APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2025
·
IF 3.7
Chenmei Peng,Pan Lei,Hongying Qi,Qianjun Zhu,Chushun Huang,Ju Fu,Chengyu Zhao
Diabetes is the third most common chronic disorder worldwide. Diabetic wounds are a severe complication that is costly and often results in non-traumatic lower limb amputation. Recent investigations have demonstrated that the gut microbiota as a “virtual organ” can regulate metabolic diseases like diabetes. Fecal microbiota transplantation (FMT) is an innovative therapeutic approach for promoting wound healing, but its function remains incompletely defined. A diabetes model was established by supplying mice with a high-fat diet and performing an intraperitoneal injection of streptozotocin. Diabetic wounds were then created, followed by bacterial transplantation. The relevant indexes of wound healing were evaluated to verify the promoting effect of FMT on the diabetic wounds. Human skin keratinocytes were also cultured, and cell scratch experiments were conducted to further investigate the underlying mechanism. The FMT regulated the levels of specific bacteria in the diabetic mice and helped restore the balance of intestinal microbes. This transplantation also enhanced wound healing in the diabetic mice by augmenting the closure rate, accelerating re-epithelialization, and boosting collagen deposition in skin wounds. Furthermore, FMT promoted the production of IL-17A, which significantly enhanced the growth and movement of human keratinocytes. Inhibiting molecules related to the IL-17A–mTOR–HIF1α signaling axis were shown to hinder wound re-epithelialization.This study clarifies the function of the IL-17A–mTOR–HIF1α signaling axis in the utilization of FMT in diabetic wound healing, providing a new therapeutic method and target for promoting the healing of diabetic wounds.
研究领域:
医学
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免疫学
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微生物学
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内分泌学
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产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2024
·Vol. 91
·期 1
·
IF 3.9
Ji Zeng,Hao Wang,Yuxi Xu,Jianying Han,Yannan Li,Shu'an Wen,Changbu Wu,Dani Li,Zheng Liu,Xiaokang Zhang,Guo-Bao Tian,Min Dong
Clostridioides difficile is an obligate anaerobic, Gram-positive bacterium that produces toxins. Despite technological progress, conducting gene expression analysis of C. difficile under different conditions continues to be labor-intensive. Therefore, there is a demand for simplified tools to investigate the transcriptional and translational regulation of C. difficile. The cell-free gene expression (CFE) system has demonstrated utility in various applications, including prototyping, protein production, and in vitro screening. In this study, we developed a C. difficile CFE system capable of in vitro transcription and translation (TX-TL) in the presence of oxygen. Through optimization of cell extract preparation and reaction systems, we increased the protein yield significantly. Furthermore, our observations indicated that this system exhibited higher protein yield using linear DNA templates than circular plasmids for in vitro expression. The prototyping capability of the C. difficile CFE system was assessed using a series of synthetic Clostridium promoters, demonstrating a good correlation between in vivo and in vitro expression. Additionally, we tested the expression of tcdB and tcdR from clinically relevant C. difficile strains using the CFE system, confirming higher toxin expression of the hypervirulent strain R20291. We believe that the CFE system can not only serve as a platform for in vitro protein synthesis and genetic part prototyping but also has the potential to be a simplified model for studying metabolic regulations in Clostridioides difficile.
