Keratinolytic Fungi Research Articles

Diversity of Soil-Borne Fungi Isolated from Places Frequently Visited by People in the City of Wrocław (Poland)

In this study, we identified culturable microscopic fungi in soil from areas frequented by people (parks, allotments, and other green areas) in the city of Wrocław (Poland). In addition to general species analysis, attention was focused on keratin-degrading fungi. From 60 soil samples (12 study sites), we obtained 75 isolates of keratinophilic and keratinolytic fungi using the hair bait method, and 54 isolates of fungi were isolated on PDA (Potato Dextrose Agar) medium. Based on morphological and molecular analyses, a total of 37 strains were identified, classified into 2 phyla, 11 families, 17 genera, and 30 filamentous species. The mean values of the Shannon Diversity Index for both experimental variants ranged from 0.074 to 0.117. The most common species was the Penicillium genus, which accounted for 33.33% of all fungal species obtained in these studies. These fungi are common in both indoor and outdoor environments. However, particularly noteworthy in this study are the species belonging to the group of dermatophytes (Arthroderma uncinatum, Keratinophyton wagnerii, Nannizzia gypsea, and Paraphyton cookei), which may pose a real biological threat to humans and animals due to their well-known potential to cause dermatomycosis.

Isolation, identification, and molecular characterization of potential keratinolytic fungus sp. from Southern Assam: relevance to poultry wastes and its biological management.

Feather waste is a highly prevalent form of keratinous waste that is generated by the poultry industry. The global daily production of feather waste has been shown to approach 5 million tons, typically being disposed of through methods such as dumping, landfilling, or incineration which contribute significantly to environmental pollutions. The proper management of these keratinous wastes is crucial to avoid environmental contamination. The study was carried out to isolate the keratinolytic fungi from the poultry disposal sites of different region of North-East India to evaluate its potential in bioremediation of the feathers wastes. Out of 12 fungal strains isolated from the sites, the fungus showing the highest zone of hydrolysis on both the skim milk and keratin agar medium was selected for the study and the molecular identification of the isolate was performed through DNA sequence analysis by amplifying the internal transcribed spacer (ITS) region. The sequence results showed higher similarity (above 95%) with Aspergillus spp. and was named Aspergillus sp. Iro-1. The strain was further analyzed for its feather degrading potential which was performed in submerged conditions under optimized conditions. The study showed that the strain could effectively degrade the feathers validated through weight loss method, and the structural deformations in the feathers were visualized through scanning electron microscopy (SEM). Aspergillus sp. Iro-1 was obtained from the southern region of Assam. It would be of great importance as the implementation of this sp. can help in the bioremediation of feathers wastes in this region. This is the first study of identification of feather degrading fungus from southern part of Assam (Barak).

Evaluation of the antidermatophytic activity of potassium salts of N-acylhydrazinecarbodithioates and their aminotriazole-thione derivatives

Nowadays, dermatophyte infections are relatively easy to cure, especially since the introduction of orally administered antifungals such as terbinafine and itraconazole. However, these drugs may cause side effects due to liver damage or their interactions with other therapeutics. Hence, the search for new effective chemotherapeutics showing antidermatophyte activity seems to be the urge of the moment. Potassium salts of N-acylhydrazinecarbodithioates are used commonly as precursors for the synthesis of biologically active compounds. Keeping that in mind, the activity of a series of five potassium N-acylhydrazinecarbodithioates (1a–e) and their aminotriazole-thione derivatives (2a–e) was evaluated against a set of pathogenic, keratinolytic fungi, such as Trichophyton ssp., Microsporum ssp. and Chrysosporium keratinophilum, but also against some Gram-positive and Gram-negative bacteria. All tested compounds were found non-toxic for L-929 and HeLa cells, with the IC30 and IC50 values assessed in the MTT assay above 128 mg/L. The compound 5-amino-3-(naphtalene-1-yl)-4,5-dihydro-1H-1,2,4-triazole-5-thione (2d) was found active against all fungal strains tested. Scanning Electron Microscopy (SEM) revealed inhibition of mycelium development of Trichophyton rubrum cultivated on nail fragments and treated with 2d 24 h after infection with fungal spores. Transmission Electron Microscopy (TEM) observation of mycelium treated with 2d showed ultrastructural changes in the morphology of germinated spores. Finally, the RNA-seq analysis indicated that a broad spectrum of genes responded to stress induced by the 2d compound. In conclusion, the results confirm the potential of N-acylhydrazinecarbodithioate derivatives for future use as promising leads for new antidermatophyte agents development.

