Impact of the Cultivation System and Plant Cultivar on Arbuscular Mycorrhizal Fungi of Spelt (Triticum aestivum ssp. Spelta L.) in a Short-Term Monoculture.

Native communities of arbuscular mycorrhizal fungi (AMF) constitute a natural biofertilization, biocontrol, and bioprotection factor for most agricultural crops, including cereals. The present study investigated the native AMF population in cultivated spelt, i.e., a cereal that has not been analyzed in this respect to date. In particular, the aim of the study was to determine the number of spores and the degree of AMF root colonization in two spelt cultivars (Franckenkorn and Badengold) from a 3-year monoculture grown in two different cultivation systems: conventional tillage and no-tillage systems. The study showed considerable accumulation of AMF spores in the soil (on average 1325 in 100 g of air-dry soil), with a wide range of their numbers, and not a very high degree of endomycorrhizal colonization (on average from 3.0% to 31%). The intensity of AMF growth in the subsequent cultivation years gradually increased and depended on the cultivation system as well as the growth stage and cultivar of the spelt. It was found that both analyzed AMF growth indices in the no-tillage system were positively correlated with each other. Moreover, their values were higher in the no-tillage system than in the conventional system, with statistical significance only for the number of spores. This was mainly observed in the variant with the Franckenkorn cultivar. The effect of the growing season was evident in both cultivation systems and spelt cultivars. It was reflected by intensification of sporulation and mycorrhization of spelt roots by AMF in summer (maturation stage) compared with the spring period (flowering stage).

Occurrence and Distribution of Fusarium Communities in the Root Zone in a Post-Bog Permanent Meadow in Relation to Mineral Fertilization and Growing Seasons.

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.

Dispersal of Aphanoascus keratinophilus by the rook Corvus frugilegus during breeding in East Poland.

The process of dispersal of the potentially disease-causing, geophilic and keratinolytic fungal strain Aphanoascus keratinophilus (the perfect, sexual stage of Chrysosporium keratinophilum) by the rook Corvus frugilegus was studied. The source of A. keratinophilus strains was pellets of the rook, thus far not considered a carrier of this particular opportunistic pathogen. Pellets collected from breeding colonies of rooks were analysed in terms of the occurrence of keratinolytic fungi with the application of the native keratin bait method. Among the 83 rook pellets analysed, 24 (29%) were infected by keratinophilic fungi. Pure cultures of the fungi were identified to species based on traditional morphological features. Traditional mycological identification was verified by the PCR-RFLP molecular identification method as well as DNA sequencing. The obtained results showed the presence of 90 Aphanoascus keratinophilus strains, 6 Chrysosporium tropicum strains, and 3 Chrysosporium pannicola strains. The PCR melting profile (PCR-MP) method was used to identify intraspecies variations of the 90 analysed A. keratinophilus strains. The dispersal of genotypes and possible pathways of A. keratinophilus dispersal and infection via rook pellets were analysed.

Possibility to Biotransform Anthracyclines by Peroxidases Produced by Bjerkandera adusta CCBAS 930 with Reduction of Geno- and Cytotoxicity and Pro-Oxidative Activity.

The aim of this study was to evaluate the bioremoval mechanism of anthracycline antibiotics by the white-rot fungus B. adusta CCBAS 930. The activity of oxidoreductases and levels of phenolic compounds and free radicals were determined during the biotransformation of anthraquinone antibiotics: daunomycin (DNR) and doxorubicin (DOX) by B. adusta strain CCBAS 930. Moreover, phytotoxicity (Lepidium sativum L.), ecotoxicity (Vibrio fischeri), genotoxicity and cytotoxicity of anthraquinone dyes were evaluated before and after biological treatment. More than 80% and 90% of DNR and DOX were removed by biodegradation (decolorization). Initial solutions of DNR and DOX were characterized by eco-, phyto-, geno- and cytotoxicity. Despite efficient decolorization, secondary metabolites, toxic to bacteria, formed during biotransformation of anthracycline antibiotics in B. adusta CCBAS 930 cultures. DNR and DOX metabolites did not increase reactive oxygen species (ROS) production in human fibroblasts and resazurin reduction. DNR metabolites did not change caspase-3 activity.

Decolorization and biodegradation of melanoidin contained in beet molasses by an anamorphic strain of Bjerkandera adusta CCBAS930 and its mutants.

