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
FOOD CHEMISTRY
·
2024
·
IF 8.5
Chenjing Xu,Jinpo Xie,Lian Yu,Bin Shu,Xiaogang Liu,Siping Chen,Qinglan Li,Shaohai Qi,Suqing Zhao
Vibrio vulnificus infection caused by contaminated aquatic products and seawater can lead to severe disease and high mortality. The development of a rapid and sensitive detection method for Vibrio vulnificus is vital to effectively prevent infection in advance. In this study, CeO 2 @PtRu with high peroxidase activity was used to construct a colorimetric immunoassay for Vibrio vulnificus detection by conjugating polyclonal antibodies via the biotin-streptavidin system. The developed colorimetric biosensor for Vibrio vulnificus demonstrated rapid operability and good sensitivity with a detection range from 10 4 CFU/mL to 10 9 CFU/mL, and the limit of detection (LOD) is 193 CFU/mL. Moreover, the colorimetric biosensor showed excellent specificity and good recoveries from 98.70% to 102.10% with RSD < 7.45% for spiked real samples. This novel CeO 2 @PtRu-based colorimetric biosensor has great application potential for the sensitive detection of Vibrio vulnificus in seafood.
研究领域:
微生物学
·
免疫学
·
生物传感技术
✓ 已验证
产品关联
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
MICROBIAL PATHOGENESIS
·
2018
·
IF 2.332
Tengteng Lv,Tongxiang Song,Huijie Liu,Ruibing Peng,Xiamin Jiang,Weiwei Zhang,Qingxi Han
Vibrio alginolyticus is a ubiquitous marine opportunistic pathogen that can infect various hosts in marine environment. In the present study, V. alginolyticus strain Wz11 was isolated from diseased cuttlefish , Sepia pharaonis , with 20% of promoted death and high survival capacity in skin mucus and tissue liquid. Its growth, siderophore production, and expressions of haemolysin and swarming related genes were characterized under iron limited conditions. The minimal inhibitory concentration (MIC) of 2,2′-dipyridyl (DP) to V. alginolyticus strain Wz11 was 640 μM. While growth of V. alginolyticus strain Wz11 was inhibited by DP , production of iron-seizing substances, haemolytic activity and swarming motility were increased. Moreover, expressions of haemolysin related genes tlh , tdh and vah and flagellar related genes flgH , fliC , fliD and fliS were also characterized using real-time reverse transcriptase PCR. Expression of tdh was up-regulated to 7.7-fold, while expressions of tlh and vah were down-regulated to 0.016-fold and 0.03-fold, respectively. The expression of fliC , flgH , fliD and fliS was up-regulated to 4.9-, 3.8-, 8.6- and 4.5-fold, respectively. Concluded from our results suggested that V. alginolyticus strain Wz11 was considered as a potential pathogen of S. pharaonis , and iron level played an important role in the production of iron-seizing substances, and activities of haemolysin and bacterial swarming as well as their related gene expressions.
