Effects of Essential Oils on in Vitro Growth of Fungi Cladobotryum dendroides and Mycogone perniciosa Infecting Button Mushroom

The aim of the studies was to investigate the effect of camel grass, lavender, patchouli, peppermint and tea tree essential oils, and their mixtures on the in vitro growth of pathogenic fungi Cladobotryum dendroides and Mycogone perniciosa, occurring in the cultivation of button mushroom (Agaricus bisporus). The mycelial growth of the tested pathogens was evaluated on PDA medium. Essential oils were added in three doses: 0.25; 0.5 and 1 mg·cm–3 of PDA medium. Camel grass and peppermint essential oils applied at the highest dose inhibited completely the in vitro growth of C. dendroides mycelium. Lavender oil used at the amount of 1 mg·cm–3 reduced the growth of the pathogen by 90 %. In the case of M. perniciosa the complete inhibition of the pathogen’s growth was observed after the addition of camel grass oil to PDA medium, irrespective of a dose, and lavender oil at the doses of 0.5 and 1 mg·cm–3. The efficacy of the tested mixtures against M. perniciosa was high. Generally, all mixtures of essential oils, irrespective of a dose, completely controlled the growth of the pathogen. The complete inhibition of the growth of C. dendroides was observed only on the medium with the addition of the mixture of camel grass and peppermint oils at the highest dose. The conducted research showed that natural essential oils due to their antifungal properties could be useful in the Integrated Disease Management for the protection of button mushroom against diseases. They could be an effective alternative to synthetic chemical fungicides.

Evaluation of Fungicides and Plant Extracts Against Pathogenic Fungi Associated With Basella Spp.

Five fungicides viz., CM 75, Dithane M 45, Knowin 50 WP, Nativo 75 WG and Rovral 50 WP were evaluated against Colletotrichum lindemuthianum, Drechslera sacchari and Fusarium semitectum following poisoned food technique. Out of five fungicides complete inhibition of radial growth of C. lindemuthianum was observed in Nativo 75 WG at 100 ppm. On the other hand, the complete inhibition of the growth of D. sacchari was observed with Rovral 50 WP at 400 ppm, whereas Nativo 50 WP showed complete growth inhibition at 500 ppm. CM 75 WP, Knowin 50 WP and Nativo 75 WG showed complete growth inhibition of F. semitectum at 100 ppm. Five different plant leaf extracts viz., Azadirachta indica A. Juss., Heliotropium indicum L., Lippia alba L., Michelia champaca L. and Thuja occidentalis L. were tested against the test pathogens. Of the five plant leaf extracts, Lippia alba showed the highest growth inhibition in C. lindemuthianum, D. sacchari and F. semitectum at 20% concentration. Asiat. Soc. Bangladesh, Sci. 46(1): 81-89, June 2020

Application of clove and dill oils as an alternative of salphos for chickpea food seed storage

Mycological investigations of 25 samples of stored chickpea food seeds (Cicer arietinum L.) from grocery stores of Gurgaon and Gorakhpur revealed occurrence of seventeen fungal species belonging to genus viz., Alternaria, Aspergillus, Chaetomium, Colletotrichum, Curvularia, Fusarium, Penicillium, Rhizopus, Rhizoctonia, and Sclerotium. In these Aspergillus flavus, A. niger, Fusarium oxysporum had dominance in terms of per cent occurrence. Only one species of Bruchid (Callosobruchus chinensis L.) occurred in all the 25 samples. The biodeterioration of seeds inoculated with fungi: A. flavus, A. niger, F. oxysporum and the insect—C. chinensis, revealed their role in seed deterioration. For chickpea food seed protection essential oils were extracted from edible commodity(clove(Lavang and dill(sowa) leaf). Clove(Lavang) oil registered highest antifungal activity inhibiting (100%) mycelial growth of fungi, viz. species Aspergillus flavus, A. niger, Fusarium oxysporum at 300 ppm but was fungicidal at 400 ppm. Dill (Sowa) oil showed complete inhibition at 400 ppm and was fungicidal at 500 ppm. While mixture of both the oils (clove and dill) showed complete inhibition (100%) and fungicidal action at 400 ppm against the dominant fungi. The oils showed 100% insect repellent activity and were found fungicidal at 0.02 ml dose and also insecticidal. The mixture of oils was cidal at 0.02 ml dose. The mixture of oils showed a broad antifungal spectrum at 500 ppm while only 70–93% inhibitory activity at 300 ppm. The oils' mixture's activity was not affected by temp, storage and autoclaving up to 150 days. Oils physico-chemical properties were studied. GC–MS analysis of clove(Lavang) oil depicted major components: 75.63%eugenol while dill(sowa) leaf oil had 25.14% apiole. Formulation of Mixture of oils was more effective showing complete seed protection i.e.no growth of fungi and insects upto 150 days storage than salphos (150 days). While salphos controlled only maximum three fungi (A. terreus, C. dematium, F. moniliforme). The formulated oils mixture did not have any adverse effect on the chickpea seeds and increased their shelf life.

