scholarly journals THE IN VITRO ANTAGONISTIC EFFECTS OF SOME BACILLUS SPP. ON THE GROWTH AND MYCOTOXIN PRODUCTION OF TOXIGENIC ASPERGILLI

Author(s):  
Miroslava Hlebová
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sujit Shah ◽  
Krishna Chand ◽  
Bhagwan Rekadwad ◽  
Yogesh S. Shouche ◽  
Jyotsna Sharma ◽  
...  

Abstract Background A plant growth-promoting endophytic bacterium PVL1 isolated from the leaf of Vanda cristata has the ability to colonize with roots of plants and protect the plant. PVL1 was isolated using laboratory synthetic media. 16S rRNA gene sequencing method has been employed for identification before and after root colonization ability. Results Original isolated and remunerated strain from colonized roots were identified as Bacillus spp. as per EzBiocloud database. The presence of bacteria in the root section of the plantlet was confirmed through Epifluorescence microscopy of colonized roots. The in-vitro plantlet colonized by PVL1 as well as DLMB attained higher growth than the control. PVL1 capable of producing plant beneficial phytohormone under in vitro cultivation. HPLC and GC-MS analysis suggest that colonized plants contain Indole Acetic Acid (IAA). The methanol extract of Bacillus spp., contains 0.015 μg in 1 μl concentration of IAA. PVL1 has the ability to produce antimicrobial compounds such as ethyl iso-allocholate, which exhibits immune restoring property. One-way ANOVA shows that results were statistically significant at P ≤ 0.05 level. Conclusions Hence, it has been concluded that Bacillus spp. PVL1 can promote plant growth through secretion of IAA during root colonization and ethyl iso-allocholate to protect plants from foreign infections. Thus, this study supports to support Koch’s postulates of bacteria establishment.


2016 ◽  
Vol 62 (6) ◽  
pp. 514-524 ◽  
Author(s):  
Sandra Rayén Quilodrán-Vega ◽  
Julio Villena ◽  
José Valdebenito ◽  
María José Salas ◽  
Cristian Parra ◽  
...  

Probiotics are usually isolated from the gastrointestinal tract of humans and animals. The search of probiotics in human milk is a recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. To our knowledge, no reports regarding the potential probiotic effect of bacteria from swine milk have been published. In this work, we isolated several lactic acid bacteria from swine milk and evaluated them for them potential as probiotics. Among the isolated strains, Lactobacillus curvatus TUCO-5E showed antagonistic effects against swine-associated gastrointestinal pathogens. TUCO-5E was able to reduce the growth of enterotoxigenic and enterohemorrhagic Escherichia coli strains as well as pathogenic salmonella. In vitro exclusion and displacement assays in intestinal epithelial cells showed a remarkable antagonistic effect for L. curvatus TUCO-5E against Salmonella sp. strain TUCO-I7 and Salmonella enterica ATCC 13096. Moreover, by using a mouse model of Salmonella infection, we were able to demonstrate that preventative administration of L. curvatus TUCO-5E for 5 consecutive days was capable of decreasing the number of Salmonella enterica serovar Typhimurium in the liver and spleen of treated mice, compared with the controls, and prevented dissemination of the pathogen to the blood stream. Therefore, we have demonstrated here that swine milk is an interesting source of beneficial bacteria. In addition, the results of this work suggest that L. curvatus TUCO-5E is a good candidate to study in vivo the protective effect of probiotics against intestinal infection and damage induced by Salmonella infection in the porcine host.


Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 375-387 ◽  
Author(s):  
N. Aileen Ryan ◽  
Peter Jones

AbstractSeventy bacteria, isolated from the rhizosphere of the potato cyst nematode (PCN) host plant, potato, were cultured in the presence and absence of potato root leachate (PRL) and the resultant culture filtrates were analysed for their ability to affect the hatch in vitro of the two PCN species. Of the isolates tested, nine had a significant effect on PCN hatch. Six affected Globodera pallida hatch and three affected G. rostochiensis hatch. Five of the isolates significantly increased hatch only when cultured in the presence of PRL. Three of the isolates decreased PCN hatch significantly in PRL. Only one isolate increased hatch significantly in the absence of PRL. No isolate affected the hatch of both species. Six of the nine isolates that significantly affected PCN hatch had been pre-selected by culturing on PRL. Bacterial isolates from PCN non-hosts (14 from wheat, 17 from sugar beet) were also tested for hatching activity. The principal effect of the hatch-active isolates from the PCN non-host plants was to increase PCN hatch in the presence of PRL. In contrast to the host bacteria results, the isolates from non-host plants affected only G. rostochiensis hatch (three wheat isolates and four sugar beet isolates significantly increased G. rostochiensis hatch); no such isolate affected G. pallida hatch significantly in the presence of PRL. Ten isolates (32%) from non-host plants had the ability to increase significantly the hatch of PCN in the absence of PRL (eight of these affected G. rostochiensis hatch and four affected G. pallida hatch), compared to only one bacterial isolate (1%) from a host plant. The majority of the isolates from non-hosts produced PCN species-specific effects, as with the bacteria isolated from potatoes, although two wheat isolates increased the hatch of both species significantly in the absence of PRL. Of 20 hatch-active bacterial isolates (from all three plants) identified, 70% were Bacillus spp. Other genera identified were Arthrobacter , Acinetobacter and Staphylococcus .


1996 ◽  
Author(s):  
Joseph W. Kloepper ◽  
Ilan Chet

Endophytes were isolated from 16.7% of surface-disinfested seeds and 100% of stems and roots of field-growth plants. Strains from Israel with broad-spectrum in vitro antibiosis were mainly Bacillus spp., and some were chitinolytic. Following dipping of cut cotton roots into suspensions of these strains, endophytes were detected up to 72 days later by isolation and by autoradiograms of 14C-labelled bacteria. Selected endophytes exhibited biological control potential based on significant reductions in disease severity on cotton inoculated with Rhizoctonia solani or Fusarium oxysporum f. sp. vasinfectum as well as control of Sclerotium rolfsii on bean. Neither salicylic acid nor chitinase levels increased in plants as a result of endophytic colonization, suggesting that the observed biocontrol was not accounted for by PR protein production. Some biocontrol endophytes secreted chitinolytic enzymes. Model endophytic strains inoculated into cotton stems via stem injection showed only limited movement within the stem. When introduced into stems at low concentrations, endophytes increased in population density at the injection site. After examining several experimental and semi-practical inoculation systems, seed treatment was selected as an efficient way to reintroduce most endophytes into plants.


2016 ◽  
Vol 42 (4) ◽  
pp. 360-362
Author(s):  
Evelynne Urzêdo Leão ◽  
◽  
Júlio Cesar da Silva ◽  
Fabíola Rodrigues Medeiros ◽  
Gabriela Silva Santa Rosa Macêdo ◽  
...  

RESUMO O feijoeiro-comum (Phaseolus vulgaris) é uma cultura de grande relevância na alimentação da população brasileira. A murcha-de-curtobacterium ou murcha bacteriana, causada por Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff). é uma doença vascular que acomete o feijoeiro causando danos significativos. Neste contexto, o objetivo deste trabalho foi avaliar a ação in vitro de Bacillus spp. na inibição de dois isolados de Cff, colonização do sistema radicular e desenvolvimento de plântulas de feijoeiro-comum. Foram realizados dois ensaios in vitro para verificar a atividade antagônica dos isolados Bacillus licheniformis, B. subtilis e B. subtilis + B. lichenformis a dois isolados de Cff. Todos os isolados de Bacillus spp. apresentaram inibição no crescimento dos isolados de Cff. Não foi observada a colonização das raízes das plântulas de feijoeiro-comum, pelos isolados bacterianos avaliados.


