl alkaloids.
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JOURNAL OF BIOTECHNOLOGY
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2026
·
IF 4
Lin Ge,Ruobing Jia,Wenxin Xu,Yu Xia,Jianjun Pei
A glycosyltransferase for efficiently converting p HBA into gastrodin was screened. • Enhancing UDP-glucose supply can significantly increase the gastrodin titer in E.coli . • Combinatorial optimization achieved 4578.03 mg/L gastrodin in engineered E. coli . Gastrodin is the principal bioactive component of Gastrodia elata , which is famous for its many remarkable pharmacological properties. In this study, several UDP-glycosyltransferases from different sources were used to evaluate and compare the biotransformation ability of p -hydroxybenzyl alcohol to gastrodin. The recombinant strain BL-RrUGT, expressing the UDP-glycosyltransferase (RrUGT) from Rhodiola rosea , exhibited the highest initial titer of 210.60 mg/L. To further augment production, we enhanced the intracellular UDP-glucose level in Escherichia coli ( E. coli ) K12 by overexpressing two pivotal biosynthetic enzymes: phosphoglucomutase and UDP-glucose pyrophosphorylase. This metabolic engineering strategy yielded the recombinant strain BL-Rr-PG, which boosted the gastrodin titer to 342.40 mg/L. Subsequently, the culture medium and fermentation conditions were optimized. This resulted in a maximum gastrodin titer of 4578.03 mg/L, with a specific productivity of 69.36 mg/L/h and a molar conversion rate of 82.72%. This output represents the highest yield of gastrodin reported in E. coli to date. Download: Download high-res image (198KB) Download: Download full-size image
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2023
·
IF 6.8
Wen-Hui Zhang,Yong-Dong Deng,Zhi-Feng Chen,Zhi-Hao Zuo,Yong-Sheng Tian,Jing Xu,Bo Wang,Li-Juan Wang,Hong-Juan Han,Zhen-Jun Li,Yu Wang,Quan-Hong Yao,Jian-Jie Gao,Xiao-Yan Fu,Ri-He Peng
2,4-Dinitrotoluene (2,4-DNT) as a common industrial waste has been massively discharged into the environment with industrial wastewater. Due to its refractory degradation, high toxicity, and bioaccumulation, 2,4-DNT pollution has become increasingly serious. Compared with the currently available physical and chemical methods, in situ bioremediation is considered as an economical and environmentally friendly approach to remove toxic compounds from contaminated environment. In this study, we relocated a complete degradation pathway of 2,4-DNT into Escherichia coli to degrade 2,4-DNT completely. Eight genes from Burkholderia sp . strain were re-synthesized by PCR-based two-step DNA synthesis method and introduced into E. coli . Degradation experiments revealed that the transformant was able to degrade 2,4-DNT completely in 12 h when the 2,4-DNT concentration reached 3 mM. The organic acids in the tricarboxylic acid cycle were detected to prove the degradation of 2,4-DNT through the artificial degradation pathway. The results proved that 2,4-DNT could be completely degraded by the engineered bacteria. In this study, the complete degradation pathway of 2,4-DNT was constructed in E. coli for the first time using synthetic biology techniques. This research provides theoretical and experimental bases for the actual treatment of 2,4-DNT, and lays a technical foundation for the bioremediation of organic pollutants.
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Catalysts
·
2022
·Vol. 12
·期 9
·997
·
IF 4.501
Xingmiao Zhu,Pengcheng Chen,Pu Zheng
4-Hydroxy benzylideneacetone (4-HBA) is an organic synthesis intermediate and can be used as a precursor for the synthesis of raspberry ketone. Herein, 2-deoxy-D-ribose 5-phosphate aldolase (DERA) was overexpressed inE. coliBL21 (DE3) as an attractive catalyst for enzymatic aldol reactions. The aldol reaction between 4-hydroxybenzaldehyde (4-HBD) and acetone to biosynthesize 4-HBA was catalyzed by whole-cellE. coliBL21 (DE3) (pRSF-Deoc). The yield and 4-HBA concentration were 92.8% and 111.35 mM, respectively, when using 120 mM 4-HBD and acetone as substrates. When the concentration of 4-HBD was increased to 480 mM, 376.4 mM 4-HBA was obtained by a fed-batch strategy with a yield of 78.4%, which was about a 28% improvement compared to the one-time addition strategy.E. coliBL21 (DE3) (pRSF-Deoc) cells were further immobilized withK-carrageenan, and the immobilized cells still maintained a residual activity of above 90% after 10 repeated uses. Our study provides a promising method of biosynthesizing 4-HBA.Keywords:4-hydroxybenzylideneacetone;2-deoxy-D-ribose 5-phosphate aldolases;whole-cell catalysis;fed-batch strategy;immobilized cells
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Frontiers in Microbiology
·
2022
·
IF 6.064
Xu Jing,Wang Bo,Wang Ming-Qing,Gao Jian-Jie,Li Zhen-Jun,Tian Yong-Sheng,Peng Ri-He,Yao Quan-Hong
Organophosphate compounds are widely used in pesticides to control weeds, crop diseases, and insect pests. Unfortunately, these synthetic compounds are hazardous and toxic to all types of living organisms. In the present work, Escherichia coli was bioengineered to achieve methyl parathion (MP) degradation via the introduction of six synthetic genes, namely, opdS, pnpAS, pnpBS, pnpCS, pnpDS, and pnpES, to obtain a new transformant, BL-MP. MP and its subsequent decomposition intermediates were completely degraded by this transformant to enter the metabolites of multiple anabolic pathways. The MP-degraded strain created in this study may be a promising candidate for the bioremediation of MP and potential toxic intermediates.
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