CRISPR/Cas9 assisted gene targeting efficiently inhibits bovine herpesvirus-1 replication

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/ CRISPR associated protein (cas) are now being accepted as a highly specific method of gene editing. Among many other applications, CRISPR/cas has an immense potential to be used as antivirals. In this study, we successfully demonstrated CRISPR/Cas9 mediated inhibition of Bovine Herpes virus -1 (BHV-1) replication. BHV-1 causes economically important diseases in bovines with establishment of latency. Six essential genes and one non-essential gene of BHV-1 were targeted to assess the impact on virus replication. Inhibition of UL52, circ, and UL27 genes showed promising results, whereas the other three genes US6, UL18, and UL34 resulted in lower level of inhibition. Non-specific gene editing in host and virus was in-silico evaluated and was demonstrated by inhibition of virus induced apoptosis. Successful editing of one viral non-essential gene without any alterations in virus replication demonstrated the potential of CRISPR/Cas9 in replicating viral genome. Complete abrogation of virus replication was observed transiently (~24 hours post-transfection/hpt) when transfected with short lived in-vitro transcribed sgRNAs. Whereas, under constant expression of sgRNAs through plasmid, complete inhibition of virus replication was observed till ~72 hours post-infection. Complete inhibition of replication was also observed with in-vitro transcribed sgRNA when booster dose of sgRNA was trasnfected at 24hpt. It has been speculated that constant expression with plasmid based delivery may result in off-target activity which can be ruled out with short lived in-vitro transcribed sgRNA.

Assessing the effectiveness of oxathiapiprolin towards Phytophthora agathidicida, the causal agent of kauri dieback disease

Phytophthora species cause disease and devastation of plants in ecological and horticultural settings worldwide. A recently identified species, P. agathidicida, infects and ultimately kills the treasured kauri trees that are endemic to New Zealand. Currently there are few options for controlling or treating P. agathidicida. In this study, we sought to assess the toxicity of the oomycide oxathiapiprolin against several lifecycle stages of two geographically distinct P. agathidicida isolates. Half maximal effective concentration (EC50) values were determined to be approximately 0.1 ng/ml for inhibiting mycelial growth, indicating that P. agathidicida mycelia are more sensitive to oxathiapiprolin than those from most other Phytophthora species that have been studied. Oxathiapiprolin was also highly effective at inhibiting the germination of zoospores (EC50 = 2-9 ng/ml for the two isolates) and oospores (complete inhibition at 100 ng/ml). In addition, oxathiapiprolin delayed the onset of detached kauri leaf infection in a dose-dependent manner. Collectively, the results presented here highlight the significant potential of oxathiapiprolin as a tool to aid in the control of kauri dieback disease.

