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  • بهناز کروژدهی، علیرضا عباسی *، معصومه بحرینی، احمد علی پوربابایی، محمدرضا شریف مقدم
    مقادیر روزافزون ضایعات کراتینی مقاوم به تجزیه که از محصولات جانبی فرآوری صنایع کشاورزی می باشند، توجه را به سمت آنزیم های کراتینولیتیک سوق داده اند. کراتینازها قادرند پروتئین نامحلول کراتین را از طریق فرایندهای غیرآلاینده به محصولات باارزش تبدیل کنند. در این مطالعه با هدف دستیابی به جدایه های توانمند تجزیه کننده کراتین، تعداد 120 سویه از منابع مختلف محیطی در محیط کشت اختصاصی پودر پر، جداسازی و خالص شد. پس از غربالگری، شش سویه که کارایی بالاتری داشتند برای ادامه مسیر انتخاب شدند. بر اساس نتایج آزمون های بیوشیمیایی و توالی یابی 16SrRNA سویه های برتر متعلق به جنس باسیلوس بودند که در پایگاه اطلاعاتی NCBI به ثبت رسیدند. این سویه ها پس از 48 ساعت 76 تا 8/80 درصد از سوبسترای پر را مورد حمله قرار دادند. فعالیت پروتئازی و کراتینازی آن ها در دماهای 20، 30، 37 و °C50 مورد ارزیابی قرار گرفت. تمامی سویه ها بر روی محیط SMA در دماهای مورد آزمایش فعال بودند به جز BK111 که در دمای°C 50 فعالیت پروتئازی نشان نداد. سویه BK206 در کلیه دماها فعالیت کراتینازی مناسبی داشت در حالی که BK107 و BK324 در دمای °C50 فعالیتی نداشتند. سویه BK111 در دماهای 20 و °C50 نتوانست بر روی محیط FMA رشد کند، سویه های BK401 و BK402 نیز در دمای °C20 هاله ای بر روی این محیط تشکیل ندادند. فعالیت کراتینازی سویه های برتر با استفاده از دو سوبسترای کراتین آزور (α کراتین) و آزوکراتین (β کراتین) مورد ارزیابی قرار گرفت که تمامی سویه ها فعالیت قابل توجهی بر روی هر دو سوبسترا نشان دادند. بالاترین فعالیت بر روی سوبسترای کراتین آزور به سویه BK324 با u/ml 345 تعلق داشت و سویه BK111 نیز u/ml 5992 فعالیت را بر روی سوبسترای آزوکراتین در روز دوم پس از تلقیح نشان داد. به طورکلی یافته های این مطالعه، پتانسیل بالای 6 سویه طبیعی برای تبدیل زیستی ضایعات کراتین به صورت سازگار با محیط زیست و بازیافت آن ها به محصولات ارزشمند را آشکار می کند.
    کلید واژگان: آزو کراتین, باسیلوس تبدیل زیستی, کراتیناز, کراتین آزور
    B. Korouzhdehi, Ar Abbasi *, M. Bahreini, Aa Pourbabaee, Mr Sharif Moghadam
    Increasing amount of resistant keratin wastes which originated from byproducts of agricultural industry is as an environmental issue. Keratinolytic enzymes secreted by bacteria are able to digest insoluble keratin and convert it to valuable products through non polluting processes. The aim of this study was isolation of keratinolytic bacteria strains which resulted to isolation and purification of 120 feather keratinolytic isolates from different environment resources in feather powder medium. Among the 120 isolates tested in vitro, six isolates were found with highest yields and belonged to Bacillus according to obtained results based on biochemical tests and 16S rRNA sequencing analysis. The results were registered in NCBI database. These isolates digested the substrates between ranges of 76-80.8% after 48 hours. Proteolytic and keratinolytic activity were tested at 20, 30, 37 and 50°C temperatures respectively. All of strains were active on SMA media at mentioned temperatures except BK111 which didn’t show proteolytic activity at 50°C. BK206 strain also showed keratinolytic activity in all temperatures while BK107 and BK324 didn’t digest at 50°C. BK111 didn’t show proteolytic activity at 20 and 50°C on FMA medium while BK401, BK402 couldn’t form clear halo on mentioned medium at 20°C. Keratinolytic activities of selected strains were assayed by both keratin azure and azokeratin substrates. The obtained results showed that all strains had significant activities on two substrates. The highest activity in keratine azure and azo keratin substrates were observed in BK324 with 325 u/ml and 5992 u/ml activities respectively after two days incubation. Generally great keratinolytic potential of six novel strains showed their promising application for keratin biodegradation.
