PREMISE: Despite the high functional importance of endophytes, we still have limited understanding of the biotic and abiotic factors that influence colonization of plant hosts along major ecological gradients and lack quantitative estimates of their colonization extent. In this study, we hypothesized that the developmental stage of the ecosystem will affect the levels of bacterial and fungal endophytic assemblages in the foliar endosphere. METHODS: We quantified levels of bacterial and fungal endophytes in leaves of four plant hosts at four stages of vegetation succession using an optimized qPCR protocol with bacteria-specific 16S and fungi-targeting primers. RESULTS: (1) The ecosystem developmental stage did not have a significant effect on the colonization levels of bacterial or fungal endophytes. (2) Colonization levels by bacterial and fungal endophytes were governed by different mechanisms. (3) Endophytic colonization levels and their relationship to foliar tissue stoichiometry were highly host specific. CONCLUSIONS: Quantifying colonization levels is important in the study of endophytic ecology, and the fast, relatively low-cost qPCR-based method can supply useful ecological information, which can significantly enhance the interpretation potential of descriptive data generated, for example, by next-generation sequencing.
- Klíčová slova
- cell counts, ecological succession, foliar endophyte, fungi‐bacteria ratios, qPCR, soil chronosequence,
- MeSH
- Bacteria * genetika růst a vývoj izolace a purifikace MeSH
- ekosystém MeSH
- endofyty * fyziologie genetika MeSH
- hostitelská specificita * MeSH
- houby * genetika izolace a purifikace fyziologie MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- listy rostlin * mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
The aim of the study was to analyse the key microbial contaminants of plant-based meat analogues (PBMA) from retail. A total of 43 samples of PBMAs (12 frozen/31 chilled) in the "ready-to-cook" category, such as hamburgers, meatballs or breaded imitation steaks were purchased in retail stores in the Czech Republic in summer (n = 21) and autumn 2022 (n = 22). The detected indicator bacteria (total viable count, lactic acid bacteria, Enterobacteriaceae, yeasts, moulds) had relatively low values in the analysed PBMA samples and only rarely reached levels of 7 log CFU/g. E. coli, STEC and coagulase-positive staphylococci were not detected by isolation from plates in any of analysed samples. Mannitol positive Bacillus spp. were isolated from almost half of the analysed samples of the PBMA. B. cereus sensu lato was isolated from 3 samples by isolation from plates, and after enrichment in 35 samples (81 %). Clostridium perfringens could not be detected by isolation from plates, nevertheless after multiplication, it was detected in 21 % of samples. Analyses of PBMA samples revealed considerable variability in microbial quality. The presence of spore-forming bacteria with the potential to cause foodborne diseases is alarming. However, to evaluate the risks, further research focused on the possibilities of growth under different conditions of culinary treatment and preservation is needed.
- Klíčová slova
- Bacillus cereus, Clostridium perfringens, Meat alternatives, Plant protein, Spore-forming bacteria,
- MeSH
- Bacteria * izolace a purifikace klasifikace růst a vývoj MeSH
- houby izolace a purifikace klasifikace MeSH
- kontaminace potravin * analýza MeSH
- masné výrobky mikrobiologie MeSH
- maso mikrobiologie MeSH
- náhražky masa MeSH
- počet mikrobiálních kolonií MeSH
- potravinářská mikrobiologie * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
There is an increasing demand for bioinoculants based on plant growth-promoting rhizobacteria (PGPR) for use in agricultural ecosystems. However, there are still concerns and limited data on their reproducibility in different soil types and their effects on endemic rhizosphere communities. Therefore, this study explored the effects of inoculating the PGPR, Pseudomonas fluorescens strain UM270, on maize growth (Zea mays L.) and its associated rhizosphere bacteriome by sequencing the 16S ribosomal genes under greenhouse conditions. The results showed that inoculation with PGPR P. fluorescens UM270 improved shoot and root dry weights, chlorophyll concentration, and total biomass in the three soil types evaluated (clay, sandy-loam, and loam) compared to those of the controls. Bacterial community analysis of the three soil types revealed that maize plants inoculated with the UM270 strain showed a significant increase in Proteobacteria and Acidobacteria populations, whereas Actinobacteria and Bacteroidetes decreased. Shannon, Pielou, and Faith alpha-biodiversity indices did not reveal significant differences between treatments. Beta diversity revealed a bacterial community differential structure in each soil type, with some variation among treatments. Finally, some bacterial groups were found to co-occur and co-exclude with respect to UM270 inoculation. Considered together, these results show that PGPR P. fluorescens UM270 increases maize plant growth and has an important effect on the resident rhizobacterial communities of each soil type, making it a potential agricultural biofertilizer.