Dermatophytosis in Bovine, Recent Clinical analysis, Treatment, and updated zoonotic infection: A Review Article

Dermatophytosis is a worldwide disease caused by pathogenic keratinolytic fungi known as dermatophytes inside the cutaneous layer of both cattle and human skin. are divided into three categories: Microsporum species, Epidermophyton species, and Trichophyton species. Infected animals develop skin lesions with a thick, grey-white crust that rises above the skin approximately 3cm in diameter or more. The back, head, and perineum are the only places where lesions are localized; otherwise, the body is covered with them, with severe cases coalescing. Trichophyton verrucosum has the greatest prevalence in bovines. Many have also reviewed new herbal extract that has been employed as a substitute therapy for fungus activity (fungicide or fungistatic) in several non-filamentous and filamentous fungi species typically identified in veterinary clinical practice. This review aims to understand the acquired and innate responses briefly, and discovered the recent technique in the detection of fungi, with treatment by chemical, extract herbal plant, and incidence by chief causal fungal species, and the final method that increases the risk of zoonotic infections between bovine and human.

Почвенно-микробиологические подходы к реконструкции назначения построек на древних поселениях

The aim of the article is reconstruction of purpose of ancient settlements construction using a combination of chemical and microbiological indicators. The study object is the Bagai-1 settlement of the Late Bronze Age in the northwestern part of the Crimean Peninsula. The chemical and microbiological properties of the occupation layer within the buildings of various shapes and sizes in different parts of the site have been studied. It was established that the Bagai-1 settlement is a stationary settlement of pastoralists, or was intended for living in the winter. Traces of cattle manure were found everywhere, which is confirmed by the high values of such soil indicators of livestock keeping as urease activity, the number of keratinolytic fungi and thermophilic bacteria in the cultural layer. The results of the research showed that most of the buildings in the settlement were related to livestock keeping. We cannot exclude the joint stay in the premises of both animals and humans, especially in the cold season when livestock was used as a source of heat. However, according to the complex of natural scientific data, no buildings have been identified that could be called exclusively residential, and in all cases the traces oflivestock are much more pronounced than the traces of human habitation. At the same time, vast areas without traces of stone buildings were found at the settlement, but with a high content of mineral forms of phosphates in the cultural layer and high values of magnetic susceptibility, which indicates the entry into the soil of a large amount of ceramics, ash, and pyrogenic residues. The combination of these properties can be considered as an indicator of human habitation.

Antifungal Potential of Cell-Free Supernatant Produced by Keratinolytic Fungi against Ganoderma boninense

Keratinolytic is a microorganism ability to degrade keratin substrates. Fungi are known to produce the enzyme keratinase. This research was carried out aiming to know the keratinolytic fungi potential in inhibiting Ganoderma boninense fungi. Five isolates of keratinolytic fungi coded A 31, A 18, A 12, K 18, and A 29 have antagonistic ability against G. boninense. A 12 and A 18 had the largest inhibitory diameter of 25.23 mm and 24 mm, respectively, after 7 days of incubation. The ability of A 12 and A 18 antagonisms was observed by testing the supernatant of keratinolytic fungi incubated in a feather meal broth medium. An 18 has the largest antagonism percentage of inhibition at 84.72% against G. boninense, followed by A12 (77.78%) and combination treatment of A 12 + A 18 (73.55%) after 7 days of incubation. Keratinolytic fungi can also grow on minimum salt chitin medium (MSCM) and produced a hydrolysis zone after 3 days of incubation. G. boninense hyphae abnormalities were observed by using a 100x magnification microscope. Moreover, hyphae lysis and dwarf, curved, rolled, and curly hyphae were also observed after giving treatment on A 12, A 18, and the combination treatment of both isolates. These results showed that both keratinolytic fungi isolates and the supernatant are powerful biocontrol agents against G. boninense. There is no previous research report on endophytic fungi inhibiting the growth of Ganoderma boninense. In the future, keratinolytic fungi can be applied in agriculture technology.

