Fungal decomposition of chicken-feather waste in submerged and solid-state fermentation / Decomposição fúngica de resíduos de pena de frango em fermentação submersa e de estado sólido

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.

A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

Fungal decomposition of chicken-feather waste in submerged and solid-state fermentation

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.

Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

Fungal decomposition of chicken-feather waste in submerged and solid-state fermentation / Decomposição fúngica de resíduos de pena de frango em fermentação submersa e de estado sólido

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.

Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

Expression and characterization of a keratinase encoding gene gm2886 in Streptomyces pactum ACT12 strain / 生物工程学报

By bioinformatics analysis, a putative keratinase gene gm2886 (Accession number: KY368946) was discovered in the genome of a feather-degrading strain, Streptomyces albidoflavus Fea-10. gm2886 was ligated into integrative Escherichia coli-Streptomyces shuttle vector pSET152 under the promoter PermE and added with C-terminal His-tag. The expression vector was transformed into Streptomyces pactum ACT12 by conjugal transfer and the recombinant protein GM2886-His6 was detected in fermentation broth. GM2886-His6 was purified and characterized. Its size was nearly 36 kDa. GM2886-His6 showed proteolytic activity towards a variety of substrates and could even degrade insoluble substrates, such as azure keratin and chicken feathers. The optimal pH and temperature of GM2886-His6 for proteolysis of casein was pH 10.0 and 50 ℃, respectively. The enzyme activity was inhibited by PMSF, but not EDTA, indicating that GM2886-His6 was a serine proteinase. Our results laid the foundation for the research of the molecular biological mechanism on feather-degrading and for the further utilization of Fea-10.

Keratinolytic Protease Production and Characterization from Bacillus Sp. Isolated from Poultry Wastes.

Keratinases originating from microorganisms are used in many industrial fields such as the recycle of keratinous wastes, leather, textile, the detergent industry and medical applications. In this study, 42 Bacillus strain were isolated from Cukurova University Research and Application and Chicken Management Unit. 8 of these isolates showed proteolytic activity on skim-milk and keratinolytic activity with keratin-azure on the basal feather-meal medium. Strain H62 with the highest keratinase activity was determined as the keratinase producer and identified as Bacillus licheniformis with microscopic, biochemical (VITEK-2, 90%) and molecular analysis (16S rRNA, 99%, B. licheniformis 9945A). The highest enzyme production was carried out at 40°C for 45 hours by adding 0.1 g/l mannitol (as carbon source), 0.1 g/l ammonium nitrate (as nitrogen source) and 15 g/l feathermeal into the basal feather-meal medium. Although keratinase showed the activity at 20-90°C and pH 5.0-13.0, optimum activity was obtained at 40°C and pH 9.5. 100% of stability was determined at pH 8.0, whereas the loss of activity was observed at pH 7.0-9.0. After a pre-incubation at 20-100°C enzyme was 100% stable whereas activity was decreased at the other temperatures. At room temperature, a loss of activity was determined after the 24th hour. EDTA, SDS and Urea increased the enzyme activity; however, Tween-20 was decreased. The enzyme was seen to be a single band with a molecular weight of 26 kDa. As a result, keratinase B. Licheniformis H62 is an enzyme that can be used in mesophyll and alkaline conditions, particularly in medical applications and as feed supplements.

Keratinolytic abilities of Micrococcus luteus from poultry waste

Keratinolytic microorganisms have become the subject of scientific interest due to their ability to biosynthesize specific keratinases and their prospective application in keratinic waste management. Among several bacterial classes, actinobacteria remain one of the most important sources of keratin-degrading strains, however members of the Micrococcaceae family are rarely scrutinized in regard to their applicatory keratinolytic potential. The tested Micrococcus sp. B1pz isolate from poultry feather waste was identified as M. luteus. The strain, grown in the medium with 1–2% chicken feathers and a yeast extract supplement, produced keratinases of 32 KU and lower level of proteases, 6 PU. It was capable to effectively decompose feathers or “soft” keratin of stratum corneum, in contrast to other “hard” hair-type keratins. The produced keratinolytic enzymes were mainly a combination of alkaline serine or thiol proteases, active at the optimum pH 9.4, 55 °C. Four main protease fractions of 62, 185, 139 and 229 kDa were identified in the crude culture fluid. The research on the auxiliary role of reducing factors revealed that reducing sulfur compounds could be applied in keratinolysis enhancement during enzymatic digestion of keratin, rather than in culture conditions. The presented M. luteus isolate exhibits a significant keratinolytic potential, which determines its feasible applicatory capacity towards biodegradation of poultry by-products or formulation of keratin-based feed components.