  • Wojciech Laba, Anna Rodziewicz
    Background
    Extensive quantities of keratinic by-products are disposed annually by animal-processing industry, causing a mounting ecological problem due to extreme resilience of these materials to enzymatic breakdown. There is a growing trend to apply cheap and environment-friendly methods to recycle keratinic wastes. Soil bacteria of profound keratinolytic potential, especially spore-forming rods from the genus Bacillus, play a significant role in keratinase-mediated biodegradation of keratins, therefore could be effective in hastening their biodegradation. Keratin hydrolysis in microbial cultures is one of the most promising techniques not only to utilize this protein but also to obtain valuable by products..
    Objectives
    The study was undertaken to investigate the biodegradation process of various keratinic materials by two Bacillus strains..
    Materials And Methods
    Two keratinolytic strains, Bacillus cereus and B. polymyxa, were subject to cultures in the presence of several keratinic appendages, like chicken feathers, barbs and rachea of ostrich feathers, pig bristle, lamb wool, human hair and stratum corneum of epidermis, as main nutrient sources. Bacterial ability to decompose these waste materials was evaluated, at the background of keratinase and protease biosynthesis, in brief four-day cultures. Keratinolytic activity was measured on soluble keratin preparation and proteases were assayed on casein. Additionally, amounts of liberated proteins, amino acids and thiols were evaluated. Residual keratin weight was tested afterwards..
    Results
    Both tested strains proved to be more adapted for fast biodegradation of feather β-keratins than hair-type α-keratins. B. cereus revealed its significant proteolytic potential, especially on whole chicken feathers (230 PU) and stratum corneum (180 PU), but also on separated barbs and rachea, which appeared to be moderate protease inducers. Keratinolytic activity of B. cereus was comparable on most substrates and maximum level obtained was 11 KU. B. polymyxa was found to be a better producer of keratinases, up to 32 KU on chicken feathers and 14 KU on both fractions of ostrich feathers. Its proteolytic activity was mostly revealed on stratum corneum and human hair. Stratum corneum was extensively degraded by both bacterial strains up to 99% - 87%, chicken feathers 47-56%, ostrich barbs and rachea, 28% and 35% at maximum, respectively. Keratin fibres of structures like human hair, lamb wool and pig bristle remained highly resilient to this short microbiological treatment, however certain extent of keratinase induction was also observed..
    Conclusions
    The obtained results prove that keratinolytic potential of both tested bacterial strains could be applied mainly in biodegradation of feathers, however, B. cereus and B. polymyxa differed in terms of keratinase and protease production on each of the substrates. Biodegradation of highly resilient structures like hair or pig bristle requires further analysis of process conditions..
    Keywords: Bacillus polymyxa, B. cereus, Keratinases, Proteases, Keratin Biodegradation
  • خلیل الرحمن خلیلی پوررودی، فاطمه داداشیان*، عاطفه سلوک، سوگل کیان ارثی

    گسترش و پیشرفت روش های استخراج، خالص سازی و اصلاح پروتئین های کراتین بدست آمده از مو، پشم، پر، سم، شاخ و ناخن باعث شده است تا استفاده از این پروتئین در تولید بیومتریال ها و همین طور منسوجات پزشکی به شدت افزایش یابد. کراتین به دلیل زیست سازگاری و زیست تخریب پذیری مطلوب، وجود توالی های آمینواسیدی RGD و LDV- که در چسبندگی سلولی بسیار حایز اهمیت هستند- و همچنین توانایی آرایش یافتگی به شکل های مختلف فیبر، فیلم، ژل و اسفنج در کاربردهای پزشکی چون انتقال دارو، مهندسی بافت و درمان زخم به طور گسترده مورد استفاده قرار گرفته است. در این مقاله، مروری بر ساختار کراتین، نحوه استخراج آن، بیومتریال های کراتینی تولید شده و کاربردهای کراتین به عنوان منسوج پزشکی صورت گرفته است. همچنین در انتها، به شکل خلاصه به برتری های کراتین نسبت به پروتئین هایی از جمله ژلاتین، سلولز، آلیجینات، کلاژن و کیتوسان اشاره شده است. با توجه به ویژگیهای جالب توجه کراتین، میتوان انتظار داشت این پروتئین جایگاهی در تولید منسوجات پزشکی بدست آورد.

