Microbial Cell Factories
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2017
·Vol. 16
·期 1
·1-10
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IF 3.681
Xiong Liang-Bin,Liu Hao-Hao,Xu Li-Qin,Sun Wan-Ju,Wang Feng-Qing,Wei Dong-Zhi
Background The strategy of modifying the sterol catabolism pathway in mycobacteria has been adopted to produce steroidal pharmaceutical intermediates, such as 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC), which is used to synthesize various steroids in the industry. However, the productivity is not desirable due to some inherent problems, including the unsatisfactory uptake rate and the low metabolic efficiency of sterols. The compact cell envelope of mycobacteria is a main barrier for the uptake of sterols. In this study, a combined strategy of improving the cell envelope permeability as well as the intracellular sterol metabolism efficiency was investigated to increase the productivity of 4-HBC.Results
MmpL3, encoding a transmembrane transporter of trehalose monomycolate, is an important gene influencing the assembly of mycobacterial cell envelope. The disruption of mmpL3 in Mycobacterium neoaurum ATCC 25795 significantly enhanced the cell permeability by 23.4% and the consumption capacity of sterols by 15.6%. Therefore, the inactivation of mmpL3 was performed in a 4-HBC-producing strain derived from the wild type M. neoaurum and the 4-HBC production in the engineered strain was increased by 24.7%. Subsequently, to enhance the metabolic efficiency of sterols, four key genes, choM1, choM2, cyp125, and fadA5, involved in the sterol conversion pathway were individually overexpressed in the engineered mmpL3-deficient strain. The production of 4-HBC displayed the increases of 18.5, 8.9, 14.5, and 12.1%, respectively. Then, the more efficient genes (choM1, cyp125, and fadA5) were co-overexpressed in the engineered mmpL3-deficient strain, and the productivity of 4-HBC was ultimately increased by 20.3% (0.0633 g/L/h, 7.59 g/L 4-HBC from 20 g/L phytosterol) compared with its original productivity (0.0526 g/L/h, 6.31 g/L 4-HBC from 20 g/L phytosterol) in an industrial resting cell bio-transformation system.Conclusion sIncreasing cell permeability combined with the co-overexpression of the key genes (cyp125, choM1, and fadA5) involved in the conversion pathway of sterol to 4-HBC was effective to enhance the productivity of 4-HBC. The strategy might also be useful for the conversion of sterol to other steroidal intermediates by mycobacteria.
研究领域:
生物工程
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微生物学
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制药工程
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JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Shanshan Sun,Haizhen Wang,Kang Yan,Jun Lou,Jiahui Ding,Shane A. Snyder,Laosheng Wu,Jianming Xu
A highly eff ;ective phenanthrene (PHE)-degrading co-culture containing Rhodococcus sp. WB9 and Mycobacterium sp. WY10 was constructed and completely degraded 100 mg L −1 PHE within 36 h, showing improved degradation rate compared to their monocultures. In the co-culture, strain WY10 played a predominant role in PHE degradation. 1-hydroxy-2-naphthoic acid was an end-product of PHE degradation by strain WB9 and accumulated in the culture medium to serve as a substrate for strain WY10 growth, thereby accelerating PHE degradation. In turn, strain WY10 degraded PHE and 1-hydroxy-2-naphthoic acid intracellularly to form phthalate and protocatechuate that were exported to the culture medium through efflux transporters. However, strain WY10 cannot take up extracellular phthalate due to the absence of phthalate transporters, restricting phthalate degradation and PHE mineralization. In the co-culture, phthalate and protocatechuate accumulated in the culture medium were taken up and degraded towards TCA cycle by strain WB9. Therefore, the metabolic cross-feeding of strains WB9 and WY10 accelerated PHE degradation and mineralization. These findings exhibiting the synergistic degradation of PHE in the bacterial co-culture will facilitate its bioremediation application.
