RESEARCH IN MICROBIOLOGY
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2015
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IF 2.705
Yuan-Shan Wang,Xing-Chang Zheng,Qi-Wei Hu,Yu-Guo Zheng
An abamectin (ABM)-degrading bacterium, Stenotrophomonas maltophilia ZJB-14120, was isolated and identified. This strain is capable of degrading 84.82% of ABM at an initial concentration of 200 mg/L over a 48 h incubation period. This strain showed efficient biodegradation ability (7.81 mg/L/h) to ABM and high tolerance (1000 mg/L) to all macrolides tested. In addition to ABM, emamectin, erythromycin and spiramycin can also be degraded by this strain. Modifications involving either reduction of the double bond between C22–C23 or replacement of the C25-group of ABM with a cyclohexyl group can completely inhibit biodegradation of ABM. The ABM-degrading capability of strain ZJB-14120 is likely to be intrinsic to its metabolism and could be inhibited by incubating with erythromycin, azithromycin, spiramycin or rifampicin. A new and successive degradation pathway was proposed based on metabolite analysis. Although there is evidence for metabolite inhibition, this strain has high ABM degradation activity and reusability. Further investigation showed that activated macrolide efflux pump(s) and an undetermined mechanism for regulating the intracellular ABM concentration are responsible for normal uptake of essential metabolites while pumping out excess harmful compounds. Strain ZJB-14120 may provide efficient treatment of water and soil contaminated by toxic levels of abamectin and emamectin.
研究领域:
微生物学
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环境科学
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农药生物学
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高影响因子
MICROBIOLOGICAL RESEARCH
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2023
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IF 6.7
Xiao-Yu Sun,Jie Deng,Chenhui Zhang,Sin-Yee Fung,Kam-Leung Siu,Ying-Ying Cheng,Liumei Ye,Jiaoxia Qin,Ke Wang,Jiu-Xin Qu,Wenying Gao,Fuxiang Wang,Dong-Yan Jin,Liang Yang
C-di-GMP is a bacterial second messenger implicated in the regulation of many key functions including antibiotic tolerance and biofilm formation. Our understanding of how c-di-GMP exerts its action via receptors to modulate different biological functions is still limited. Here we used a c-di-GMP affinity pull-down assay coupled to LC-MS/MS to identify c-di-GMP-binding proteins in the opportunistic pathogen Stenotrophomonas maltophilia. This analysis identified Smlt3238 (SodA), a protein of the superoxide dismutase family, as a c-di-GMP-binding protein. Microscale thermophoresis showed that purified SodA protein bound c-di-GMP with an estimated dissociation constant (Kd) value of 141.5 μM. Using various in vivo and in vitro experiments, we demonstrated that c-di-GMP modulates the enzyme activity of SodA directly. Circular dichroism experiments revealed that SodA protein gradually altered its basic structure with increasing levels of c-di-GMP. Phenotypic experiments conducted in the presence of a range of intracellular c-di-GMP levels showed that SodA function is modulated by c-di-GMP. The findings thus identify a novel c-di-GMP binding protein that governs oxidative stress tolerance in S. maltophilia .
研究领域:
微生物学
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分子生物学
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生物化学
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2016
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IF 4.836
Yifei Leng,Jianguo Bao,Gaofeng Chang,Han Zheng,Xingxing Li,Jiangkun Du,Daniel Snow,Xu Li
Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30 °C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations. When additional substrate was present, the substrate that caused increased biomass resulted in a decreased biotransformation rate of tetracycline. According to disk diffusion tests, the biotransformation products of tetracycline had lower antibiotic potency than the parent compound. Six possible biotransformation products were identified, and a potential biotransformation pathway was proposed that included sequential removal of N-methyl, carbonyl, and amine function groups. Results from this study can lead to better estimation of the fate and transport of antibiotics in the environment and has the potential to be utilized in designing engineering processes to remove tetracycline from water and soil.
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高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Xing Zhang,Xiao Liu,Shuhuan Lin,Xiaoli Zhu,Ziye Zhang,Baoshou Shen,Shi Zhou
Immobilization technology is a promising way to improve effectiveness and stability of microbial remediation for polycyclic aromatic hydrocarbons (PAHs), in which carrier material is one of key factors restricting removal efficiency. In this study, fulvic acid-wheat straw biochar (FA/WS) composites were applied for immobilization of an efficient PAHs degrading bacterium Stenotrophomonas maltophilia (SPM). FA/WS&SPM showed superior degradation capacity than free bacteria and biochar-immobilized bacteria, with the removal efficiency of pyrene (20 mg L -1 ) reaching 90.5 % (7 days). Transcriptome analysis revealed that FA in the carrier materials can promote transportation and degradation of pyrene, and cell growth, as well as inhibit cell apoptosis. Enzyme activity and degradation products detection showed that SPM utilized both phthalic acid and salicylic acid metabolic pathways to degrade pyrene. Practicality of FA/WS&SPM for different kinds of PAHs remediation had been verified in contaminated soil, demonstrating a great potential in the field of PAHs polluted sites remediation.
