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Food Microbiology Aug 2024Quantifying spore germination and outgrowth heterogeneity is challenging. Single cell level analysis should provide supplementary knowledge regarding the impact of...
Quantifying spore germination and outgrowth heterogeneity is challenging. Single cell level analysis should provide supplementary knowledge regarding the impact of unfavorable conditions on germination and outgrowth dynamics. This work aimed to quantify the impact of pH on spore germination and outgrowth, investigating the behavior of individual spore crops, produced under optimal and suboptimal conditions. Bacillus mycoides (formerly B. weihenstephanensis) KBAB4 spores, produced at pH 7.4 and at pH 5.5 were incubated at different pH values, from pH 5.2 to 7.4. The spores were monitored by microscopy live imaging, in controlled conditions, at 30 °C. The images were analyzed using SporeTracker, to determine the state of single cells. The impact of pH on germination and outgrowth times and rates was estimated and the correlation between these parameters was quantified. The correlation between germination and outgrowth times was significantly higher at low pH. These results suggest that an environmental pressure highlights the heterogeneity of spore germination and outgrowth within a spore population. Results were consistent with previous observations at population level, now confirmed and extended to single cell level. Therefore, single cell level analyses can be used to quantify the heterogeneity of spore populations, which is of interest in order to control the development of spore-forming bacteria, responsible for food safety issues.
Topics: Humans; Spores, Bacterial; Bacillus; Spores; Hydrogen-Ion Concentration; Bacillus subtilis
PubMed: 38637073
DOI: 10.1016/j.fm.2024.104509 -
BMC Plant Biology Feb 2024Zinc (Zn) and nickel (Ni) are nutrients that are crucial for plant growth; however, when they are present at higher concentrations, they can cause toxicity in plants....
BACKGROUND
Zinc (Zn) and nickel (Ni) are nutrients that are crucial for plant growth; however, when they are present at higher concentrations, they can cause toxicity in plants. The present study aimed to isolate plant growth promoting endophytic bacteria from Viburnum grandiflorum and assess its plant and defense promoting potential alone and in combination with RP in zinc (Zn) and nickel (Ni) toxic soil. The isolated endophytic bacteria were identified using 16s rRNA gene sequencing. For the experiment, twelve different treatments were applied using Zn, Ni, isolated endophytic Bacillus mycoides (Accession # MW979613), and rock phosphate (RP). The Ni, Zn and RP were used at the rate of (100 mg/kg) and (0.2 g/kg) respectively. A pot experiment with three replicates of each treatment was conducted using a complete randomized design (CRD).
RESULTS
The results indicated that Ni (T5 = seed + 100 mg/kg Ni and T9 = seed + 100 mg/kg Zn) and Zn concentrations inhibited plant growth, but the intensity of growth inhibition was higher in Ni-contaminated soil. Bacillus mycoides and RP at 100 mg/Kg Zn (T12 = inoculated seed + 100 mg/kg Zn + RP0.2 g/kg.) increased the shoot length, leaf width, protein and sugar content by 57%, 13%, 20% and 34%, respectively, compared to the control. The antioxidant enzymes superoxide dismutases (SOD), peroxidase (POD) were decreased in contaminated soil. Furthermore, Ni and Zn accumulation was inhibited in T11 (seed + 100 mg/kg Zn + RP0.2 g/Kg) and T12 (inoculated seed + 100 mg/kg Zn + RP0.2 g/Kg) by 62 and 63% respectively. The Cu, Ca, and K, contents increased by 128, 219 and 85, Mn, Na, and K by 326, 449, and 84% in (T3 = inoculated seed) and (T4 = inoculated seed + RP 0.2 g/Kg) respectively.
CONCLUSIONS
Ni was more toxic to plants than Zn, but endophytic bacteria isolated from Viburnum grandiflorum, helped wheat (Triticum aestivum) plants and reduced the toxic effects of Ni and Zn. The effect of Bacillus mycoides was more prominent in combination with RP which promoted and suppressed heavy-metal toxicity. The reported combination of Bacillus mycoides and RP may be useful for improving plant growth and overcoming metal stress.
Topics: Triticum; Nickel; Phosphates; RNA, Ribosomal, 16S; Metals, Heavy; Zinc; Bacteria; Soil; Soil Pollutants; Bacillus
PubMed: 38373884
DOI: 10.1186/s12870-024-04812-3 -
ISME Communications Nov 2023Bacillus species are ubiquitous in nature and have tremendous application potential in agriculture, medicine, and industry. However, the individual species of this genus...
