scholarly journals ANTAGONISTIC ACTIVITY OF PAENIBACILLUS POLYMYXA, BACILLUS AMYLOLIQUEFACIENS AND THEIR LASER STIMULATION AGAINST PHYTOPATHOGENS

2021 ◽  
Vol 3 (27) ◽  
pp. 135-134
Author(s):  
M.V. Maslova ◽  
◽  
E.V. Grosheva ◽  
A.V. Budagovsky ◽  
O.N. Budagovskaya ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Pseudomonas Syringae ◽  
Bacterial Strain ◽  
Bacillus Amyloliquefaciens ◽  
Paenibacillus Polymyxa ◽  
Culture Method ◽  
Antagonistic Activity ◽  
Light Irradiation ◽  
Bacterial Cells ◽  
Coherent Light

Nowadays, thanks to organic farming development, particular attention is paid to the biological methods of plants protection, especially from diseases. Therefore, new biological preparations creation and studying their effectiveness are promising directions. The aim of the research was to study the antagonistic activity of the bacteria Paenibacillus polymyxa and Bacillus amyloliquefaciens against some phytopathogens (Pseudomonas syringae van Hall, Fusarium oxysporum Schltdl, Alternaria alternata (Fr.) Keissl.), as well as their reaction to laser irradiation. The research was carried out in the Research Problem Laboratory “Biphotonika” of the Michurinsk State Agrarian University and the Department of Agricultural Microbiology of the Research Institute of Agriculture of Crimea in 2016–2021. The antagonistic activity of the bacteria was evaluated by the double culture method. The effectiveness of irradiation (as a result of their treatment with coherent light) was determined by the change in the number of bacterial cells in the suspension. The study of the activity of bacteria-antagonists against pathogens showed that the suppression of P. syringae, F. oxysporum, A. alternata growth in the double culture with P. polymyxa compared to the control variants was 32.5 %; 4.0 % and 77.9 %, respectively. B. amyloliquefaciens suppressed the growth of P. syringae by 25.9 %, F. oxysporum – by 49.0 %; A. alternate – by 61.1 %. An increase in the number of cells in suspensions of P. polymyxa and B. amyloliquefaciens after coherent light irradiation by 26.6 % and 36.7 %, respectively, was also found. Thus, to control P. syringae, bacterial strain of P. polymyxa P was more effective. The bacterial strain B. amyloliquefaciens 01-1 showed antagonistic activity against F. oxysporum. Both studied microorganisms were effective against A. alternata. To increase the activity of cell division of antagonist strains of phytopathogens, it is advisable to use coherent light irradiation. In future, it is advisable to test the level of antagonistic activity of the bacteria P. polymyxa and B. amyloliquefaciens after laser irradiation.

Viability and respiratory activity ofPseudomonas syringaecells starved in buffer

1995 ◽  
Vol 41 (4-5) ◽  
pp. 372-377 ◽  
Author(s):  
João P. S. Cabral
Keyword(s):  
Oxygen Consumption ◽  
Electron Transport ◽  
Pseudomonas Syringae ◽  
Respiratory Activity ◽  
Bacterial Cells ◽  
Intact Cells ◽  
Rate Of Oxygen Consumption ◽  
Metabolic Activities ◽  
Different Levels ◽  
Number Of Cells

Pseudomonas syringae cells starved in buffer released orcinol-reactive molecules and materials that absorbed ultraviolet light. The number of cells culturable in nutrient medium decreased more rapidly than the number of intact particles determined by microscopy. The results suggested that starvation resulted in the lysis of an increasing number of cells, and that a fraction of the intact particles were not culturable. Starvation also resulted in a decrease in the rate of oxygen consumption with acetate, glycerol, and succinate, but at different levels. Whereas the respiration of acetate and glycerol decreased concomitantly with culturability, the respiration of succinate decreased to levels similar to the concentration of intact cells, suggesting that all intact particles respired the succinate, but only the culturable cells respired the acetate and glycerol. The results suggest that measuring the activity of the electron-transport system can overestimate the viability of starved bacterial cells, and that complex metabolic activities such as the respiration of acetate and glycerol are probably better suited for the evaluation of this parameter.Key words: Pseudomonas syringae, starvation, culturability, viability, respiration.

scholarly journals Effects of atmospheric conditions on ice nucleation activity of <i>Pseudomonas</i>

2012 ◽  
Vol 12 (22) ◽  
pp. 10667-10677 ◽  
Author(s):  
E. Attard ◽  
H. Yang ◽  
A.-M. Delort ◽  
P. Amato ◽  
U. Pöschl ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Pseudomonas Syringae ◽  
Ice Nucleation ◽  
Acidic Ph ◽  
Bacterial Cells ◽  
Atmospheric Conditions ◽  
Ice Nucleation Protein ◽  
Ice Melt ◽  
Nucleation Activity ◽  
Ice Nucleation Activity