Peptidase with Keratinolytic Activity Secreted by Aspergillus terreus During Solid-State Fermentation

The aim of this study was to evaluate peptidase production by Aspergillus terreus in solid-state bioprocess and evaluate its parameters. The best conditions were 5.0 g of wheat bran as substrate, incubation temperature 30°C, inoculum 2.0x105 spores/g and 75% saline volume, with production reaching 677 U/mL (5400 U/g culture medium) after 72 h of fermentation. Biochemical characterization of the crude enzymatic extract showed the optimum pH and temperature of 6.5 and 55°C, respectively. The stability at different temperatures and pH values showed that the extract could endure different pH. The evaluation of the ions influence and inhibitors proved that the enzyme required an ion for better activity, which was corroborated with the inhibition of EDTA and PMSF, characterizing serine and/or metallo peptidase. The extract was also tested for specific activities and showed promising results for keratinolytic and collagenolytic activities (0.252 and 0.165 OD/mL, respectively).

Isolation of Microsporum gypseum in soil samples from different geographical regions of Brazil, evaluation of the extracellular proteolytic enzymes activities (keratinase and elastase) and molecular sequencing of selected strains

A survey of Microsporum gypseum was conducted in soil samples in different geographical regions of Brazil. The isolation of dermatophyte from soil samples was performed by hair baiting technique and the species were identified by morphology studies. We analyzed 692 soil samples and the recuperating rate was 19.2%. The activities of keratinase and elastase were quantitatively performed in 138 samples. The sequencing of the ITS region of rDNA was performed in representatives samples. M. gypseum isolates showed significant quantitative differences in the expression of both keratinase and elastase, but no significant correlation was observed between these enzymes. The sequencing of the representative samples revealed the presence of two teleomorphic species of M. gypseum (Arthroderma gypseum and A. incurvatum). The enzymatic activities may play an important role in the pathogenicity and a probable adaptation of this fungus to the animal parasitism. Using the phenotypical and molecular analysis, the Microsporum identification and their teleomorphic states will provide a useful and reliable identification system.

Formulation of economical microbial feed using degraded chicken feathers by a novel Streptomyces sp: mitigation of environmental pollution

A new Streptomyces sp. IF 5 was isolated from the feather dumped soil and found to have a tremendous keratinase activity. The strain enabled the degradation of the chicken feathers very effectively in 60 h. The 16S rRNA sequence of 1474 bp long was submitted to the National centre for Biotechnological information. The keratinolytic activity in the culture medium was 1181 U/ml. The release and analyses of sulphydryl groups in the culture medium evident the degradation activity by the Streptomyces sp. IF 5. The idea of the present study was to use the degraded chicken feathers as the substrate for the growth and cultivation of microorganisms. We have designed a very economical culture medium that includes the usage of some basal salts alone and degraded chicken feathers (10 g/l). The results of the specific growth rate of the tested microbes confirm the usage of the new designed medium for microbial culturing.

Increased expression of keratinase and other peptidases by Candida parapsilosis mutants

Keratinases are enzymes of great importance involved in pathogenic processes of some fungi. They also have a widespread ecological role since they are responsible for the degradation and recycling of keratin. On the one hand, studying them furthers our knowledge of pathogenicity mechanisms, which has important implications for human health, and on the other hand, understanding their ecological role in keratin recycling has biotechnological potential. Here, a wild-type keratinolytic Candida parapsilosis strain isolated from a poultry farm was treated with ethyl methanesulfonate in order to generate mutants with increased keratinase activity. Mutants were then cultured on media with keratin extracted from chicken feathers as the sole source of nitrogen and carbon. Approximately 500 mutants were screened and compared with the described keratinolytic wild type. Three strains, H36, I7 and J5, showed enhanced keratinase activity. The wild-type strain produced 80 U/mL of keratinolytic activity, strain H36 produced 110 U/mL, strain I7, 130 U/mL, and strain J5, 140 U/mL. A 70 percent increase in enzyme activity was recorded for strain J5. Enzymatic activity was evaluated by zymograms with proteic substrates. A peptidase migrating at 100 kDa was detected with keratin, bovine serum albumin and casein. In addition, a peptidase with a molecular mass of 50 kDa was observed with casein in the wild-type strain and in mutants H36 and J5. Gelatinase activity was detected at 60 kDa. A single band of 35 kDa was found in wild-type C. parapsilosis and in mutants with hemoglobin substrate.

