Isolation and identification of a novel endophytic bacterial strain with antifungal activity from wild blueberryVaccinium uliginosum

2007 ◽  
Vol 57 (4) ◽  
pp. 673-676 ◽  
Author(s):  
Dake Xu ◽  
Xiuying Xia ◽  
Na Xu ◽  
Lijia An
2011 ◽  
Vol 343-344 ◽  
pp. 1212-1216 ◽  
Author(s):  
Cun Kun Chen ◽  
Wen Sheng Wang ◽  
Jia Ning ◽  
Yuan Hui Gao

In order to investigate the reasons for the occurrence of melon disease, according to Koch’s postulates, the pathogenic fungi which caused the disease of postharvest melon“86-1”has been isolated and three kinds of bacterial strain has been identified. By identifying the pathogenicity, results revealed that they are Alternaria sp., Fusarium sp. and Penicillium sp.. They are the major pathogenic fungi which caused the decay of the postharvest Hami melon.


Author(s):  
Nadege D. Nganou ◽  
Eliane S. Tchinda ◽  
Alphonse T. Sokamte ◽  
Franklin K. Ngoualem ◽  
Steve F. Nodem ◽  
...  

Aim: The aim of this study was to evaluate the sanitary quality of smoked fish by determining their mycotoxin content, and also the chemical composition, antifungal activity of Cymbopogon citratus and Ocimum basilicum essential oils from Cameroon against some mycotoxigenic fungal strains responsible of the smoked fish biodegradation. Place and Duration of Study: Laboratory of Food Microbiology and Biotechnology, National School of Agro-Industrial Sciences, University of Ngaoundere, Cameroon, from August 2019 to April 2020. Methodology: Fifteen samples of smoked fishes have been collected in August 2019 from “petit marché” market (Ngaoundere, Cameroon). Physico-chemical parameters of smoked fishes were evaluated. Mycotoxin (AFB1, CIT, and OTA) contents have been determined with HPLC. Isolation and identification of molds were done using their macroscopic and microscopic characteristics, and the identity of the strains was done by PCR sequencing methods. For plants, 15 kg of Cymbopogon citratus leaves and 5 kg of Ocimum basilicum leaves have been harvested on 10 September 2019 in Ngaoundere and used for the essential oil’s extraction. Essential oil extraction has been done through hydrodistillation and the determination of its chemical composition done with GC/MS. Results: Major part of samples contains at least one mycotoxin, in quantities which are beyond the safe dose. Eleven species of molds have been identified: Aspergillus spp., Penicillium citrinum, and Mucor hiemalis. Amongst the isolated species, those which can produce mycotoxins are: Penicillium citrinum, Aspergillus versicolor, Aspergillus fumigatus, Aspergillus carbonarius, Aspergillus niger, and Fusarium moniliforme. Geranial (42.4%), Neral (33.5%) and Myrcene (10.8%) are major compounds found in the essential oil of C. citratus while monoterpens (60.8%), Eugenol (30.7%), Linalol (29.4%) and 1,8-Cineol (14.3%) are the major compounds found in the essential oil of O. basilicum.  Conclusion: Essential oils of C. citratus and O. basilicum are efficient against isolated toxigenic species. C. citratus being more efficient than O. basilicum.


2020 ◽  
Vol 13 (10) ◽  
Author(s):  
Nguyen Thi Trung ◽  
Nguyen Tien Cuong ◽  
Nguyen Thi Thao ◽  
Dao Thi Mai Anh ◽  
Do Thi Tuyen

Background: Fusarium sp. and Rhizoctonia sp. fungi have been always threats to short-term crops. In Vietnam, corn and soybean suffer serious losses annually. Therefore, it is necessary to utilize an environmentally friendly antifungal compound that is highly effective against phytopathogenic fungi. Pseudomonas sp. is a popular soil bacterial strain and well known for its high antifungal activity. Objectives: This study was carried out to evaluate and assess the antifungal activity of a local bacterial strain namely DA3.1 that was later identified as Pseudomonas aeruginosa. This would be strong scientific evidence to develop an environmentally friendly biocide from a local microorganism strain for commercial use. Methods: The antifungal compound was purified from ethyl acetate extraction of deproteinized cell culture broth by a silica gel column (CH2Cl2/MeOH (0% - 10% MeOH)). The purity of the isolated compound was determined by HPLC, and its molecular structure was elucidated using spectroscopic experiments including one-dimensional (1D) (1H NMR, 13C NMR, DEPT) and two-dimensional (2D) (HMBC and HSQC) spectra. The activity of the purified compound against Fusarium sp. and Rhizoctonia sp. fungi was measured using the PDA-disk diffusion method, and its growth-promoting ability was evaluated using the seed germination test of corn and soybean. Results: The results showed that the antifungal compound produced by Pseudomonas aeruginosa DA3.1 had a retention factor (Rf) of 0.86 on thin layer chromatography (TLC). Based on the evidence of spectral data including proton nuclear magnetic resonance (1H NMR), carbon nuclear magnetic resonance (13C NMR), distortionless enhancement by polarization transfer (DEPT), heteronuclear multiple bond correlation (HMBC), and heteronuclear single quantum coherence (HSQC), the chemical structure was elucidated as phenazine-1-carboxylic. The purified compound showed inhibitory activity against F. oxysporum and R. solani and exhibited the ability of the germination of corn and soybean seeds. The results revealed the benefit of native P. aeruginosa DA3.1 and phenazine-1-carboxylic acid for use as a biocontrol agent, as well as a plant growth promoter. Conclusions: The antifungal compound isolated from local Pseudomonas DA3.1 was identified as phenazine-1-carboxylic acid that posed high antifungal activity and was a plant germination booster.


Food Control ◽  
2019 ◽  
Vol 106 ◽  
pp. 106743 ◽  
Author(s):  
Linlin Shang ◽  
Xuexia Bai ◽  
Chi Chen ◽  
Lijun Liu ◽  
Mingyan Li ◽  
...  

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