Abstract. Although ice nuclei from bacterial origin are known to be efficient at the highest temperatures known for ice catalysts, quantitative data are still needed to assess their role in cloud processes. Here we studied the effects of three typical cloud conditions (i) acidic pH (ii) NO2 and O3 exposure and (iii) UV-A exposure on the ice nucleation activity (INA) of four Pseudomonas strains. Three of the Pseudomonas syringae strains were isolated from cloud water and the phyllosphere and Pseudomonas fluorescens strain CGina-01 was isolated from Antarctic glacier ice melt. Among the three conditions tested, acidic pH caused the most significant effects on INA likely due to denaturation of the ice nucleation protein complex. Exposure to NO2 and O3 gases had no significant or only weak effects on the INA of two P. syringae strains whereas the INA of P. fluorescens CGina-01 was significantly affected. The INA of the third P. syringae strain showed variable responses to NO2 and O3 exposure. These differences in the INA of different Pseudomonas suggest that the response to atmospheric conditions could be strain-specific. After UV-A exposure, a substantial loss of viability of all four strains was observed whereas their INA decreased only slightly. This corroborates the notion that under certain conditions dead bacterial cells can maintain their INA. Overall, the negative effects of the three environmental factors on INA were more significant at the warmer temperatures. Our results suggest that in clouds where temperatures are near 0 °C, the importance of bacterial ice nucleation in precipitation processes could be reduced by some environmental factors.

The potential biocontrol agent Paenibacillus polymyxa TP3 produces fusaricidin-type compounds involved in the antagonism against gray mold pathogen Botrytis cinerea

2021 ◽  
Author(s):  
Shuen-Huang Tsai ◽  
Yu-Ting Chen ◽  
Yu-Liang Yang ◽  
Bo-Yi Lee ◽  
Chien-Jui Huang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Botrytis Cinerea ◽  
Biological Control Agent ◽  
Imaging Mass Spectrometry ◽  
Paenibacillus Polymyxa ◽  
Field Trials ◽  
Gray Mold ◽  
Control Agent ◽  
Antagonistic Activity ◽  
New Variant

Paenibacillus polymyxa is a beneficial bacterium for plant health. Paenibacillus polymyxa TP3 exhibits antagonistic activity toward Botrytis cinerea and alleviates gray mold symptoms on the leaves of strawberry plants. Moreover, suppression of gray mold on the flowers and fruits of strawberry plants in field trials, including vegetative cells and endospores, was demonstrated, indicating the potential of strain TP3 as a biological control agent. To examine the anti-B. cinerea compounds produced by P. polymyxa TP3, matrix‐assisted laser‐desorption/ionization time‐of‐flight mass spectrometry was performed and fusaricidin-corresponding mass spectra were detected. Moreover, fusaricidin-related signals appeared in imaging mass spectrometry of TP3 when confronted with B. cinerea. By using liquid chromatography-mass spectrometry-based molecular networking approach, several fusaricidins were identified including a new variant of m/z 917.5455 with serine in the first position of the hexapeptide. Via advanced mass spectrometry and network analysis, fusaricidin-type compounds produced by P. polymyxa TP3 were efficiently disclosed and were presumed to play roles in the antagonism against gray mold pathogen B. cinerea.

scholarly journals Influence of Microbiologically Enriched Mineral Fertilizers on Selected Groups of Microorganisms in the Rhizosphere of Strawberry Plants

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lidia Sas-Paszt ◽  
Urszula Smolińska ◽  
Beata Kowalska ◽  
Magdalena Szczech ◽  
Anna Lisek ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Bacillus Amyloliquefaciens ◽  
Soil Microorganisms ◽  
Paenibacillus Polymyxa ◽  
Mineral Fertilizers ◽  
Bacterial Strains ◽  
Beneficial Effects ◽  
Purpureocillium Lilacinum ◽  
Bacteria And Fungi ◽  
Positive Effect