研究领域:
微生物学
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环境科学
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Pathogens
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2020
·Vol. 9
·期 6
·454
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IF 3.018
Abualgasim Elgaili Abdalla,Shuangquan Yan,Jie Zeng,Wanyan Deng,Longxiang Xie,Jianping Xie
Mycobacterium tuberculosisrepresents an ancient deadly human pathogen that can survive and multiply within macrophages. The effectors are key players for the successful pathogenesis of this bacterium.M. tuberculosisopen reading frame (ORF)Rv0341, a pathogenic mycobacteria-specific gene, was found to be upregulated in macrophages isolated from human tuberculosis granuloma and inside the macrophages during in vitro infection byM. tuberculosis. To understand the exact role of this gene, we expressed theRv0341gene inM. smegmatis, which is a non-pathogenicMycobacterium. We found that Rv0341 expression can alter colony morphology, reduce the sliding capability, and decrease the cell wall permeability ofM. smegmatis. Furthermore, Rv0341 remarkably enhancedM. smegmatissurvival within macrophages and under multiple in vitro stress conditions when compared with the control strain. Ms_Rv0341 significantly induced expression of TNF-α, IL-1β, and IL-10 compared withM. smegmatisharboring an empty vector. In summary, these data suggest that Rv0341 is one of theM. tuberculosisvirulence determinants that can promote bacilli survival in harsh conditions and inside macrophages.Keywords:Mycobacterium tuberculosis;Rv0341;stress;infection;macrophages;cytokines
研究领域:
微生物学
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免疫学
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传染病学
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INFECTION GENETICS AND EVOLUTION
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2015
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IF 3.015
Qinqin Huang,Hongping Luo,Minqiang Liu,Jie Zeng,Abualgasim Elgaili Abdalla,Xiangke Duan,Qiming Li,Jianping Xie
Clustered regularly interspaced short palindromic repeats (CRISPR) are present in the genome of 40% bacteria and 90% archaea . CRISPR and accompanying Cas proteins constitute an adaptive immune system against disruptive mobile genetic elements . Two CRISPRs and 9 genes encoding CRISPR-associated proteins have been found in the genome of Mycobacterium tuberculosis . The CRISPR-associated Cas2 is an endoribonuclease required for the acquisition of new spacers. In this study, Cas2 encoded by Rv2816c was expressed in Mycobacterium smegmatis lacking CRISPR-Cas system and its role in stress responses of M. smegmatis in vitro and within macrophages was studied. We found that Cas2 mediated M. smegmatis stress response changes were associated with the altered expression of sigma factors which involved in mycobacterial stress response and virulence. We also found that Cas2 decreased the survival of M. smegmatis within macrophages. This study provides new insights on the role of Cas2.
研究领域:
微生物学
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免疫学
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分子生物学
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2023
·Vol. 24
·期 24
·17370
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IF 5.6
Yingying Lei,Khaista Rahman,Xiaojian Cao,Bing Yang,Wei Zhou,Aikebaier Reheman,Luxia Cai,Yifan Wang,Rohit Tyagi,Zhe Wang,Xi Chen,Gang Cao
The human stress hormones catecholamines play a critical role in communication between human microbiota and their hosts and influence the outcomes of bacterial infections. However, it is unclear howM. tuberculosissenses and responds to certain types of human stress hormones. In this study, we screened several human catecholamine stress hormones (epinephrine, norepinephrine, and dopamine) for their effects onMycobacteriumgrowth. Our results showed that epinephrine significantly stimulated the growth ofM. tuberculosisin the serum-based medium as well as macrophages. In silico analysis and molecular docking suggested that the extra-cytoplasmic domain of the MprB might be the putative adrenergic sensor. Furthermore, we showed that epinephrine significantly enhancesM. tuberculosisbiofilm formation, which has distinct texture composition, antibiotic resistance, and stress tolerance. Together, our data revealed the effect and mechanism of epinephrine on the growth and biofilm formation ofM. tuberculosis, which contributes to the understanding of the environmental perception and antibiotic resistance ofM. tuberculosisand provides important clues for the understanding of bacterial pathogenesis and the development of novel antibacterial therapeutics.Keywords:M. tuberculosis;M. smegmatis;epinephrine;mprB;biofilm;antibiotic resistance
研究领域:
微生物学
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医学
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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
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2021
·Vol. 118
·期 16
·e2025658118
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IF 11.205
Yanting Tang,An Mu,Yuying Zhang,Shan Zhou,Weiwei Wang,Yuezheng Lai,Xiaoting Zhou,Fengjiang Liu,Xiuna Yang,Hongri Gong,Quan Wang,Zihe Rao
Encapsulins containing dye-decolorizing peroxidase (DyP)-type peroxidases are ubiquitous among prokaryotes, protecting cells against oxidative stress. However, little is known about how they interact and function. Here, we have isolated a native cargo-packaging encapsulin from Mycobacterium smegmatis and determined its complete high-resolution structure by cryogenic electron microscopy (cryo-EM). This encapsulin comprises an icosahedral shell and a dodecameric DyP cargo. The dodecameric DyP consists of two hexamers with a twofold axis of symmetry and stretches across the interior of the encapsulin. Our results reveal that the encapsulin shell plays a role in stabilizing the dodecameric DyP. Furthermore, we have proposed a potential mechanism for removing the hydrogen peroxide based on the structural features. Our study also suggests that the DyP is the primary cargo protein of mycobacterial encapsulins and is a potential target for antituberculosis drug discovery.