We used a ligninolytic strain of the white-rot fungus B. adusta CCBAS 930 and its mutants with modified ligninolytic activity to assess their potential to remove of molasses. The analyzed strains have been shown to be able to decolorize 1% or 2% molasses solutions containing brown-colored toxic melanoidins. It was found that the decolorization process was determined by the transition to the stage of production of sporulating aerial mycelium (liquid and agar cultures) coupled with an increase in peroxidase activity, which was accompanied by a decrease in the level of melanoidin, free radicals, and phenolic compounds. Four different peroxidase activities were detected in post-culture liquids, i.e. horseradish-like (HRP-like), manganese-dependent (MnP), lignin (LiP), and versatile (VP) peroxidase activities. The HRP-like peroxidase was characterized by the highest activity. The efficiency of removal of melanoidins from a 1% molasses solution by the parental strain and the mutants was dependent on the culture method. The highest efficiency was noted in immobilized cultures (threefold higher than in the mycelium-free cultures), which was accompanied by stimulation of HRP-like peroxidase activity. Mutant 930-5 was found to be the most effective in the decolorization and decomposition of melanoidin. The HRP-like activity in the immobilized cultures of B. adusta 930-5 was 640-fold higher than in the mycelium-free cultures of the fungus. Moreover, decolorization and biodegradation of melanoidin by B. adusta CCBAS 930 and 930-5 was coupled with detoxification.

Modification of post-industrial lignin by fungal strains of the genus Trichoderma isolated from different composting stages.

One of the links in the environmental management chain is the environmentally friendly utilization of the emerging post-industrial waste and improvement of the methods of processing thereof. The aim and novelty of this research was to evaluate the potential of fungi to purify wastewater containing post-industrial lignin, i.e. waste originating from the pulp and paper industry. Trichoderma were dominant in the composts with different qualities and quantities of lignocellulosic compounds. The Trichoderma strains used in the research were isolated from two lignocellulosic composts at three different time points (from 10-, 20- and 30-week-old composting mass). Eighteen strains of the genus Trichoderma were tested for their ability to biodegrade 0.2% post-industrial lignin. It was evaluated by determination of decolorization, activities of ligninolytic enzymes, and concentration of phenolic compounds in the post-culture liquid. The Trichoderma strains isolated from 10-week-old compost I and 30-week-old compost II showed the highest decolorization activity and biotransformation of dark post-industrial lignin. All strains secreted horseradish-like peroxidase (HRP-like), superoxide dismutase-like (SOD-like), xylanase, and phenolic compounds. Strains isolated from 30-week-old compost I and from 10-week-old compost II released the greatest amounts of phenolic compounds into the culture liquid containing post-industrial lignin. The strains isolated from 10- and 20-week-old compost were characterized by high SOD-like and HRP-like activity, respectively. The concentration of phenolic compounds measured with HPLC in Trichoderma fungus culture VII from compost I corresponded with the decolorization degree and high HRP-like activity. The study results indicate that the genus Trichoderma with decolorization activity isolated from the first composting stages can be used in the biotransformation of post-industrial lignin waste.

Growth conditions, physiological properties, and selection of optimal parameters of biodegradation of anticancer drug daunomycin in industrial effluents by Bjerkandera adusta CCBAS930.

The study characterizes the anamorphic Bjerkandera adusta strain CCBAS 930, including growth conditions, physiological properties, and enzymatic activities related to basic metabolism and specific properties coupled with the fungal secondary metabolism. It was established that the fungus grows in a wide pH range (3.5-7.5), up to 3% of salt concentration and a temperature of 5-30 °C. Media rich in natural organic components (potato, maize extracts, whey) are optimal for biomass propagation. Minimal media, containing mineral salts and glucose as well as static growth conditions, are required to obtain idiophasic mycelium, equivalent to the secondary metabolism of the fungus. Of the 7 complex C, N, and energy sources tested, the strain did not utilize only fibrous cellulose. Lipolytic activity reached the highest values of the enzymatic activities corresponding to those capabilities. The specific properties of strain B. adusta CCBAS 930 determined by the production of HRP-like peroxidase were related to the decolorization and biodegradation of anthraquinone derivative daunomycin. The decolorization of 30% of daunomycin effluents occurred most rapidly in iso-osmotic medium and non-enriched with nitrogen, containing 0.25% glucose, pH = 5.0-6.0, and 25-30 °C. In agitated cultures, the strain decolorized solutions of daunomycin by biosorption, which coincided with the inhibition of aerial mycelium production and HRP-like biosynthesis. Based on knowledge, potential and real possibilities of using the strain in bioremediation of colored industrial sewage were discussed.