1995 ◽  
Vol 30 (1) ◽  
pp. 21-27 ◽  
Author(s):  
JENS KARSTOFT ◽  
LARS B????TH ◽  
INGER JANSEN ◽  
LARS EDVINSSON
Keyword(s):  

2020 ◽  
Vol 8 (1) ◽  
pp. 69 ◽  
Author(s):  
Marco Camardo Leggieri ◽  
Amedeo Pietri ◽  
Paola Battilani

No information is available in the literature about the influence of temperature (T) on Penicillium and Aspergillus spp. growth and mycotoxin production on cheese rinds. The aim of this work was to: (i) study fungal ecology on cheese in terms of T requirements, focusing on the partitioning of mycotoxins between the rind and mycelium; and (ii) validate predictive models previously developed by in vitro trials. Grana cheese rind blocks were inoculated with A. versicolor, P. crustosum, P. nordicum, P. roqueforti, and P. verrucosum, incubated at different T regimes (10–30 °C, step 5 °C) and after 14 days the production of mycotoxins (ochratoxin A (OTA); sterigmatocystin (STC); roquefortine C (ROQ-C), mycophenolic acid (MPA), Pr toxin (PR-Tox), citrinin (CIT), cyclopiazonic acid (CPA)) was quantified. All the fungi grew optimally around 15–25 °C and produced the expected mycotoxins (except MPA, Pr-Tox, and CIT). The majority of the mycotoxins produced remained in the mycelium (~90%) in three out of five fungal species (P. crustosum, P. nordicum, and P. roqueforti); the opposite occurred for A. versicolor and P. verrucosum with 71% and 58% of STC and OTA detected in cheese rind, respectively. Available predictive models fitted fungal growth on the cheese rind well, but validation was not possible for mycotoxins because they were produced in a very narrow T range.


2020 ◽  
Vol 5 (3) ◽  
pp. 27
Author(s):  
Muhammad Wajid ◽  
Adil Mahmood ◽  
Haseeb Anwar ◽  
Muhammad Imran Hamid ◽  
Yannong Xiao ◽  
...  

There is a vast variety of microbes available in soil performing diverse functions for plants including root colonization for protection against pathogens and nutrient acquisition. In the present study, efficacy of rhizospheric microbial strains and plant extracts were evaluated against citrus nematode for their nematicidal activity. Three different concentrations of plant extracts were evaluated in vitro, results depicts that 10% solution of Tagetes erecta (root) has given 46% the highest percentage mortality at 48hrs followed by Tagetes erecta (leaf) and Datura stramonium killed 41% and 37% nematodes respectively, similarly for 20% of plant extract in distilled water, the highest mortality rate was recorded for T. erecta (root) 68% followed by D. stramonium 47% and Acacia nilotica 44% at 48hrs of application. While using a higher concentration 30% of SS. the percentage mortality elevated multifold i.e.  Marigold root has killed maximum 76% nematodes followed by Marigold leaves and Dhatura with mortality rate 69% and 58% respectively at 48 hrs of interval. While Eucalyptus killed lowest no of nematodes. Additionally, five bacterial isolates were evaluated for their nematicidal activity. Results indicated that for bacterial cell suspension, Pseudomonas putida has shown maximum mortality rate at 84% followed by Bacillus subtilis 73% & Pseudomonas geniculata 65% at 48hrs of interval. Similarly, in the 2nd set of experiment bacterial culture filtrates has exhibited promising results, maximum mortality rate was recorded for Bacillus spp. 81% followed by B. subtilis 76%, Ps putida 63%, after 48hrs of incubation. Moreover, an insight investigation of bacterial extracellular metabolites and plant extracts would enable researchers to develop purposeful products and compositions


2002 ◽  
Vol 46 (1) ◽  
pp. 225-228 ◽  
Author(s):  
Bruno Pradines ◽  
Florence Ramiandrasoa ◽  
Jean Marc Rolain ◽  
Christophe Rogier ◽  
Joel Mosnier ◽  
...  

ABSTRACT FR160, a catechol iron chelator, and tetracyclines or norfloxacin exert in vitro additive or synergistic activity against a chloroquine-resistant Plasmodium falciparum clone. FR160 shows antagonistic effects in association with macrolides, ofloxacin, and rifampin.


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