WATER RESEARCH
·
2020
·
IF 9.13
Cong Huang,Qian Liu,Zhi-Ling Li,Xiao-dan Ma,Ya-Nan Hou,Nan-Qi Ren,Ai-Jie Wang
The denitrification desulfurization system can be used to remediate wastewater containing carbon, nitrogen, and sulfur. However, the relationship between autotrophic and heterotrophic bacteria remains poorly understood. To better understand the roles and relations of core bacteria, an expanded granular sludge bed (EGSB) reactor was continuously operated under autotrophic (stage I), heterotrophic (stage II) and mixotrophic (stages III–VII) conditions with a 490-day period. Stage IV represented the excellent S 0 recovery rate (69.5%). The different trophic conditions caused the obvious succession of dominant bacterial genera. Autotrophic environment (stage I) enriched mostly Thiobacillus , and heterotrophic environment (stage II) was dominated with Azoarcus and Pseudomonas. Thauera, Arcobacter and Azoarcus became the predominant genera under mixotrophic conditions (stage III-VII). Strains belonged to these core genera were further isolated, and all seven isolates were confirmed with denitrifying sulfur oxidation capacity. Heterotrophic strain HDD1 (genus of Thauera ) possessed both the highest sulfide degradation and S 0 recovery rates. Expression levels of cbbM and gltA genes were positively related with the autotrophic and heterotrophic conditions, respectively. NirK gene was highly expressed between log 3.7–log 4.3 during the entire run. Expression of both sqr and soxB genes were closely related with sulfur conversion. More than 57.5% of S 0 recovery rate could be obtained as sqr gene expression was greater than log 3.2, and while, sulfate was the primary form as soxB gene expression higher than log 3.9. The correlation between core microbial genera was very low from network, indicating a complex and non-specific mutualistic network between bacterial functional groups under each nutrient condition, and a stable coexistence state was possibly formed through utilizing each the secondary or waste metabolites in the mixotrophic conditions. This relationship was beneficial to the stability of the microbial community structure in the denitrification desulfurization system.
研究领域:
环境微生物学
·
废水处理
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
PLoS Pathogens
·
2024
·Vol. 20
·期 7
·e1012410
·
IF 5.5
Xiaojun Zhong,Fuwen Liu,Tianqi Liang,Ranran Lu,Mengting Shi,Xiujuan Zhou,Menghua Yang
One of the greatest challenges encountered by enteric pathogens is responding to rapid changes of nutrient availability in host. However, the mechanisms by which pathogens sense gastrointestinal signals and exploit available host nutrients for proliferation remain largely unknown. Here, we identified a two-component system in Vibrio parahaemolyticus , TtrRS, which senses environmental tetrathionate and subsequently activates the transcription of the ttrRS - ttrBCA-tsdBA gene cluster to promote V. parahaemolyticus colonization of adult mice. We demonstrated that TsdBA confers the ability of thiosulfate oxidation to produce tetrathionate which is sensed by TtrRS. TtrRS autoregulates and directly activates the transcription of the ttrBCA and tsdBA gene clusters. Activated TtrBCA promotes bacterial growth under micro-aerobic conditions by inducing the reduction of both tetrathionate and thiosulfate. TtrBCA and TsdBA activation by TtrRS is important for V. parahaemolyticus to colonize adult mice. Therefore, TtrRS and their target genes constitute a tetrathionate-responsive genetic circuit to exploit the host available sulfur compounds, which further contributes to the intestinal colonization of V. parahaemolyticus .
Access to host nutrients is regarded as a critical step for the pathogen infection. However, the human gastrointestinal tract is colonized by an enormous number of microbes, which limits pathogens’ access to nutrient supplies. Sulfur is one of the most abundant elements on Earth and is also essential to all living organisms. The mechanisms by which bacteria, especially intestinal pathogens, regulate the bioavailability of utilizable sulfur in the host are poorly understood. Here, we characterized a tetrathionate-responsive genetic circuit, which was involved in the utilization of sulfur compounds including tetrathionate and thiosulfate in V. parahaemolyticus , and thus contributed to the bacterial intestinal colonization. Our study provides new insight into the ability of bacterial pathogens to sense gastrointestinal signals and exploit host nutrients for their colonization, which contributes to a better understanding of the pathogenesis of enteric pathogens.
