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Applying the mutation of Bacillus subtilis and the optimization of feather fermentation medium to improve Keratinase activity  [PDF]
Xin Zhang
Advances in Biological Chemistry (ABC) , 2012, DOI: 10.4236/abc.2012.21008
Abstract: Energetic Bacillus subtilis was preliminarily isolated from feather meal selection medium experiment, which could be used to produce Keratinase. Through using the ultraviolet ray produced by ultraviolet light and the compound mutation of sodium nitrite solution, a mutated strain was produced which can yield Kerati-nase with a high activity. The activity of Keratinase was 75.9% higher than that before the compound mutation. This was achieved by optimizing the fermentation medium of mutated strain. The optimum fermentation medium had the parameters as feather meal 5.5%, maize silage 0.8%, K+ 0.018 mol/L, Mg2+ 0.065 mol/L, Ca2+ 0.072 mol/L, Fe2+ 0.010 mol/L, and Na+ 0.088 mol/L. Based on the optimized fermentation medium, the highest yielding rate for producing enzyme was 1.117 U/mL, 25.22% higher than that before the optimization. The amino acid in the fermentation medium fluid reached 22.66 mg/mL. This paper presents a simple, and low cost way to produce high quality bio-fermentation feather meal.
Keratinase Production by Three Bacillus spp. Using Feather Meal and Whole Feather as Substrate in a Submerged Fermentation  [PDF]
Ana Maria Mazotto,Rosalie Reed Rodrigues Coelho,Sabrina Martins Lage Cedrola,Marcos Fábio de Lima,Sonia Couri,Edilma Paraguai de Souza,Alane Beatriz Vermelho
Enzyme Research , 2011, DOI: 10.4061/2011/523780
Abstract: Three Bacillus species (B. subtilis LFB-FIOCRUZ 1270, B. subtilis LFB-FIOCRUZ 1273, and B. licheniformis LFB-FIOCRUZ 1274), isolated from the poultry industry, were evaluated for keratinase production using feathers or feather meal as the sole carbon and nitrogen sources in a submerged fermentation. The three Bacillus spp. produced extracellular keratinases and peptidases after 7 days. Feather meal was the best substrate for keratinase and peptidase production in B. subtilis 1273, with 412?U/mL and 463?U/ml. The three strains were able to degrade feather meal (62–75%) and feather (40–95%) producing 3.9–4.4?mg/ml of soluble protein in feather meal medium and 1.9–3.3?mg/ml when feather medium was used. The three strains produced serine peptidases with keratinase and gelatinase activity. B. subtilis 1273 was the strain which exhibited the highest enzymatic activity. 1. Introduction Feather waste is a byproduct of the domestic poultry industry and is 90% keratin [1, 2]. However, the use of feather waste as a dietary protein supplement for animal feedstuffs is only carried out on a limited basis, due to its poor digestibility [3]. Keratin is an insoluble protein and is resistant to degradation by common peptidases, such as trypsin, pepsin, and papain [4, 5]. This resistance is due to the constituent amino acid composition and configuration that provide structural rigidity. The mechanical stability of keratin and its resistance to biochemical degradation depend on the tightly packed protein chains in α-helix (α-keratin) and β-sheet (β-keratin) structures. In addition, these structures are cross-linking by disulfide bridges in cystines residues [3, 4, 6]. A current value-added use for feathers is the conversion to feather meal using physical and chemical treatments. However these methods can destroy certain heat-sensitive amino acids, such as methionine, lysine, and tryptophan, generating other nonnutritive amino acids, for instance, lanthionine and lysinoalanine [7]. An alternative and attractive method for improving the digestibility of feathers or feather meal is biodegradation by keratinolytic microorganisms [8, 9]. A number of keratinolytic microorganisms can produce keratinases (E.C., peptidases which are capable of degrading keratin. Various authors have reported that, among the keratinolytic microorganisms, some species of Bacillus [10–12], actinomycetes [9, 13, 14], and fungi [15–17] are able to produce these keratinases and peptidases. Biodegradation of poultry waste by keratinases is an environment friendly biotechnological process, which
Efficient Degradation of Feather by Keratinase Producing Bacillus sp.  [PDF]
P. Jeevana Lakshmi,Ch. M. Kumari Chitturi,V. V. Lakshmi
International Journal of Microbiology , 2013, DOI: 10.1155/2013/608321