- Klíčová slova
- Bioinoculant, Maize, Plant growth-promoting Rhizobacteria, Plant rhizobiome,
- MeSH
- Bacteria klasifikace genetika izolace a purifikace růst a vývoj MeSH
- biodiverzita MeSH
- biomasa MeSH
- fylogeneze MeSH
- kořeny rostlin * mikrobiologie růst a vývoj MeSH
- kukuřice setá * mikrobiologie růst a vývoj MeSH
- Pseudomonas fluorescens * genetika růst a vývoj fyziologie MeSH
- půda * chemie MeSH
- půdní mikrobiologie * MeSH
- rhizosféra * MeSH
- RNA ribozomální 16S genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- půda * MeSH
- RNA ribozomální 16S MeSH
In the past few decades, the pressure of higher food production to satisfy the demand of ever rising population has inevitably increased the use synthetic agrochemicals which have deterioration effects. Biostimulants containing beneficial microbes (single inoculants and microbial consortium) were found as an ideal substitute of synthetic chemical fertilizers. In recent years, microbial consortium is known as a better bioinoculant in comparison to single inoculant bioformulation because of multifarious plant growth-promoting advantages. Looking at the advantageous effect of consortium, in present investigation, different bacteria were isolated from rhizospheric soil and plant samples collected from the Himalayan mountains on the green slopes of the Shivaliks, Himachal Pradesh. The isolated bacteria were screened for nitrogen (N) fixation, phosphorus (P) solubilization and potassium (K) solubilization plant growth promoting attributes, and efficient strains were identified through 16S rRNA gene sequencing and BLASTn analysis. The bacteria showing a positive effect in NPK uptake were developed as bacterial consortium for the growth promotion of eggplant crop. A total of 188 rhizospheric and endophytic bacteria were sorted out, among which 13 were exhibiting nitrogenase activity, whereas 43 and 31 were exhibiting P and K solubilization traits, respectively. The selected three efficient and potential bacterial strains were identified using 16S rRNA gene sequencing as Enterobacter ludwigii EU-BEN-22 (N-fixer; 35.68 ± 00.9 nmol C2H4 per mg protein per h), Micrococcus indicus EU-BRP-6 (P-solubilizer; 201 ± 0.004 mg/L), and Pseudomonas gessardii EU-BRK-55 (K-solubilizer; 51.3 ± 1.7 mg/mL), and they were used to develop a bacterial consortium. The bacterial consortium evaluation on eggplant resulted in the improvement of growth (root/shoot length and biomass) and physiological parameters (chlorophyll, carotenoids, total soluble sugar, and phenolic content) of the plants with respect to single culture inoculation, chemical fertilizer, and untreated control. A bacterial consortium having potential to promote plant growth could be used as bioinoculant for horticulture crops growing in hilly regions.
