scholarly journals Microbial Decontamination of Onion by Corona Discharge Air Plasma during Cold Storage

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Eun Ha Chang ◽  
Yeoung Seuk Bae ◽  
Il Sheob Shin ◽  
Hyun Jin Choi ◽  
Ji Hyun Lee ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Cold Storage ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Treatment Time ◽  
Inhibitory Effect ◽  
Active Species ◽  
Conidial Germination ◽  
Air Plasma

Corona discharge air plasma (CDAP) is a nonthermal decontamination technology which is generating antimicrobial agents such as photons, electrons, positively and negatively charged ions, atoms, and free radicals. We investigated the effect of a corona discharge under atmospheric pressure on the sterilization of postharvest fungal pathogens on onion. The main antimicrobial reactive substance generated by CDAP was O3. The active species such as nitric oxide (NO) and nitric dioxide (NO2) were nearly detected in this experiment. CDAP treatment revealed different isolation frequencies depending on postharvest pathogens from diseased onions, showing less isolation frequency of Fusarium spp. and Alternaria sp. than that of Botrytis spp. when compared with untreatment onions during 10-month cold storage. CDAP treatment at 2∼2.6 ppm of O3 slightly stimulated the mycelial growth of Alternaria sp., while the treatment at 20∼24 ppm of O3 gradually inhibited mycelial growth by treatment time. However, Botrytis sp. showed different patterns of mycelial growth with CDAP treatment. Less than 4 hours’ treatment of CDAP slightly inhibited the mycelial growth of Botrytis sp., while 8 hours’ treatment of CDAP slightly stimulated the mycelial growth of Botrytis sp. not depending on the concentration of O3. The inhibitory effect of CDAP on the conidial germination of Alternaria sp. and Botrytis sp. was examined with treatment time and intensity of CDAP. The conidial germination of Alternaria sp. treated with CDAP at the concentration of 13.7∼14.4 ppm of O3 was strongly inhibited by time, showing y = 2.66x2 − 85.139x + 4.88 and R2 = 0.98. When the conidia of Alternaria sp. were exposed for 2 hours with varying plasma O3 concentration, the conidial germination was strongly inhibited as the concentration of O3 increases, showing y = −0.09x2 + 6.905x − 0.764 and R2 = 0.95. The conidia of Botrytis sp. also showed similar patterns to CDAP. The inhibitory effect of CDAP on the germination of postharvest pathogens depends on treatment time and O3 concentration.

Preliminary in Vitro Investigations on The Inhibitory Activity of The Original Dietary Supplement Oxidal® on Pathogenic Bacterial Strains

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov
Keyword(s):  
Dietary Supplement ◽  
Broad Spectrum ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Clinical Effectiveness ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Microbial Strains

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.

scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

Evaluation of antibacterial, teratogenicity and antibiofilm effect of sulfated chitosans extracted from marine waste against microorganism

2021 ◽  
pp. 088391152110142
Author(s):  
Velu Gomathy ◽  
Venkatesan Manigandan ◽  
Narasimman Vignesh ◽  
Aavula Thabitha ◽  
Ramachandran Saravanan
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Marine Litter ◽  
Ionization Time ◽  
Gram Positive Bacteria ◽  
Mineral Components ◽  
Ft Ir

Biofilms play a key role in infectious diseases, as they may form on the surface and persist after treatment with various antimicrobial agents. The Staphylococcus aureus, Klebsiella pneumoniae, S. typhimurium, P. aeruginosa, and Escherichia coli most frequently associated with medical devices. Chitosan sulphate from marine litter (SCH-MW) was extracted and the mineral components were determined using atomic absorption spectroscopy (AAS). The degree of deacetylation (DA) of SCH was predicted 50% and 33.3% in crab and shrimp waste respectively. The elucidation of the structure of the SCH-MW was portrayed using FT-IR and 1H-NMR spectroscopy. The molecular mass of SCH-MW was determined with Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). The teratogenicity of SCH-MW was characterized by the zebrafish embryo (ZFE) model. Antimicrobial activity of SCH-MW was tested with the agar well diffusion method; the inhibitory effect of SCH-MW on biofilm formation was assessed in 96 flat well polystyrene plates. The result revealed that a low concentration of crab-sulfated chitosan inhibited bacterial growth and significantly reduced the anti-biofilm activity of gram-negative and gram-positive bacteria relatively to shrimp. It is potentially against the biofilm formation of pathogenic bacteria.