Study of the Effect of Echinophora platyloba Ethanolic Extract on Survival of Listeria monocytogenes in Lighvan Cheese During Ripening Time

Listeria monocytogenes is one of the most frequent foodborne bacteria that can be transmitted through dairy products. The demand for replacing chemical preservatives with natural compounds has increased recently. The aim of this study was to investigate the effect of Echinophora platyloba DC ethanolic extract on the survival of L. monocytogenes in Lighvan cheese during ripening time. Three concentrations of E. platyloba ethanolic extract (0, 0.5, 1 and 1.5%) were added to raw milk at the beginning of Lighvan cheese manufacture, and the population of L. monocytogenes was counted on days 15, 30, 60 and 90. Furthermore, the pH and salt concentration of Lighvan cheese were evaluated in these periods. The results showed that an increase in the concentration of ethanolic extract, as well as the ripening time of Lighvan cheese, resulted in a significant decrease (p<0.05) in the levels of L. monocytogenes (cfu/g). Moreover, the logarithm of the L. monocytogenes population (log cfu/g) was significantly decreased (p<0.05) as the concentration of the added ethanolic extract was enhanced over the ripening time, but no significant changes in pH and salt concentration were observed in Lighvan cheese (p>0.05). It was found that the optimal concentration of E. platyloba ethanolic extract for the complete inhibition of L. monocytogenes was 1-1.5% following 90 days of the ripening.

An Application of Mixture Oil of Syzygium Aromaticum(Clove) and Anethum Graveolens (Dill or Sowa) As An Alternative of Salphos For Food Seed Storage of Chickpea

Mycological investigations of 25 seed samples of stored chick pea (Cicer arietinum L.) from grocery stores of Gurgaon and Gorakhpur revealed occurrence of seventeen fungal species belonging to genus viz., Alternaria , Aspergillus, Chaetomium,Colletotrichum, Curvularia, Fusarium,Penicillium,Rhizopus,Rhizoctonia, and Sclerotium. In these Aspergillus flavus, A. niger, Fusarium oxysporum had dominance in terms of per cent occurrence.Only one species of Bruchid (Callosobruchus chinensis L) occurred in all the 25 samples.The biodeterioration of seeds inoculated with fungi : A. flavus, A. niger ,F.oxysporum and the insect – C. chinensis, revealed their role in seed deterioration. For chickpea food seed protection essential oils were extracted from edible commodity(Lavang(clove bud) and sowa leaf). Lavang oil registered highest antifungal activity inhibiting (100%) mycelial growth of fungi, viz. species Aspergillus flavus, A. niger,Fusarium oxysporum at 300ppm but was fungicidal at 400ppm. Sowa oil showed complete inhibition at 400ppm and was fungicidal at 500ppm.While mixture of both the oils showed complete inhibition (100%) and fungicidal action at 400ppm against the dominant fungi.The oils showed 100% insect repellent activity and were found fungicidal at 0.02ml dose and also insecticidal .The mixture of oils was cidal at 0.02ml dose.The mixture of oils showed a broad antifungal spectrum at 500ppm while only 70-93% inhibitory activity at 300ppm.The oils' mixture's activity was not affected by temp,storage and autoclaving up to 150 days.Oils physico-chemical properties were studied. GC-MS analysis of Lavang oil depicted major components: 75.63 %eugenol while sowa leaf oil had 25.14% apiole. Formulation of Mixture of oils was more effective showing complete seed protection i.e.no growth of fungi and insects upto 150 days storage than salphos (150 days). While salphos controlled only maximum three fungi (A.terreus,C.dematium,F.moniliforme).The formulated oils mixture did not have any adverse effect on the chickpea seeds and increased their shelf life.

Effect of Thermal Treatment of Chamomile (Marticaria chamomella) Extract on the Growth Inhibition of Some Pathogenic Fungi

This Study shows the effect of thermal treatment of chamomile (Marticaria chamomella) extract with different concentrations (5,10,15,20,25,30) mg / ml, on inhibition of some pathogenic fungi such as Trichophyton rubrum and Aspergillus fumigatus under the different temperature degrees (25,50,75, 100)°C. The aqueous extract of chamomile gave complete inhibition against the fungus Trichophyton rubrum at (20,25,30) mg/ml under temperatures of (25,50,75,100)°C While, the aqueous extract of chamomile gave complete inhibition against the fungus Aspergillus fumigatus at concentrations (25,30) mg/ml under the temperature degree of (75,100) °C.