研究领域:
微生物学
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分子生物学
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生物技术
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2024
·Vol. 91
·期 1
·
IF 3.9
Yuan-Ru Xiong,Yuan-Chun Fang,Min He,Ke-Jing Li,Lei Qi,Yang Sui,Ke Zhang,Xue-Chang Wu,Liang Meng,Ou Li,Dao-Qiong Zheng
This study explored the genomic alterations in Yarrowia lipolytica, a key yeast in industrial biotechnology, under both spontaneous and mutagen-induced conditions. Our findings reveal that spontaneous mutations occur at a rate of approximately 4 × 10−10 events per base pair per cell division, primarily manifesting as single-nucleotide variations (SNVs) and small insertions and deletions (InDels). Notably, C-to-T/G-to-A transitions and C-to-A/G-to-T transversions dominate the spontaneous SNVs, while 1 bp deletions, likely resulting from template slippage, are the most frequent InDels. Furthermore, chromosomal aneuploidy and rearrangements occur, albeit at a lower frequency. Exposure to ultraviolet (UV) light, methylmethane sulfonate (MMS), and Zeocin significantly enhances the rates of SNVs and alters their mutational spectra in distinct patterns. Notably, Zeocin-induced SNVs are predominantly T-to-A and T-to-G substitutions, often occurring within the 5′-TGT*−3′ motif (* denotes the mutated base). Additionally, Zeocin exhibits a higher potency in stimulating InDels compared to UV and MMS. Translesion DNA synthesis is implicated as the primary mechanism behind most Zeocin-induced SNVs and some InDels, whereas non-homologous end joining serves as the main pathway for Zeocin-mediated InDels. Intriguingly, the study identifies the gene YALI1_E21053g, encoding a protein kinase, as negatively associated with Zeocin resistance. Overall, our results not only deepened our knowledge about the genome evolution in Y. lipolytica but also provided reference to develop innovative strategies to harness its genetic potential.
研究领域:
微生物学
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遗传学
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分子生物学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2017
·Vol. 83
·期 23
·
IF 3.807
Cui-Wei Chu,Bin Liu,Na Li,Shi-Gang Yao,Dan Cheng,Jia-Dong Zhao,Ji-Guo Qiu,Xin Yan,Qin He,Jian He
Thiobencarb is a thiocarbamate herbicide used in rice paddies worldwide. Microbial degradation plays a crucial role in the dissipation of thiobencarb in the environment. However, the physiological and genetic mechanisms underlying thiobencarb degradation remain unknown. In this study, a novel thiobencarb degradation pathway was proposed in Acidovorax sp. strain T1. Thiobencarb was oxidized and cleaved at the C—S bond, generating diethylcarbamothioic S-acid and 4-chlorobenzaldehyde (4CDA). 4CDA was then oxidized to 4-chlorobenzoic acid (4CBA) and hydrolytically dechlorinated to 4-hydroxybenzoic acid (4HBA). The identification of catabolic genes suggested further hydroxylation to protocatechuic acid (PCA) and finally degradation through the protocatechuate 4,5-dioxygenase pathway. A novel two-component monooxygenase system identified in the strain, TmoAB, was responsible for the initial catabolic reaction. TmoA shared 28 to 32% identity with the oxygenase components of pyrimidine monooxygenase from Agrobacterium fabrum, alkanesulfonate monooxygenase from Pseudomonas savastanoi, and dibenzothiophene monooxygenase from Rhodococcus sp. TmoB shared 25 to 37% identity with reported flavin reductases and oxidized NADH but not NADPH. TmoAB is a flavin mononucleotide (FMN)-dependent monooxygenase and catalyzed the C—S bond cleavage of thiobencarb. Introduction of tmoAB into cells of the thiobencarb degradation-deficient mutant T1m restored its ability to degrade and utilize thiobencarb. A dehydrogenase gene, tmoC, was located 7,129 bp downstream of tmoAB, and its transcription was clearly induced by thiobencarb. The purified TmoC catalyzed the dehydrogenation of 4CDA to 4CBA using NAD+ as a cofactor. A gene cluster responsible for the complete 4CBA metabolic pathway was also cloned, and its involvement in thiobencarb degradation was preliminarily verified by transcriptional analysis.IMPORTANCE Microbial degradation is the main factor in thiobencarb dissipation in soil. In previous studies, thiobencarb was degraded initially via N-deethylation, sulfoxidation, hydroxylation, and dechlorination. However, enzymes and genes involved in the microbial degradation of thiobencarb have not been studied. This study revealed a new thiobencarb degradation pathway in Acidovorax sp. strain T1 and identified a novel two-component FMN-dependent monooxygenase system, TmoAB. Under TmoAB-mediated catalysis, thiobencarb was cleaved at the C—S bond, producing diethylcarbamothioic S-acid and 4CDA. Furthermore, the downstream degradation pathway of thiobencarb was proposed. Our study provides the physiological, biochemical, and genetic foundation of thiobencarb degradation in this microorganism.