研究领域:
微生物学
·
病原生物学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 20
·12486
·
IF 6.208
Joanna Xuan Hui Goh,Loh Teng-Hern Tan,Jodi Woan-Fei Law,Kooi-Yeong Khaw,Nurul-Syakima Ab Mutalib,Ya-Wen He,Bey-Hing Goh,Kok-Gan Chan,Learn-Han Lee,Vengadesh Letchumanan
The increasing prevalence of resistance in carbapenems is an escalating concern as carbapenems are reserved as last-line antibiotics. Although indiscriminate antibiotic usage is considered the primary cause for resistance development, increasing evidence revealed that inconsequential strains without any direct clinical relevance to carbapenem usage are harboring carbapenemase genes. This phenomenon indirectly implies that environmental microbial populations could be the ‘hidden vectors’ propelling carbapenem resistance. This work aims to explore the carbapenem-resistance profile ofVibriospecies across diverse settings. This review then proceeds to identify the different factors contributing to the dissemination of the resistance traits and defines the transmission pathways of carbapenem resistance. Deciphering the mechanisms for carbapenem resistance acquisition could help design better prevention strategies to curb the progression of antimicrobial resistance development. To better understand this vast reservoir selecting for carbapenem resistance in non-clinical settings,Vibriospecies is also prospected as one of the potential indicator strains for carbapenem resistance in the environment.
研究领域:
微生物学
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传染病学
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抗生素研究
·
分子生物学
✓ 已验证
DOI
高影响因子
CURRENT MICROBIOLOGY
·
2022
·Vol. 79
·期 6
·1-11
·
IF 2.343
Bao Jingjiao,Guo Dengkang,Jin Lei,Li Tiejun,Shi Hui
Vibrio fluvialis is a marine opportunistic pathogen that frequently causes diseases in aquatic animals and humans. V. fluvialis can produce quorum sensing signaling molecules to coordinate cell density-dependent behavioral changes, including N-acyl homoserine lactone (AHL), which acts as a vital mediator of virulence-associated gene expression. Currently, several AHL molecules in V. fluvialis have been detected via biological and physicochemical methods, although different detection approaches have generated diverse AHL profiles. Here, we describe the AHL-producing bacterium, V. fluvialis BJ-1, which was isolated from marine sediments from the East China Sea. V. fluvialis BJ-1 could stimulate AHL-mediated β-galactosidase synthesis of the biosensor Agrobacterium tumefaciens NTL4 (pZLR4) but could not induce violacein production in the AHL reporter strain, Chromobacterium violaceum CV026. This bacterial isolate exhibited strong AHL-producing activity at low cell density; however, the AHL activity declined when population density remained at high levels. Analysis of the AHLs by Ultra-High-Performance Liquid Chromatography tandem Mass Spectrometry demonstrated that V. fluvialis BJ-1 produced five different AHL signaling molecules, including two linear chain AHL products (C 8 - and C 10 -HSL), and three β-carbon-oxidative AHL products (3-O-C 8 -, 3-O-C 10 - and 3-O-C 12 -HSL). Significantly, the present study is the first to accurately define the AHL profile of marine V. fluvialis . In future, the coupling of UHPLC to ESI–MS/MS is expected to be utilized for the accurate determination of AHL profiles in marine Vibrio .