Synthesis of Indoleacetic Acid, Gibberellic Acid and ACC-Deaminase by Mortierella Strains Promote Winter Wheat Seedlings Growth under Different Conditions.

The endogenous pool of phytoregulators in plant tissues supplied with microbial secondary metabolites may be crucial for the development of winter wheat seedlings during cool springs. The phytohormones may be synthesized by psychrotrophic microorganisms in lower temperatures occurring in a temperate climate. Two fungal isolates from the Spitzbergen soils after the microscopic observations and "the internal transcribed spacer" (ITS) region molecular characterization were identified as Mortierella antarctica (MA DEM7) and Mortierella verticillata (MV DEM32). In order to study the synthesis of indoleacetic acid (IAA) and gibberellic acid (GA), Mortierella strains were grown on media supplemented with precursor of phytohormones tryptophan at 9, 15 °C, and 20 °C for nine days. The highest amount of IAA synthesis was identified in MV DEM32 nine-day-culture at 15 °C with 1.5 mM of tryptophan. At the same temperature (15 °C), the significant promoting effect (about 40% root and shoot fresh weight) of this strain on seedlings was observed. However, only MA DEM-7 had the ACC (1-aminocyclopropane-1-carboxylate) deaminase activity with the highest efficiency at 9 °C and synthesized IAA without tryptophan. Moreover, at the same conditions, the strain was confirmed to possess the strong promoting effect (about 40% root and 24% shoot fresh weight) on seedlings. Both strains synthesized GA in all tested terms and temperatures. The studied Mortierella strains had some important traits that led them to be considered as microbial biofertilizers components, improving plant growth in difficult temperate climates.

Microbiological analysis of bioaerosols collected from Hospital Emergency Departments and ambulances.

INTRODUCTION AND OBJECTIVE: The goal of the study was a microbiological, qualitative and quantitative analysis of bioaerosol at the workplace of medical personnel (Health Emergency Departments (HEDs), ambulances), and comparative administration offices with an expected neutral occupational exposure to biological agents measured with individual Button Sampler. MATERIAL AND METHODS: Personal sampling was performed with Button Sampler instrument loaded with gelatine filters in 10 HEDs, in 9 ambulances and in 9 offices to assess the occupational biological agents' exposure in air. Sampling was conducted from March until April 2016. Samples were quantitatively assessed for viable and total number of bacteria and fungi. Routine procedures for microbiological diagnostics were implemented. Data were analysed using Kruskal-Wallis and Mann-Whitney statistical tests with α=0.05. P value less than 0.05 were considered significant. RESULTS: At the workplaces assessed, the concentrations of viable microorganisms in HEDs were 1.3×102 - 4.2×103 CFU/m3 for bacteria, 3.4×100 - 8.1×101 CFU/m3 for fungi; in ambulances 1.3×102 - 1.4×103 CFU/m3 (bacteria), 6.7×100 - 6.5×102 CFU/m3 (fungi) and in offices 4.2×101 - 5.0×103 CFU/m3 (bacteria), 0 - 7.9×102 CFU/m3(fungi). In outdoor air, the number of microorganisms reached the level: 1.0×102 - 5.9×102 CFU/m3 for bacteria and 1.5×102 - 8.2×102 CFU/m3 for fungi. The predominant isolated bacteria were Gram-positive cocci. The prevalent fungi species belonged to the genus Aspergillus and Penicillium. CONCLUSIONS: The quantitative assessment of examined indoor air was similar to control outdoor air, and were relatively low. The level of microbiological contamination did not exceed 5×103 CFU/m3 which is recommended as an admissible level in public spaces in Poland.

Activities of Versatile Peroxidase in Cultures of Clonostachys rosea f. catenulata and Clonostachys rosea f. rosea during Biotransformation of Alkali Lignin.

