scholarly journals Evaluation of the Biocontrol Potential of Purpureocillium lilacinum QLP12 against Verticillium dahliae in Eggplant

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xingjie Lan ◽  
Jing Zhang ◽  
Zhaofeng Zong ◽  
Qing Ma ◽  
Yang Wang

A fungus with broad spectrum antifungal activity was isolated from the soil in Qinling Mountain, Shaanxi Province, in China. The fungus was identified as Purpureocillium lilacinum based on ITS rDNA gene analysis. The strain, coded as QLP12, showed high inhibition activity on fungal mycelium growth in vitro, especially to Mucor piriformis, Trichothecium roseum, Rhizoctonia solani, and Verticillium dahliae, and its potential for biocontrol efficacy of eggplant. Verticillium wilt disease caused by Verticillium dahliae among 10 fungal species tested was explored. In greenhouse experiments, QLP12 showed an excellent growth-promoting effect on eggplant seed germination (76.7%), bud growth (79.4%), chlorophyll content (47.83%), root activity (182.02%), and so on. QLP12 can colonize the eggplant interior and also develop in rhizosphere soil. In greenhouse, the incidence of Verticillium wilt decreased by 83.82% with pretreated QLP12 fermentation broth in the soil. In the field, QLP12 showed prominent biocontrol effects on Verticillium wilt by reducing the disease index over the whole growth period, a decline of 40.1%. This study showed that the strain QLP12 is not only an effective biocontrol agent for controlling Verticillium wilt of eggplant, but also a plant growth-promoting fungus that deserves to be further developed.

2009 ◽  
Vol 23 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Kenichi Miyako ◽  
Laura J. Cobb ◽  
Malik Francis ◽  
Alden Huang ◽  
Bonnie Peng ◽  
...  

Abstract IGF-binding proteins (IGFBPs) have multiple cellular effects, which occur by both IGF-dependent and -independent mechanisms. IGFBP-2 is involved in the regulation of both normal and carcinogenic cell growth. To further understand the actions of IGFBP-2, we carried out a yeast two-hybrid screen to search for intracellular partner proteins using a human prostate cDNA library. We isolated Pim-1-associated protein-1 (PAP-1)-associated protein-1 (PAPA-1) as an IGFBP-2-binding protein, whose expression and subcellular localization is regulated by both IGFBP-2 and androgens. Coimmunoprecipitation and glutathione S-transferase pull-down assay confirmed the interaction in vitro, and confocal microscopy showed the colocalization of IGFBP-2 and PAPA-1 in the nucleus. Suppression of PAPA-1 by small interfering RNA treatment enhanced the growth-promoting effect of IGFBP-2. Conversely, IGFBP-2-promoted bromodeoxyuridine incorporation into LNCaP cells was abrogated by the simultaneous overexpression of myc-hPAPA-1. Mouse embryonic fibroblasts from IGFBP-2 knockout mouse showed diminished growth activity compared with wild type, and expression of FLAG-mPAPA-1 decreased cell proliferation in IGFBP-2 knockout, but not control mouse embryonic fibroblasts. These studies suggest that the growth-promoting role of IGFBP-2 in prostate cancer is inhibited by its intracellular interaction with PAPA-1.


2013 ◽  
Vol 21 (2) ◽  
pp. 87-93
Author(s):  
Elżbieta Węgrzynowicz-Lesiak ◽  
Anna Jarecka Boncela ◽  
Justyna Góraj ◽  
Marian Saniewski

ABSTRACT The knowledge about the role of jasmonates in ethylene production by pathogenic fungi is ambiguous. In this study, we describe the effect of methyl jasmonate (JA-Me) and gums formed in stone fruit trees on the growth and in vitro ethylene production by mycelium of Verticillium dahliae and Alternaria alternata. Methyl jasmonate at concentrations of 100, 250 and 500 μg·cm-3 inhibited the mycelium growth of V. dahliae and A. alternata, proportionally to the concentrations used. After 8 days of incubation, JA-Me at concentration of 500 μg·cm-3 limited the area of mycelium of these pathogens by 7-8 times but did not entirely inhibited the pathogen growth. Addition of gums produced by trees of cherry and peach to a medium containing 40 μg·cm-3 JA-Me did not influence the mycelium growth of V. dahliae, but gums of plum and apricot trees stimulated mycelium growth, in comparison to JA-Me only. Methyl jasmonate at concentrations of 2 and 40 μg·cm-3 stimulated the ethylene production by mycelium of V. dahliae and A. alternata. It is possible that methyl jasmonate stimulated ethylene production in mycelium of these pathogens through interaction with some fractions of galactans formed during hydrolysis of agar. The lack of interaction of JA-Me with polysaccharides of stone fruit trees gums concerning ethylene production was documented and it needs further explanation.