    کلید واژگان: کراتین, زیست ماده, الیاف پروتئینی, زخم پوش, منسوجات پزشکی
    Khalilorrahman Khalilipourroodi, Fatemeh Dadashian *, Atefeh Solouk, Sogol Kianersi

    Improvement and development of extraction, purification and modification of keratin proteins which are extracted from hair, wool, feathers, hooves, horns and nails has led to increase in this protein utilization for biomaterial constructions. Having had properties such as biocompatibility, biodegradation,existence of RGD and LDV amino acid sequences ,which are critical elements in cell attachment, and self- assembling to different forms including fibers, films, gels and sponges, keratin has used for many variable medical applications: drug delivery, tissue engineering and wound healing. This article takes keratin’s structure, its extraction methods, keratin- based biomaterials that have been made till today and some of keratin’s medical applications into consideration. Finally at the end of the article we have pointed some of keratin’s merits in comparison with some proteins namely gelatin, cellulose, aliginate, collagen and chitosan, breifly. Based on keratin’s properties, it can be projected that this protein will find its state among biomaterials.

    Keywords: Keratin, Biomaterial, protein fibers, wound dressing, medical textiles
  • Ania Ahani Azari *, Neda Kouroshzadeh, Hamidreza Pordeli
    A large amount of feather is produced each year in the poultry industries which is buried in landfill or burned in the power plant generator. Feathers are purified keratinous proteins that can be degraded by bacteria and fungi. The aim of this study was to isolate and identify keratinase producing bacteria from the feather waste dumping sites around Gorgan district, Golestan province, Iran. Soil samples were collected from six poultry farms and slaughterhouses. The keratinolytic bacteria were isolated and identified based on feather and keratin degradation in feather meal broth and keratin agar. Isolates that showed more keratinolytic activity were identified using morphological, biochemical, and molecular tests. Then, the effect of pH and temperature was examined on the growth of the isolates. Based on the results, keratinase-producing isolates belonged to the Bacillus genus, among the isolates, the most keratinolytic activity was related to Bacillus megaterium strain SR7 and it showed the best growth at pH 6.8 and 37°C in feather meal broth and keratin agar. The results of the present study were consistent with the results of many similar studies and found that Bacillus strains are important producers of keratinase enzyme and therefore promising organisms for the management of chicken feather wastes through efficient biodegradation.
    Keywords: isolation, feather, Keratin-degrading bacteria, Molecular identification, landfill
  • نیلوفر اصلاحی*، شادی مکتوبی
    در این کار تحقیقاتی رنگ پذیری پارچه نایلونی با رنگزای طبیعی سماق بررسی شده و اثر کراتین روی خواص رنگرزی آن مطالعه شده است. برای این منظور ابتدا کراتین به روش هیدرولیز سولفیتی از الیاف ضایعاتی پر مرغ استخراج شده و در ادامه اصلاح سطح نایلون با استفاده از کراتین بازیافتی به روش رمق کشی انجام گردید. ارزیابی ساختار شیمیایی با استفاده از طیف سنجی مادون قرم انجام شد و نتایج حاصل اصلاح سطح الیاف نایلون با کراتین را اثبات نمود. نتایج رنگرزی با سماق نیز نشان دهنده رمق کشی بالای پارچه اصلاح شده با کراتین نسبت به پارچه خام و دندانه دار می باشد. لذا می توان از کراتین به منظور بهبود جذب رنگ با مواد رنگزای طبیعی استفاده نمود. ارزیابی پارامترهای ثباتی نیز نشان دهنده ثبات شست و شویی و سایشی بالای پارچه رنگرزی شده با سماق می باشد. در نهایت ارزیابی خاصیت ضد میکروب پارچه های نایلون رنگرزی شده در برابر دو باکتری S. aureus (گرم مثبت ATCC25923) و E.coli (گرم منفی ATCC25922) انجام شد و نتایج نشان دهنده خاصیت ضدباکتری سماق می باشد.