The aim of this study was the evaluation of activities of versatile peroxidase (VP) in cultures of Clonostachys sp. (Gliocladium sp.) strains during biotransformation of 0.2% alkali lignin (AL). The principal component analysis (PCA) method was applied to determine the main factors and correlation between biotransformation of 0.2% AL, activity of VPs, pH value, and Clonostachys sp. strains. The biotransformation of 0.2% AL in cultures of microscopic fungi included decolorization (medium lightening) and colorization (darkening of the medium). The versatile peroxidase synthesized by the microscopic fungi tested showed activity for oxidation of Mn(II) and guaiacol, but the activity for oxidation of guaiacol in the presence of Mn(II) was significantly higher. The PCA analysis indicated a strong correlation between biotransformation of 0.2% AL and pH and between oxidation of Mn(II), guaiacol without and in the presence of Mn(II) ions, strains, and pH.

Nests of Marsh harrier (Circus aeruginosus L.) as refuges of potentially phytopathogenic and zoopathogenic fungi.

Birds' nests may be refuges for various species of fungi including that which are potentially phytopathogenic and zoopathogenic. Among the 2449 isolates of fungi obtained from nests of Marsh harriers 96.8% belonged to filamentous fungi. In total, 37 genera were identified from 63 fungi species. Within the mycobiotas of the examined nests populations of fungi which are potentially pathogenic for humans, homoiothermous animals and plants dominated. Among 63 species, 46 (72%) were potentially pathogenic fungi of which 18 species were potentially phytopathogenic and 32 species were pathogenic for homoiothermous animals. Inter alia species of fungi were found in the Marsh harriers nests: Aspergillus fumigatus, Aspergillus flavus, Scopulariopsis brevicaulis, Chrysosporium keratinophilum and Fusarium poae, Fusarium sporotrichioides. In terms of numbers, dominant in Marsh harrier nests were fungi pathogenic to birds, other homoiothermous animals and humans. On that basis it was concluded that Marsh harrier nests are both a source of fungal infections for that species and one of the links in the epidemiological cycle of opportunistic fungi for humans.

Comparative study of eco- and cytotoxicity during biotransformation of anthraquinone dye Alizarin Blue Black B in optimized cultures of microscopic fungi.

The aim of this study was to select optimal conditions (C and N sources, initial pH and temperature) for biodecolorization of 0.03% anthraquinone dye Alizarin Blue Black B (ABBB) by microscopic fungi: Haematonectria haematococca BwIII43, K37 and Trichoderma harzianum BsIII33. The phenolic compounds, phytotoxicity (Lepidium sativum L.), biotoxicity (Microtox), cytotoxicity and yeast viability assay were performed to determine the extent of ABBB detoxification. Biodecolorization and detoxification of 0.03% ABBB in H. haematococca BwIII43 and T. harzianum BsIII33 cultures was correlated with extracellular oxidoreductases activity. In turn, secondary products, toxic to human fibroblasts and respiring sod1 Saccharomyces cerevisiae cells, were formed in H. haematococca K37 strain cultures, despite efficient decolorization.

Identification and characteristics of biological agents in work environment of medical emergency services in selected ambulances.

OBJECTIVES: Assessment of microbial air quality and surface contamination in ambulances and administration offices as a control place without occupational exposure to biological agents; based on quantitative and qualitative analysis of bacteria, yeasts and filamentous fungi found in collected samples. MATERIAL AND METHODS: The sampling was done by wet cyclone technology using the Coriolis recon apparatus, imprint and swab methods, respectively. In total, 280 samples from 28 ambulances and 10 offices in Warszawa were tested. Data was analyzed using Shapiro-Wilk normality test, Kruskal-Wallis test with α = 0.05. P value ≤ 0.05 was considered as significant. RESULTS: The levels of air contamination were from 0 to 2.3×101 colony-forming unit (CFU)/m3 for bacteria and for yeast and filamentous fungi were from 0 to 1.8×101 CFU/m3. The assessment of office space air samples has shown the following numbers of microorganisms: bacteria from 3.0×101 to 4.2×101 CFU/m3 and yeast and filamentous fungi from 0 to 1.9×101 CFU/m3. For surface contamination the mean bacterial count in ambulances has been between 1.0×101 and 1.3×102 CFU/25 cm2 and in offices - between 1.1×101 and 8.5×101 CFU/25 cm2. Mean fungal count has reached the level from 2.8×100 to 4.2×101 CFU/25 cm2 in ambulances and 1.3×101 to 5.8×101 CFU/25 cm2 in offices. The qualitative analysis has revealed the presence of Acinetobacter spp. (surfaces), coagulase - negative Staphylococci (air and surfaces), Aspergillus and Penicillium genera (air and surfaces). CONCLUSIONS: The study has revealed a satisfactory microbiological quantity of analyzed air and surface samples in both study and control environments. However, the presence of potentially pathogenic microorganisms in the air and on surfaces in ambulances may endanger the medical emergency staff and patients with infection. Disinfection and cleaning techniques therefore should be constantly developed and implemented. Int J Occup Med Environ Health 2017;30(4):617-627.