研究领域:
微生物学
·
海洋生物学
·
水产养殖学
✓ 已验证
DOI
PubMed
高影响因子
Toxics
·
2022
·Vol. 10
·期 5
·255
·
IF 4.472
Jun Yang,Anqi Liao,Shulin Hu,Yiwen Zheng,Shuli Liang,Shuangyan Han,Ying Lin
Bisphenol A (BPA) and heavy metals are widespread contaminants in the environment. However, the combined toxicities of these contaminants are still unknown. In this study, the bioluminescent bacteriaVibrio qinghaiensisQ67 was used to detect the single and combined toxicities of BPA and heavy metals, then the joint effects of these contaminants were evaluated. The results show that chronic toxicities of chromium (Cr), cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), nickel (Ni), and BPA were time–dependent; in fact, the acute toxicities of these contaminants were stronger than the chronic toxicities. Furthermore, the combined toxicities of BPA and heavy metals displayed BPA + Hg > BPA + Cr > BPA + As > BPA + Ni > BPA + Pb > BPA + Cd in the acute test and BPA + Hg > BPA + Cd > BPA + As > BPA + Cd in the chronic test, which suggested that the combined toxicity of BPA and Hg was stronger than that of other mixtures in acute as well as chronic tests. Additionally, both CA and IA models underestimated the toxicities of mixtures at low concentrations but overestimated them at high concentrations, which indicates that CA and IA models were not suitable to predict the toxicities of mixtures of BPA and heavy metals. Moreover, the joint effects of BPA and heavy metals mainly showed antagonism and additive in the context of acute exposure but synergism and additive in the context of chronic exposure. Indeed, the difference in the joint effects on acute and chronic exposure can be explained by the possibility that mixtures inhibited cell growth and luminescence in chronic cultivation. The chronic toxicity of the mixture should be considered if the mixture results in the inhibition of the growth of cells.Keywords:mixture toxicity;bisphenol A;heavy metal;joint effect;Vibrio qinghaiensisQ67
研究领域:
环境科学
·
毒理学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 17
·12624-12637
·
IF 3.84
Haifeng Su,Yun Zhao,Maolin Wang,Yuanjian Xu
Classic chemical mutagenesis has a demonstrated potential to create a strain of Clostridium with improved fermentation performance for obtaining high butanol yield. However, screening methods to select the desired bacterial phenotype from large populations are not currently feasible or readily available. In this paper, a simple, novel screening method to select target strains by using trypan blue dye as an indicator in solid starch media to detect the target mutant bacterium was devised. A well performing mutant strain Clostridium beijerinckii no. 15 was obtained using this screening method. It was derived from wild-type C. beijerinckii NCIMB 8052 by N-methyl-N′-nitro-N-nitrosoguanidine (NTG) mutagenesis, and its fermentative capability for producing butanol was investigated, using hydrolysate of fresh cassava and other substrates. The mutant strain C. beijerinckii no. 15 produced a maximum yield of 15.06 g L−1 butanol and 23.78 g L−1 total solvents, when the fresh cassava substrate was given a simple pretreatment at 121 °C for 1 h. For other substrates, the highest butanol yields: 20.67 g L−1 from glucose, 17.96 g L−1 from liquefied dextrin, and 13.59 g L−1 from liquefied corn powder (P ≤ 0.05) were also achieved. Experimental trials showed that the mutant strain had a significantly greater fermentation ability, and produced a high-yield butanol from fresh cassava hydrolysates. Further research showed that the highest overall yield of butanol resulted from the improvement of enzymatic activity of C. beijerinckii no. 15's α-amylase (P ≤ 0.05). Also, the protein structure of the α-amylase was predicted and its amino acid mutation sites were analyzed. Results revealed that these mutant amino acids may have somehow improved α-amylase activity and thus, led to producing more butanol. Our research will contribute to efforts to develop C. beijerinckii fermentation of fresh cassava to produce butanol.
研究领域:
微生物学
·
生物技术
·
发酵工程
✓ 已验证
DOI
高影响因子
METHODS
·
2019
·
IF 3.782
Hongshun Hao,Shouchen Hao,Hongman Hou,Gongliang Zhang,Yunxia Hou,Zuowei Zhang,Jingran Bi,Shuang Yan
A novel photoelectrochemical (PEC) immunosensor based on CdSe quantum dots (QDs) sensitized Ho 3+ /Yb 3+ -TiO 2 for the detection of Vibrio parahaemolyticus (VP) was assembled. The working electrode was constructed via the layer-by-layer (LBL) method with the Ho 3+ /Yb 3+ -TiO 2 , CdSe QDs, NHS/EDC, antibody of VP (anti-VP), bovine serum albumin (BSA) modified on the surface of the FTO in sequence. Ascorbic acid (AA) acts as an electron donor to combine photogenerated holes in order to provide a stable current system. Ho 3+ and Yb 3+ co-doping TiO 2 broadened the spectral response range of TiO 2 to the infrared region and improved the photocurrent responsiveness of TiO 2 . The PEC immunosensor, with Ho 3+ /Yb 3+ ratio of 1:5, Ho 3+ /Yb 3+ -TiO 2 of 2 mg/mL and PBS solution of pH 7.4, had an optimal photocurrent responsiveness. Immobilization of anti-VP was by classical NHS/EDC coupling reactions between COOH groups of CdSe QDs and NH 2 groups of the anti-VP. The results indicated that PEC immunosensors had a low detection limit of 25 CFU/mL, a wide detection range of 10 2 –10 8 CFU/mL, high stability, low price, and short detection time. This method could be promising for the rapid and ultrasensitive detection of pathogenic microorganisms in the food.