研究领域:
环境微生物学
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分子生物学
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生物化学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2024
·
IF 3.9
Zhonghua Wang,Wei Song,Wanqing Wei,Hejia Qi,Weiwei Meng,Jia Liu,Xiaomin Li,Cong Gao,Liming Liu,Guipeng Hu,Yiwen Zhou,Jing Wu
Natural chondroitin sulfate (CS), extracted from animal cartilage, is widely used in the pharmaceuticals and foods. However, contamination with animal-derived heteropolysaccharides presents significant challenges, including potential immune responses. To address this, we developed a green and efficient method for synthesizing chondroitin sulfate E (CSE) via enzymatic synthesis, identifying EcCHST15, a sulfotransferase that catalyzes the conversion of chondroitin sulfate A (CSA) to CSE. We investigated the novel catalytic mechanism of CHST15 through quantum mechanical (QM) calculations and experimental validation, confirming its alignment with the SN2 reaction mechanism. Subsequently, we enhanced the catalytic efficiency of CHST15 using protein engineering, improving the catalytic efficiency from 18.1% in the wild type (WT) to 62.5% in the M7 mutant—a 3.5-fold increase. Finally, we constructed a six-enzyme cascade whole-cell catalyst, achieving a 72.2% conversion of 15 g/L CSA to produce CSE within 24 h. These findings offer a promising strategy for the industrial production of CSE.
研究领域:
生物技术
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制药
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生物化学
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蛋白质工程
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酶学
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DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2018
·Vol. 84
·期 14
·
IF 3.633
Haijie Ma,Mingshuang Wang,Yunpeng Gai,Huilan Fu,Bin Zhang,Ruoxin Ruan,Kuang-Ren Chung,Hongye Li
This study determined the function of thioredoxin and glutaredoxin systems in the phytopathogenic fungus Alternaria alternata via analyzing mutants obtained from the targeted deletion of genes encoding thioredoxin peroxidase (Tsa1), thioredoxin reductase (Trr1), and glutathione reductase (Glr1). Trr1 and Glr1, but not Tsa1, are required for growth and conidiation. The reduced growth and conidiation seen in the Trr1 or Glr1 deletion mutant can be restored by glutathione. Deletion mutants showing growth inhibition by oxidants are defective for H2O2 detoxification and induce smaller lesions on citrus leaves. Trr1 and Glr1, but not Tsa1, also contribute to NaCl resistance. Glr1 is required for sorbitol resistance and is responsible for resistance to mancozeb and boscalid but not chlorothalonil fungicides, a novel phenotype that has not been reported in fungi. Trr1 is required for resistance to boscalid and chlorothalonil fungicides but confers susceptibility to mancozeb. The Tsa1 deletion mutant displays wild-type sensitivity to the tested fungicides. The expression of Tsa1 and Trr1 is regulated by the oxidative stress responsive regulators Yap1, Hog1, and Skn7. The expression of Tsa1, but not Trr1, is also regulated indirectly by the NADPH oxidase. The results indicate that the capability to resist oxidative stress is required for virulence of A. alternata.IMPORTANCE The thioredoxin and glutaredoxin systems are important thiol antioxidant systems in cells, and knowledge of these two systems in the plant-pathogenic fungus A. alternata is useful for finding new strategies to reduce the virulence of this pathogen. In this study, we demonstrated that thiol antioxidant system-related genes (Tsa1, Trr1, and Glr1) are required for H2O2 detoxification and virulence in A. alternata. Moreover, deletion of Trr1 results in hypersensitivity to the fungicides chlorothalonil and boscalid, and Glr1 deletion mutants are highly sensitive to mancozeb, which is the fungicide mostly used in citrus fields. Therefore, our findings demonstrate that the ability to detoxify reactive oxygen species (ROS) plays a critical role in pathogenesis on citrus and provide novel insights into the physiological functions of thiol-containing systems in fungicide sensitivity for A. alternata.
