Extensive research efforts have been dedicated to describing degradation of wood, which is a complex process; hence, microorganisms have evolved different enzymatic and non-enzymatic strategies to utilize this plentiful plant material. This review describes a number of fungal and bacterial organisms which have developed both competitive and mutualistic strategies for the decomposition of wood and to thrive in different ecological niches. Through the analysis of the enzymatic machinery engaged in wood degradation, it was possible to elucidate different strategies of wood decomposition which often depend on ecological niches inhabited by given organism. Moreover, a detailed description of low molecular weight compounds is presented, which gives these organisms not only an advantage in wood degradation processes, but seems rather to be a new evolutionatory alternative to enzymatic combustion. Through analysis of genomics and secretomic data, it was possible to underline the probable importance of certain wood-degrading enzymes produced by different fungal organisms, potentially giving them advantage in their ecological niches. The paper highlights different fungal strategies of wood degradation, which possibly correlates to the number of genes coding for secretory enzymes. Furthermore, investigation of the evolution of wood-degrading organisms has been described.

Discovered in 1883, laccase is one of the first enzymes ever described. Now, after almost 140 years of research, it seems that this copper-containing protein with a number of unique catalytic properties is widely distributed across all kingdoms of life. Laccase belongs to the superfamily of multicopper oxidases (MCOs)—a group of enzymes comprising many proteins with different substrate specificities and diverse biological functions. The presence of cupredoxin-like domains allows all MCOs to reduce oxygen to water without producing harmful byproducts. This review describes structural characteristics and plausible evolution of laccase in different taxonomic groups. The remarkable catalytic abilities and broad substrate specificity of laccases are described in relation to other copper-containing MCOs. Through an exhaustive analysis of laccase roles in different taxa, we find that this enzyme evolved to serve an important, common, and protective function in living systems.

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Both hormonal balance and plant growth may be shaped by microorganisms synthesizing phytohormones, regulating its synthesis in the plant and inducing plant resistance by releasing elicitors from cell walls (CW) by degrading enzymes (CWDE). It was shown that the Trichoderma DEMTkZ3A0 strain, isolated from a healthy rye rhizosphere, colonized the rhizoplane of wheat seedlings and root border cells (RBC) and caused approximately 40% increase of stem weight. The strain inhibited (in over 90%) the growth of polyphagous Fusarium spp. (F. culmorum, F. oxysporum, F. graminearum) phytopathogens through a mechanism of mycoparasitism. Chitinolytic and glucanolytic activity, strongly stimulated by CW of F. culmorum in the DEMTkZ3A0 liquid culture, is most likely responsible for the lysis of hyphae and macroconidia of phytopathogenic Fusarium spp. as well as the release of plant resistance elicitors. In DEMTkZ3A0 inoculated plants, an increase in the activity of the six tested plant resistance markers and a decrease in the concentration of indoleacetic acid (IAA) auxin were noted. IAA and gibberellic acid (GA) but also the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) enzyme regulating ethylene production by plant were synthesized by DEMTkZ3A0 in the liquid culture. IAA synthesis was dependent on tryptophan and negatively correlated with temperature, whereas GA synthesis was positively correlated with the biomass and temperature.

Three bioactive fractions, extracellular laccase (ex-LAC), crude endopolysaccharides (c-EPL), and a low molecular subfraction of secondary metabolites (ex-LMS), were isolated from the idiophasic cultures of the white rot fungus Cerrena unicolor. For the first time, we determined the antioxidant properties of these samples by chemiluminometric measurement (a) and assessment of the scavenging effect on ABTS (b) and the DPPH reduction rate (c). The highest reducing capability was found for the ex-LMS fraction: 39–90% for (a), 20–90% for (b), and 10–59% for (c) at the concentration of 6.25–800 µg/mL. The scavenging abilities of the C. unicolor c-EPL were between 36 and 70% for (a), 2 and 60% for (b), and 28 and 32% for (c) at the concentration of 6.25–800 µg/mL. A very high prooxidative potential was observed for the ex-LAC probes. The preliminary toxicity tests were done using the Microtox system and revealed the following percentage of the toxic effect against Vibrio fischeri: 85.37% for c-EPL, 50.67% for ex-LAC, and 99.8% for ex-LMS, respectively. The ex-LAC sample showed the antibacterial activity against Escherichia coli, c-EPL against Staphylococcus aureus, and ex-LMS against both bacterial strains, respectively, but the stronger inhibitory effect was exerted on S. aureus.

The wood-degrading basidiomycete Cerrena unicolor C-139 has been suggested as a potential producer of the industrially important enzyme laccase. Basic culture parameters influencing the enzyme synthesis in shakenflask and aerated bioreactor cultures were evaluated to improve the yields of the process. Production of extracellular laccase was considerably enhanced by the addition of Cu 2+ in the micromolar range to a carbon-sufficient and nitrogen-sufficient culture medium (C/N = 16.69). When an optimised medium containing glucose (10 g/L) and L-asparagine (1.5 g/L) was used, and enzyme synthesis was stimulated by addition of 10 lM Cu 2+ to the culture medium on days 3, 6 and 9, maximal laccase productivity obtained after 17 days' cultivation in shaken flask cultures was above 100,000 nkat/L. In fermenter fungal cultures, the influence of stabilisation of medium pH on laccase activity was additionally studied. The use of a bioreactor with an automatic pH control set at pH 6.5 after 48-h incubation resulted in the enzyme activity of 65,000 nkat/L after 8 days' cultivation.

Twelve Flammulina velutipes strains originating from Poland were identified using internal transcribed spacer (ITS) region sequencing. Based on the sequences obtained, the genomic relationship of the analyzed strains was determined. All F. velutipes strains were also characterized using Biolog FF MicroPlates to obtain data on C-substrate utilization and mitochondrial activity. The ability to decompose various substrates differed among the F. velutipes strains up to five times. The highest catabolic activities were characteristic for only two strains with capabilities to decompose up to 22 carbon sources. The correlation between carbon repression and laccase production by F. velutipes was analyzed based on glucose assimilation by these strains. Moreover, the influence of metal ions (Cu2+, Cd2+), veratric and ferulic acids, and temperature on laccase activities in the analyzed strains was determined. The results obtained proved that all the inducers influenced laccase expression in almost all the analyzed strains. However, the degree of induction depended not only on the strain used but also on the day of the induction.

A new exopolysaccharide preparation isolated from stationary cultures of the white rot fungus Ganoderma applanatum (GpEPS) was tested in terms of its bioactive properties including its cytotoxic and immunostimulatory effect. The results indicate that the tested GpEPS (at concentrations above 22.85 µg/mL and 228.5 µg/mL) may exhibit selective activity against tumor cells (cell lines SiHa) and stimulate production of TNF-α THP-1-derived macrophages at the level of 752.17 pg/mL. The GpEPS showed antibacterial properties against Staphyloccoccus aureus and a toxic effect against Vibrio fischeri cells (82.8% cell damage). High cholesterol-binding capacity and triglycerides-binding capacity (57.9% and 41.6% after 24 h of incubation with the tested substances, resp.) were also detected for the investigated samples of GpEPS.