Bacillus species are ubiquitous in nature and have tremendous application potential in agriculture, medicine, and industry. However, the individual species of this genus vary widely in both ecological niches and functional phenotypes, which, hence, requires accurate classification of these bacteria when selecting them for specific purposes. Although analysis of the 16S rRNA gene has been widely used to disseminate the taxonomy of most bacterial species, this gene fails proper classification of Bacillus species. To circumvent this restriction, we designed novel primers and optimized them to allow exact species resolution of Bacillus species in both synthetic and natural communities using high-throughput amplicon sequencing. The primers designed for the tuf gene were not only specific for the Bacillus genus but also sufficiently discriminated species both in silico and in vitro in a mixture of 11 distinct Bacillus species. Investigating the primers using a natural soil sample, 13 dominant species were detected including Bacillus badius, Bacillus velezensis, and Bacillus mycoides as primary members, neither of which could be distinguished with 16S rRNA sequencing. In conclusion, a set of high-throughput primers were developed which allows unprecedented species-level identification of Bacillus species and aids the description of the ecological distribution of Bacilli in various natural environment.
PubMed: 38012258
DOI: 10.1038/s43705-023-00330-9 -
Polymers Oct 2023In view of implementing green technologies for bioplastic turning polices, novel durable feedstock for ICRI89 used for efficient polyhydroxybutyrate (PHB) generation is...
In view of implementing green technologies for bioplastic turning polices, novel durable feedstock for ICRI89 used for efficient polyhydroxybutyrate (PHB) generation is proposed herein. First, two food waste (FW) pretreatment methods were compared, where the ultrasonication approach for 7 min was effective in easing the following enzymatic action. After treatment with a mixture of cellulase/amylases, an impressive 25.3 ± 0.22 g/L of glucose was liberated per 50 g of FW. Furthermore, a notable 2.11 ± 0.06 g/L PHB and 3.56 ± 0.11 g/L cell dry eight (CDW) over 120 h were generated, representing a productivity percentage of 59.3 wt% using 25% FW hydrolysate. The blend of polyhydroxybutyrate/poly (methyl methacrylate) (PHB/PMMA = 1:2) possessed the most satisfactory mechanical properties. For the first time, PHB was chemically crosslinked with PMMA using dicumyl peroxide (DCP), where a concentration of 0.3 wt% had a considerable effect on increasing the mechanical stability of the blend. FTIR analysis confirmed the molecular interaction between PHB and PMMA showing a modest expansion of the C=O stretching vibration at 1725 cm. The DCP-PHB/PMMA blend had significant thermal stability and biodegradation profiles comparable to those of the main constituent polymers. More importantly, a 3-Dimetional (3D) filament was successfully extruded with a diameter of 1.75 mm, where no blockages or air bubbles were noticed via SEM. A new PHB/PMMA "key of life" 3D model has been printed with a filling percentage of 60% and a short printing time of 19.2 min. To conclude, high-performance polymeric 3D models have been fabricated to meet the pressing demands for future applications of sustainable polymers.
PubMed: 37896417
DOI: 10.3390/polym15204173 -
Microbial Cell Factories Aug 2023Endophytes, especially those isolated from herbal plants, may act as a reservoir of a variety of secondary metabolites exhibiting biological activity. Some endophytes...
Endophytes, especially those isolated from herbal plants, may act as a reservoir of a variety of secondary metabolites exhibiting biological activity. Some endophytes express the ability to produce the same bioactive compounds as their plant hosts, making them a more sustainable industrial supply of these substances. Urtica dioica L. (common stinging nettle) is a synanthropic plant that is widely used in herbal medicine due to the diversity of bioactive chemicals it contains, e.g., polyphenols, which demonstrate anti-inflammatory, antioxidant, and anti-cancerous capabilities. This study aimed at isolating endophytic bacteria from stinging nettles for their bioactive compounds. The endophytic isolates were identified by both biochemical and molecular methods (16S rRNA) and investigated for enzymes, biosurfactants, and polyphenols production. Each of the isolated bacterial strains was capable of producing biosurfactants and polyphenols. However, three of the isolated endophytes, identified as two strains of Bacillus cereus and one strain of Bacillus mycoides, possessed the greatest capacity to produce biosurfactants and polyphenols. The derivatized extracts from culture liquid showed the 1.633 mol l (9.691 mg l) concentration of polyphenol compounds. Therefore, the present study signifies that endophytic B. cereus and B. mycoides isolated from Urtica dioica L. could be a potential source of biosurfactants and polyphenols. However, further study is required to understand the mechanism of the process and achieve efficient polyphenol production by endophytic bacteria.
