Bacteria have developed different intra- and inter-specific communication mechanisms that involve the production, release, and detection of signaling molecules, because these molecules serve as the autoinducers involved in "quorum sensing" systems. Other communication mechanisms employ volatile signaling molecules that regulate different bacterial processes. The Arthrobacter agilis strain UMCV2 is a plant growth promoting actinobacterium, which induces plant growth and inhibits phytopathogenic fungi by emitting the dimethylhexadecylamine (DMHDA). However, little is known about the effect of this volatile compound on A. agilis UMCV2 itself, as well as on other bacteria. By exposing A. agilis UMCV2 and bacteria of the genus Bacillus and Pseudomonas to different concentrations of DMHDA, this study showed the dose-dependent effects of DMHDA on A. agilis UMCV2 growth, cellular viability, swarming motility, and expression of marker genes of the flagellar apparatus of bacteria. DMHDA was found to also modulate swarming motility of Bacillus sp. ZAP018 and P. fluorescens UM270, but not that of P. aeruginosa PA01. These data indicate that DMHDA is involved in both intra- and inter-specific bacterial interaction.
- MeSH
- Arthrobacter účinky léků růst a vývoj MeSH
- Bacillus účinky léků růst a vývoj MeSH
- methylaminy farmakologie MeSH
- mikrobiální interakce účinky léků MeSH
- pohyb účinky léků MeSH
- Pseudomonas účinky léků růst a vývoj MeSH
- quorum sensing účinky léků MeSH
- těkavé organické sloučeniny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Aquaculture is the fastest growing food-production sector, and common carp (Cyprinus carpio) is one of the most cultivated fish species in the world. Due to its intrinsic characteristics, fish meat is highly susceptible to microbiological spoilage. Pseudomonas and Shewanella are the primary and secondary occurring microbiota during storage of fish meat, with significant contribution to spoilage with the formation of hydrolytic enzymes (lipases and proteases). RESULTS: With in vitro testing, we show that rosemary extract (Inolens4), buffered vinegar and their combination (SyneROX) exhibit antimicrobial effects against P. fragi, P. psychrophila, S. putrefaciens and S. xiaemensis at concentrations of 3.13 and 1.56 mg mL-1 . The combination was the most effective in inhibiting growth of selected bacteria in food model, and production of lipases and proteases during 9 days at 5 °C. In situ testing of antimicrobial dip treatment of carp meat determined that aerobic mesophilic, total psychrotrophic, Pseudomonas and hydrogen sulfide producer counts were reduced in all treatments, with the most prominent influence being shown by the combination and buffered vinegar. CONCLUSIONS: Our study highlights the importance of a multilevel assessment of the antimicrobial potential of biopreservatives under conditions comparable to those of the selected food. Investigation with bacteria and food model provided coherent and consistent data for the evaluation of the antimicrobial potential for carp meat. Combination of buffered vinegar (as active antimicrobial) and rosemary extract, with well-known and researched antioxidant properties but low in situ antimicrobial activity, represents a good potential for combined effect in preservation of fish meat. © 2020 Society of Chemical Industry.
- MeSH
- antibakteriální látky farmakologie MeSH
- chuť MeSH
- kapři mikrobiologie MeSH
- konzervace potravin MeSH
- kyselina octová antagonisté a inhibitory MeSH
- mikrobiální testy citlivosti MeSH
- potrava z moře (živočišná) mikrobiologie MeSH
- potravinářská mikrobiologie MeSH
- Pseudomonas účinky léků růst a vývoj MeSH
- rostlinné extrakty chemie MeSH
- rozmarýn chemie MeSH
- Shewanella účinky léků růst a vývoj MeSH
- sulfan analýza MeSH
- vodní hospodářství MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Microbial bioremediation of heavy metal-contaminated soil is a potential technique to reduce heavy metals in crop plants. However, the dynamics and roles of the local microbiota in bioremediation of heavy metal-contaminated soil following microbial application are rarely reported. In this study, we used Pseudomonas chenduensis strain MBR for bioremediation of Cd-contaminated paddy soil and investigated its effects on the dynamics of the local soil bacterial community and Cd accumulation in rice. Cd accumulation in rice grains and roots were significantly reduced by the addition of the strain MBR. The addition of the strain MBR caused greater changes in bacterial communities in rhizosphere soil than in bulk soil. MBR enhanced the roles of microbial communities in transformation of Cd fractions, especially in rhizosphere soil. The strain MBR likely regulated abundant subcommunities more than rare subcommunities to improve Cd bioremediation, especially in rhizosphere soil. Consequently, the dynamics and functional roles of the local microbial communities differed significantly during bioremediation between abundant and rare subcommunities and between rhizosphere soil and bulk soil. This study provides new insight into the microbiota-related mechanisms underlying bioremediation.
