scholarly journals Potencial in vitro de Bacillus spp. no controle de Curtobacterium flaccumfaciens pv. flaccumfaciens em feijoeiro-comum

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.

2021 ◽  
Vol 65 (3) ◽  
pp. 9-14
Author(s):  
M. Harčárová ◽  
E. Čonková ◽  
P. Naď ◽  
P. Váczi ◽  
M. Proškovcová

Abstract In this study, the antifungal activity of cell-free supernatant (CFS) of Lactobacillus spp. (Lactobacillus plantarum CCM 1904; L81, Lactobacillus fermentum; 2I3, Lactobacilus reuteri; 2/6, L26;) and Bacillus spp. (Bacillus subtilis CCM 2794, Bacillus licheniformis CCM 2206) against two strains of Fusarium graminearum CCM F-683 and Fusarium graminearum CCM 8244 were investigated in vitro. All tested CFS of Lactobacillus spp. were able to inhibit the growth of both strains of Fusarium graminearum. The highest inhibitory effect (IE) (56.5 %) against F. graminearum CCM F-683 was observed for CFS Lactobacillus fermentum (2I3) at the minimum inhibitory concentration (MIC) (2.25 ± 0.56 mg.ml–1). CFS of Lactobacillus reuteri (2/6) showed the best IE (40.0 %) against F. graminearum CCM 8244 (2/6) at the MIC 1.25 mg.ml–1. However, no inhibitory effect of Bacillus subtilis and Bacillus licheniformis CFS against both strains of F. graminearum were observed, even at the highest tested concentration of 5.0 mg.ml–1.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.


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.


Biochimie ◽  
2005 ◽  
Vol 87 (6) ◽  
pp. 529-537 ◽  
Author(s):  
L.A. Trachuk ◽  
A.S. Shcheglov ◽  
E.I. Milgotina ◽  
G.G. Chestukhina

2017 ◽  
Vol 42 (2) ◽  
pp. e12485
Author(s):  
Usha Rani Telikicherla ◽  
Mahadeva Naika ◽  
Anilakumar Kandangath Raghavan ◽  
Sashikala Vadakkoot Balakrishnan

1997 ◽  
Vol 43 (1) ◽  
pp. 1-8 ◽  
Author(s):  
M. Srinivasan ◽  
F. B. Holl ◽  
D. J. Petersen

The ability of Bacillus spp. to alter the nodulation of Phaseolus vulgaris by Rhizobium etli was assessed. The simultaneous presence of both Rhizobium etli TAL 182 and Bacillus megaterium S49 on plant roots during the early stages of plant growth was necessary for enhanced nodulation of Phaseolus vulgaris by the Rhizobium microsymbiont. Coinoculation with both bacterial species also facilitated heterologous nodulation of Rhizobium TAL 182 on Phaseolus acutifolius. These results are consistent with earlier reports of increased root hair proliferation and lateral root formation in response to coinoculation. Split-root experiments revealed that coinoculation partially suppressed host-controlled regulation of nodulation, implicating a plant interaction with the two bacterial species. Changes to the nodulation potential of R. etli due to coinoculation with Bacillus spp. demonstrate the potential for root-associated organisms other than rhizobia to alter the dynamics of the legume–Rhizobium symbiosis.Key words: Bacillus, nodulation enhancement, heterologous nodulation.


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.


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