scholarly journals Pengaruh Perlakuan Waktu dan Suhu Penyimpanan Dingin terhadap Mutu Kubis Bunga (Brassica Oleracea Var. Botrytis L.)

2019 ◽  
Vol 8 (1) ◽  
pp. 138
Author(s):  
Chyntia Wulandari Eka Saputri ◽  
I. A. Rina Pratiwi Pudja ◽  
Pande Ketut Diah Kencana
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Cold Storage ◽  
Storage Time ◽  
Consumption Rate ◽  
Storage Temperature ◽  
Treatment Time ◽  
O2 Consumption ◽  
Damage Level ◽  
Four Levels

Tujuan dari penelitian ini adalah untuk menentukan waktu perlakuan optimal dan suhu penyimpanan dingin untuk mutu kubis bunga. Penelitian ini menggunakan rancangan acak lengkap (RAL) yang terdiri dari dua faktor, faktor pertama adalah suhu yang digunakan dan faktor kedua adalah waktu selama show case. Faktor pertama terdiri dari dua level, yaitu (P1): show case temperature 8oC, dan (P2): show case temperature 15oC dan tambah kontrol (P0). Faktor kedua terdiri dari empat level, yaitu (A0): penyimpanan selama 0 jam, (A1): penyimpanan selama 12 jam, (A2): penyimpanan selama 16 jam, (A3): penyimpanan selama 20 jam dan diulang untuk 3 kali ulangan. Kubis bunga sebagai kontrol disimpan pada suhu kamar (28 ± 1 ?). Parameter kualitas yang diamati dalam penelitian ini termasuk penurunan berat badan, tingkat konsumsi O2, warna (warna berbeda), uji organoleptik termasuk umur simpan dan tingkat kerusakan. Hasil penelitian menunjukkan parameter penurunan susut bobot, laju konsumsi O2, warna, umur simpan, tingkat kerusakan pada suhu perlakuan suhu terbaik adalah suhu 8 ? dan waktu penyimpanan 20 jam (P1A3).Kata kunci: kembang kol, waktu penyimpanan, suhu penyimpanan dingin   The purpose of this study was to determine the optimal treatment time and cold storage temperature for the quality of cabbage flowers. This study uses a completely randomized design (CRD) consisting of two factors, the first factor is the temperature used and the second factor is the time during the showcase. The first factor consists of two levels, namely (P1): showcase temperature of 8oC, and (P2): showcase temperature of 15oC and added a control (P0). The second factor consists of four levels, namely (A0): storage for 0 hours, (A1): storage for 12 hours, (A2): storage for 16 hours, (A3): storage for 20 hours and repeated for 3 replications. Flower cabbage as control was stored at room temperature (28 ± 1 ?). The quality parameters observed in this study included weight loss, O2 consumption rate, color (color different), organoleptic tests including shelf life and damage level. The results showed the parameters of weight loss, O2 consumption rate, color, shelf life, damage rate at the best temperature of 8 ? and storage time of 20 hours (P1A3). Keywords: cauliflower, storage time, cold storage temperature

scholarly journals Induction of Soil Suppressiveness Against Rhizoctonia solani by Incorporation of Dried Plant Residues into Soil

2006 ◽  
Vol 96 (12) ◽  
pp. 1372-1379 ◽  
Author(s):  
Masahiro Kasuya ◽  
Andriantsoa R. Olivier ◽  
Yoko Ota ◽  
Motoaki Tojo ◽  
Hitoshi Honjo ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Volatile Substance ◽  
Disease Suppression ◽  
Plant Residues ◽  
Infested Soil ◽  
Antagonistic Bacteria ◽  
Damping Off ◽  
Soil Suppressiveness

Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.

scholarly journals Fungicidal effect of silver nanoparticles on toxigenic fungi in cocoa

2016 ◽  
Vol 51 (12) ◽  
pp. 1929-1936 ◽  
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Faccelo Osma Cruz ◽  
Oscar Orlando Ortíz-Rodriguez
Keyword(s):  
Silver Nanoparticles ◽  
Fusarium Solani ◽  
Theobroma Cacao ◽  
Mycelial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Inhibitory Effect ◽  
Plant Tissues ◽  
Inhibition Effect ◽  
Toxigenic Fungi

Abstract: The objective of this work was to evaluate the microbicidal effect of silver nanoparticles (AgNPs) on potentially toxigenic fungi affecting cocoa (Theobroma cacao) crops. These fungi, isolated from diseased cocoa pods, were characterized phenotypically and genotypically. The microbicidal effect was assessed by measuring radial mycelial growth, in synthetic culture media, and at different AgNP concentrations in plant tissues. The inhibition effect was monitored in Petri dishes, and changes in fungal structures were observed through scanning electron microscopy. Two potentially toxigenic fungi were highly prevalent: Aspergillus flavus and Fusarium solani. The inhibition assays, performed in liquid and solid synthetic culture media, showed that AgNPs did not significantly affect the growth of these fungi, even at the highest concentration (100 ppm). By contrast, they showed a positive inhibitory effect in plant tissues, especially in the cortex, when infected with A. flavus, in which an 80 ppm dose completely inhibited fungal growth. However, once fungi have managed to penetrate inside the pods, their growth is unavoidable, and AgNP effect is reduced. On F. solani, the studied nanomaterial only induced some texture and pigmentation changes. The microbicidal effect of chemically synthesized silver nanoparticles is greater in plant tissues than in culture media.

scholarly journals Bacterial Inhibition on Beauveria bassiana Contributes to Microbiota Stability in Delia antiqua

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangyuan Zhou ◽  
Yunxiao Gao ◽  
Mei Liu ◽  
Letian Xu ◽  
Xiaoqing Wu ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Mycelial Growth ◽  
Bacterial Species ◽  
Management Strategies ◽  
Underlying Mechanism ◽  
Conidial Germination ◽  
Delia Antiqua ◽  
Bacterial Microbiota ◽  
Fungal Microbiota ◽  
Microbial Environment

Given the multiple roles of associated microbiota in improving animal host fitness in a microbial environment, increasing numbers of researchers have focused on how the associated microbiota keeps stable under complex environmental factors, especially some biological ones. Recent studies show that associated microbiota interacts with pathogenic microbes. However, whether and how the interaction would influence microbiota stability is limitedly investigated. Based on the interaction among Delia antiqua, its associated microbiota, and one pathogen Beauveria bassiana, the associated microbiota's response to the pathogen was determined in this study. Besides, the underlying mechanism for the response was also preliminarily investigated. Results showed that B. bassiana neither infect D. antiqua larvae nor did it colonize inside the associated microbiota, and both the bacterial and fungal microbiota kept stable during the interaction. Further experiments showed that bacterial microbiota almost completely inhibited conidial germination and mycelial growth of B. bassiana during its invasion, while fungal microbiota did not inhibit conidial germination and mycelial growth of B. bassiana. According to the above results, individual dominant bacterial species were isolated, and their inhibition on conidial germination and mycelial growth of B. bassiana was reconfirmed. Thus, these results indicated that bacterial instead of fungal microbiota blocked B. bassiana conidia and stabilized the associated microbiota of D. antiqua larvae during B. bassiana invasion. The findings deepened the understanding of the role of associated microbiota–pathogen microbe interaction in maintaining microbiota stability. They may also contribute to the development of novel biological control agents and pest management strategies.

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