- Klíčová slova
- Agricultural sustainability, Growth parameters, NPK consortium, Physiological parameters, Plant growth promotion,
- MeSH
- Bacteria * genetika klasifikace metabolismus izolace a purifikace růst a vývoj MeSH
- draslík metabolismus MeSH
- dusík metabolismus MeSH
- fixace dusíku * MeSH
- fosfor * metabolismus MeSH
- fylogeneze MeSH
- kořeny rostlin mikrobiologie MeSH
- mikrobiální společenstva * MeSH
- půdní mikrobiologie * MeSH
- rhizosféra MeSH
- RNA ribozomální 16S * genetika MeSH
- Solanum melongena * mikrobiologie MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- draslík MeSH
- dusík MeSH
- fosfor * MeSH
- RNA ribozomální 16S * MeSH
UNLABELLED: Infection control measures to prevent viral and bacterial infection spread are critical to maintaining a healthy environment. Pathogens such as viruses and pyogenic bacteria can cause infectious complications. Viruses such as SARS-CoV-2 are known to spread through the aerosol route and on fomite surfaces, lasting for a prolonged time in the environment. Developing technologies to mitigate the spread of pathogens through airborne routes and on surfaces is critical, especially for patients at high risk for infectious complications. Multifunctional coatings with a broad capacity to bind pathogens that result in inactivation can disrupt infectious spread through aerosol and inanimate surface spread. This study uses C-POLAR, a proprietary cationic, polyamine, organic polymer with a charged, dielectric property coated onto air filtration material and textiles. Using both SARS-CoV-2 live viral particles and bovine coronavirus models, C-POLAR-treated material shows a dramatic 2-log reduction in circulating viral inoculum. This reduction is consistent in a static room model, indicating simple airflow through a static C-POLAR hanging can capture significant airborne particles. Finally, Gram-positive and Gram-negative bacteria are applied to C-POLAR textiles using a viability indicator to demonstrate eradication on fomite surfaces. These data suggest that a cationic polymer surface can capture and eradicate human pathogens, potentially interrupting the infectious spread for a more resilient environment. IMPORTANCE: Infection control is critical for maintaining a healthy home, work, and hospital environment. We test a cationic polymer capable of capturing and eradicating viral and bacterial pathogens by applying the polymer to the air filtration material and textiles. The data suggest that the simple addition of cationic material can result in the improvement of an infectious resilient environment against viral and bacterial pathogens.
- Klíčová slova
- Gram-negative, Gram-positive, SARS-CoV-2, cationic polymer,
- MeSH
- aerosoly MeSH
- Bacteria účinky léků růst a vývoj MeSH
- Coronavirus bovis účinky léků MeSH
- COVID-19 * prevence a kontrola MeSH
- fomity mikrobiologie virologie MeSH
- gramnegativní bakterie účinky léků MeSH
- kationty * chemie farmakologie MeSH
- lidé MeSH
- polymery * farmakologie chemie MeSH
- SARS-CoV-2 * účinky léků MeSH
- skot MeSH
- textilie mikrobiologie virologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aerosoly MeSH
- kationty * MeSH
- polymery * MeSH
The study aimed to assess the potential of phyllospheric bacterial strains isolated from cauliflower plants as biocontrol agents against black rot disease caused by Xanthomonas campestris pv. campestris, through both in vitro and in vivo evaluations. A total of 46 bacterial strains were isolated from healthy and infected cauliflower leaves of both resistant and susceptible plants, and evaluated them for various traits, including plant growth-promoting activities and in vitro antagonistic activity against Xanthomonas campestris pv. campestris. Further, a pot experiment was conducted with the susceptible cauliflower genotype (Pusa Sharad) and 10 selected phyllospheric bacterial isolates to assess their biocontrol efficacy against the disease. The results showed that 82.60% of phyllospheric bacterial isolates were positive for phosphate solubilization, 63.04% for ammonia production, 58.69% for HCN production, 36.95% for siderophore production, and 78.26% had the capacity to produce IAA. Out of the 46 isolates, 23 exhibited in vitro antagonistic activity against X. campestris pv. campestris and 10 isolates were selected for a pot experiment under glasshouse conditions based on their good plant growth-promoting activities and antagonistic assay. The results revealed that bacterial isolate CFLB-27 exhibited the highest biocontrol efficiency (65.41%), followed by CFLB-24 (58.30%), CFLB-31 (47.11%), and CFLB-26 (46.03%). These four isolates were identified as Pseudomonas fluorescens CFLB-27, Bacillus velezensis CFLB-24, Bacillus amyloliquefaciens CFLB-31, and Stenotrophomonas rhizophila CFLB-26. This study provides valuable insights into the potential of phyllospheric bacteria as an effective tool for disease management in sustainable agriculture.