Topics: Urtica dioica; Bacillus cereus; Bacteria; Endophytes; Polyphenols; Enzymes; Genotype
PubMed: 37649058
DOI: 10.1186/s12934-023-02167-2 -
Microorganisms Jul 2023Causing major health and ecological disturbances, polychlorinated biphenyls (PCBs) are persistent organic pollutants still recovered all over the world. Microbial PCB...
Causing major health and ecological disturbances, polychlorinated biphenyls (PCBs) are persistent organic pollutants still recovered all over the world. Microbial PCB biotransformation is a promising technique for depollution, but the involved molecular mechanisms remain misunderstood. Ligninolytic enzymes are suspected to be involved in many PCB transformations, but their assessments remain scarce. To further inventory the capabilities of microbes to transform PCBs through their ligninolytic enzymes, we investigated the role of oxidase and peroxidase among a set of microorganisms isolated from a historically PCB-contaminated site. Among 29 isolated fungi and 17 bacteria, this work reports for the first time the PCB-transforming capabilities from fungi affiliated to , , , , , , and genera and bacteria affiliated to , , , , , sp., , and . In the same way, this is the first report of fungal isolates affiliated to the specie and genus that displayed oxidase (putatively laccase) and peroxidase activity, respectively, enhanced in the presence of PCBs (more than 4-fold and 20-fold, respectively, compared to controls). Based on these results, the observed activities are suspected to be involved in PCB transformation.
PubMed: 37630447
DOI: 10.3390/microorganisms11081887 -
Phytopathology Feb 2024Frequent fungicide applications are required to manage grapevine powdery mildew (). However, this practice is costly and has led to widespread fungicide resistance. A...
Frequent fungicide applications are required to manage grapevine powdery mildew (). However, this practice is costly and has led to widespread fungicide resistance. A method of monitoring in-field fungicide efficacy could help growers maximize spray-interval length, thereby reducing costs and the rate of fungicide resistance emergence. The goal of this study was to evaluate if hyperspectral sensing in the visible to shortwave infrared range (400 to 2,400 nm) can quantify foliar fungicide efficacy on grape leaves. Commercial formulations of metrafenone, isolate J (), and sulfur were applied on Chardonnay grapevines in vineyard or greenhouse settings. Foliar reflectance was measured with handheld hyperspectral spectroradiometers at multiple days post-application. Fungicide efficacy was estimated as a proxy for fungicide residue and disease control measured with the Blackbird microscopy imaging robot. Treatments could be differentiated from the untreated control with an accuracy of 73.06% for metrafenone, 67.76% for , and 94.10% for sulfur. The change in spectral reflectance was moderately correlated with the cube root of the area under the disease progress curve for metrafenone- and sulfur-treated samples ( = 0.38 and 0.36, respectively) and with sulfur residue ( = 0.42). treatment impacted foliar physiology by enhancing the leaf mass/area and reducing the nitrogen and total phenolic content as estimated from spectral reflectance. The results suggest that hyperspectral sensing can be used to monitor in-situ fungicide efficacy, and the prediction accuracy depends on the fungicide and the time point measured. The ability to monitor in-situ fungicide efficacy could facilitate more strategic fungicide applications and promote sustainable grapevine protection. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Topics: Fungicides, Industrial; Plant Diseases; Sulfur; Bacillus; Benzophenones
PubMed: 37565813
DOI: 10.1094/PHYTO-02-23-0061-R -
International Journal of Molecular... May 2023Fluoro-substituted pyrazoles have a wide range of biological activities, such as antibacterial, antiviral, and antifungal activities. The aim of this study was to...
Fluoro-substituted pyrazoles have a wide range of biological activities, such as antibacterial, antiviral, and antifungal activities. The aim of this study was to evaluate the antifungal activities of fluorinated 4,5-dihydro-1-pyrazole derivatives on four phytopathogenic fungi: , , f. sp, and . Moreover, they were tested on two soil beneficial bacteria- and -as well as two entomopathogenic nematodes (EPNs)- and . The molecular docking was performed on the three enzymes responsible for fungal growth, the three plant cell wall-degrading enzymes, and acetylcholinesterase (AChE). The most active compounds against fungi were 2-chlorophenyl derivative () (43.07% of inhibition) and 2,5-dimethoxyphenyl derivative () (42.23% of inhibition), as well as against (46.75% of inhibition). Compounds were shown to be safe for beneficial soil bacteria and nematodes, except for compound on EPN (18.75% mortality), which also showed the strongest inhibition against AChE (79.50% of inhibition). The molecular docking study revealed that antifungal activity is possible through the inhibition of proteinase K, and nematicidal activity is possible through the inhibition of AChE. The fluorinated pyrazole aldehydes are promising components of future plant protection products that could be environmentally and toxicologically acceptable.