研究领域:
生物传感
·
食品安全检测
·
微生物学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Ziru Lian,Rong Pan,Jiangtao Wang
Norfloxacin chitosan/chitosan oligosaccharide microcapsules (NCCM) were prepared by emulsion-chemical crosslinking method. The characteristics of obtained microcapsules were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and release experiments. Cumulative release profile of norfloxacin from the chitosan microcapsules in natural seawater was measured and the controlled release of drugs was at a uniform rate in 48 h. The chitosan microcapsules were applied onto the antibacterial study of the shrimp culture in natural seawater. It is observed that the seawater in the NCCM added groups was relatively clear and the biomass of Vibrio increased slowly in contrast to the control and norfloxacin groups. The inhibition rate of Vibrio in norfloxacin groups obvioursly decreased after the 5 th day, whereas, it remained high and stable during experiment period in NCCM groups. The results showed that the chitosan microcapsules as release materials have excellent antibacterial effects on Vibrio in the farming of Penaeus vannamei Boone. The controlled release could obviously reduce dosage of antibiotics and delivery times, and effectively improve the utilization rate of norfloxacin drugs for shrimps
研究领域:
水产养殖学
·
药剂学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biosensors-Basel
·
2023
·Vol. 13
·期 1
·111
·
IF 5.4
Tianyi Yang,Yanju Chen,Jinsong He,Jian Wu,Meixia Wang,Xiaoping Zhong
A rapid and intuitive method for detecting Vibrio parahaemolyticus (VP) was established by a designed reaction vessel which coupled CRISPR/Cas12a with loop-mediated isothermal nucleic acid amplification (LAMP). There were two spaces in the vessel-holding LAMP reaction solution and CRISPR reaction solution, respectively, which were separated with a polyvinyl alcohol (PVA) membrane. The PVA membrane could be dissolved with a water solution. The thermolabile hemolysin (TLH) gene of VP was employed as the detection target. After the target sequence of the TLH gene was amplified with LAMP, the PVA membrane would be dissolved and the CRISPR reaction solution mixed with the LAMP reaction solution. In this way, amplicons could be detected with CRISPR/Cas12a in the reaction vessel. The fluorescent signals produced by the positive samples were clearly identified by the naked eye under a UV light, while the negative samples were dark. The whole detection procedure could be finished within 35 min with a detection limit of 100 copies/µL. The designed reaction vessel is easy to produce and can effectively prevent contamination due to the opening of the reaction vessel after the LAMP reaction. Thus, it will have the potential to provide a new solution for rapid detection in the field.Keywords:polyvinyl alcohol;dissolvable membrane;CRISPR/Cas12a;LAMP reaction;Vibrio parahaemolyticus
研究领域:
分子生物学
·
病原体检测
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Niu Haiyue,Zhang Jianming,Zhang Chengcheng,Xin Xiaoting,Liu Daqun
The specific effects of minerals and bacteria in salt on fermented vegetables are unclear. In this study, four different salts were used for radish fermentation to investigate the key factor in salt affecting fermented radish and establish a correlation between the key factor and fermented radish flora. Radish salted with sea salt and well salt had better quality in both industry and laboratory, as reflected by its acidity, color, texture, and flavors. The minerals and halophilic bacteria present in salt can affect the quality of fermented radishes by altering the bacterial community. However, the correlation between minerals and halophilic bacteria remains unclear. The key factor associated to radish fermentation was the dominant halophilic microbes. Bacteria in mineral-rich salts affected radish more on day 35; Salinibacter, Desulfovermiculus, Aliifodinibius, and Halovibrio in salt affected Lactobacillus, Leuconostoc, and Vibrio in radish. In contrast, bacteria in refined salts affected radish more on day 14; Desulfovermiculus, Aliifodinibius, Halovibrio, and Tepidimonas in salt affected most bacteria in radish, particularly lactic acid bacteria (LAB). Key halophilic microbes was found to have a greater effect on fermented radish quality than salt composition. This study provides a theoretical basis for improving the quality and standardization of fermented radish.