- Klíčová slova
- Pseudomonas fluorescens CFLB-27, Xanthomonas campestris pv. campestris, Biocontrol efficiency, Black rot, Phyllospheric bacterial isolates,
- MeSH
- antibióza * MeSH
- Bacteria klasifikace izolace a purifikace genetika růst a vývoj MeSH
- biologická ochrana MeSH
- Brassica * mikrobiologie MeSH
- listy rostlin * mikrobiologie MeSH
- nemoci rostlin * mikrobiologie prevence a kontrola MeSH
- Xanthomonas campestris * genetika růst a vývoj MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologická ochrana MeSH
The phosphorus (P) concentration is increasing in parts of the Baltic Sea following the spring bloom. The fate of this excess P-pool is an open question, and here we investigate the role of microbial degradation processes in the excess P assimilation phase. During a 17-day-long mesocosm experiment in the southwest Finnish archipelago, we examined nitrogen, phosphorus, and carbon acquiring extracellular enzyme activities in three size fractions (<0.2, 0.2-3, and >3 µm), bacterial abundance, production, community composition, and its predicted metabolic functions. The mesocosms received carbon (C) and nitrogen (N) amendments individually and in combination (NC) to distinguish between heterotrophic and autotrophic processes. Alkaline phosphatase activity occurred mainly in the dissolved form and likely contributed to the excess phosphate conditions together with grazing. At the beginning of the experiment, peptidolytic and glycolytic enzymes were mostly produced by free-living bacteria. However, by the end of the experiment, the NC-treatment induced a shift in peptidolytic and glycolytic activities and degradation of phosphomonoesters toward the particle-associated fraction, likely as a consequence of higher substrate availability. This would potentially promote retention of nutrients in the surface as opposed to sedimentation, but direct sedimentation measurements are needed to verify this hypothesis.
- Klíčová slova
- excess phosphate, extracellular enzyme activity, mesocosm, northern Baltic Sea, organic matter degradation, postspring-bloom,
- MeSH
- Bacteria * metabolismus genetika růst a vývoj MeSH
- dusík * metabolismus MeSH
- eutrofizace MeSH
- fosfáty * metabolismus MeSH
- fosfor * metabolismus MeSH
- heterotrofní procesy MeSH
- mořská voda * mikrobiologie chemie MeSH
- oceány a moře MeSH
- uhlík * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Finsko MeSH
- oceány a moře MeSH
- Názvy látek
- dusík * MeSH
- fosfáty * MeSH
- fosfor * MeSH
- uhlík * MeSH
Bentonite is an integral part of the engineered barrier system (EBS) in deep geological repositories (DGR) for nuclear waste, but its indigenous microorganisms may jeopardize long-term EBS integrity. To predict microbial activity in DGRs, it is essential to understand microbial reactions to the early hot phase of DGR evolution. Two bentonites (BCV and MX-80) with varied bentonite/water ratios and saturation levels (compacted to 1600 kg.m- 3 dry density/powder/suspension), were subjected to heat (90-150 °C) and irradiation (0.4 Gy.h- 1) in the long-term experiments (up to 18 months). Molecular-genetic, microscopic, and cultivation-based techniques assessed microbial survivability. Exposure to 90 °C and 150 °C notably diminished microbial viability, irrespective of bentonite form, with negligible impacts from irradiation or sample type compared to temperature. Bentonite powder samples exhibited microbial recovery after 90 °C heating for up to 6 months but not 12 months in most cases; exposure to 150 °C had an even stronger effect. Further long-term experiments at additional temperatures combined with the mathematical prediction of temperature evolution in DGR are recommended to validate the possible evolution and spatial distribution of microbially depleted zones in bentonite buffer around the waste canisters and refine predictions of microbial effects over time in the DGR.