Topics: Animals; Antifungal Agents; Soil; Acetylcholinesterase; Molecular Docking Simulation; Pyrazoles; Bacteria; Fusarium; Rhabditida; Fungi
PubMed: 37298285
DOI: 10.3390/ijms24119335 -
Plants (Basel, Switzerland) Mar 2023The heavy use of mineral fertilizers causes imbalances in the biological processes that take place in soil. Therefore, it is necessary to develop more effective...
The heavy use of mineral fertilizers causes imbalances in the biological processes that take place in soil. Therefore, it is necessary to develop more effective fertilizers or fertilizer complexes that ensure agricultural productivity and soil conservation. There is currently a lack of knowledge regarding the effectiveness of biologically enriched, complex mineral fertilizers for spring barley fertilization. The hypothesis of this study was that bacteria-enriched (, , , and ), complex mineral fertilizers (NPK) have significant impacts on the yield and potential for economic use of spring barley. Experimental studies were carried out for three years (2020-2022) with sandy loam soil in southern Lithuania. Four different spring barley fertilization scenarios (SCs) were investigated. In SC-1 (control), complex mineral fertilizer (NPK) was not applied. In the other SCs, spring barley was sown with a drill and fertilizers were incorporated locally during the sowing operation: fertilization scenario SC-2 used 300 kg ha, SC-3 used 150 kg ha preceded by a bacteria-inoculated complex mineral fertilizer (NPK), and SC-4 used 300 kg ha with the same bacterial complex. The results showed that the bacterial inoculant increased the efficiency of the mineral fertilizer and had an effect on plant growth in barley. For three consecutive years in the same plots, the bacterial inoculant showed significant positive effects on grain yield (changes of 8.1% in 2020, 6.8% in 2021, and 17.3% in 2022 between SC-2 and SC-4). Comparing the several different fertilizer scenarios from an economic point of view, it was observed that the highest profit per hectare was obtained with SC-4 in all three years of the study. Comparing SC-4 and SC-2, an increase of 13.7% was observed in 2020, followed by 9.1% and 41.9% in 2021 and in 2022, respectively. This study will be useful for farmers, biological inoculant manufacturers, and scientists researching the effectiveness of biological inoculants for growing agricultural crops. We found that it is possible to increase the yield of barley (7-17%) using the same rate of mineral fertilization by enriching it with bacterial inoculants. Further studies should be conducted to determine the effects of the bacterial inoculant on crop yield and soil over a period longer than 3 years.
PubMed: 36986916
DOI: 10.3390/plants12061227 -
Heliyon Dec 2022Castor ( L.) is cultivated for seed oil and to feed (leaves) Eri silkworm, (Donovan) Hutt. blight affects castor cultivation resulting substantial yield loss (∼30%)....
BACKGROUND
Castor ( L.) is cultivated for seed oil and to feed (leaves) Eri silkworm, (Donovan) Hutt. blight affects castor cultivation resulting substantial yield loss (∼30%). Uses of synthetic fertilizers and agrochemicals for disease management have serious concerns as the castor leaves are fed to eri silkworms for rearing. Application of plant growth promoting rhizobacteria for disease suppression and to enhance plant growth will be a healthier choice in castor cultivation. The aim of this study was to assess the efficacy of blight disease suppression by native rhizobacteria isolated from wasteland castor and their ability on plant growth promotion.
METHODOLOGY
We isolated 50 bacterial antagonists from castor rhizosphere using the dilution plate method and evaluated their antagonistic activity against the castor blight pathogen, . Based on antimicrobial bioassay and plant growth promotion (PGP) traits (phosphate solubilization, ACC deaminase activities, production of IAA, GA, HCN, NH and siderophore), salt and acid tolerance; we have chosen ten potential isolates and identified them through 16SrRNA gene sequencing and analysis. Disease suppression and plant growth studies were evaluated in pot experiments.
RESULTS AND CONCLUSION
Three isolates namely, (LRP-2), (HF-1) and (UR-6) showed potential antagonistic activities and PGP traits which were selected for disease suppression and PGP studies. Application of PGPR consortia (LRP-2+HF-1) could suppress the plants from infection in challenged inoculation. Mix inoculation of LRP-2 and UR-6 showed synergistic effect and enhanced plant growth in pot experiments. Combinations of (LRP-2), (HF-1) and (UR-6) can be applied as bio-control and bio-fertilizer formulation to protect castor from blight and also to enhance plant growth.
PubMed: 36466578
DOI: 10.1016/j.heliyon.2022.e11886