研究领域:
真菌学
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植物病理学
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分子生物学
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真菌遗传学
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抗氧化系统
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2026
·
IF 4.2
Hua Li,Fangjuan Li,Yajie Shi,Xinxin Wang,Xiaomeng Wang,Guanyu Zheng,Lixiang Zhou,Barth F. Smets
The dissemination of extracellular antibiotic resistance genes (eARGs) through horizontal gene transfer poses a serious threat to global water safety. While Escherichia coli MG1655 is known to employ intracellular nucleases to defend against foreign DNA, the potential of its cell lysate to enzymatically degrade plasmid-borne eARGs and disrupt their environmental propagation remains unexplored. This study demonstrated that E. coli MG1655 cell lysate can degrade the plasmid-borne ampR gene by 99.9% within 48 h, and the maximum first-order degradation rate constant measured by long amplicon qPCR was 0.20 h−1 at the selected dosage state. This degradation eliminated the ability of the plasmid pUC19 for transformation, reducing it to below detectable levels (<10−6 transformants/recipients). The DNase I, produced by the chromosomal endA gene, was identified as the likely nuclease driving eARG cleavage. Environmental conditions critically modulated degradation efficiency: humic acid (50 mg/L) decreased the rate by 41.3%, while divalent cations (e.g., Mg2+) increased the rate by 1.65-fold. To transmit laboratory findings into real-world application, a polyacrylamide hydrogel-immobilized lysate (PAM-cell lysate) was engineered, which outperformed free lysate in treating plasmid-spiked real wastewater, sustaining 99.9% of ampR removal across three treatment cycles. This research demonstrated that PAM-cell lysate, without genetic modification, can be a cost-effective and scalable solution for attenuating the spread of eARGs in water, advancing the development of complementary enzymatic strategies for sustainable water remediation.
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DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2026
·
IF 4.2
Zhengyu Hou,Hejuan Pan,Shihan Wang,Yulin Li,Yang Yu,Pei Qiao,Haixia Wang,Weihong Zhong
Phthalate esters (PAEs) are ubiquitous in the environment, and their microbial metabolism is associated with transport proteins. In this study, multiple novel membrane proteins were identified, revealing their pivotal role in PAEs degradation. Based on whole-genome and transcriptomic analyses, approximately 20 potential PAEs transport membrane proteins were predicted to be involved in PAEs degradation by Rhodococcus sp. AH-ZY2. Among them, four protein genes (0620, 3572, 4497, and 5299) exhibited increased transcription levels (Log2F(c)>2.8) in response to di-n-octyl-phthalate (DnOP) as the sole carbon source, instead of fructose, were selected for functional verification. Gene knockout and complementation experiments showed that these four transport protein genes, belonging to the MFS family (0620, 3572, and 5299) and the ABC family (4497), respectively, exhibited the function to transport multiple PAEs into cells. Specifically, membrane protein 5299 could transport the most diverse kinds of PAEs. Molecular docking results also showed that Ser and Arg play a key role in the PAEs transport process of membrane protein 5299, and the PAEs-binding pocket size of 5299 in the transition region was larger than that of 0620, 3572, and 4497. Then, the expression of the genes encoding 0620, 3572, 5299, and 4497 was enhanced after they were cloned into the plasmid pNV18 and transformed into the strain AH-ZY2. The enhancement of 5299 expression exhibited a better improvement in PAEs degradation than the other three genes. This study provides four novel transport proteins and a new strategy for effective bioremediation of PAEs via enhanced membrane transport.
