scholarly journals Biocontrol of toxigenic strain of Aspergillus flavus isolated from the root tubers of safed musli (Chlorophytum borivilianum Sant. F) using its rhizospheric mycoflora

2017 ◽  
Vol 9 (2) ◽  
pp. 1049-1053
Author(s):  
Yashasvita Chauhan

Miraculous herb safed musli (Chlorophytum borivilianum Sant. F), family liliaceae, is well recognized for its immense potential as an aphrodisiac. The root tubers of this herbal drug were found to be invested with Aspergillus flavus during field and storage. Therefore, the present study was designed to explore the ability of 26 co-existing rhizospheric mycoflora to inhibit A. flavus invasion and subsequent aflatoxin contamination of safed musli. The interaction of these moulds with highly toxigenic strain (CB55) of A. flavus was evaluated by dual culture method and type of interaction was graded. Most likely antagonistic effects were shown by fifteen (15) moulds, out of which Type ‘C’ interaction was evidenced in the case of six moulds; A. clavatus, A. terreus, Botryotrichum piluliferum, Candida albicans, Cephalosporium acremonium, and Cunninghamella sp. Further, ‘D’ type interaction was displayed by seven moulds which include A. niger, Colletotrichum sp., Drechslera sp., Mucor haemalis, Mycelia sterilia, Rhizopus arrhizus and Stachybotrys atra and ‘E’ type interaction was noted in the case of Trichoderma viride and Trihcothecium roseum. Regarding human health it is critical to use an ecofriendly approach to control the invasion of toxigenic moulds with root tubers of safed musli.

2019 ◽  
Vol 28 (2) ◽  
pp. 219-226
Author(s):  
Zuhra Yasmin ◽  
Shamim Shamsi

Four antagonistic fungi Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tiegh. and Trichoderma viride Pers. were isolated from field soil of Rauwolfia serpentina by serial dilution method and selected to evaluate their antagonistic potentiality against Colletotrichum gloeosporiodes (Penz.) Sacc, the causal agent of anthracnose of Rauwolfia serpentina (L.) Benth. ex Kurz following dual culture colony interaction, volatile and non-volatile metabolites. In dual culture method Trichoderma viride showed maximum (84.28%) inhibition of test fungi followed by Aspergillus niger (77.39%), A. fumigatus (43.71%) and A. flavus (29.32%). Volatile metabolites of T. viride showed higher (77.64%) inhibition of test fungi followed by A. flavus (75.58%), A. fumigatus (60.88%) and A. niger (58.23%). Non-volatile metabolites of antagonistic fungi showed that A. flavus showed (94.42%) inhibition of test fungus followed by T. viride (90.90%), A. niger (86.13%) and A. fumigatus (73.73%). Aspergillus flavus, A. niger and T. viride may be exploited commercially as a biocontrol agent against anthracnose disease of R. serpentina. Dhaka Univ. J. Biol. Sci. 28(2): 219-226, 2019 (July)


2021 ◽  
Vol 25 (12) ◽  
pp. 32-43
Author(s):  
D. Syamala ◽  
S. Nabanita Kumar ◽  
P. Lalitha

Groundnuts are often prone to contamination by Microorganisms during pre-harvest or post-harvest storage. One such contaminant is Aspergillus flavus which is abundantly found in soil and air. Several strains of A. flavus are known to produce mycotoxins named as aflatoxins. These aflatoxins are potent carcinogenic agents whose destruction has become a challenging task in the present scenario. Various physical and chemical methods are available to eliminate the growth of Aspergillus flavus but these methods have several demerits. The present study is based on biological control of Aspergillus flavus using Trichoderma viride strain TV 10. Antagonistic studies of Tv 10 against A.flavus were carried out by performing dual culture technique.


2019 ◽  
Vol 43 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Md Delwar Hosen ◽  
Shamim Shamsi

Four soil fungi were isolated from the soil by serial dilution and were identified as Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. The soil fungi were selected to evaluate their antagonistic potential against seed borne fungus Fusarium merismoides isolated from sesame. In dual culture colony interaction Trichoderma viride showed the highest (45.88%) growth inhibiting effect on F. merismoides followed by A. niger (40.00%), A. flavus (36.37) and A. fumigatus (30.77%). Volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (67.69%) and non-volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (75.00%). Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 17-23, 2019


2015 ◽  
Vol 8 (2) ◽  
pp. 235-244 ◽  
Author(s):  
K.E. Damann Jr.