Abstract In recent years, the use of bio-fertilizers enriched with specially selected microorganisms has been used more and more often. The beneficial effects of bio-fertilizers enriched with consortia of microorganisms on strawberry plants have been reported previously. The purpose of the research was to determine the effect of bio-fertilizers containing selected fungal and bacterial strains on the microorganisms living in the rhizosphere of strawberry plants. In the experiments described in this paper, synthetic mineral fertilizers were enriched with selected microorganisms. The fertilizer urea was enriched with the fungi Aspergillus niger and Purpureocillium lilacinum, while the fertilizers Polifoska 6 and Super Fos Dar 40 with strains of the bacteria Bacillus sp., Bacillus amyloliquefaciens, and Paenibacillus polymyxa. Bacteria and fungi belonging to these species can exert a positive effect on the growth of many plants. The results obtained in this study showed that the application of fertilizers enriched with microorganisms had different effects on the analyzed populations of soil microorganisms in the rhizosphere of strawberry plants. There were evidences of both, an adverse effect of the applied fertilizer and/or microorganisms, but more often, the beneficial effect was found on the abundance of the microorganisms in the rhizosphere of the strawberry. The most effective for the population of Pseudomonas bacteria was application of urea and fungi and Polifoska and bacteria. The highest number of phosphorus utilizing bacteria B was scored in the treatments containing NPK, NPK + fungi and urea 60% + fungi. The application of NPK + fungi and urea 100% + fungi as well as Super Fos Dar with bacteria was most beneficial for population of actinomycetes.

scholarly journals Studies on the disinfection efficiency of hoa sen medical instrument sterilizing equipment at the general, obstetrics and paediatrics hospitals in TraVinh Province

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Pham Hoang Long ◽  
Nguyen Hoai Chau ◽  
Nguyen Chi Thanh ◽  
Ngo Quoc Buu
Keyword(s):  
Cell Membrane ◽  
Removal Efficiency ◽  
Medical Instrument ◽  
Culture Method ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
E Coli ◽  
Before And After ◽  
Microbiological Criteria ◽  
Bacterial Cell Membrane

This research aims to study on the disinfection efficiency of Hoa Sen medical instrument sterilizing equipment based on the application of ECA technology at General Hospital and Obstetrics and Paediatrics Hospitals in Tra Vinh. Disinfection using ECA technology is a method that does not require the introduction of special oxidizing agents except of water and salt. ECA solution - Anolyte solution has very strong oxidants, which oxidize components such as protein, lipid, etc. (usually of the bacterial cell membrane) that make the cell membrane decomposed, reducing 77−93% of the respiratory ability of bacterial cells, weakening them and eventually being destroyed. Hoa Sen medical instrument sterilizing equipment has a similar construction form as a regular double washing table with two wash basins, wherein one sink with a faucet which produces purified water, while other one has a faucet that gives anolyte solution for sterilization. Both faucets are based on a touch support. At the bottom of the sink an anolyte solution production system was installed. Valorization of the disinfection ability of the Hoa Sen medical instrument sterilizing equipment was based on the determination of the number of microorganisms on the surface of the instrument before and after being soaked with an antiseptic washing table. Microbiological criteria are the number of aerobic bacteria, E. Coli and Coliforms. Analytical samples were quantified by culture method on agar plates. Analysis of total aerobic bacteria, E. Coli and Coliforms bacteria according to Vietnam Standard TCVN 4884:2015, TCVN 6846:2007 and TCVN 6848:2007, respectively. The results showed that bacterial removal efficiency was elevated with a novel Hoa Sen sterilizing equipment anolyte. In laboratory scale, E. Coli and Coliforms bacteria with a density of 105 CFU/mL were completely removed in 30 sec contact with an anolyte solution of 300 mg/L active chlorine concentration. In hospital scale, the removal efficiency of total aerobic bacteria on the surface of medical instruments after surgery was 99% for one minute disinfection time. For E. Coli and Coliforms bacteria, the results of the analysis were not detected in both cases before and after sterilization. 

scholarly journals Effect of Laser Irradiation on Cell Function and Its Implications in Raman Spectroscopy

2018 ◽  
Vol 84 (8) ◽  
pp. e02508-17 ◽  
Author(s):  
Xiaofei Yuan ◽  
Yanqing Song ◽  
Yizhi Song ◽  
Jiabao Xu ◽  
Yinhu Wu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cell Growth ◽  
Single Cell ◽  
Laser Irradiation ◽  
Living Cells ◽  
Growth Characteristics ◽  
Single Cell Level ◽  
Bacterial Cells ◽  
Cell Level ◽  
Gram Negative