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DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2025
·
IF 3.7
Ruomu Chen,Yutian Gan,Wanting Huang,Chenyang Wang,Junhong Ge,Yuanyuan Cheng,Wenjing Qiao,Jiandong Jiang,Kai Chen
Bisphenol F (BPF) is an emerging environmental pollutant widely present in surface water and wastewater systems. Microbial activity is crucial in driving its degradation, offering a potential avenue for mitigating its environmental impact. Although the degradation pathway for BPF has been identified in various bacteria, the biodegradation mechanisms remain unclear. In this study, we isolated a highly efficient BPF-degrading strain of Sphingobium yanoikuyae DN12, which could utilize BPF as the sole carbon and energy source for growth, from a river sediment in Anhui Province, China. Through ultra-performance liquid chromatography high-resolution mass spectrometry (UPLC-HRMS) analysis, we found that oxidation and hydrolysis are key steps for BPF biodegradation. Utilizing whole-genome sequencing, comparative transcriptomics analysis, and biochemical identification, a gene cluster bpf was identified to be involved in BPF degradation. BpfAB is a two-component oxidoreductase responsible for converting BPF to 4,4'-dihydroxybenzophenone (DHBP). BpfC is a Baeyer–Villiger monooxygenase responsible for converting DHBP to 4-hydroxyphenyl-4-hydroxybenzoate (HPHB). Isotope tracing demonstrated that the oxygen atom incorporated by BpfAB originates from water, whereas that incorporated by BpfC derives from molecular oxygen (O2). BpfD is an α/β hydrolase responsible for converting HPHB to 4-hydroxybenzoate and 1,4-hydroquinone. Analysis of the taxonomic and habitat of 325 prokaryotic genomes revealed that BpfA-like homologs are predominantly found in the phylum Pseudomonadota, primarily inhabiting soil and aquatic environments. This study enhances our understanding of the biodegradation mechanism of BPF and provides guidance for the effective remediation of BPF-contaminated environments.
研究领域:
环境微生物学
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生物修复
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微生物代谢
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环境科学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2022
·
IF 5.005
Hao Ren,Haixia Wang,Yang Wang,Yiyang Chen,Zhenmei Lu
Tetrahydrofuran (THF) has been recognized as a water contaminant because of its human carcinogenicity, extensive use, and widespread distribution. Previously reported multicomponent monooxygenases (MOs) involved in THF degradation were highly conserved, and all of them were from Gram-positive bacteria. In this study, a novel THF-degrading gene cluster (dmpKLMNOP) encoding THF hydroxylase was identified on the chromosome of a newly isolated Gram-negative THF-degrading bacterium, Cupriavidus metallidurans ZM02, and functionally characterized. Transcriptome sequencing and RT-qPCR demonstrated that the expression of dmpKLMNOP was upregulated during the growth of strain ZM02 on THF or phenol. The deletion of oxygenase alpha or beta subunit or the reductase component disrupted the degradation of THF but did not affect the utilization of its hydroxylated product 2-hydroxytetrahydrofuran. Cupriavidus pinatubonensis JMP134 heterologously expressing dmpKLMNOP from strain ZM02 could grow on THF, indicating that the THF hydroxylase DmpZM02KLMNOP is responsible for the initial degradation of THF. Furthermore, the THF and phenol oxidation activities of crude enzyme extracts were detected, and the highest THF and phenol catalytic activities were 1.38 ± 0.24 μmol min−1 mg−1 and 1.77 ± 0.37 μmol min−1 mg−1, respectively, with the addition of NADPH and Fe2+. The characterization of THF hydroxylase associated with THF degradation enriches our understanding of THF-degrading gene diversity and provides a novel potential enzyme for the bioremediation of THF-containing pollutants.IMPORTANCE Multicomponent MOs catalyzing the initial hydroxylation of THF are vital rate-limiting enzymes in the THF degradation pathway. Previous studies of THF degradation gene clusters have focused on Gram-positive bacteria, and the molecular mechanism of THF degradation in Gram-negative bacteria has rarely been reported. In this study, a novel THF hydroxylase encoded by dmpKLMNOP in strain ZM02 was identified to be involved in both THF and phenol degradation. Our findings provide new insights into the THF-degrading gene cluster and enzymes in Gram-negative bacteria.
