Keratinolytic fungi representing the genus Arthroderma that were isolated from the soils of a rook (Corvus frugilegus) colony were used as biological agents for the disposal of waste feathers. The aim of this study was to assess the abilities of Arthroderma tuberculatum and Arthroderma multifidum fungi with a varied inflow of keratin matter to biodegrade waste feathers. The evaluation was based on the determination of feather mass loss, the activity of keratinolytic enzymes, and the content of mineral N and S forms. It was found that the activity of protease released by the fungi contributed to an increase in the level of soluble proteins and peptides and the concentration of ammonium ions, as well as alkalization of the culture medium. Keratinase activity was significantly correlated with sulfate release, especially in A. tuberculatum cultures. The strains of A. tuberculatum fungi isolated from the soil with the highest supply of organic matter, i.e., strains III, IV, and V, had the lowest enzymatic activity, compared to the A. multifidum strains, but they released mineral nitrogen and sulfur forms that are highly important for fertilization, as well as nutritionally important peptides and amino acids. A. tuberculatum strains can be used for the management of waste feathers that can be applied in agricultural practice.

Fungi that decompose keratinized animal remains are an important component of the arable soil microbiome. The aim of the study is to characterize the communities of keratinophilic and co-inhabiting (non-keratinophilic) fungi in four cultivated soils that differ in physico-chemical properties, with particular emphasis on granulometric fractions, which have so far been omitted from studies concerning the ecology of these micromycetes. Fungi were isolated using the keratin-baiting method. Fungal species identification was carried out on the basis of their macro- and micromorphological features. The Simpson diversity index and Marczewski–Steinhaus similarity index were calculated for precise determination of the relationships between fungal communities. In the studied soils, Trichophyton ajelloi and Ctenomyces serratus dominated among keratinophilic fungi, while Purpureocillium lilacinum and Metacordyceps chlamydosporia, from the orders Eurotiales and Hypocreales, were dominant among non-keratinophilic fungi. The frequency of keratinophilic fungi was significantly positively correlated with pH and the content of two granulometric fractions, as opposed to non-keratinophilic fungi. This was reflected in the higher growth rates of keratinomycetes in loamy soil, chernozem, and rendzina, i.e., soils with a higher content of silt and clay fractions compared to sandy soil characterized by a high content of sand fractions. The species composition of both groups of fungi was most similar between loamy soil and chernozem, whereas the greatest differences were found for sandy soil and rendzina. Chernozem was characterized by the highest diversity of fungal species from both groups of fungi. The study, in addition to providing information about ecological factors, provided a collection of keratinomycete strains that can be used as a starting material for subsequent research stages regarding keratinolytic activity of these fungi and their potential use in agricultural practices.

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The aim of the study was to optimize culture conditions and medium composition to accelerate the biodegradation of chicken feather waste by keratinolytic soil strains of Trichophyton ajelloi, which are poorly known in this respect, as well as to propose hitherto unconsidered culture conditions for these fungi in order to obtain a biopreparation with a high fertilization value. Different pH of the medium, incubation temperatures, amounts of chicken feathers, additional carbon sources, and culture methods were tested. The process of optimizing keratin biodegradation was evaluated in terms of measuring the activity of keratinase, protease, disulfide reductase, concentration of released soluble proteins and peptides, total pool of amino acids, ammonium and sulfate ions, changes in medium pH, and feather weight loss. It was found that the studied fungal strains were capable of decomposing and mineralizing keratin from feather waste. Regarding the fertilizer value of the obtained hydrolysates, it was shown that the release of sulfate and ammonium ions was highest in a stationary culture containing 2% feathers with an initial pH of 4.5 and a temperature of 28 °C. Days 14–21 of the culture were indicated as the optimal culture time for these fungi to obtain biopreparations of high fertilizing value.

The present study is the first report of a detailed analysis of the frequency of Fusarium and genera related to Fusarium colonizing the root zone of clovers and grasses growing in a permanent meadow established on peat-muck soil in a post-bog habitat. The isolation of fungi was carried out on the Nash and Snyder medium with the plate dilution method. The taxonomic identification of the collection of pure fungal cultures was based on morphological features revealed by macroscopic and microscopic observations. The species dominance coefficients, Marczewski–Steinhaus and Simpson species diversity index were calculated. Eight Fusarium complexes were distinguished. The distribution of the Fusarium population was uneven, which was generally reflected in a higher frequency of the F. oxysporum species complex in the clover root zone and M. nivale, F. avenaceum from the Fusarium tricinctum species complex, and F. culmorum from the F. sambucinum species complex in the grass root zone. The highest similarity of fungi was determined in the rhizoplane and the endorhizosphere. The highest species diversity and the highest population size were determined in the rhizosphere soil. The fertilization treatment reduced the growth rates in the Fusarium sensu lato and in genera related to Fusarium, as evidenced by the decrease in the total abundance and species richness. The root colonization by the Fusarium, especially the F. oxysporum species complex, was not accompanied by plant pathologies, which suggests a saprotrophic and endophytic rather than parasitic character of the relationships with the plant host.

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The use of fertilizers based on organic waste as a result of microbial biodegradation and biotransformation is becoming increasingly common practice in plant cultivation. This is to limit the chemicals used in agriculture and thus protect the environment and consumer health. The aim of this study was to evaluate a hitherto unexplored effect of hydrolysates obtained after biodegradation of chicken feather waste by a soil strain of the keratinolytic fungus Trichophyton ajelloi on germination, early growth, and development of plants, in particular with high sulfur requirements, and to verify, in model conditions, their impact on soil biological activity and the total pool of soil DNA. Undiluted and diluted keratin hydrolysate generally stimulated seed germination as well as root and shoot growth of the Lepidium sativum L. (garden cress) and Brassica napus L. var. napus (oilseed rape) on sandy soil (Cambisol I), loamy soil (Cambisol II), and Chernozem. In the model experiment, in the variants with and without oilseed rape on sandy soil and Chernozem, the introduction of keratin hydrolysate generally increased the total abundance of microorganisms. In sandy soil, feather hydrolysate mostly increased respiratory activity, dehydrogenase activity, and alkaline phosphatase activity by an average of approx. 38% and the total DNA pool by 15% and 23% in the variant with and without plants. The activity of protease and acid phosphatase increased by an average of 4% and 6% only in the variant without oilseed rape. Respiratory and enzymatic activity in Chernozem, in the variants with and without oilseed rape, tended to show a downward trend, despite periodically recorded increases. The total DNA pool has increased by 8% in the oilseed rape variant. Oilseed rape biomass was almost two-fold higher after adding feather hydrolysate to both soils, and its yield was higher by 98% in Chernozem than in sandy soil. The results have demonstrated that keratin hydrolysate can be used as a biofertilizer.

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