研究领域:
微生物学
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结构生物学
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抗结核药物研究
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JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
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2026
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IF 5.4
Yishu Zhao,Haiying Jia,Yan Wang,Shanshan Sha,Dong An,Shufeng Yang,Lei Qian,Yufang Ma,Liming Xu
The N-acetylglucosamine-1-phosphate transferase (WecA)is a potential target for developing anti-tuberculosis drugs, due to its critical role in the synthesis of mycobacterial cell wall. The enzymatic study of WecA and the discovery of WecA inhibitors are therefore justified. However, WecA is a membrane protein with 11 transmembrane domains, making it difficult to be obtained, and even more difficult to perform activity studies. In order to gain sufficient WecA protein for activity investigation, the Escherichia coli (E. coli) Lemo21(DE3) strain was utilised in this study. The expression level of WecA was precisely regulated by T7 lysozyme. Purified WecA was obtained by affinity chromatography and identified by mass spectrometry. The kinetic properties of WecA were determined based on the detection of the product UMP. In addition, tunicamycin proved to be a competitive inhibitor. These results will lay theoretical foundations for the elucidation of WecA catalytic mechanism and the development of WecA inhibitors.
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BMC MICROBIOLOGY
·
2025
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IF 4.2
Wang L,Wang X,Xu L,Wang B,Ji D,Ye Y,Lu Y.
Background Tuberculosis remains a major global health threat, especially with the increasing prevalence of drug-resistant Mycobacterium tuberculosis (Mtb). There is an urgent need to develop new antibiotics with novel mechanisms of action. Zinc pyrithione (ZnPT), a bidentate metal-chelating agent, displays potent in vitro activity against bacteria and fungi. This study aimed to evaluate the antimycobacterial activity of ZnPT and to explore its potential mechanisms. Methods The bactericidal activity of ZnPT against Mtb strains was evaluated using minimum inhibitory concentration and minimum bactericidal concentration assays. The role of copper was assessed through metal chelator supplementation studies, while intracellular metal accumulation was quantified using inductively coupled plasma mass spectrometry (ICP-MS). Mechanistic analyses included transcriptomic profiling, enzyme activity assays, and targeted metabolomics to assess effects on iron-sulfur (Fe-S) cluster biogenesis and energy metabolism. Results ZnPT demonstrated potent bactericidal activity against both drug-sensitive and drug-resistant Mtb strains. Copper supplementation significantly enhanced the efficacy of ZnPT, and ICP-MS confirmed elevated intracellular copper levels. Transcriptomic analysis revealed disruption of multiple pathways, including the copper ion stress response, sulfur metabolism, Fe-S cluster biogenesis, siderophore biosynthesis, and intermediary metabolism. Notably, ZnPT induced upregulation of the sulfur mobilization (SUF) operon while repressing electron transfer ferredoxins, indicating disturbed Fe-S cluster homeostasis. Enzyme assays showed marked inhibition of cysteine desulfurase activity, a key step in Fe-S cluster assembly. Targeted metabolomics revealed depletion of tricarboxylic acid (TCA) cycle intermediates and accumulation of metabolic bottlenecks, indicating impaired Fe-S enzyme activity. ZnPT treatment further led to dysfunction of the electron transport chain, reduced proton motive force, and ATP depletion. Conclusions ZnPT exhibits antimycobacterial activity by disrupting Fe-S cluster biogenesis and impairing energy metabolism in Mtb.
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BIOMEDICAL AND ENVIRONMENTAL SCIENCES
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2019
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IF 1.917
Zhen Yong GUO,Wei Jie ZHAO,Mei Qin ZHENG,Shuo LIU,Chen Xia YAN,Peng LI,Shao Fa XU
Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate (BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis ( Mtb ) multidrug-resistant (MDR) isolates, extensively drug-resistant (XDR) isolates, and the H37RV strain. BP/CL activity against the H37Rv strain was assessed in liquid cultures, in macrophages, and in mice. Results BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units (CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro . In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment (isoniazid + rifampin + pyrazinamide) after 2 months of treatment. Conclusion BP/CL may provide a new option to clinically treat MDR tuberculosis.