2000 ◽  
Vol 46 (10) ◽  
pp. 892-897 ◽  
Author(s):  
Tomohiro Hosoi ◽  
Akio Ametani ◽  
Kan Kiuchi ◽  
Shuichi Kaminogawa

In an effort to demonstrate the potential usefulness of Bacillus subtilis (natto) as a probiotic, we examined the effect of this organism on the growth of three strains of lactobacilli co-cultured aerobically in vitro. Addition of B. subtilis (natto) to the culture medium resulted in an increase in the number of viable cells of all lactobacilli tested. Since B. subtilis (natto) can produce catalase, which has been reported to exhibit a similar growth-promoting effect on lactobacilli, we also examined the effect of bovine catalase on the growth of Lactobacillus reuteri JCM 1112 and L. acidophilus JCM 1132. Both catalase and B. subtilis (natto) enhanced the growth of L. reuteri JCM 1112, whereas B. subtilis (natto) but not catalase enhanced the growth of L. acidophilus JCM 1132. In a medium containing 0.1 mM hydrogen peroxide, its toxic effect on L. reuteri JCM 1112 was abolished by catalase or B. subtilis (natto). In addition, a serine protease from B. licheniformis, subtilisin, improved the growth and viability of L. reuteri JCM 1112 and L. acidophilus JCM 1132 in the absence of hydrogen peroxide. These results indicate that B. subtilis (natto) enhances the growth and (or) viability of lactobacilli, possibly through production of catalase and subtilisin.Key words: Bacillus subtilis (natto), Lactobacillus, probiotic, catalase, subtilisin.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1348
Author(s):  
Yifan Chen ◽  
Jianren Ye ◽  
Qingqing Kong

In the present study, the potassium-solubilizing characteristics of Bacillus aryabhattai SK1-7 and its growth-promoting effect on plants were evaluated to determine the biotechnological potential of this bacterium in alleviating soil potassium deficiency. The potassium-solubilizing activity of SK1-7 was determined by fermentation. Additionally, the fermentation broth was determined by flame spectrophotometry. The aluminum and silicon ion contents in SK1-7 fermentation broth were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) after digestion with nitric acid hydrogen peroxide hydrofluoric acid. Scanning electron microscopy (SEM)-based observations were performed to assess the morphological changes in potassium feldspar surfaces digested by potassium-solubilizing bacteria. In addition, the effects of SK1-7 on plant growth and soil physical and chemical properties were analyzed. After incubation for 7 days in a potassium-solubilizing medium, the concentration of potassium dissolved reached 10.8 μg/mL and the percentage of potassium released was 32.6%. The pH rapidly decreased from 7.2 to 4.321 within the first day and then further decreased to 3.90 after 7 days. After 7 days, the concentrations of aluminum and silicon in the fermentation broth were 1.01 and 24.19 μg/mL, respectively. The growth promotion assay results showed that SK1-7 has good growth-promoting effects on poplar and can effectively improve the available potassium content in poplar rhizosphere soil. The SK1-7 strain can effectively dissolve insoluble potassium to release soluble potassium ions and clearly promotes the growth of poplar after being applied to soil. Thus, the SK1-7 strain is a potassium-solubilizing microorganism with good application prospects.


2020 ◽  
Vol 18 (2) ◽  
pp. 169-177
Author(s):  
Atiqur Rahman ◽  
Shah A. Siddiqui ◽  
M. Oliur Rahman ◽  
Sun C. Kang

Background: In the prokaryotic unicellular bacteria, Streptomyces species are the most frequent producers of bioactive secondary metabolites. Our continuous quest for new antibiotics from Actinomycetes genera put us forward for isolation of a strain Streptomyces sp. 150 from the soil samples collected at the Daegu University premises in Korea. Objective: The aims of this study was to isolate and identify bioactive compounds from the isolated microorganism and assess the efficacy of the compounds in controlling foodborne pathogens and phytopathogens. Methods: The isolated bacterium was characterized by the taxonomic analyses and a compound was isolated from the fermentation broth by applying different chromatographic techniques e.g. column chromatography, TLC and PTLC. The structure of the compound was established by UV, IR, 1H-NMR and 13C-NMR spectral data analyses. The antibacterial and antifungal efficacy of the compound was assessed by disc diffusion assay, poisoned food technique, MIC determination and SEM analysis. Results: Different chromatographic techniques resulted in isolation and purification of a secondary metabolite from the fermentation broth of Streptomyces sp. 150. The analyses of the spectroscopic data identified the compound as cyclo(L-Pro-L-Tyr). The compound exhibited potential efficacy in controlling all the seven foodborne pathogenic bacteria with corresponding inhibition zone and minimum inhibitory concentration (MIC) ranging from 15.1 to 20.1 mm and 15.6 to 62.5 μg/mL respectively, and tested phytopathogenic fungi with mycelium growth inhibition varying from 57.1 to 68.5% and MIC from 125 to 250 μg/mL. Moreover, in scanning electron microscopy, morphological changes in Listeria monocytogenes ATCC 19166 at MIC dose of compound was observed. Conclusion: This study demonstrated the possibility to use the compound cyclo(L-Pro-L-Tyr) in food and agrochemical industries to control foodborne pathogens and phytopathogens.


Author(s):  
Rohankumar R. Chavan ◽  
Somnath D. Bhinge ◽  
Mangesh A. Bhutkar ◽  
Dheeraj S. Randive ◽  
Ganesh H. Wadkar ◽  
...  

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