A statistical method was developed to test for equivalence of microbial communities analysed by next-generation sequencing of amplicons. The test uses Bray-Curtis distances between the microbial community structures and is based on a two-sample jackknife procedure. This approach was applied to investigate putative effects of the antifungal biocontrol strain RU47 on fungal communities in three arable soils which were analysed by high-throughput ITS amplicon sequencing. Two contrasting workflows to produce abundance tables of operational taxonomic units from sequence data were applied. For both, the developed test indicated highly significant equivalence of the fungal communities with or without previous exposure to RU47 for all soil types, with reference to fungal community differences in conjunction with field site or cropping history. However, minor effects of RU47 on fungal communities were statistically significant using highly sensitive multivariate tests. Nearly all fungal taxa responding to RU47 increased in relative abundance indicating the absence of ecotoxicological effects. Use of the developed equivalence test is not restricted to evaluate effects on soil microbial communities by inoculants for biocontrol, bioremediation or other purposes, but could also be applied for biosafety assessment of compounds like pesticides, or genetically engineered plants.
- MeSH
- biologická kontrola škůdců metody MeSH
- biostatistika metody MeSH
- DNA fungální chemie genetika MeSH
- fylogeneze MeSH
- houby klasifikace růst a vývoj izolace a purifikace MeSH
- mezerníky ribozomální DNA chemie genetika MeSH
- očkovadla agrotechnická * MeSH
- Pseudomonas růst a vývoj MeSH
- půdní mikrobiologie * MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- společenstvo * MeSH
- Publikační typ
- časopisecké články MeSH
There is a growing interest in the use of bioinoculants to assist mineral fertilizers in improving crop production and yield. Azotobacter and Pseudomonas are two agriculturally relevant strains of bacteria which have been established as efficient bioinoculants. An experiment involving addition of graded concentrations of zinc oxide (ZnO) nanoparticles was undertaken using log phase cultures of Azotobacter and Pseudomonas. Growth kinetics revealed a clear trend of gradual decrease with Pseudomonas; however, Azotobacter exhibited a twofold enhancement in growth with increase in the concentration of ZnO concentration. Scanning electron microscopy (SEM), supported by energy-dispersive X-ray (EDX) analyses, illustrated the significant effect of ZnO nanoparticles on Azotobacter by the enhancement in the abundance of globular biofilm-like structures and the intracellular presence of ZnO, with the increase in its concentration. It can be surmised that extracellular mucilage production in Azotobacter may be providing a barrier to the nanoparticles. Further experiments with Azotobacter by inoculation of wheat and tomato seeds with ZnO nanoparticles alone or bacteria grown on ZnO-infused growth medium revealed interesting results. Vigour index of wheat seeds reduced by 40-50% in the presence of different concentrations of ZnO nanoparticles alone, which was alleviated by 15-20%, when ZnO and Azotobacter were present together. However, a drastic 50-60% decrease in vigour indices of tomato seeds was recorded, irrespective of Azotobacter inoculation.
- MeSH
- Azotobacter účinky léků růst a vývoj MeSH
- bakteriální nálož MeSH
- biofilmy účinky léků MeSH
- mikroskopie elektronová rastrovací MeSH
- nanočástice metabolismus toxicita MeSH
- oxid zinečnatý metabolismus toxicita MeSH
- pšenice účinky léků MeSH
- Pseudomonas účinky léků růst a vývoj MeSH
- Solanum lycopersicum účinky léků MeSH
- spektrometrie rentgenová emisní MeSH
- zemědělské plodiny účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
DNA replication of plasmids in Gram-negative bacteria has been an object of study at CIB-CSIC for nearly 30 years. We have been focused on the enterobacterial antibiotic resistance factor R1 (1981-1992) and the pPS10 replicon from the phytopathogen Pseudomonas savastanoi (since 1984). Our group has used multidisciplinary (genetic, biochemical and biophysical-structural) approaches to unravel the molecular mechanism for the activation of RepA. Rep-type plasmidic proteins are either transcriptional repressors or replication initiators/inhibitors, depending on their association state (dimers vs. monomers) and targeting of alternative (operator or iteron) DNA sites. We discovered that allosteric DNA-binding remodels the structure of RepA N-terminal domain (WH1), transforming alpha-helical portions into beta-strands. This precisely tunes the distances between the DNA reading heads in WH1 and the C-terminal domain (WH2), to match the target operator or iteron sequences. We have recently moved into engineering such structural transformation in RepA-WH1 to build-up synthetic protein devices that allow for customized ligand (DNA)-promoted amyloidogenesis. Our basic studies on plasmid DNA replication are relevant for settling the bases of a minimalist bacterial model to tackle transmissible amyloid proteinopathies and are a valuable tool for bottom-up synthetic biology.
- MeSH
- amyloid biosyntéza genetika MeSH
- amyloidóza enzymologie genetika MeSH
- bakteriální léková rezistence genetika imunologie účinky léků MeSH
- bakteriální proteiny biosyntéza genetika účinky léků MeSH
- financování organizované MeSH
- gramnegativní bakterie genetika růst a vývoj MeSH
- klinické laboratorní techniky využití MeSH
- lidé MeSH
- plazmidy biosyntéza genetika chemie MeSH
- Pseudomonas enzymologie genetika růst a vývoj MeSH
- replikace DNA genetika účinky léků MeSH
- rostliny MeSH
- statistika jako téma MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