Effect of Keratin Hydrolysates Obtained from Feather Decomposition by Trichophyton ajelloi on Plant Germination, Growth and Biological Activity of Selected Arable Soils under Model Conditions

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.

Optimization of keratinase production by keratinolytic fungus Chrysosporium tropicum and its potentiality in bidegradation of chicken feathers

The current study has been designed to investigate the possible biodegradtion of native keratin by fungi isolated from chicken feathers collected from chicken farms in Egypt. Out of 56 fungal isolates 23 species and 2 species varieties showed different degrees of keratinolytic activity, with Chrysosporium tropicum showing the highest keratinase productivity (23.15 U/ml) as well as the highest value of specific activity for keratinase (197.90 U/mg protein) indicating a great degree of purity for the enzyme. Our present study indicates that the highest production of keratinase by C. tropicum was recorded at pH 8 and a temperature of 35 °C during a period of 20 days. In addition the optimal value of ionic strength for keratinase production was 100 mM NaCl. Monitoring the influence of constituents deprivation from basal salt medium on production of keratinase enzyme showed that K+, Fe2+, Mg2+, Ca2+ and Zn2+ were necessary for keratinase production. Sulfur deprivation has no significant influence on keratinase production. Keratinase activity of C. tropicum showed that, the optimal values of temperature and ionic strength were 35–40 °C and 80 mM NaCl, individually. The optimum pH range was (7.8–9). These promising findings demonstrate a high potentiality of C. tropicum keratinase in keratin proteolysis, suggesting that keratinase producing isolates of C. tropicum may be suitable as a biodegradation agent.

Partial purification and characterization of keratinase produced by keratinolytic fungi, Earliella scabrosa A2 and Aspergillus flavus A11

Chicken feather waste originating from the poultry industry and its processing is a potential source of protein and amino acids that can still be used as functional compounds. This study aimed to study the keratinolytic activity of local fungal isolates in vitro as a keratin-degrading agent. Keratinase secreted by keratinolytic fungal isolates were produced and characterized in 1% (w/v) Feather Meal Broth (FMB) composed of pure chicken feathers. Fungal isolates used in this study were A2 and A11 which were later identified based on ITS-rDNA genetic similarity to Earliella scabrosa and Aspergillus flavus, respectively. Crude enzymes were precipitated using an increasing ammonium sulphate salt gradient. The enzyme activity of Earliella scabrosa A2 and Aspergillus flavus A11 were 19 and 7.5 U/mL respectively. The crude enzymes showed an increase of activity during 80% of precipitation for isolate A2 with 10 U/mL and for isolate A11 with 18.6 U/mL. The specific activity after dialysis were 61.99 U/mg for isolate A2 and 75.11 U/mg for isolate A11. The optimum condition of keratinase activity for isolate A2 were at pH 7 and 30°C while isolate A11 showed its optimum activity at pH 8 and 45°C.

Keratinophyton chongqingense sp. nov. and Keratinophyton sichuanense sp. nov., from soil in China.

Keratinophyton is a genus of well-known keratinophilic fungi found in various terrestrial habitats. During a survey of keratinolytic fungi in China, a total of 12 isolates of Keratinophyton species, representing eight taxa, were obtained from the soil. Two of these isolates were described as new species based on their morphological characteristics and molecular analyses of the internal transcribed spacer region and the rRNA gene of the nuclear large subunit. Descriptions and illustrations of these two novel species, which are named Keratinophyton chongqingense sp. nov. and Keratinophyton sichuanense sp. nov., are provided herein.

A new species of Arthrographis (Eremomycetaceae, Dothideomycetes), from the soil in Guizhou, China

During a survey of keratinolytic fungi in China, a new species, Arthrographis multiformispora was isolated from soil samples. Morphologically, A. multiformispora differs from other species in the genus by the presence of globose or subglobose chlamydospores and cylindrical arthroconidia. Phylogenetically, our four strains were clustered together with high support values and separated from other clades. We provided a description, illustrations, and phylogenetic tree for the new species.