The term ‘competitive exclusion’ involving physical blockage of growth or access of the toxigenic strain to the seed target has been used to describe the mechanism of biological control of aflatoxin contamination. However, recent evidence suggests that a form of intraspecific aflatoxin inhibition requiring growth of the competing strains together during the infection process in such a way that hyphae physically interact or touch is the trigger for preventing induction of aflatoxin synthesis. This direct touch-based inhibition of aflatoxin synthesis is posited to be the mechanistic basis of biological control in this system. Evidence for this idea comes from the published observations that co-culture of toxigenic and atoxigenic strains in a suspended disc system, in which the hyphae physically interact, prevents aflatoxin production. However, growth of the same strains in the same medium in the two compartments of a filter insert plate well system, separating the atoxigenic and toxigenic strains with a 0.4 μm or 3.0 μm filter, allows aflatoxin production approaching that of the toxigenic strain alone. When the strains are mixed and placed in both the insert and the well compartments, the intraspecific aflatoxin inhibition occurs as it did in the suspended disc culture system. This further suggests that neither nutrient competition nor soluble signal molecules, which should pass through the filter, are involved in intraspecific aflatoxin inhibition. When the two strains are separated by a 12 μm filter that would allow some passage of conidia or hyphae between the compartments the aflatoxin synthesis is approximately half that of the toxigenic strain alone. This phenomenon could be termed ‘competitive inclusion’ or ‘competitive phenotype conversion’. Work of others that relates to understanding the phenomenon is discussed, as well as an Aspergillus flavus population biology study from the Louisiana maize agro-ecosystem which has biological control implications.


1991 ◽  
Vol 54 (8) ◽  
pp. 623-626 ◽  
Author(s):  
ROBERT L. BROWN ◽  
PETER J. COTTY ◽  
THOMAS E. CLEVELAND

In field plot experiments, an atoxigenic strain of Aspergillus flavus interfered with preharvest aflatoxin contamination of corn when applied either simultaneously with or one day prior to a toxigenic strain. The atoxigenic strain reduced preharvest aflatoxin contamination 80 to 95%. The atoxigenic strain was also effective in reducing postharvest aflatoxin contamination caused by both an introduced toxigenic strain and by strains resident on the kernels. The results suggest that atoxigenic strains of A. flavus may have potential use as biological control agents directed at reducing both preharvest and postharvest aflatoxin contamination of corn.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1394
Author(s):  
Mohammed Faruk Hasan ◽  
Mohammed Asadul Islam ◽  
Biswanath Sikdar

Background: Fusarium species is one of the most devastating fungi responsible for fruit and vegetable crops rot worldwide. The present study was designed to find an ecofriendly control measure for pathogenic Fusarium species, using suitable bioagents. Methods: Medicinal plant extracts were evaluated or their antifungal activities against Fusarium species using the poisoned food method. Antagonistic potency of some nonpathogenic microbes was also assessed on Fusarium species using the dual culture method. Results: Highest inhibition of growth of Fusarium sp. was observed with 68.1% (0.389 mg per 90 mm Petri plate) of mycelia on Coccinia grandis plant leaf extract, in comparison to the control grown with 100.0% (1.22 mg/dish). The highest inhibition of radial growth was observed using Trichoderma viride on Fusarium sp. (46.01% inhibition). Conclusions: The findings of present study would be benevolent for antifungal drug development to control Fusarium sp. causing fruit and vegetable rot.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fei Tian ◽  
Sang Yoo Lee ◽  
So Young Woo ◽  
Hwa Young Choi ◽  
Seongeun Heo ◽  
...  