Feather degradation by strains of Bacillus isolated from decomposing feathers

Feather waste is generated in large amounts as a by-product of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. Eight strains of Bacillus, isolated from decomposing feathers were tested for the hydrolysis of feather wastes in the laboratory. Among these strains, Bacillus cereus KB043 was the best feather degrading organism when grown on basal medium containing 1 percent hen feather as sole source of carbon and nitrogen. It caused 78.16 ± 0.4 percent degradation with a significant release of soluble protein (1206.15 ± 14.7 µg mL-1) and cysteine (20.63 ± 0.4 µg mL-1) in the cultivation fluid. The strain also showed the highest level of keratinase activity (39.10 ± 0.4 U mL-1). These data indicates that the Bacillus cereus KB043 could be useful in management of poultry wastes.

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus, Aspergillus flavus Strain K-03

A keratinolytic enzyme secreted by Aspergillus flavus K-03 cultured in feather meal basal medium (FMBM) containing 2% (w/v) chicken feather was purified and characterized. Keratinolytic enzyme secretion was the maximal at day 16 of the incubation period at pH 8 and 28degrees C. No relationship was detected between enzyme yield and increase of fungal biomass. The fraction obtained at 80% ammonium sulfate saturation showed 2.39-fold purification and was further purified by gel filtration in Sephadex G-100 followed by ion exchange chromatography on DEAE-Sephadex A-50, yielding an active protein peak showing 11.53-fold purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymograms indicated that the purified keratinase is a monomeric enzyme with 31 kDa molecular weight. The extracellular keratinase of A. flavus was active in a board range of pH (7~10) and temperature (30degrees C~70degrees C) profiles with the optimal for keratinase activity at pH 8 and 45degrees C. The keratinase activity was totally inhibited by protease inhibitors such as phenylmethylsulfonyl fluoride (PMSF), iodoacetic acid, and ethylenediaminetetraacetate (EDTA) while no reduction of activity by the addition of dithiothreitol (DTT) was observed. N-terminal amino acid sequences were up to 80% homologous with the fungal subtilisins produced by Fusarium culmorum. Therefore, on the basis of these characteristics, the keratinase of A. flavus K-03 is determined to be subtilisins-like.

Immobilization of Keratinase from Aspergillus flavus K-03 for Degradation of Feather Keratin

Extracellular keratinase isolated from Aspergillus flavus K-03 was immobilized on calcium alginate. The properties and reaction activities of free and immobilized keratinase with calcium alginate were characterized. The immobilized keratinase showed proteolytic activity against soluble azo-casein and azo-keratin, and insoluble feather keratin. Heat stability and pH tolerance of keratinase were greatly enhanced by immobilization. It also displayed a higher level of heat stability and an increased tolerance toward alkaline pHs compared with free keratinase. During the durability test at 40degrees C, 48% of the original enzyme activity of the immobilized keratinase was remained after 7 days of incubation. The immobilized keratinase exhibited better stability, thus increasing its potential for use in industrial application.

Effect of Locally Applied Keratinase on Thickness of Rat Skin

The aim of this study is to elucidate the effect of keratinase on epidermis of rat skin. Twenty-five male Sprague-Dolly rats were used. The hair on the back were removed and 2x2cm area was marked. The rats were divided five groups; 1) Control group(Co), 2) Cleansing gel group(Cl), 3) Cleansing gel+keratinase group, 4) Exfoliant gel group(Ex), and 5) Exfoliant gel+ keratinase group(Ex+K). The solutions were applied to the back area twice a day for five days. On fifth day, the skins were harvested, fixed and prepared for histologic sections. The thickness of keratin layer, living epidermis, dermis, and cell layer number of living epidermis were measured. In the group containing keratinase(Cl+K, Ex+K), the thickness of keratin layer and living layer were thinner than other groups. However, there were no significant differences of the cell layer number of living epidermis and thickness of the dermis among the five groups. We think the keratinase may have the effect thinning the keratin layer as well as the thickness of living epidermis, without effecting the living cell and dermal component. The keratinase containing soap may be of benefit to remove the excess keratin layers in human.