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.

Keratinophilic and Keratinolytic Fungi in Cave Ecosystems: A Culture-Based Study of Brestovská Cave and Demänovská Ľadová and Slobody Caves (Slovakia)

Despite speleomycological research going back to the 1960s, the biodiversity of many specific groups of micromycetes in underground sites still remains unknown, including keratinolytic and keratinophilic fungi. These fungi are a frequent cause of infections in humans and animals. Since subterranean ecosystems are inhabited by various animals and are a great tourist attraction, the goal of our research was to provide the first report of keratinophilic and keratinolytic fungal species isolated from three caves in Tatra Mts., Slovakia (Brestovská, Demänovská Ľadová and Demänovská Slobody). Speleomycological investigation was carried out inside and outside the explored caves by combining culture-based techniques with genetic and phenotypic identifications. A total of 67 fungal isolates were isolated from 24 samples of soil and sediment using Vanbreuseghem hair bait and identified as 18 different fungal species. The study sites located inside the studied caves displayed much more fungal species (17 species) than outside the underground (3 species), and the highest values of the Shannon diversity index of keratinophilic and keratinolytic fungi were noted for the study sites inside the Demänovská Slobody Cave. Overall, Arthroderma quadrifidum was the most common fungal species in all soil and/or sediment samples. To the best of our knowledge, our research has allowed for the first detection of fungal species such as Arthroderma eboreum, Arthrodermainsingulare, Chrysosporiumeuropae, Chrysosporiumsiglerae, Keratinophytonwagneri, and Penicillium charlesii in underground sites. We also showed that the temperature of soil and sediments was negatively correlated with the number of isolated keratinophilic and keratinolytic fungal species in the investigated caves.

Antifungal Susceptibility Testing of Five Antifungal Agents against Clinically Isolated Dermatophytes Species from a Tertiary Care Hospital in Northern India

Introduction: Dermatophytosis form approximately 15-75% of all the mycological infections. Dermatophytes are closely related keratinolytic fungi with ability to degrade keratin and invade the skin, hair and nails causing dermatophytosis. Aim: To evaluate the Minimum Inhibitory Concentration (MIC) of antifungal drug against the isolated dermatophytes by broth microdilution method. Materials and Methods: The present cross-sectional study was conducted in the Department of Microbiology, Muzaffarnagar Medical College, Muzaffarnagar, Uttar Pradesh, India. The duration of the study was August 2018-August 2020. A 10-20% KOH mount was prepared from the skin scrapings, nail clippings, and hair bits to look for fungal elements. The specimens were also inoculated on Mycosel media and Sabouraud Dextrose Agar (SDA) with chloramphenicol. The dermatophytes were identified on the basis of colony characteristics, Lacto Phenol Cotton Blue (LPCB) mount, nutritional requirement, temperature tolerance, urease production, and in-vitro hair perforation test. Antifungal susceptibility testing was done for all fungal isolates and performed by broth microdilution method. The descriptive statistics were reported as means with their Standard Deviation (SD). Data were statistically evaluated with International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) Statistics for Mac, Version 25.0., IBM Corp., Chicago IL. Results: In this study, the MIC range for all the 165 isolates for dermatophytes tested for antifungal susceptibility showed that itraconazole, terbinafine and voriconazole showed the lowest MIC range of 0.0019-0.5 μg/mL followed by griseofulvin and fluconazole at MIC range of 0.125-32 μg/mL. The MIC50 of itraconazole and terbinafine was seen lowest at 0.0313 μg/mL followed by voriconazole at 0.0625 μg/mL, griseofulvin at 0.25 μg/mL for all isolated dermatophytes. Highest MIC50 with 4 μg/ mL was found for fluconazole against T. mentagrophytes and T. violaceum. MIC90 of terbinafine, itraconazole and voriconazole was seen lowest at 0.25 μg/mL followed by griseofulvin at 1 μg/ mL for all isolated dermatophytes. Highest MIC90 of fluconazole was recorded at 16 μg/mL for all isolated dermatophytes. Conclusion: Highest MIC50 with 8 μg/mL was found for fluconazole against all isolated dermatophytes. MIC90 of terbinafine, itraconazole and voriconazole was seen lowest at 0.25 μg/mL followed by gresiofulvin at 1 μg/mL for all isolated dermatophytes. Highest MIC90 of fluconazole was recorded at 16 μg/mL for all isolated dermatophytes.

