Fungal interactions induce changes in hyphal morphology and enzyme production.

In nature, species interacts/competes with one other within their surrounding for food and space and the type of interactions are unique to each species. The interacting partners secrete different metabolites, which may have high importance in human welfare. Fungal-fungal interactions are complex mechanisms that need better understanding. Here, 14 fungal isolates were facilitated in 105 possible combinations to interact on potato dextrose agar. Morphologically, no changes were observed when the same fungal isolates were allowed to interact within them. However, 10 interactions between different fungal isolates showed mutual replacement with each fungus; capturing territory from the other. Contrastingly, 35 interactions resulted into complete replacement as one of the fungi was inhibited by rapid growth of the other fungus. In 46 interactions, formation of barrage was observed leading to deadlock type of interaction wherein both fungi have restricted growth. To study in details about the barrage formation, two fungal interactions were taken (i) T. coccinea vs. L. lactinea and (ii) T. coccinea vs. T. versicolor. Microscopic changes in the hyphal growth during interaction were observed. There was significant increase in the enzymatic activities including cellulase, xylanase and chitinase during in-vitro fungal-fungal interaction, suggesting the importance of such interactions for commercial enzyme production.

Melanin production and laccase mediated oxidative stress alleviation during fungal-fungal interaction among basidiomycete fungi.

Fungal-fungal interaction often leads to the change in metabolite profile of both the interacting fungus which may have potential implication in industry or agriculture. In the present study, we performed two sets of fungal-fungal interaction-Trametes coccinea (F3) with Leiotrametes lactinea (F9) and T. coccinea (F3) with T. versicolor (F1) to understand the changes in the metabolite profile during the interaction process and how this process impacts the hyphal/mycelial morphology of the participating fungi. The metabolites produced during interaction of T. coccinea (F3) with L. lactinea (F9) and T. coccinea (F3) with T. versicolor (F1) was analysed through liquid chromatography coupled to mass spectroscopy (LC-MS). Most of the metabolites secreted or produced during interaction are associated with defensive response. Further, visualization with scanning electron microscopy revealed that interaction between the tested fungi led to the changes in the hyphal morphology. The bipartite fungal interaction resulted in the production of a dark brown colour pigment-melanin as confirmed by the LC-MS, FTIR and NMR analysis. Moreover, the fungal-fungal interaction also led to increase in the production of laccase, a group of multicopper oxidases involved in detoxification of toxic compounds. Further, increased activity of superoxide dismutase, an enzyme that catalyzes the dismutation of the superoxide anion to hydrogen peroxide was also recorded during fungal-fungal interaction. Quantitative real-time PCR revealed upregulation of lcc1 (encoding a laccase enzyme) and few other stress related genes of T. versicolor during its hyphal interaction with T. coccinea, suggesting a direct correlation between laccase production and melanin production.