    کلید واژگان: نایلون, کراتین بازیافتی, رنگزای طبیعی, سماق, رنگرزی
    Niloofar Eslahi *, Shadi Maktoobi
    In this research, the dyeing of nylon fabrics with sumac as a natural dye was investigated and the effect of keratin treatment on the dyeing properties was studied. For this purpose, first keratin was extracted from chicken feathers by the reduction hydrolysis method, and then surface modification of nylon fabric with the extracted keratin was performed via the exhaustion method. The chemical structure of the treated fabrics was evaluated by FTIR and the results proved the successful keratin treatment on the surface of the fabrics. The obtained results showed high dye absorption of keratin-treated fabric in comparison with mordant-treated and untreated fabrics. Thus, keratin could be used for enhancing the absorption of natural dyes. Colorfastness properties of the dyed fabrics with sumac were evaluated and high washing and rubbing fastness were attained. Finally, the antibacterial properties of the dyed fabrics against both gram-positive and gram-negative bacteria were performed and the results showed the antibacterial activity of sumac.
    Keywords: Nylon, recycled keratin, Natural Dye, Sumac, dyeing
  • مریم حاج ملکی، رامین خواجوی*، طیبه تولیت
    سابقه و هدف
    از آنجایی که سمیت سلولی و خواص ضدمیکروبی دو عامل ضروری در زخم بندهای پیشرفته محسوب میگردند، تحقیقات بسیاری جهت معرفی و کاربرد موادی با این خصوصیات انجام گرفته است. هدف این تحقیق، استخراج ماده ارزشمند کراتین از ضایعات موی انسان و تبدیل آن به داربستی نانولیفی جهت دستیابی به خصوصیات ضدمیکروبی ارتقا یافته و حداقل سمیت سلولی بود.
    روش بررسی
    کراتین به وسیله روشی قلیایی استخراج و از طریق الکتروفورز (SDS-PAGE) مشخصه سازی گردید. کراتین استخراج شده با غلظت های مختلف به همراه پلیمر پلی وینیل الکل و نانوذرات نقره از طریق روش الکتروریسی به داربستهای نانولیفی تبدیل شد. میکروسکوپ الکترونی پویشی، آزمون ضدمیکروبی(AATCC100-2004) و آزمون MTT بصورت مستقیم (ISO10993-5) بترتیب جهت بررسی مورفولوژی،سنجش فعالیت ضدمیکروبی و سازگاری سلولی داربست ها به کار رفتند.
    یافته ها
    کراتین استخراج شده با وزن مولکولی kDa 65-56 در ماده استخراج شده مشاهده گردید. داربست هایی سه بعدی از نانو الیاف با قطری در محدوده nm180-90 حاوی غلظتهای متفاوت از کراتین با موفقیت تولید شدند. با افزایش غلظت کراتین در داربست های نانولیفی اثر ممانعتی در برابر باکتری های گرم منفی(Escherichia_coli (ATCC8793 و گرم مثبت (Staphylococcus_aureus (ATCC6538 به مقدار قابل توجهی ارتقا یاقت. با حضور کراتین عدم سمیت سلولی داربست ها در مقایسه با نمونه شاهد به مقدار 21% افزایش نشان داد.