Potential of keratinolytic fungi isolated from chicken and goat farms soil, North Sumatra

Potential of keratinolytic fungi isolated from chicken and goat farms soil, North Sumatra

Clinico-Mycological Profile of Dermatophytosis in a Tertiary Care Hospital of Eastern Nepal

Background: Dermatophytes are keratinophilic and keratinolytic fungi which are responsible for dermatophytosis. There are three genera of dermatophytes; Trichophyton, Microsporum and Epidermophyton. As they have affinity to keratin rich tissue, they produce dermal inflammatory response, intense itching and cosmetically poor appearance. The varied clinical presentation of tinea results in delay in diagnosis, poor compliance in follow up of cases, and consequently spread of infection in the community has rekindled interest in rapid identification of species. Materials and Methods: A hospital based cross sectional study was carried out in the department of Microbiology, Nobel medical college from January 2019 to December 2019. Clinically suspected 200 cases of dermatophytosis attending Out Patient Department were studied. Isolation and identification was done by various tests like macroscopic, microscopic and biochemical tests. Results: Out of 200 specimens, 138 (69%) were skin scraping, 42 (21%) were nail clipping and 20 (10%) were hair stubs. Highest incidence was seen in the age group 21-40 years with 115 (57.5%) cases followed by 41-60 years 46 (23%) cases. In our study male preponderance of 158 (79%) and female of 42 (21%) were seen. Tinea corporis was found to be the commonest clinical type with 96 (48%) cases followed by tinea unguinum, 42 (21%), Tinea cruris 10 (11.36%), Tinea capitis 5 (5.68%), Tinea faciei 4 (4.54%), Tinea pedis 2 (2.27%). Among the fungal isolates Trichophyton rubrum (67.04%) was the most common etiological agent followed by Trichophyton mentagrophytes (13.63%), Epidermophyton 10 (11.36%), Trichophyton violaceum 4 (4.54%) and Epidermophyton floccosum 3 (3.4%). Conclusion: The most common clinical presentation was tinea corporis followed by tinea unguinum. T. rubrum was the most common etiological agent of dermatophytosis

Strain improvement of a new keratinolytic fungi

Strain improvement of a new keratinolytic fungi

Arthroderma tuberculatum and Arthroderma multifidum Isolated from Soils in Rook (Corvus frugilegus) Colonies as Producers of Keratinolytic Enzymes and Mineral Forms of N and S.

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.

<p><strong>Molecular phylogeny and morphology of <em>Cunninghamella guizhouensis </em>sp. nov. (Cunninghamellaceae, Mucorales), from soil in Guizhou, China</strong></p>

During a survey of keratinolytic fungi in China, three Cunninghamella strains were isolated. Phylogenetic analyses of ITS and ITS+LSU+EF-1α sequence data showed that these strains constitute a new species related to C. blakesleeana, C. bigelovii, C. multiverticillata and C. phaeospora. The new species differs from C. multiverticillata and C. phaeospora in the shape and size of its teminal and lateral vesicles and can be distinguished from C. blakesleeana and C. bigelovii by the absent of zygosporangia, and the shape and size of it sporangioles. The results of phylogenetic and morphological analyses indicate that the three strains are a new species of Cunninghamella. Descriptions and illustrations of this novel species are provided in this paper.

Utilization of Keratinolytic Lichtheimia corymbifera AS1 for Degradation of Cattle Hoove – a Slaughter House Waste to Use in Plant Growth

In this study, four keratinolytic fungi were isolated from soil. Amongst that one was producing much keratinase, it was identified as Lichtheimia corymbifera AS1. The organism was capable of producing keratinase (11.8 U/mL) and also of capable degrading 96 % of cattle hooves, a waste obtained from slaughter house in 60 days. The hydrolysate of the hooves degraded medium was used to check its role in seed germination and plant growth. The hydrolysate was found to have much positive influence over the plant growth. Thus, it is helping in degrading waste and helpful for plant growth.