ABSTRACTLasers are instrumental in advanced bioimaging and Raman spectroscopy. However, they are also well known for their destructive effects on living organisms, leading to concerns about the adverse effects of laser technologies. To implement Raman spectroscopy for cell analysis and manipulation, such as Raman-activated cell sorting, it is crucial to identify nondestructive conditions for living cells. Here, we evaluated quantitatively the effect of 532-nm laser irradiation on bacterial cell fate and growth at the single-cell level. Using a purpose-built microfluidic platform, we were able to quantify the growth characteristics, i.e., specific growth rates and lag times of individual cells, as well as the survival rate of a population in conjunction with Raman spectroscopy. Representative Gram-negative and Gram-positive species show similar trends in response to a laser irradiation dose. Laser irradiation could compromise the physiological function of cells, and the degree of destruction is both dose and strain dependent, ranging from reduced cell growth to a complete loss of cell metabolic activity and finally to physical disintegration. Gram-positive bacterial cells are more susceptible than Gram-negative bacterial strains to irradiation-induced damage. By directly correlating Raman acquisition with single-cell growth characteristics, we provide evidence of nondestructive characteristics of Raman spectroscopy on individual bacterial cells. However, while strong Raman signals can be obtained without causing cell death, the variety of responses from different strains and from individual cells justifies careful evaluation of Raman acquisition conditions if cell viability is critical.IMPORTANCEIn Raman spectroscopy, the use of powerful monochromatic light in laser-based systems facilitates the detection of inherently weak signals. This allows environmentally and clinically relevant microorganisms to be measured at the single-cell level. The significance of being able to perform Raman measurement is that, unlike label-based fluorescence techniques, it provides a “fingerprint” that is specific to the identity and state of any (unlabeled) sample. Thus, it has emerged as a powerful method for studying living cells under physiological and environmental conditions. However, the laser's high power also has the potential to kill bacteria, which leads to concerns. The research presented here is a quantitative evaluation that provides a generic platform and methodology to evaluate the effects of laser irradiation on individual bacterial cells. Furthermore, it illustrates this by determining the conditions required to nondestructively measure the spectra of representative bacteria from several different groups.

scholarly journals Exploring Elicitors of the Beneficial Rhizobacterium Bacillus amyloliquefaciens SQR9 to Induce Plant Systemic Resistance and Their Interactions With Plant Signaling Pathways

2018 ◽  
Vol 31 (5) ◽  
pp. 560-567 ◽  
Author(s):  
Gengwei Wu ◽  
Yunpeng Liu ◽  
Yu Xu ◽  
Guishan Zhang ◽  
Qirong Shen ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Pseudomonas Syringae ◽  
Bacillus Amyloliquefaciens ◽  
Systemic Resistance ◽  
Plant Signaling ◽  
Relative Contribution ◽  
Induced Plant Resistance ◽  
Plant Growth Promoting ◽  
Induction Of Resistance ◽  
Growth Promoting

Beneficial rhizobacteria have been reported to produce various elicitors that induce plant systemic resistance, but there is little knowledge concerning the relative contribution of multiple elicitors from a single beneficial rhizobacterium on the induced systemic resistance in plants and the interactions of these elicitors with plant signaling pathways. In this study, nine mutants of the plant growth–promoting rhizobacterium Bacillus amyloliquefaciens SQR9 deficient in producing the extracellular compounds, including fengycin, bacillomycin D, surfactin, bacillaene, macrolactin, difficidin, bacilysin, 2,3-butandiol, and exopolysaccharides, were tested for the induction of systemic resistance against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea and the transcription of the salicylic acid, jasmonic acid, and ethylene signaling pathways in Arabidopsis. Deficiency in producing any of these compounds in SQR9 significantly weakened the induced plant resistance against these phytopathogens. These SQR9-produced elicitors induced different plant defense genes. For instance, the enhancement of 1,3-glucanase (PR2) by SQR9 was impaired by a deficiency of macrolactin but not surfactin. SQR9 mutants deficient in the lipopeptide and polyketide antibiotics remained only 20% functional for the induction of resistance-related gene transcription. Overall, these elicitors of SQR9 could act synergistically to induce plant systemic resistance against different phytopathogens through different signaling pathway genes, and the bacterial antibiotics are major contributors to the induction.

scholarly journals THE PRODUCTION OF BACTERICIDAL SUBSTANCES BY AEROBIC SPORULATING BACILLI

1941 ◽  
Vol 73 (5) ◽  
pp. 629-640 ◽  
Author(s):  
René J. Dubos ◽  
Rollin D. Hotchkiss
Keyword(s):  
Insoluble Fraction ◽  
Physiological Effect ◽  
Antagonistic Activity ◽  
Bacterial Cells ◽  
Animal Tissues ◽  
Gram Positive ◽  
Culture Collections ◽  
Gram Negative

