Rainwater contains substantial bacteria and rain is an efficient pathway for the dissemination of bacteria from the atmosphere to land and water surfaces.However,quantitative information on rainwater bacteria is very ...Rainwater contains substantial bacteria and rain is an efficient pathway for the dissemination of bacteria from the atmosphere to land and water surfaces.However,quantitative information on rainwater bacteria is very limited due to the lack of a reliable method.In this study,the epifluorescence microscopy enumeration with the LIVE/DEAD BacLight Bacterial Viability Kit stain was verified to quantify the abundance of viable and non-viable bacterial cells in rainwater,with the 4＇,6-diamidino-2-phenylindole（DAPI） stain for the reference of total cell counts.Results showed that the total counts of bacterial cells by LIVE/DEAD BacLight staining were consistent with those by DAPI staining,and the average detection efficiency was（109 ± 29）%.The ratio of cell count with glutaraldehyde fixation to that without fixation was（106 ± 5）%on average.The bacterial concentration in negative control was usually an order of magnitude lower than that in rainwater samples.However,in case of small precipitation,the abundance in negative control could be more than that in rainwater samples.These results indicate that the enumeration with LIVE/DEAD BacLight bacterial viability assay coupled with glutaraldehyde fixation and careful negative control investigation is an approach applicable to the measurement of the concentration and viability of bacterial cells in rainwater.展开更多
This study examines the effects of different organic carrier materials,chicken manure,mill mud,and cow manure on the long-term viability and metabolite profiles of rhizobacterial strains Mesorhizobium sp.and Rhizobium...This study examines the effects of different organic carrier materials,chicken manure,mill mud,and cow manure on the long-term viability and metabolite profiles of rhizobacterial strains Mesorhizobium sp.and Rhizobium sp.Over one year,growth curve analysis revealed significant differences in bacterial proliferation.Mill mud supported the most robust growth,with a doubling of 11 days,compared to chicken and cow manure,which exhibited growth saturation after five to eight months.Non-targeted 1H-NMR metabolite profiling revealed distinct sugar and amino acid profiles across carriers.Mill mud exhibited a broader range of sugars,including sucrose,maltose,and mannose,while chicken and cow manure primarily contained monosaccharides like glucose,xylose,and mannitol.Amino acids such as lysine and glutamate were higher in chicken manure,followed by cow manure and mill mud.Plant growth-promoting metabolites were detected in all carriers,with Mesorhizobium sp.and Rhizobium sp.enhancing their production by up to 200%in mill mud and cow manure.Both bacterial strains utilized sugars from the carriers,with Mesorhizobium sp.showing more consistent sugar metabolism.These findings suggest that mill mud is an effective carrier for sustaining rhizobacterial viability and enhancing metabolite production,benefiting biofertilizer formulations and soil health.展开更多
The study aims to identify the potential acute effects of suspended aluminum nitride（Al N）nanoparticles（NPs） on soluble microbial products（SMP） of activated sludge.Cultured activated sludge loaded with 1,10,50,1...The study aims to identify the potential acute effects of suspended aluminum nitride（Al N）nanoparticles（NPs） on soluble microbial products（SMP） of activated sludge.Cultured activated sludge loaded with 1,10,50,100,150 and 200 mg/L of Al N NPs were carried out in this study.As results showed,Al N NPs had a highly inverse proportionality to bacterial dehydrogenase and OUR,indicating its direct toxicity to the activated sludge viability.The toxicity of Al N NPs was mainly due to the nano-scale of Al N NPs.In SMP,Al N NPs led to the decrease of polysaccharide and humic compounds,but had slight effects on protein.The decrease of tryptophan-like substances in SMP indicated the inhibition of Al N NPs on the bacterial metabolism.Additionally,Al N NPs reduced obviously the molecular weight of SMP,which might be due to the nano-scale of Al N.展开更多
Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the singl...Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the single-cell level,FCM has gained an increased popularity in microbiological research,food safety monitoring,water quality control,and clinical diagnosis.Here we will review the recent applications of flow cytometry in areas such as(1)total bacterial cell count,(2)bacterial viability analysis,(3)specific bacterial detection and identification,(4)characterization of physiological changes under environmental perturbations,and(5)biological function studies.Nevertheless,despite these widespread applications,challenges still remain for the detection of small sizes of bacteria and biochemical features that cannot be brightly stained via fluorescence.Recent improvement in FCM instrumentation will be discussed,and particularly the development of high sensitivity flow cytometry for advanced analysis of single bacterial cells will be highlighted.展开更多
基金supported by a Grant-in-Aid for Challenging Exploratory Research(No.15K12192)from the Japan Society for the Promotion of Science(JSPS)The State Scholarship Fund of Chinese Scholarship Council(CSC No.201406010350)provides Mr.Wei Hu the scholarship for his study and stay at the Prefectural University of Kumamoto
文摘Rainwater contains substantial bacteria and rain is an efficient pathway for the dissemination of bacteria from the atmosphere to land and water surfaces.However,quantitative information on rainwater bacteria is very limited due to the lack of a reliable method.In this study,the epifluorescence microscopy enumeration with the LIVE/DEAD BacLight Bacterial Viability Kit stain was verified to quantify the abundance of viable and non-viable bacterial cells in rainwater,with the 4＇,6-diamidino-2-phenylindole（DAPI） stain for the reference of total cell counts.Results showed that the total counts of bacterial cells by LIVE/DEAD BacLight staining were consistent with those by DAPI staining,and the average detection efficiency was（109 ± 29）%.The ratio of cell count with glutaraldehyde fixation to that without fixation was（106 ± 5）%on average.The bacterial concentration in negative control was usually an order of magnitude lower than that in rainwater samples.However,in case of small precipitation,the abundance in negative control could be more than that in rainwater samples.These results indicate that the enumeration with LIVE/DEAD BacLight bacterial viability assay coupled with glutaraldehyde fixation and careful negative control investigation is an approach applicable to the measurement of the concentration and viability of bacterial cells in rainwater.