    نتیجه گیری
    ماده ارزشمند کراتین با روش قلیایی از منبعی اقتصادی استخراج گردید. درکنار خصوصیات ذاتی و اثبات شده کراتین نظیر سازگاری با پوست انسان، داربستهای حاوی این ماده خصوصیات ضدمیکروبی و عدم سمیت سلولی ارتقا یافته‫ای از خود نشان دادند که باعث می‫شود بعنوان کاندیدی بالقوه جهت کاربری در زخم بندهای پیشرفته مطرح گردد.
    کلید واژگان: داربست های نانولیفی, ضایعات موی انسانی, کراتین, الکتروریسی, زخم بند پیشرفته
    Maryam Hajmaleki, Ramin Khajavi *, Tayebeh Toliyat
    Background
    As cytotoxicity and antibacterial properties are considered as two essential factors for advanced wound care dressings, many attempts have been made to introduce and apply potent substances to provide these requirements. In this study, keratin as a valuable substance extracted of human hair waste and fabricated to a nanofibrous scaffold for achieving to least cytotoxic and improved antibacterial properties.
    Materials And Methods
    Keratin was extracted of human hair waste by an alkaline method and it was characterized by SDS-PAGE electrophoresis method. Extracted keratin was accompanied in different concentrations with PVA and silver nanoparticles and then fabricated into nano-fibrous scaffold through electrospinning method. Fabricated scaffolds were investigated and compared by scanning electron microscopy, measuring antibacterial activity (AATCC Test method 100-2004) and MTT assay (directly and by ISO 10993-5 standard method).
    Results
    Keratin with molecular masses of 56—65 kDa observed in the extracted substance. 3D scaffolds of nanofibers with diameter between 90-180 nm fabricated with different concentrations of kertain successfully. With the increase in keratin concentrations in fabricated scaffolds, their antibacterial activity against both Escherichia coli (ATCC8793) and Staphylococcus aureus (ATCC6538) bacteria were improved significantly. Furthermore, incorporating of keratin caused improved cell viability about 21% more in compare with the control sample.
    Conclusion
    Valuable keratin was obtained from an economical source with an alkaline method. Beside the intrinsic and proven properties of keratin such as compatibility with human skin, introducing this substance to nanofibrous scaffolds caused improved antibacterial properties and cell viability making it as a potent candidate for advanced wound caring purposes.
    Keywords: Nanofibrous Scaffold, Human hair waste, Keratin, Electrospinning, Advanced Wound dressing
  • Gholamreza Goudarzi, Fatemeh Dadashian, Alireza Vatanara, Zargham Sepehrizadeh

    It is highly economical to extract keratin from the waste chicken feathers due to their high keratin content, plentiful availability, and sustainable resources. Various methods of keratin extraction have been reported in the last few decades. In addition, sodium sulfide (Na2S) treatment has received more attention due to its simplicity and ability to produce on an industrial scale. Although several studies have been conducted on improving keratin extraction yield through Na2S treatment, there need to be more systematic studies to evaluate and optimize the effect of different extraction parameters and their interactions to maximize extraction efficiency. In this research, the response surface method (RSM) established on the central composite practical design (CCPD) was employed satisfactorily to understand the influence of experimental parameters and their interactions to determine the optimal conditions for keratin extraction. Na2S concentration, extraction time, and extraction temperature were chosen as the most critical parameters for investigation. Experimentally, the extraction yield of 94±0.5% was obtained under the RSM-optimized conditions (i.e. 80 °C, 6.3 hr., and 32.0 g l-1 Na2S concentration), which is in close agreement with the model-predicted value (95%). The optimized keratin extraction yield in this study is relatively high. Physicochemical properties of the extracted powder were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results revealed that the extracted material contains both β-keratins and α-keratins, which have great potential for advanced healthcare and medical applications.