研究领域:
微生物学
·
海洋生物学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2022
·Vol. 40
·期 24
·2947-2955
·
IF 5.56
Pengcheng Ma,Yuan Chen,Ning Shao,Junyu Zhang,Yueming Wu,Runhui Liu
Comprehensive Summary The massive use of antibiotics in aquaculture and resulted antibacterial resistance problem urgently need antibiotic substitutions. Herein, we report a promising substitution of aquaculture antibiotics using a synergistic combination of biodegradable peptide polymers and curcumin, a natural compound from plant. The synergistic combination shows strong antibacterial activity against V. fluvialis and some other common bacteria in aquaculture. The membrane-damaging antibacterial mechanism echoes our finding that the synergistic combination will not induce bacteria to develop resistance after continuous use. The synergistic combination also displays effective cure on V. fluvialis -infected zebrafish. The biodegradability of the peptide polymer enables the combination to lose antibacterial activity and will not cause selective pressure on bacterial in the environment. Our study indicates potential application of synergistic composition, biodegradable peptide polymer and curcumin, as promising antibiotic substitution in aquaculture, which represents a promising strategy to address the global challenge of antimicrobial resistance.
研究领域:
水产养殖学
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微生物学
·
材料科学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yangxi Xiang,Yue Shi,Lianlian Sun,Weikang Liang,Kaiyu Chen,Chenghua Li
Pattern recognition receptors (PRRs) mediate the innate immune responses and play a crucial role in host defense against pathogen infections. Apextrin C-terminal (ApeC)-containing proteins (ACPs), a newly discovered class of PRRs specific to invertebrates, recognize pathogens through their ApeC domain as intracellular or extracellular effectors. However, the other immunological functions of ACPs remain unclear. In this study, a membrane-localized ACP receptor was identified in the sea cucumber Apostichopus japonicus (denoted as AjACP1). The ApeC domain of AjACP1, which was located outside of its cell membrane, exhibited the capability to recognize and aggregate Vibrio splendidus . AjACP1 was upregulated upon V. splendidus infection, internalizing into the cytoplasm of coelomocytes. AjACP1 overexpression enhanced the phagocytic activity of coelomocytes against V. splendidus , while knockdown of AjACP1 by RNA interfere inhibited coelomocyte endocytosis. Inhibitor experiments indicated that AjACP1 regulated coelomocyte phagocytosis through the actin-dependent endocytic signaling pathway. Further investigation revealed that AjACP1 interacted with the subunit of the actin-related protein 2/3 complex ARPC2, promoting F-actin polymerization and cytoskeletal rearrangement and thereby affecting the coelomocyte phagocytosis of V. splendidus via the actin-dependent endocytic signaling pathway. As a novel membrane PRR, AjACP1 mediates the recognition and phagocytic activity of coelomocytes against V. splendidus through the AjACP1-ARPC2-F-actin polymerization and cytoskeletal rearrangement pathway.
研究领域:
免疫学
·
海洋生物学
·
分子生物学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Shasha Fang,Yue Geng,Lu Wang,Jun Zeng,Shimin Zhang,Yucheng Wu,Xiangui Lin
Polybrominated diphenyl ethers (PBDEs) are persistent pollutants that may undergo microbial-mediated debromination in anoxic environments, where diverse anaerobic microbes such as methanogenic archaea co-exist. However, current understanding of the relations between PBDE pollution and methanogenic process is far from complete. To address this knowledge gap, a series of anaerobic soil microcosms were established. BDE-47 (2, 2′, 4, 4′-tetrabromodiphenyl ether) was selected as a model pollutant, and electron donors were supplied to stimulate the activity of anaerobes . Debromination and methane production were monitored during the 12 weeks incubation, while obligate organohalide-respiring bacteria (OHRBs), methanogenic, and the total bacterial communities were examined at week 7 and 12. The results demonstrated slow debromination of BDE-47 in all microcosms, with considerable growth of Dehalococcoides and Dehalogenimonas over the incubation observed in most BDE-47 spiked treatments. In addition, the accumulation of intermediate metabolites positively correlated with the abundance of Dehalogenimonas at week 7, suggesting potential role of these OHRBs in debromination. Methanosarcinaceae were identified as the primary methanogenic archaea, and their abundance were correlated with the production of debrominated metabolites at week 7. Furthermore, it was observed for the first time that BDE-47 considerably enhanced methane production and increased the abundance of mcrA genes, highlighting the potential effects of PBDE pollution on climate change. This might be related to the inhibition of reductive N- and S-transforming microbes, as revealed by the quantitative microbial element cycling (QMEC) analysis. Overall, our findings shed light on the intricate interactions between PBDE and methanogenic processes, and contribute to a better understanding of the environmental fate and ecological implication of PBDE under anaerobic settings.