- Klíčová slova
- Bentonite buffer, Deep geological repository, Elevated temperature, Extremophiles, Gamma radiation, Microbial limiting factors, Radioactive waste disposal,
- MeSH
- Bacteria * klasifikace účinky záření genetika růst a vývoj MeSH
- bentonit * chemie MeSH
- mikrobiální viabilita * účinky záření MeSH
- půdní mikrobiologie MeSH
- radioaktivní odpad analýza MeSH
- vysoká teplota * MeSH
- záření gama * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bentonit * MeSH
- radioaktivní odpad MeSH
Plant growth-promoting rhizobacteria (PGPR) boost crop yields and reduce environmental pressures through biofilm formation in natural climates. Recently, biofilm-based root colonization by these microorganisms has emerged as a promising strategy for agricultural enhancement. The current work aims to characterize biofilm-forming rhizobacteria for wheat growth and yield enhancement. For this, native rhizobacteria were isolated from the wheat rhizosphere and ten isolates were characterized for plant growth promoting traits and biofilm production under axenic conditions. Among these ten isolates, five were identified as potential biofilm-producing PGPR based on in vitro assays for plant growth-promoting traits. These were further evaluated under controlled and field conditions for their impact on wheat growth and yield attributes. Surface-enhanced Raman spectroscopy analysis further indicated that the biochemical composition of the biofilm produced by the selected bacterial strains includes proteins, carbohydrates, lipids, amino acids, and nucleic acids (DNA/RNA). Inoculated plants in growth chamber resulted in larger roots, shoots, and increase in fresh biomass than controls. Similarly, significant increases in plant height (13.3, 16.7%), grain yield (29.6, 17.5%), number of tillers (18.7, 34.8%), nitrogen content (58.8, 48.1%), and phosphorus content (63.0, 51.0%) in grains were observed in both pot and field trials, respectively. The two most promising biofilm-producing isolates were identified through 16 s rRNA partial gene sequencing as Brucella sp. (BF10), Lysinibacillus macroides (BF15). Moreover, leaf pigmentation and relative water contents were significantly increased in all treated plants. Taken together, our results revealed that biofilm forming PGPR can boost crop productivity by enhancing growth and physiological responses and thus aid in sustainable agriculture.
- MeSH
- Bacteria klasifikace genetika metabolismus růst a vývoj izolace a purifikace MeSH
- biofilmy * růst a vývoj MeSH
- biomasa MeSH
- kořeny rostlin * mikrobiologie růst a vývoj MeSH
- pšenice * mikrobiologie růst a vývoj MeSH
- půdní mikrobiologie * MeSH
- rhizosféra * MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
Aerobic anoxygenic phototrophic (AAP) bacteria are an important component of freshwater bacterioplankton. They can support their heterotrophic metabolism with energy from light, enhancing their growth efficiency. Based on results from cultures, it was hypothesized that photoheterotrophy provides an advantage under carbon limitation and facilitates access to recalcitrant or low-energy carbon sources. However, verification of these hypotheses for natural AAP communities has been lacking. Here, we conducted whole community manipulation experiments and compared the growth of AAP bacteria under carbon limited and with recalcitrant or low-energy carbon sources under dark and light (near-infrared light, λ > 800 nm) conditions to elucidate how they profit from photoheterotrophy. We found that AAP bacteria induce photoheterotrophic metabolism under carbon limitation, but they overcompete heterotrophic bacteria when carbon is available. This effect seems to be driven by physiological responses rather than changes at the community level. Interestingly, recalcitrant (lignin) or low-energy (acetate) carbon sources inhibited the growth of AAP bacteria, especially in light. This unexpected observation may have ecosystem-level consequences as lake browning continues. In general, our findings contribute to the understanding of the dynamics of AAP bacteria in pelagic environments.
- Klíčová slova
- acetate, aerobic anoxygenic phototrophic bacteria, carbon limitation, freshwater lakes, lignin, microbial ecology,
- MeSH
- aerobní bakterie metabolismus růst a vývoj MeSH
- Bacteria metabolismus růst a vývoj genetika MeSH
- ekosystém MeSH
- fototrofní procesy * MeSH
- heterotrofní procesy MeSH
- jezera mikrobiologie MeSH
- světlo MeSH
- uhlík * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- uhlík * MeSH