研究领域:
环境微生物学
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生物技术
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酶学
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基因组学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2024
·
IF 3.9
Yingying Qian,Lin Lai,Minggen Cheng,Hua Fang,Dandan Fan,Gerben J. Zylstra,Xing Huang
Amphenicol antibiotics, such as chloramphenicol (CHL), thiamphenicol (TAP), and florfenicol (Ff), are high-risk emerging pollutants. Their extensive usage in aquaculture, livestock, and poultry farming has led to an increase in bacterial antibiotic resistance and facilitated the spread of resistance genes. Yet, limited research has been conducted on the co-resistance of CHL, TAP, and Ff. Herein, a novel amidase AphA was identified from a pure cultured strain that can concurrently mediate the hydrolytic inactivation of CHL, TAP, and Ff, yielding products p-nitrophenylserinol, thiamphenicol amine (TAP-amine), and florfenicol amine (Ff-amine), respectively. The antibacterial activity of these antibiotic hydrolysates exhibited a significant reduction or complete loss in comparison to the parent compounds. Notably, AphA shared less than 26% amino acid sequence identity with previously reported enzymes and exhibited high conservation within the sphingomonad species. Through enzymatic kinetic analysis, the AphA exhibited markedly superior affinity and catalytic activity toward Ff in comparison to CHL and TAP. Site-directed mutagenesis analysis revealed the indispensability of catalytic triad residues, particularly serine 153 and histidine 277, in forming crucial hydrogen bonds essential for AphA’s hydrolytic activity. Comparative genomic analysis showed that aphA genes in some species are closely adjacent to various transposable elements, indicating that there is a high potential risk of horizontal gene transfer (HGT). This study established a hydrolysis resistance mechanism of amphenicol antibiotics in sphingomonads, which offers theoretical guidance and a novel marker gene for assessing the prevalent risk of amphenicol antibiotics in the environment.
研究领域:
微生物学
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分子生物学
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环境科学
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基因组学
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DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2020
·Vol. 86
·期 19
·
IF 4.016
Haixia Wang,Xiaoyu Wang,Hao Ren,Xuejun Wang,Zhenmei Lu
3-Hydroxypyridine (3HP) is an important natural pyridine derivative. Ensifer adhaerens HP1 can utilize 3HP as its sole sources of carbon, nitrogen, and energy to grow, but the genes responsible for the degradation of 3HP remain unknown. In this study, we predicted that a gene cluster, designated 3hpd, might be responsible for the degradation of 3HP. The analysis showed that the initial hydroxylation of 3HP in E. adhaerens HP1 was catalyzed by a four-component dehydrogenase (HpdA1A2A3A4) and led to the formation of 2,5-dihydroxypyridine (2,5-DHP). In addition, the SRPBCC component in HpdA existed as a separate subunit, which is different from other SRPBCC-containing molybdohydroxylases acting on N-heterocyclic aromatic compounds. Moreover, the results demonstrated that the phosphoenolpyruvate (PEP)-utilizing protein and pyruvate-phosphate dikinase were involved in the HpdA activity, and the presence of the gene cluster 3hpd was discovered in the genomes of diverse microbial strains. Our findings provide a better understanding of the microbial degradation of pyridine derivatives in nature and indicated that further research on the origin of the discovered four-component dehydrogenase with a separate SRPBCC domain and the function of PEP-utilizing protein and pyruvate-phosphate dikinase might be of great significance.IMPORTANCE 3-Hydroxypyridine is an important building block for the synthesis of drugs, herbicides, and antibiotics. Although the microbial degradation of 3-hydroxypyridine has been studied for many years, the molecular mechanisms remain unclear. Here, we show that 3hpd is responsible for the catabolism of 3-hydroxypyridine. The 3hpd gene cluster was found to be widespread in Actinobacteria, Rubrobacteria, Thermoleophilia, and Alpha-, Beta-, and Gammaproteobacteria, and the genetic organization of the 3hpd gene clusters in these bacteria shows high diversity. Our findings provide new insight into the catabolism of 3-hydroxypyridine in bacteria.
研究领域:
微生物学
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生物化学
·
分子生物学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）