研究领域:
环境科学
·
微生物学
·
生态学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Lijuan Feng,Changyan Xiao,Yuqin Luo,Yan Qiao,Dongzhi Chen
Three common seaweeds including Ulva fasciata, Codium cylindricum and Ishige okamurai were used for the remediation of maricultural wastewater and sediment in the presence/absence of trace level of oxytetracycline (OTC) in lab-scale experiments. Higher NO 3 − -N and PO 4 3- -P removal rates were achieved due to the presence of seaweeds, and trace OTC also had a positive effect on NO 3 − -N removal. A slight variation of 2.10–2.15% were observed in the total relative abundances of antibiotic resistance genes (ARGs) of different sediment samples after one-month operation. However, the variation of ARGs profiles by the co-existence of different seaweeds and OTC was in the descending order of Ishige okamurai > Codium cylindricum > Ulva fasciata , which was in accordance with the variation of microbial hosts at genus level. The abundance of dominant tetracycline resistance genes promoted by the co-existence of different seaweeds and OTC in compared with the presence of single seaweed or OTC via metagenomic sequencing and qPCR analysis, and the co-existence of Ishige okamurai and OTC exhibited the largest impact. The potential pathogens were more sensitive to the co-existence of seaweed and OTC than single seaweeds. Meanwhile, a variety of ARGs were enriched in the pathogens, and the dominant pathogenic bacteria of Vibrio had 133 Vibrio species with 28 subtypes of ARGs. The variation of ARGs profiles in the sediment were strongly related with the dominant phyla Proteobacteria, Actinobacteria, Firmicutes, Planctomycetes and Cyanobacteria . Besides, Nitrate level exhibited more significant effect on ∑ARGs, ARGs resistant to vancomycin and streptogramin _a, while phosphate level exhibited more positively significant effect on ARGs resistant to fosmidomycin, ATFBT and cephalosporin.
研究领域:
环境科学
·
微生物学
·
海洋生物学
·
基因组学
✓ 已验证
DOI
PubMed
高影响因子
npj Clean Water
·
2024
·Vol. 7
·期 1
·1-13
·
IF 10.4
Chen Chao,Yang Yu,Choo Kwang-Ho,Ng How Yong,Takizawa Satoshi,Hou Li-an
Membrane biofouling poses an ongoing challenge in seawater reverse osmosis (SWRO) desalination. Here we delved into the impact of seasonal variations in microbial communities on membrane biofouling and innovatively fabricated quorum sensing inhibitors (acylase (AC) and methyl anthranilate (MA))-modified membranes to combat it. Results indicated that Proteobacteria dominated in seawater and membrane biofilm across all seasons, while other phyla varied seasonally. At the class level, the two leading bacteria on the membrane were Gamma- and Alphaproteobacteria , constituting 14–48% and 4–27%, respectively. Genera like Arcobacter , Vibrio , and Rhodobacteraceae were identified as keystone species that exhibited a significant positive correlation with extracellular polymeric substance (EPS) and biofilm formation, leading to a substantive reduction in membrane flux by 70 to 77%. The introduction of AC and MA inhibitors on the membrane suppressed keystone bacteria Rhodobacteraceae and Arcobacter and affected their metabolism, thereby significantly reducing EPS by 65–69% and 55–59%, respectively, and alleviating membrane flux decline by 30–32% and 18–22%, respectively, compared to the pristine membrane. These findings shed new light on the seasonal patterns of membrane biofouling and provide valuable insights into anti-biofouling strategies based on QS inhibition for collaborative biofilm formation.
研究领域:
环境科学
·
微生物学
·
水处理
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）