Negative correlation between mycological surfaces pollution in hospital emergency departments and blood monocytes phagocytosis of healthcare workers.

The aim of the present study was to find a possible relationship between the presence of yeast and filamentous fungi in hospital emergency departments and the activity levels of blood granulocytes and monocytes in emergency personnel. The study of mycological pollution was conducted in winter; the samples were collected from 10 Warsaw hospitals emergency departments (HE D) and in 10 control locations (office spaces) and included air samples and swabbing of floor and walls. The blood for immunological investigation was taken in spring, from 40 men, 26 to 53 years old, healthcare workers of these departments, who have been working for at least 5 years in their current positions, and from 36 corresponding controls, working in control offices. Evaluation of blood leukocyte subpopulations was done by hematological analyzer and cytometry analysis and monocyte and granulocyte phagocytosis by Phagotest. There were no significant differences in the level of mycological contamination between the test and control places. The qualitative analysis of the surfaces and air samples revealed a prevalence of strains belonging to Aspergillus spp. and Penicillium spp. genus. Statistical analysis revealed the existence of negative correlation between the number of phagocytizing blood monocytes and fungi spores content on floor and wall surfaces in hospital emergency departments (r = -0.3282, p < 0.05 and positive correlation between the number of phagocytizing monocytes in the blood of office workers and fungi pollution of control offices (r = 0.4421, p < 0.01).

Evaluation of Dye Compounds' Decolorization Capacity of Selected H. haematococca and T. harzianum Strains by Principal Component Analysis (PCA).

The selected strains of microscopic fungi, Haematonectria haematococca (BwIII43, K37) and Trichoderma harzianum (BsIII33), decolorized the following monoathraquinone dyes with different efficiency: 0.03 % Alizarin Blue Black B, 0.01 % Carminic Acid, 0.01 % Poly R-478, and 0.2 % post-industrial lignin. The most effective was the removal of 0.03 % Alizarin Blue Black B (50-60 %) and 0.01 % Carminic Acid (55-85 %). The principal component analysis (PCA) method was applied to determine the main enzyme responsible for the biodecolorization process of the dye substrates and indicated that horseradish-type (HRP-like), lignin (LiP), and manganese-dependent (MnP) peroxidases were responsible for the decolorization of anthraquinone dyes by the strains tested. The participation of particular enzymes in the decolorization of monoanthraquinone dyes ranged from 44.48 to 51.70 % for 0.01 % Carminic Acid and from 38.46 to 61.12 % for Poly R-478. The highest precipitation in decolorization of these dyes showed HRP-like peroxidase, respectively, 54-74 and 70-95 %. The degree of decolorization of 0.2 % post-industrial lignin by the selected strains of H. haematococca and T. harzianum amounted to 58.20, 61.38, and 65.13 %, respectively. The rate of 0.2 % post-industrial lignin decolorization was conditioned by the activity of HRP-like (71-90 %) and LiP (87-94 %) peroxidases.

Microsatellite-primed PCR for intra-species genetic relatedness in Trichophyton ajelloi strains isolated in poland from various soil samples.

Trichophyton ajelloi is a geophilic dermatophyte that specializes in the decomposition of native keratin. It exists in soil with a permanent influx of keratin matter. In the present study, two PCR-based methods were used for the identification and intra-species differentiation of T. ajelloi strains isolated from 3 types of soils with different physicochemical properties. The first method, employed for molecular identification, was PCR amplification of the 5.8S rRNA gene and its flanking regions encoding internal transcribed spacers (ITSs), followed by restriction enzyme digestion using endonuclease HinfI. The second method, employed for molecular differentiation, was microsatellite-primed PCR (MSP-PCR) using the repetitive oligonucleotide (GACA)4. All the T. ajelloi strains were also identified using a traditional culture method. Our results showed that molecular identification using the PCR-restriction fragment length polymorphism (PCR-RFLP) method agreed with the identification made using the traditional approach. On the other hand, PCR-RFLP results showed no strain differentiation, while MSP-PCR using the (GACA)4 primer identified different varieties among the T. ajelloi strains. The reasons for the intra-species differentiation of T. ajelloi have been discussed.

