Improvement of Antagonistic Activity of Bacillus megaterium MHT6 against Fusarium moniliforme using He-Ne Laser Irradiation

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.

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Antagonistic activity “in vitro” of some saprophytic fungi occurring on the phylloplane of rice, wheat and maize

Boletín Micológico ◽

10.22370/bolmicol.1987.3.3.1539 ◽

2019 ◽

Vol 3 (3) ◽

Author(s):

A. Mangiarotti ◽

G. Del Frate ◽

A. M. Picco ◽

G. Caretta

Keyword(s):

Botrytis Cinerea ◽

Alternaria Alternata ◽

Penicillium Chrysogenum ◽

Fusarium Moniliforme ◽

Antagonistic Activity ◽

Pyricularia Oryzae ◽

Gibberella Zeae ◽

Aspergillus Clavatus ◽

Stachybotrys Atra

Fue investigada la actividad antagónica in vitro de un total de 51 cepas pertenecientes a 16 géneros fúngicos detectados con mayor frecuencia en el filoplano del centeno, arroz y maíz.El antagonismo fue observado con el método de los cultivos duales en medios con agar, entre estos hongos y los fitopatógenos: Drechslera oryzae, Pyricularia oryzae y Helminthosporium maydis. Los más antagónicos son: Penicillium chrysogenum, P. thomii y Stachybotrys atra; ellos antagonizaron en particular con Botrytis cinerea, Fusarium moniliforme y Alternaria alternata. El antagonismo más exitoso contra los tres patógenos mencionados fue con P. chrysogenum y P. charlesii, quienes fueron notoriamente activos. Las cepas de Chaetomium globosum, Gibberella zeae, Fusarium moniliforme, Trichothecium roseum y B. cinerea presentan una actividad antagónica contra H. maydis; Cladosporium cladosporioides contra P. oryzae y D. oryzae; Aspergillus clavatus frente a D. oryzae. Los resultados son discutidos en relación al control biológico de estos patógenos de cereales

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Antagonistic activity of probiotic bacillus megaterium against streptococcus mutans

International Journal of Pharma and Bio Sciences ◽

10.22376/ijpbs.2017.8.1p270-274 ◽

2017 ◽

Vol 8 (1) ◽

Cited By ~ 2

Author(s):

C. SUMATHI ◽

A. NANDHINI ◽

JAYANTHA PADMANABAN

Keyword(s):

Streptococcus Mutans ◽

Bacillus Megaterium ◽

Antagonistic Activity

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Characterisation of Plant Growth-Promoting Endophytic Bacteria from Sugarcane and Their Antagonistic Activity against Fusarium moniliforme

Tropical Life Sciences Research ◽

10.21315/tlsr2021.32.3.6 ◽

2021 ◽

Vol 32 (3) ◽

pp. 97-118

Author(s):

Nittaya Pitiwittayakul ◽

Duanpen Wongsorn ◽

Somboon Tanasupawat

Keyword(s):

Plant Growth ◽

Endophytic Bacteria ◽

Fusarium Moniliforme ◽

Growth Promotion ◽

Antagonistic Activity ◽

Rrna Gene ◽

Burkholderia Gladioli ◽

Plant Growth Promoting ◽

Chemical Usage

The use of endophytic bacteria in agriculture provides an effective way of improving crop yield and significantly reducing chemical usage, such as fungicides. This research was conducted to explore endophytic bacteria with plant growth promotion (PGP) and antifungal activities against Fusarium moniliforme AIT01. In this study, we obtained 52 isolates of endophytic bacteria associated with the roots and stems of sugarcane from Nakhon Ratchasima province, Thailand. In vitro antagonistic activity test showed that 14 out of 52 isolates had antagonistic activity against the fungal pathogen F. moniliforme AIT01. These antagonistic endophytic bacteria were identified as belonging to six different species as follows: Nguyenibacter vanlangensis, Acidomonas methanolica, Asaia bogorensis, Tanticharoenia aidae, Burkholderia gladioli and Bacillus altitudinis based on phenotypic characteristics, along with phylogenetic analysis of their 16S rRNA gene sequences. Seven isolates effectively inhibited F. moniliforme AIT01 mycelial growth by up to 40%. The volatile compounds of six isolates reduced the growth of F. moniliforme AIT01 by over 23%. Moreover, riceberry rice seedlings previously treated with B. gladioli CP28 were found to strongly reduce infection with phytopathogen by 80% in comparison to the non-treated control. Furthermore, the isolates also showed relevant PGP features, including ammonia production, zinc and phosphate solubilisation, auxin and siderophore biosynthesis. These results demonstrated that the tested endophytic bacteria could be successfully utilised as a source of PGP and biocontrol agent to manage diseases caused by F. moniliforme.

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Chronic Laser Exposure Effects on Rabbit Retina

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093523 ◽

1972 ◽

Vol 30 ◽

pp. 54-55

Author(s):

Burton B. Silver ◽

Theodore Lawwill

Keyword(s):

Laser Irradiation ◽

Laser Light ◽

Broad Band ◽

Argon Laser ◽

Atropine Sulfate ◽

Ultrastructural Changes ◽

Laser Exposure ◽

Rabbit Retina ◽

Histological Changes ◽

Threshold Doses

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.

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Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170918 ◽

1994 ◽

Vol 52 ◽

pp. 636-637

Author(s):

S. Cao ◽

A. J. Pedraza ◽

L. F. Allard

Keyword(s):

Aluminum Nitride ◽

Laser Irradiation ◽

Electroless Deposition ◽

Thermal Evaporation ◽

Surface Region ◽

Near Surface ◽

Laser Patterning ◽

Electroless Copper ◽

Excimer Laser Irradiation ◽

Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

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