Several species of aerobic sporulating bacilli recently isolated from soil, sewage, manure, and cheese, as well as authentic strains obtained from type culture collections, have been found to exhibit antagonistic activity against unrelated microorganisms. Cultures of these aerobic sporulating bacilli yield an alcohol-soluble, water-insoluble fraction,—tyrothricin,—which is bactericidal for most Gram-positive and Gram-negative microbial species. Two different crystalline products have been separated from tyrothricin. One, which may be called tyrocidine, is bactericidal in vitro for both Gram-positive and Gram-negative species; the other substance, gramicidin, is effective only against Gram-positive microorganisms. In general, tyrocidine behaves like a protoplasmic poison and like other antiseptics, loses much of its activity in the presence of animal tissues. Gramicidin on the contrary exerts a much more subtle physiological effect on the susceptible bacterial cells and, when applied locally at the site of the infection, retains in vivo a striking activity against Gram-positive microorganisms.

scholarly journals Specific and Sensitive Detection of Enterobacter mori Using Reliable RT-PCR

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1070-1074 ◽  
Author(s):  
M. M. Lou ◽  
G. L. Jin ◽  
W. X. Tian ◽  
G. Q. Zhang ◽  
X. Y. Fan ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Infected Plant ◽  
Rpob Gene ◽  
Effective Control ◽  
Bacterial Cells ◽  
Pcr Assay ◽  
Strong Positive Reaction ◽  
Polymerase Chain ◽  
Serious Disease ◽  
Type Strains

Enterobacter mori, the causal agent of bacterial wilt in mulberry, is becoming a serious disease in mulberry orchards in China. Because no effective control strategy has been devised for this disease, the reliable screening of mulberry material for latent infection became necessary. Hence, a fast polymerase chain reaction (PCR) assay for the detection of E. mori was developed in this study. The primers were designed within regions of the RNA polymerase β-subunit (rpoB) gene. The method is fast and simple and showed 100% sensitivity (no false negatives) and 100% specificity (no false positives), which was tested with 4 representative E. mori strains, 9 Enterobacter type strains, 2 strains of the other major mulberry bacterial pathogens (Ralstonia solanacearum and Pseudomonas syringae pv. mori) in China, 7 strains of other plant-associated pathogens, and 50 unidentified epiphytic bacterial isolates from mulberry plants. The real-time PCR assays reliably detected the DNA at at least 10 fg/μl and the bacterial cells at 102 CFU/ml from mulberry shoots and roots suspension. The strong positive reaction in testing of all symptomatic plants (with 100% positive) and parts of asymptomatic latent infected plant samples (with 36.4% positive) provided proof that this method is reliable and sensitive and suitable for screening plant material with latent infections of E. mori.

scholarly journals Specific and Rapid Enumeration of Viable but Nonculturable and Viable-Culturable Gram-Negative Bacteria by Using Flow Cytometry

2010 ◽  
Vol 76 (15) ◽  
pp. 5088-5096 ◽  
Author(s):  
Mohiuddin M. Taimur Khan ◽  
Barry H. Pyle ◽  
Anne K. Camper
Keyword(s):  
Flow Cytometry ◽  
Pseudomonas Syringae ◽  
Phase 1 ◽  
Epifluorescence Microscopy ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Culture Methods ◽  
Viable But Nonculturable ◽  
Gram Negative ◽  
Analytical Technique

ABSTRACT An issue of critical concern in microbiology is the ability to detect viable but nonculturable (VBNC) and viable-culturable (VC) cells by methods other than existing approaches. Culture methods are selective and underestimate the real population, and other options (direct viable count and the double-staining method using epifluorescence microscopy and inhibitory substance-influenced molecular methods) are also biased and time-consuming. A rapid approach that reduces selectivity, decreases bias from sample storage and incubation, and reduces assay time is needed. Flow cytometry is a sensitive analytical technique that can rapidly monitor physiological states of bacteria. This report outlines a method to optimize staining protocols and the flow cytometer (FCM) instrument settings for the enumeration of VBNC and VC bacterial cells within 70 min. Experiments were performed using the FCM to quantify VBNC and VC Escherichia coli O157:H7, Pseudomonas aeruginosa, Pseudomonas syringae, and Salmonella enterica serovar Typhimurium cells after staining with different fluorescent probes: SYTO 9, SYTO 13, SYTO 17, SYTO 40, and propidium iodide (PI). The FCM data were compared with those for specific standard nutrient agar to enumerate the number of cells in different states. By comparing results from cultures at late log phase, 1 to 64% of cells were nonculturable, 40 to 98% were culturable, and 0.7 to 4.5% had damaged cell membranes and were therefore theoretically dead. Data obtained using four different Gram-negative bacteria exposed to heat and stained with PI also illustrate the usefulness of the approach for the rapid and unbiased detection of dead versus live organisms.

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