研究领域:
食品科学
·
微生物学
·
发酵技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2024
·Vol. 108
·期 1
·1-12
·
IF 3.9
Lin Yilin,Fang Meimei,Liu Jun,Zhang Yehui,Yu Yigang
Abstract Phenyllactic acid (PLA) generally recognized as a natural organic acid shows against Vibrio parahaemolyticus activity. In this study, V. parahaemolyticus ATCC17802 ( Vp 17802) was cultured under the stress of 1/2MIC PLA, and then the antibacterial mechanisms were explored via transcriptomics. The minimum inhibitory concentration (MIC) of PLA against Vp 17802 was 3.2 mg/mL, and the time-kill analysis resulted that Vp 17802 was inhibited. PLA was able to destroy the bacterial membrane, leading to the leakage of intracellular substances and decline of ATP levels. The RNA-sequencing analysis results indicated that 1616 significantly differentially expressed genes were identified, among which 190 were up-regulated and 1426 were down-regulated. Down-regulation of the icd2 gene in the TCA cycle mediates blockage of tyrosine metabolic, arginine biosynthesis, and oxidative phosphorylation, causing insufficient energy supply of Vp 17802. Moreover, PLA could cause amino acids, metal ions, and phosphate transporters to be blocked, affecting the acquisition of nutrients. The treatment by PLA altered the expression of genes encoding functions involved in quorum sensing, flagellar assembly, and cell chemotaxis pathway, which may be interfering with the biofilm formation in Vp 17802, reducing cell motility. Overall, 1.6 mg/mL PLA inhibited the growth of Vp 17802 by disrupting to uptake of nutrients, cell metabolism, and the formation of biofilms. The results suggested a new direction for exploring the activity of PLA against Vp 17802 and provided a theoretical basis for bacterial pathogen control in the food industry. Key points •RNA sequencing was carried out to indicate the antibacterial mechanism of Vp17802. •The icd2 gene in the TCA cycle mediates blockage of metabolic of Vp17802. •The biofilm formation has interfered with 1.6 mg/mL PLA, which could reduce cell motility and virulence. Graphical Abstract
研究领域:
微生物学
·
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CONTROL
·
2021
·
IF 5.548
Wenxiu Zhu,Jingzhu Gao,Hongli Liu,Jiaxiu Liu,Tong Jin,Ningbo Qin,Xiaomeng Ren,Xiaodong xia
Vibrio parahaemolyticus ( V. parahaemolyticus ) is an important foodborne pathogen , which is frequently associated with seafood consumption and commonly causes gastroenteritis. The biofilm formed by V. parahaemolyticus in the food production chain poses a continuous threat to food safety, therefore effective antibiofilm strategy is in urgent need. Sodium butyrate is widely used in food, feed, cosmetics and other industries, and could be used as a flavoring agent in food as well as a dietary supplement for health. This study aims to examine the antibiofilm effect of sodium butyrate against V. parahaemolyticus. We found that sodium butyrate could inhibit biofilm formation at subinhibitory concentrations (SICs). Microscopic images coupled with extracellular polysaccharide quantification showed that V. parahaemolyticus biofilm was loosely structured with fewer biofilm constituents when treated with sodium butyrate. XTT reduction assay illustrated that sodium butyrate interfered with the metabolic activity of cells encased inside biofilm and decreased their viability. Sodium butyrate decreased the motility and surface hydrophobicity of V. parahaemolyticus , and interfered with quorum sensing by using two reporter strains. The RT-qPCR analysis revealed that sodium butyrate down-regulated genes associated with biofilm formation. These findings suggest that sodium butyrate has the potential to be developed as a potent agent against V. parahaemolyticus biofilm in food industries.
研究领域:
微生物学
·
食品科学
✓ 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）