Abstract: Keratinase producing microorganisms are being increasingly utilized for degradation and recycling of poultry feather waste. Two native strains BF11 (Bacillus subtilis) and BF21 (Bacillus cereus) degrading keratin completely were characterized. The native strains produced more than 10?KU/mL of enzyme. Strain improvement resulted in isolation of MBF11 and MBF21 from BF11 and BF21 isolates, respectively. Optimization of nutritional and physical parameters of these MBF isolates at laboratory scale increased the overall keratinase activity by 50-fold resulting in a yield of 518–520?KU/mL. Fermentation media designed with starch as carbon source and soya bean meal as nitrogen source supported high levels of enzyme production. The optimum conditions for enzyme production were determined to be pH 8.5 and temperatures of 45–55°C for MBF11 and 37°C for MBF21, respectively. Culture filtrate showed a significant increase in the amounts of cysteine, cystine, methionine, and total free amino acids during the fermentation period. The ratio of organic sulphur concentration was also considerably higher than that of the inorganic sulphate in the culture filtrate suggesting the hydrolysis of disulphide by the isolates. 1. Introduction Feather is generated in bulk quantities as a by-product in the poultry industry globally. It is a very rich source of protein with β-keratin constituting 91% of feather protein. The presence of keratin makes feather recalcitrant to most common proteases like trypsin, pepsin, papain, and so forth, thus slowing down its degradation process in nature [1]. Typically, each bird has up to 125?gm of feather and with more than 400 million chickens being processed every week worldwide, the daily accumulation of feather waste reaches five million tons [2]. The bulk of feather waste is poorly recycled in nature and has limited utility due to the chemically unreactive nature of keratin. Conventionally, this waste has been converted into feed supplement, resulting in feed of poor quality which is nonviable economically [3]. Thus, recycling of this by-product is neither profitable nor environmentally friendly. The disposal of this waste is a global environmental issue leading to pollution of both air and underground water resources [4]. In recent years, feather treated with microbial keratinase is attracting wide attention with several applications. Keratinase-treated feather is increasingly considered as a viable source of dietary protein in food and feed supplements, as the enzyme-treated end product retained high nutritive value. Keratinases are
Microbial Degradation of Native Keratin in Batch Fermentation  [PDF]
El-Fadaly,K.A. Zaied
Pakistan Journal of Biological Sciences , 1999,
Abstract: Feather fermentation was carried out using different bacterial strains of the genera Bacillus and Micrococcus and their transconjugants as well. During the time course of fermentation, keratin biodegradation was monitored by measuring both activities of keraitnase and proteinase as well as the content of total free amino acids. Results of the parental strains proved that B. licheniformis CF7 was the most producing strain in keratinase and free amino acids after 15 days of fermentation being 206.7 KU/ml and 73.3 g/ml cultural filtrate, respectively. B. subtilis IBF6 was in the first in proteinase production giving 148.3 TU/ml cultural filtrate. Experimental data of transconjugants illustrated that all of them gave higher yield than their mid parents after the 3rd day of fermentation. The percent of yield reached to 274, 335, and 269 per cent for keratinase, proteinase and free amino acids as well. The same trend of these results was found after calculating the relative increase of these parameters. Values of estimated the correlation coefficient (r) suggesting that the increase in free amino acids is a good indicator for the action of both keratinase and proteinase on keratin.
Production of an Extra Cellular Feather Degrading Enzyme by Bacillus licheniformis Isolated from Poultry Farm Soil in Namakkal District (Tamilnadu)  [PDF]
P. Tamilmani,A. Umamaheswari,A. Vinayagam,B. Prakash
International Journal of Poultry Science , 2008,
Abstract: Chicken feather is recognized as a solid waste generated from poultry farms and is abundant in Namakkal district, Tamilnadu, India. Feather is commonly treated by high temperature and pressure; it is used as animal food stuffs. However, feather degradation by biological methods has been increasingly interested because of environmental awareness. In this study, unidentified bacterial strains isolated from soil samples. They had show ability of feather degradation by making a clear zone around their colonies in FMA medium. The zoned isolates were identified by morphological and biochemical tests. The Bacillus licheniformis were also examined for keratinase production by shake flask fermentation in a basal medium containing 1% feather. The fermentation mediums were optimized. Fermentation process was carried out at 37°C for 7 days at 150 rpm. Crude keratinase were extracted and purified by salt precipitation, dialysis and column chromatography and measured the activity of keratinase.
