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Armillaria fungi are frequently documented as economically and ecologically significant plant pathogens, recognised as the causal agents of Armillaria root rot disease. Armillaria mellea is one of the most aggressive pathogens in the Armillaria genus. None of the chemicals tested against Armillaria have been effective in fully eradicating an established A. mellea mycelium from an infection site and/or preventing plant mortality, which makes studies about the chemical sensitivity of A. mellea essential. In this work, the inhibitory effects of 120 different chemical agents on the growth rate of A. mellea were examined using the Biolog Phenotype MicroArray system of chemical sensitivity panels. Among the tested substances, aromatic and membrane function compounds showed the highest inhibitory activity against A. mellea. Interestingly, our results demonstrated promising potential for application of caffeine as an A. mellea-oriented fungicide. Further studies were conducted to explore the antifungal activity of a low-cost and locally available caffeine-rich waste, i.e. spent coffee grounds (SCG) against A. mellea. It is noteworthy that the hyphal growth of A. mellea was significantly inhibited when cultivated on malt extract agar supplemented with SCG. Current findings uncovered, for the first time, the potential use of caffeine-rich wastes for designing management strategies to practically control the spread of A. mellea. [ABSTRACT FROM AUTHOR]

Mushrooms produce various classes of secondary metabolites that could be used as antivirals in the future. The aim of this study was to determine the antiviral activity of methanolic extracts obtained from two edible mushrooms, Boletus bellinii (B. bellinii) and Boletus subtomentosus (B. subtomentosus), collected from the north forests of Tunisia, against Herpes Simplex Virus type 2 and Coxsackie Virus B type 3. In vitro micro-inhibition assays and cytotoxicity screening were performed on Vero cells. The tested Boletus methanolic extracts were found to be non-cytotoxic at high doses (50% cytotoxic concentration – CC50 > 1 mg/mL) and exhibited relevant viral inhibition with 50% inhibitory concentration, i.e., IC50 of 3.60 ± 0.66 µg/mL and 35.70 ± 7.42 µg/mL for B. bellinii, and 5.67 ± 1.02 µg/mL and 56.88 ± 9.56 µg/mL for B. subtomentosus, against HSV-2 and CVB-3, respectively. Interestingly, Boletus methanolic extracts showed high selectivity index (SI) values against both viruses, with the highest values against HSV-2 (SI > 800). Both viral strains were inhibited when treated with extracts during the early stages of virus replication. Inonotusin A was isolated and identified as the compound responsible for these activities. The latter is a novel antiviral agent that may have clinical utility or serve as a lead compound for further development. This study is the first attempt to investigate the antiviral activity of inonotusin A, isolated from the genus Boletus. The information from the present work should be a valuable reference for future studies on the antiviral activity of inonotusin A. [ABSTRACT FROM AUTHOR]

Actinobacteria are an extremely diverse group of bacteria known for their ability to produce a range of biotechnologically relevant enzymes. Tunisian Forest ecosystems are relatively unexplored in terms of actinobacterial diversity and their enzyme activities, offering an excellent opportunity to isolate new potent actinobacterial strains that produce bioactive natural products. In this study, actinobaceria were isolated from soil samples collected from four forests in the Northern part of Tunisia, using Starch-casein media and characterized by morphological, molecular (16 S rRNA) and phenotypic (enzymatic activities) methods. Isolate's colonies showed a color ranging from whitish, brownish, yellow, green, black, pink-purple and orange, similar to actinobacterial morphology. Analysis of the 16 S rRNA gene sequences of the isolates showed that they belong to the phylum Actinobateria, Specifically the genera Streptomyces, Nocardioides, Arthrobacter, Kocuria and Paenarthrobacter genera with the prevalence of Streptomyces members such as S. albidochromogenes and S. neopeptinius. The analysis of enzymatic profiles, showed that actinobacterial isolates represent a promising source of enzymes with potential biotechnological applications including amylases, CMCase, pectinases, xylanases and laccases. [ABSTRACT FROM AUTHOR]

The rare fungus Hericium erinaceus (Bull.) Pers. was collected from temperate forests in northwestern Tunisia and described for the first time in Africa. In this paper, we report data about the distribution, ecology, morphology and molecular identification of H. erinaceus. Collected data may help expand our knowledge on this critically endangered rare species worldwide. [ABSTRACT FROM AUTHOR]