研究领域:
微生物学
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传染病学
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药理学
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ACS Infectious Diseases
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2025
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IF 3.8
Xingli Han,Zhiyong Liu,Biao Zhou,Yuanyuan Shi,H.M. Adnan Hameed,Yamin Gao,Cuiting Fang,Xiongfang Zhao,Linzhuan Wu,Xiaoli Xiong,Wei Yu,Bin Hong,Tianyu Zhang
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), represents a global health challenge, necessitating new treatments with distinct mechanisms of action (MOA) to combat drug resistance. Chuangxinmycin (CM), characterized by its indole-dihydrothiopyran heterocyclic skeleton, exhibits potent antibacterial activity both in vitro and in vivo, with a minimum inhibitory concentration (MIC) of 0.25 μg/mL against Mtb. However, the MOA of CM against Mtb has remained obscure. Through comprehensive genetic, chemical rescue, and protein-drug interaction studies, coupled with biochemical analyses, we reveal that CM selectively binds and inhibits tryptophanyl-tRNA synthetase (TrpRS) encoded by trpS, rather than anthranilate synthase (TrpE). Overexpression of trpS in Mtb results in a 128-fold increase in the MIC of CM, indicating a fundamental cause of resistance, whereas overexpression of trpE leads to modest resistance, suggesting a secondary effect. Conversely, knockdown of trpS or trpE enhances the susceptibility of Mtb to CM. Meanwhile, promoters of trpS in CM-resistant Mtb mutants exhibit increased activity compared to the wild type. Furthermore, drug–protein interaction and biochemical assays have confirmed that while CM effectively inhibits TrpRS, mutants of TrpE show decreased affinity for tryptophan. These results establish that CM exerts its anti-Mtb effects by interfering with the tryptophan-tRNA linkage essential for protein synthesis.
研究领域:
微生物学
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药理学
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ACS Infectious Diseases
·
2024
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IF 4
Jing Wu,Yong Zhang,Wenqi Li,Hao Tang,Ying Zhou,Di You,Xiaohe Chu,Hanbing Li,Jinsai Shang,Nan Qi,Bang-Ce Ye
Cholesterol is a key carbon source for Mycobacterium tuberculosis (Mtb) survival and persistence within macrophages. However, little is known about the role of cholesterol metabolism by Mtb in host–Mtb interplay. Here, we report the immune suppression mediated by Mtb’s cholesterol metabolites. Conducting the cholesterol metabolic profiling and loss-of-function experiments, we show that the cholesterol oxidation products catalyzed by a thiolase FadA5 from Mtb H37Ra, 4-androstenedione (AD), and its derivant 1,4-androstenedione (ADD) inhibit the expression of pro-inflammatory cytokines and thus promote bacterial survival in bone marrow-derived macrophages (BMDMs). Our time-resolved fluorescence resonance energy transfer (TR-FRET)-based screening further identifies the nuclear receptor LXRα as the target of ADD. Activation of LXRα via ADD impedes the nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPK) signaling and reduces cholesterol accumulation in lipid rafts upon TLR4 simulation, thereby compromising the inflammatory responses. Our findings provide the evidence that Mtb could suppress the host immunity through its cholesterol metabolic enzyme and products, which are potential targets for screening novel anti-tuberculosis (TB) agents.
研究领域:
微生物学
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免疫学
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传染病
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代谢
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JOURNAL OF DRUG TARGETING
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2019
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IF 3.277
Lambert Nzungize,Md Kaisar Ali,Xiaoyu Wang,Xue Huang,Wenmin Yang,Xiangke Duan,Shuangquan Yan,Chunyan Li,Abualgasim Elgaili Abdalla,Ponmani Jeyakkumar,Jianping Xie
Tuberculosis, especially multidrug resistant cases, remains an enormous public health threat. Mycobacterium tuberculosis metC (Rv3340) an enzyme involved in methionine biosynthesis was identified and characterised for antimicrobial susceptibility. We reported that the overexpression of Rv3340 in Mycobacterium smegmatis (Ms_Rv3340) produces hydrogen sulphide (H2S) for its energy in harsh conditions. The produced H2S sustained Ms_Rv3340 against streptomycin, whereas the chemical inhibition of H2S caused streptomycin lethality to Ms_Rv3340. Further analysis showed that cysteine–H2O2 treatment of Ms-Rv3340 initiated DNA damage via Fenton reaction. Ms_Rv3340 downregulated the expression levels of three streptomycin responsive genes. To our knowledge, no study has been previously reported that M. tuberculosis metC (Rv3340) can generates H2S modulating resistant to streptomycin which provides a greater perception toward the treatment and control of tuberculosis.
研究领域:
微生物学
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医学
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分子生物学
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