研究领域:
环境科学
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微生物学
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高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Yue Yu,Kejian Tian,Pengfei Hao,Yibing Wang,Menghan Chang,Dandan Zhou,Jinming Gu,Fenglin Zhang,Hongliang Huo
Annual global plastic waste exceeds 287 million tonnes, devastating ecosystems and health. As a promising solution, yellow mealworm larvae have shown the ability to degrade plastics. In this study, we explored the regional characteristics of the yellow mealworm and isolated a novel enteric bacterium, S . maltophilia ZSL2493, from the intestinal tract of yellow mealworm larvae, which achieved a biodegradation efficiency of 14.7% of polystyrene (PS) within 30 days. The two most promising candidate enzymes, kynurenine 3-monooxygenase (Kmo) and 4-hydroxyphenylpyruvate dioxygenase (Hpd), were identified by transcriptome mining and molecular docking simulations. Their depolymerisation ability was also confirmed by heterologous expression experiments. Recombinant Kmo and Hpd reduced the mass of PS by 6.14% and 3.96%, respectively, within 30 days. Quantitative analysis by liquid chromatography showed that the yield of styrene monomer was 1.37 μg/mL (Kmo-treated group) and 0.95 μg/mL (Hpd-treated group), respectively, after 30 days of incubation, which is a direct evidence of the enzyme's cleavage of polymer chains. This study elucidates the key enzymatic drivers in the biodegradation of PS and promotes the development of enzymatic recycling strategies for difficult-to-degrade plastics.
研究领域:
环境生物技术
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微生物学
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酶学
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高分子科学
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生物降解
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废弃物管理
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生物信息学
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分子生物学
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高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
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2020
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IF 3.448
Junjie Yu,Junjie Wu,Dewei Xie,Lei Du,Ya-Jie Tang,Jingli Xie,Dongzhi Wei
A novel prolyl endopeptidase from Stenotrophomonas maltophilia , SmPEP, was discovered and characterized. The specific activity of the recombinant SmPEP expressed by Escherichia coli BL21 (DE3), was 68.3 U/mg at pH 8.0 and 37 °C. In order to improve the substrate specificity for long-chain peptide, rational design was applied based on the structure constructed by homology modeling. Inter-domain sites within the β-propeller domain were chosen for the mutation to weaken the inter-domain interaction and form an open conformation for long-chain substrate entering into the active site. The substrate specificity on a designed long-chain substrate, PQPQLPYPQPQLP, of the mutants F263A and E184 G increased 8.77 and 5.75 times respectively versus wild-type. After the saturated mutation of the both sites, the reactive rate of mutant F263 V on 13-mer peptide was 10.2 times higher than that of the wild-type. Then the mutant F263 V was used in the hydrolysis of casein, and the ACE inhibitory activity of the hydrolysate was significantly improved compared with wild type enzyme, which verified the efficiency of the design strategy.
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BIOCHEMICAL ENGINEERING JOURNAL
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2026
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IF 3.6
Junwei Tang,Yan Liao,Qian Zhang,Jingying Gu,Xinqing Qiu,Juanjuan Yin,Siting Lu,Zhongning Liu,Weiwei Yang,Chaolan Zhang
In this study, focusing on the phthalates (PAEs) pollution situation dominated by Dibutyl phthalate (DBP) - Di-2-ethylhexyl phthalate (DEHP) compound pollution in the environment, a novel PAEs-degrading strain Stenotrophomonas maltophilia WM-8 was isolated from the soil of a plastic greenhouse. Under the combined pollution stress of 200 mg/L PAEs (100 mg/L DBP+100 mg/L DEHP), WM-8 demonstrated the capability to degrade over 95% of DBP and DEHP within 5 days, and its efficient degradation performance was maintained across a wide range of environmental conditions (pH 6–9, NaCl 0.75–20 g/L, PAEs 200–600 mg/L). SEM and FTIR analyses indicated that PAEs exerted a stress effect on WM-8, leading to the production of a substantial number of proteins and phospholipids, which facilitated the degradation process. UPLC-MS analysis revealed 10 degradation intermediates, and the potential degradation pathways involved deesterification reactions, β-oxidation reactions and transesterification reactions. These findings provide new insights into the bioremediation of PAEs in combined pollution scenarios.
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高影响因子
Journal of Animal Science and Biotechnology
·
2023
·Vol. 14
·期 1
·1-17
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IF 7
He Zhaoqi,Zhao Caijun,He Yuhong,Liu Zhuoyu,Fan Guyue,Zhu Kun,Wang Yiqi,Zhang Naisheng,Fu Yunhe,Hu Xiaoyu
Background Mastitis is an inflammatory disease of the mammary gland that has serious economic impacts on the dairy industry and endangers food safety. Our previous study found that the body has a gut/rumen-mammary gland axis and that disturbance of the gut/rumen microbiota could result in ‘gastroenterogenic mastitis’. However, the mechanism has not been fully clarified. Recently, we found that long-term feeding of a high-concentrate diet induced mastitis in dairy cows, and the abundance of Stenotrophomonas maltophilia (S. maltophilia) was significantly increased in both the rumen and milk microbiota. Accordingly, we hypothesized that ‘gastroenterogenic mastitis’ can be induced by the migration of endogenous gut bacteria to the mammary gland. Therefore, this study investigated the mechanism by which enterogenic S. maltophilia induces mastitis.Results First, S. maltophilia was labelled with superfolder GFP and administered to mice via gavage. The results showed that treatment with S. maltophilia promoted the occurrence of mastitis and increased the permeability of the blood-milk barrier, leading to intestinal inflammation and intestinal leakage. Furthermore, tracking of ingested S. maltophilia revealed that S. maltophilia could migrate from the gut to the mammary gland and induce mastitis. Subsequently, mammary gland transcriptome analysis showed that the calcium and AMPK signalling pathways were significantly upregulated in mice treated with S. maltophilia. Then, using mouse mammary epithelial cells (MMECs), we verified that S. maltophilia induces mastitis through activation of the calcium-ROS-AMPK-mTOR-autophagy pathway.Conclusion sIn conclusion, the results showed that enterogenic S. maltophilia could migrate from the gut to the mammary gland via the gut-mammary axis and activate the calcium-ROS-AMPK-mTOR-autophagy pathway to induce mastitis. Targeting the gut-mammary gland axis may also be an effective method to treat mastitis.
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高影响因子
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