    Keywords: Chicken feather, keratin, Sodium Sulfide treatment, response surface methodology
  • Bechr Hamrita *, Sabrine Hamed, Rania Elayeb, Ferdaws Hafi, Mondher Njehi, Hatem Majdoum, Manel Mhadheb, Sami Achour
    The extraction of keratin from natural feathers has been studied for its use in various cosmetics and drug delivery applications. There are various reducing agents to dissolve the hard keratin such as sodium dodecyl sulfate and 2-mercaptoethanol, in the present work, a novel extraction methodhas been developed using sodium sulphite, sodium bisulphite, and sodium dodecyl sulfate in the presence of urea, 2-mercaptoethanol, Ethylenediaminetetraacetic acid (EDTA), and thiourea. To increase extraction yield, the weight of feathers, time of incubation, pH, and temperature were investigated using a Central Composite Design and Mixture plan for Optimization. With the present process, we evaluated the apport of keratin treatment and extraction techniques utilizing sodium sulphite, sodium bisulphite, and sodium dodecyl sulfate in the presence of urea, 2-mercaptoethanol, Ethylenediaminetetraacetic acid (EDTA), and thiourea. The percentage yield and keratin concentration were measured using UV-Vis absorbance, Bradford, and Biuret assays. Then, the protein profile and their functional groups were characterized using Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and Fourier Transform Infrared Spectroscopy (FTIR). The purpose was to compare the different procedures in terms of keratin protein quality and quantity, as well as their cost-effectiveness, and to determine the optimum conditions for the keratin extraction process. The results proved that the yield of white chicken feathers keratin (81.2 %) increased using sodium sulphite (1M), sodium bisulphite (0.1 M), and Sodium Dodecyl Sulfate (0.1 M).  The highest protein production was measured at 80°C in 10 h with 5 g of feathers at pH 10. This process of keratin extraction can be used from the laboratory to industrial production with high recoverability and stable properties.
    Keywords: Optimization, Mixture plan, Waste poultry feathers, Keratin extraction, Business Model
  • Md. Nur E Alam *_Nasifa Akter_Shimul Chakma_Kanish Fatema_Abul Kashem Azad_Murshid Jaman Chowdhury_Md. Abu Sayid Mia

    Keratin is a highly specialized fibrous protein, which is found in feathers, hair, wool and nails. Bioremediation of these waste materials is an issue requiring serious attention regarding environmental concern. In the present research work keratin protein is extracted from poultry chicken feather which is now treated as valueless product of poultry processing plants. Although it contains high keratin protein content, this byproduct is dumped continuously into the environment without further treatment. Millions of tons of chicken feathers are produced every year from poultry industry of Bangladesh which disposed off into environment without any industrial treatment.  This protein rich valuable byproduct can be recycled and utilized effectively which has great economic and ecological importance. In this study, alkali-enzymatic hydrolysis was done for the extraction of keratin protein from feather.  Desired result was found in reflux condensation system which yielded 76.2% protein hydrolysate compared to conventional hot plate hydrolysis which was yielded 52.63%. Detection and concentration of protein were determined by Biuret and Kjeldahl methods respectively.

    Keywords: Chicken feather, Hydrolysis, Keratin protein, Reflux condensation
  • Fereshteh Abbasi *, Abdolhadi Farrokhnia, Zahra Abbasi
    In this paper, human hair, as a waste material, was utilized in order to prepare keratin nanoparticles. The characterization of keratin nanoparticles was performed applying Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-Ray diffraction (XRD). The average diameter of keratin nanoparticles was found to be 63.7 nm, using particle size analyzer. Subsequently, the keratin nanoparticles were employed for Cr (VI) ions adsorption. The batch experiment was carried out to find the optimum conditions; i.e. contact time, pH, adsorbent dose and initial concentration of Cr (VI) ions. The adsorption capacity was extremely pH-dependent, and the maximum adsorption of Cr (VI) happened in the acidic pH range. The results demonstrated that the maximum adsorption capacity, obtained in acidic pH, was 161.29 mg/g. The equilibrium data were well fitted by Freundlich isotherm. The kinetic studies were performed with the Lagergren’s first-order, Pseudo-second order, Elovich, and Intra-particle diffusion models. In this sense, in order to describe kinetic data, we came to this understanding that Pseudo-second order model was the best choice. The thermodynamic parameters of the adsorption process indicated that the Cr (VI) adsorption on keratin nanoparticles is endothermic and spontaneous.
    Keywords: Cr (VI) ions, Keratin nanoparticles, Isotherm, Adsorption Kinetics, Hair Waste, optimum
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