Preliminary Study on Keratinase from Two Indonesian Isolates  [cached]
S Rahayu,D Syah,MT Suhartono
Journal of Animal Production , 2010,
Abstract: Keratinases (E.C. constitute a group of enzymes capable of disrupting the highly stable keratin structure consisting of disulphide, hydrogen, and hydrophobic bonds in the form of α-helices and β-sheets B. licheniformis MB-2 and Bacillus sp. MTS are two feather-degrading bacteria isolated from Tompaso crater at North Sulawesi and sulfuric land around Tangkuban Perahu in West Java. They were both capable of breaking down whole chicken feathers. In addition both isolates were capable of degrading other proteinous substrates rich in beta structure such as coccon, silk, human hair and fish scales. Result of fermentation experiment implied that addition of nitrogen sources (0.02% yeast extract and 0.02% tryptone) to the basal medium increased keratinase production. Our experiments showed that keratinase production of Bacillus sp. MTS was higher and faster than that from B. licheniformis MB-2. Maximum extracellular keratinase activity of the enzyme derived from B. licheniformis was obtained during stationary phase at 72 h, while Bacillus sp. MTS was reached at 48 h. Disulfide reductase activity also detected in the extracellular fluid of Bacillus sp. MTS. The maximum condition for extracellular keratinase activity was 55oC and the enzyme showed two maximum pHs : pH 8.0 and pH 10. The zymogram analysis indicated sixth protein bands of 17, 25, 32, 53, 96 and 122 kD which were able to hydrolyze gelatin substrate in-situ. (Animal Production 12(1): 60-68 (2010)Key Words : Bacillus, feather, keratinase, disulfide reductase
Biological treatment of chicken feather waste for improved biogas production
Forgács Gergely,Alinezhad Saeid,Mirabdollah Amir,Feuk-Lagerstedt Elisabeth,Horváth Ilona Sárvári,
Gergely Forgács
,Saeid Alinezh,Amir Mirabdollah,Elisabeth Feuk-Lagerstedt,Ilona Sárvári Horváth

环境科学学报(英文版) , 2011,
Abstract: A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers (4%, W/V) were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm3/kg dry feathers (i.e., 0.4 Nm3/kg volatile solids of feathers), corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre-hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm3/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm3 CH4/kg dry feathers as maximum yield.
Feather wastes digestion by new isolated strains Bacillus sp. in Morocco
Ilham Zerdani, Mohamed Faid, Abderahim Malki
African Journal of Biotechnology , 2004,
Abstract: Eight strains of Bacillus were isolated from non treated soil, characterized and used for the digestion of feather wastes in the laboratory. Non-protein nitrogen (NPN) and total protein (TP) were determined during the incubation time and the microbial counts of the different strains during feather hydrolysis were also monitored. Results of the screening test showed that the solid pieces of feather were completely digested by all the strains. The most efficient isolated strain selected was compared with Bacillus subtilis ATCC 6633. Results showed that the total protein decreased from 13.6% to 1.92 % with the isolated strain, and from 12.25 % to 2.99% with the standard strain. The NPN reached a concentration of 43.2mg/100g and 20.5 mg/100g with the isolated and standard strains, respectively. Key Words: Feather, keratin, Bacillus, fermentation, process African Journal of Biotechnology Vol.3(1) 2004: 67-70
Isolation and identification of a keratinase-producing strain of Aeromonas bacterium

QI Qing-Wen,ZHANG Guang-Xiang,FENG Ting,LAI Si-Si,HUANG Cai-Qin,LI Wei,

微生物学通报 , 2011,
Abstract: Not all of aeromonas species were pathogenic, and some bacteria of this genus were found to have important utilization value in recent years. Effective utilization of discarded feather by microorganism-decomposing method could meet the requirements of environment and Low-carbon economy. However, screening and evaluation of more microbe resources should be favourable for solving the thorny problem on poor efficiency and low speed of biodegradation. In the study, keratinase-producing strains were isolated from decaying feather using feather selective medium, casein plate and enzyme activity assay of keratinase in fermentation liquid of feather. The morphological observation of cell and colony, sugar fermentation experiments, Gram stain, PCR and sequence analysis of 16S rDNA were performed for taxonomic classification. The strain named FD41 with the highest relative keratinase activity (RKA, viz. the ratio of keratinase activity unit to A600 value of feather fermentation liquid) of 3.864 U/OD600 was isolated. The BLAST using the 16S rDNA sequence (GenBank accession No. HM587254) of FD41 showed that the first 100 sequences, all from Aeromonas, shared high homology to HM587254 with 99% identity. According to the results of taxonomic classification, the strain FD41 was identified as an Aeromonas bacterium. This is the first report on keratinase-producing strain of Aeromonas bacterium. The measurement values of keratinase activity of fermentation liquid were found to be influenced signally by cell proliferation. The different strains and inoculation amounts resulted in very distinct proliferation curves of bacterium in liquid medium. These results suggested that the RKA was appropriate index and equalizing inoculation amount was prerequisite for screening and identifying of strains with high enzyme activity at same condition of liquid culture.
Journal of Applied Sciences in Environmental Sanitation , 2012,
Abstract: A culture medium was optimized for the production of extra cellular keratinase by a newly isolated strain of Bacillus sp. from Goa, India in shake-flask culture. The keratinase production was increased by approximately 40-fold when the strain was grown in an inexpensive optimized medium (120 U.mL-1) compared to the un-optimized medium (3.80 U.mL-1). The maximum amount of keratinase activity was produced at 37°C when the bacterium was cultured for 72 h in medium containing feather meal as the sole source of carbon and 0.025% yeast extract with initial pH of 7.0 under submerged fermentation. The isolated keratinilytic Bacillus sp also exhibited remarkable feather degrading ability. These results suggest potential biotechnological applications of this bacterium that involve hydrolysis of keratin, including the improvement of the nutritional properties of feathers (and other keratins) used as supplementary feedstuffs.

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