Anthraquinone dyes decolorization capacity of anamorphic Bjerkandera adusta CCBAS 930 strain and its HRP-like negative mutants.

Cultures of the anamorphic fungus Bjerkandera adusta CCBAS 930 decolorizing, in stationary cultures, 0.01 % solutions of carminic acid and Poly R-478, were characterised by a strong increase in the activity of the horseradish peroxidase (HRP-like) and manganese-dependent peroxidase (MnP) at a low activity of lignin peroxidase. Genotypically modified mutants of B. adusta CCBAS 930: 930-5 and 930-14, with total or partial loss of decolorization capabilities relative to anthraquinonic dyes, showed inhibition of the activity of HRP-like peroxidase and MnP. Whereas, compared to the parental strain, in the mutant cultures there was an increase in the activity of lignin peroxidase and laccase. The paper presents a discussion of the role of the studied enzymatic activities in the process of decolorization of anthraquinonic dyes by the strain B. adusta CCBAS 930.

Aspergillus fumigatus and other thermophilic fungi in nests of wetland birds.

A study was performed on the numbers and species diversity of thermophilic fungi (growing at 45 °C in vitro) in 38 nests of 9 species of wetland birds, taking into account the physicochemical properties of the nests and the bird species. It was found that in nests with the maximum weight (nests of Mute Swan), the number and diversity of thermophilic fungi were significantly greater than in other nests, with lower weight. The diversity of the thermophilic biota was positively correlated with the individual mass of bird and with the level of phosphorus in the nests. The dominant species within the mycobiota under study was Aspergillus fumigatus which inhabited 95% of the nests under study, with average frequency of ca. 650 cfu g(-1) of dry mass of the nest material. In a majority of the nests studied (nests of 7 bird species), the share of A. fumigatus exceeded 50% of the total fungi growing at 45 °C. Significantly higher frequencies of the fungal species were characteristic of the nests of small and medium-sized piscivorous species, compared with the other bird species. The number of A. fumigatus increased with increase in the moisture level of the nests, whereas the frequency of occurrence of that opportunistic pathogen, opposite to the general frequency of thermophilic mycobiota, was negatively correlated with the level of phosphorus in the nest material, and with the body mass and length of the birds. The authors indicate the causes of varied growth of thermophilic fungi in nests of wetland birds and, in particular, present a discussion of the causes of accumulation of A. fumigatus, the related threats to the birds, and its role as a source of transmission in the epidemiological chain of aspergillosis.

Biodegradation of keratin waste: Theory and practical aspects.

Keratin-rich by-products, i.e. bristles, horns and hooves, chicken feathers and similar, are a source of nutrients for animals (amino acids) and plants (N, S). Contemporary developments in the management of keratin waste in feeds and fertilizers comply with human and animal health protection regulations and respect the principles of ecological development. Biotechnological methods employing keratinolytic bacteria and microscopic fungi play a key role in processing keratin waste. This study reviews the current knowledge on the ecology and physiology of keratinolytic microorganisms and presents the biodegradation mechanism of native keratin. The structure and chemical composition of keratin proteins are described, and methods of keratin waste biotransformation into products of practical industrial and natural value, especially composts, are discussed.

Dynamics of growth and succession of bacterial and fungal communities during composting of feather waste.

Succession of communities of different bacteria and fungi, mainly proteolytic and keratinolytic ones, was observed during composting of chicken feathers with pine bark (FB) and with pine bark/rye straw (FBS). The succession was dominated by fungal than bacterial communities. Bacteria, including Actinomycetes, grew intensively during the first 2-4 weeks of composting and included mainly proteolytic, rarely cellulolytic, populations; afterwards, bacteria were gradually replaced by fungi. Meso- and thermophilic ubiquitous fungi, including cellulolytic ones, appeared among fungal representatives as the first, while keratinolytic strains were detected in the compost biomass at the 6th week of the process. The development of strains within the second fungal group was significantly more intensive than that of cellulolytic populations. The intensity of growth of particular ecological-physiological communities was found to be dependent on chemical content and C/N ratio of biomass and was the strongest in C/N=25 composts.