Keratinolytic Activity of Five Aspergillus Species Isolated from Poultry Farming Soil in Korea

Various soil samples were collected from twenty-four areas of ten different poultry farms in Korea and screened for prevalence of keratinolytic fungi. Fourteen species of feather-associated fungi belonging to ten genera Acremonium, Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Monascus, Mucor, Penicillum, and Verticillium isolated from poultry soils were grown on keratin medium. Especially, Aspergillus spp. populations associated with the soil sample is 1x10(5) cfu/g. A. flavus, A. fumigatus, A. niger, A. nidulans, and A. terreus could utilize keratin of chicken feather and degrade it, producing sulphydryl-containing compounds detected as keratinase, cysteine and total proteins. Keratinolytic activities of five Aspergillus species also changed the pH of the medium more alkaline than those that were less keratinolytic.

Isolation and Characterization of Keratinases from Different Kinds of Dermatophytes / 대한의진균학회지

BACKGROUND: Several groups of workers have isolated and purified the keratinolytic proteinases from some species of dermatophytoses. But it is not efficient to compare the interspecies of dermatophytosis because the separation and purification are done by different conditions. OBJECTIVE: To compare the characteristics and difference of the keratinases which are isolated and purified from Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis in the same conditions. METHODS: Proteinases elaborated from T. rubrum, T. mentagrophytes and M. canis were purified by precipitation using ammonium sulfate and by SMART. SDS-polyacrylamide gel electrophoresis was carried out, and the effect of various inhibitors was investigated. A variety of substrates for KPase were tested. RESULTS: 1. The keratinases were isolated and purified 17.3, 22.0, 17.6-fold from T. rubrum, T. mentagrophytes and M. canis. 2. Each molecular weight of the keratinolytic proteinases isolated and purified from T. rubrum, T. mentagrophytes and M. canis was 53 kDa, 65 kDa, 77 kDa. 3. Phenylmethylsulfonylfluoride inhibited the keratinase activity in T. rubrum, T. mentagrophytes and M. canis 4. The keratinases from T. rubrum, T. mentagrophytes and M. canis digested much more human stratum corneum and human nail than human scalp hair, but keratinase from M. canis digested much more human scalp hair than human stratum corneum and human nail. CONCLUSION: The results show keratinases from T. rubrum, T. mentagrophytes and M. canis were different each other, but they may be a kind of serine proteinase. The keratinases from T. rubrum, T. mentagrophytes and M. canis may play an important role in tinea pedis and tinea unguis by affecting the human stratum corneum and human nail, and the keratinase from M. canis may play an important role in tinea capitis by affecting the human hair.

Study on the Biochemical Mechanism of Degrading Keratins by Streptomyces fradiae / 微生物学通报

The biochemical mechanism of degrading keratins by S.fradiae var S-221 was primarily studied.The compounds (Na_ 2 SO_ 4 , Na_ 2 SO_ 3 and sulfdryl acohol), which respecitively enhance specific activity of keratinase, activate keratinase intensively and mainly act on the disulfide bonds reductase in the keratinase, Na_ 2 SO_ 3 activates intensively both disulfide bonds reductase and polypeptide hydrolytase at 0.01 mol/L, whereas Na_ 2 S_ 2 O_ 3 , which acts on the disulfide bonds reductase, inhibits keratinase.On the condition that substrate, keratins exists, S.fradiae var S-221 is induced to produce exo-keratinase, which is a multiproteinase, containing disulfide bonds reductase, which is a key enzyme degrading keratins, then, with polypeptidic, hydrolytase, graduately hydrolyzates denatured keratins into polypeptides, oligopeptides and free amino acids, so that keratins have been decomposed completely.Sulfur in the keratins was transferred into sulfhydryl compounds, H_ 2 S and sulfates in the course of keratinolysine.