基金jointly funded by Soil CRC(PIA3.4.001)and Griffith Universitysupported by the Cooperative Research Centre for High Performance Soils whose activities are funded by the Australian Government's Cooperative Research Centre Program.
文摘This study examines the effects of different organic carrier materials,chicken manure,mill mud,and cow manure on the long-term viability and metabolite profiles of rhizobacterial strains Mesorhizobium sp.and Rhizobium sp.Over one year,growth curve analysis revealed significant differences in bacterial proliferation.Mill mud supported the most robust growth,with a doubling of 11 days,compared to chicken and cow manure,which exhibited growth saturation after five to eight months.Non-targeted 1H-NMR metabolite profiling revealed distinct sugar and amino acid profiles across carriers.Mill mud exhibited a broader range of sugars,including sucrose,maltose,and mannose,while chicken and cow manure primarily contained monosaccharides like glucose,xylose,and mannitol.Amino acids such as lysine and glutamate were higher in chicken manure,followed by cow manure and mill mud.Plant growth-promoting metabolites were detected in all carriers,with Mesorhizobium sp.and Rhizobium sp.enhancing their production by up to 200%in mill mud and cow manure.Both bacterial strains utilized sugars from the carriers,with Mesorhizobium sp.showing more consistent sugar metabolism.These findings suggest that mill mud is an effective carrier for sustaining rhizobacterial viability and enhancing metabolite production,benefiting biofertilizer formulations and soil health.
基金supported by the National Natural Science Foundation of China(No.51378368)the Foundation of State Key Laboratory of Pollution Control and Resource Reuse(Tongji University),China(No.PCRRT16003)Shenzhen Science and Technology Research Fund(No.CXZZ20150330151321966)
文摘The study aims to identify the potential acute effects of suspended aluminum nitride（Al N）nanoparticles（NPs） on soluble microbial products（SMP） of activated sludge.Cultured activated sludge loaded with 1,10,50,100,150 and 200 mg/L of Al N NPs were carried out in this study.As results showed,Al N NPs had a highly inverse proportionality to bacterial dehydrogenase and OUR,indicating its direct toxicity to the activated sludge viability.The toxicity of Al N NPs was mainly due to the nano-scale of Al N NPs.In SMP,Al N NPs led to the decrease of polysaccharide and humic compounds,but had slight effects on protein.The decrease of tryptophan-like substances in SMP indicated the inhibition of Al N NPs on the bacterial metabolism.Additionally,Al N NPs reduced obviously the molecular weight of SMP,which might be due to the nano-scale of Al N.
基金the National Key Basic Research Program of China(2013CB933703)the National Natural Science Foundation of China(91313302,21105082,21225523,21472158,21027010,21521004)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13036)
文摘Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the single-cell level,FCM has gained an increased popularity in microbiological research,food safety monitoring,water quality control,and clinical diagnosis.Here we will review the recent applications of flow cytometry in areas such as(1)total bacterial cell count,(2)bacterial viability analysis,(3)specific bacterial detection and identification,(4)characterization of physiological changes under environmental perturbations,and(5)biological function studies.Nevertheless,despite these widespread applications,challenges still remain for the detection of small sizes of bacteria and biochemical features that cannot be brightly stained via fluorescence.Recent improvement in FCM instrumentation will be discussed,and particularly the development of high sensitivity flow cytometry for advanced analysis of single bacterial cells will be highlighted.
