Date Published: February 5, 2019
Publisher: Public Library of Science
Author(s): Anna Pawlik, Marta Ruminowicz-Stefaniuk, Magdalena Frąc, Andrzej Mazur, Jerzy Wielbo, Grzegorz Janusz, Daniel Cullen.
Cerrena unicolor is a wood-degrading basidiomycete with ecological and biotechnological importance. Comprehensive Biolog-based analysis was performed to assess the metabolic capabilities and sensitivity to chemicals of C. unicolor FCL139 growing in various sawdust substrates and light conditions. The metabolic preferences of the fungus towards utilization of specific substrates were shown to be correlated with the sawdust medium applied for fungus growth and the light conditions. The highest catabolic activity of C. unicolor was observed after fungus precultivation on birch and ash sawdust media. The fungus growing in the dark showed the highest metabolic activity which was indicated by capacity to utilize a broad spectrum of compounds and the decomposition of 74/95 of the carbon sources. In all the culture light conditions, p-hydroxyphenylacetic acid was the most readily metabolized compound. The greatest tolerance to chemicals was also observed during C. unicolor growth in darkness. The fungus was the most sensitive to nitrogen compounds and antibiotics, but more resistant to chelators. Comparative analysis of C. unicolor and selected wood-decay fungi from different taxonomic and ecological groups revealed average catabolic activity of the fungus. However, C. unicolor showed outstanding capabilities to catabolize salicin and arbutin. The obtained picture of C. unicolor metabolism showed that the fungus abilities to decompose woody plant material are influenced by various environmental factors.
Wood degrading saprotrophic fungi have evolved unique biochemical pathways allowing them to assimilate a vast array of both simple and complex nutrients and to produce a variety of metabolites. Elucidating the mechanism of biological wood decay is ecologically important not only due to the role of fungi in the carbon cycle, but also due to its economic significance . Both the environmental and economic roles of saprotrophic fungi arise from their metabolic versatility, which includes the production of a wide range of enzymes directly or indirectly linked to the degradation of organic residues . Wood-destroying fungi that cause cell wall degradation can be classified according to the type of decay produced. The best-known types are brown rot, soft rot, and white rot. Each fungal type produces a different set of enzymes and is able to degrade different plant materials and thus colonize different ecological niches. Environmental factors greatly influence decay caused by brown rot and white rot fungi . To sense light, only a few photoreceptor systems have developed during evolution. In fungi, photoreceptors controlling metabolism, developmental processes, and physiological adaptations as well as the circadian clock have already been found, suggesting that these organisms were able to sense light from blue to far red [4, 5].
Fungal metabolic traits are becoming increasingly important in their identification and taxonomy [27–29]. Technologies based on phenotyping arrays and microplates ensure the most comprehensive metabolic profiling of organisms, offering characteristics of species, individual strains, and entire ecological groups. The combination of the data into a biochemical map can also detect pathways or enzymatic steps unique for a particular strain, species, or genus, which may have potential commercial use .