AbstractAflatoxin is a group of polyketide-derived carcinogenic and mutagenic secondary metabolites produced by Aspergillus flavus that negatively impact global food security and threaten the health of both humans and livestock. Aflatoxin biosynthesis is strongly affected by the fungal developmental stage, cultivation conditions, and environmental stress. In this study, a novel float culture method was used to examine the direct responses of the A. flavus transcriptome to temperature stress, oxidative stress, and their dual effects during the aflatoxin production stage. The transcriptomic response of A. flavus illustrated that the co-regulation of different secondary metabolic pathways likely contributes to maintaining cellular homeostasis and promoting cell survival under stress conditions. In particular, aflatoxin biosynthetic gene expression was downregulated, while genes encoding secondary metabolites with antioxidant properties, such as kojic acid and imizoquins, were upregulated under stress conditions. Multiple mitochondrial function-related genes, including those encoding NADH:ubiquinone oxidoreductase, ubiquinol-cytochrome C reductase, and alternative oxidase, were differentially expressed. These data can provide insights into the important mechanisms through which secondary metabolism in A. flavus is co-regulated and facilitate the deployment of various approaches for the effective control and prevention of aflatoxin contamination in food crops.


2018 ◽  
Vol 2 (4) ◽  
pp. 196-199
Author(s):  
Matei Sorin ◽  
Matei Gabi-Mirela ◽  
Dumitrașcu Monica

Abstract Soils from rural zones with high natural value (HNV) agriculture systems are an important source of beneficial microbial species that can be useful for various biotechnological purposes, such as transfer of suppressiveness against plant pathogens from suppressive to disease-inducing soils by using inoculation with antagonistic selected strains. The main goal of the paper was to present the results of the research carried out on strains isolated from soil microbial populations in HNV agriculture system (Mureș county, Romania) responsible for specific suppressiveness against soil-borne phytopathogens. The dual culture method was used for assessing the mechanisms involved in antagonism against a plant pathogenic strain from genus Fusarium. The global microbial activity measured as soil respiration was intense. Total counts of bacteria and fungi estimated by dilution plate were also high. The community of heterotrophic aerobic bacteria included 13 species. Associations of fluorescent pseudomonads and actinomycetes were dominant and presented antagonistic activity against Fusarium. Twenty fungal species presented cellulolytic capability evidenced by growth on culture media with cellulose as sole source of carbon. Over cellulolytic capacity, the selected isolate of Trichoderma viride presented antagonistic activity against pathogenic Fusarium strain. Both biochemical mechanism and hyperparasitism were evidenced as involved in its antifungal activity.


2021 ◽  
Vol 25 (2) ◽  
pp. 147
Author(s):  
Lalu Muhammad Sakti Surya Jagat ◽  
Ida Bagus Gede Darmayasa ◽  
I Made Sara Wijana

Aspergillus flavus contamination of agriculture in Indonesia can cause problems to animal health and productivity. Some factors can support the appearance of contamination in feed, especially temperature and humidity. The main objective of this research was to investigate potency of Rhizopus spp. on inhibit A. flavus FNCC6109 in broiler chicken concentrate feed. The experiments were conducted dual culture method and the inhibition test of the Rhizopus spp. filtrate culture was incubated for 3, 4 and 5 days on in vitro. The in vivo test was directly applied in broiler chicken concentrate feed which added Rhizopus spp. filtrate culture concentration at 10% (v/v), 20% (v/v), 30% (v/v), 40% (v/v), dan 50% (v/v). The results showed that the Rhizopus spp. filtrate culture significantly (P?0,05) to inhibit the growth of A. flavus FNCC6109 both in vitro and in vivo. The percentage inhibition of Rhizopus spp. filtrate culture incubated for 5 days showed 67,47±2,10% relatively better results than 3 and 4 days, and therefore was used in the in vivo. Application of 50% (v/v) Rhizopus spp. filtrate culture to the broiler chicken concentrate feed significantly reduced 82% population of A. flavus FNCC6109 after 15 days incubated relative to that of negative control (concentrate feed without addition Rhizopus spp. filtrate culture and A. flavus FNCC6109).


2019 ◽  
pp. 1-7 ◽  
Author(s):  
M. Ravi Teja ◽  
K. Vijay Krishna Kumar ◽  
H. Sudini

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.


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