Feather Hydrolysate Research Articles

Characterization of feather-degrading bacterial populations from birds’ nests – Potential strains for biomass production for animal feed

Feather degrading bacteria from birds’ nests were characterized to find safe bacterial strains that could be utilized to convert feathers into soluble form and bacterial biomass for feed purposes. Of all tested 571 isolates 122 were keratinolytic. Partial sequencing of the 16S rRNA gene revealed that the keratinolytic isolates represented Proteobacteria (genera Pseudomonas and Stenotrophomonas) and Firmicutes (genera Bacillus, Exiguobacterium, Paenibacillus, Rummeliibacillus, and Sporosarcina). Bacillus cereus group and gram-negative bacterial isolates were not further characterized due to safety concerns related to potential pathogenicity or potential exposure of animals or workers to endotoxins (lipopolysaccharide part of the gram-negative cell wall). Keratinolytic strains showed clear differences in their ability to solubilize feathers with feather weight losses up to 30%. Amino acid composition of feather hydrolysates shifted from feather composition towards more bacterial-like composition. Especially the levels of lysine could be increased in the feather hydrolysate with bacterial fermentation. Feathers can be effectively hydrolyzed with non-pathogenic bacteria without any additional nutrients. The resulting feather hydrolysate is easier to digest than feather material and it has an improved amino acid composition regarding some limiting amino acids. The amino acid content of the final product can be tailored by varying the fermentation time and thus the ratio of bacterial cells to the feather hydrolysate.

Chicken feather hydrolysate as an inexpensive complex nitrogen source for PHA production by Cupriavidus necator on waste frying oils.

Millions of tons of feathers, important waste product of poultry-processing industry, are disposed off annually without any further benefits. Thus, there is an inevitable need for new technologies that enable ecologically and economically sensible processing of this waste. Herein, we report that alkali-hydrolysed feathers can be used as a complex nitrogen source considerably improving polyhydroxyalkanoates production on waste frying oil employing Cupriavidus necator.

Production of feather protein hydrolyzed by B. subtilis AMR and its application in a blend with cornmeal by extrusion

The poultry industry produces approximately 6 million tons of feathers as a by-product annually. The major constituent of feather is protein (80–90% of which is keratin). In order to use feather protein in animal feedstuffs, it must be hydrolyzed by chemical, physical or enzymatic processes. The aim of this study was to improve the production of chicken feather hydrolysates using keratinolytic Bacillus subtilis AMR and evaluate the effectiveness of a blend of this hydrolysate with cornmeal produced by extrusion. The addition of sucrose (0.5 g/L) to the feather medium increased the keratinolytic activity of B. subtilis AMR by 1.3 fold. The highest enzymatic activity and production of soluble protein were achieved at pH 8.0. The fermented feather medium presented large amounts of protein with low molecular weight that provided greater nutrient bioavailability. The physicochemical properties of the extrudates showed that the addition of hydrolyzed feather improved the ash and total N content. All essential amino acids were detected in the corn–feather hydrolysate extrudate. This work represents the first study that describes the use of microbial feather hydrolysate in a blend with cornmeal to make an extruded product. These results demonstrated the potential use of this hydrolysate as a supplement in animal feed.

Biofertilizing potential of feather hydrolysate produced by indigenous keratinolytic Amycolatopsis sp. MBRL 40 for rice cultivation under field conditions

Abstract Extracellular keratinase-producing strain Amycolatopsis sp. MBRL 40 exhibited antifungal activity against four important rice fungal pathogens and plant growth promoting traits such as indole 3-acetic acid (IAA) production and phosphate (P) solubilization. The strain could produce IAA in the degraded feather medium (3 µg/ml) and increased production was observed when the medium was supplemented with 0.2% tryptophan (7 µg/ml). The strain could solubilize significant amounts of tricalcium P (117 µg/ml). Rice seeds treated with MBRL 40 showed higher germination percentages and vigor indices, and enhanced seedling growth over control under gnotobiotic conditions. Under field conditions, rice plants grown in presence of dried hydrolysate pellet (P), hydrolysate filtrate (S) and feather hydrolysate with bioinoculant (B+F) exhibited significantly enhanced growth and higher number of tillers per plant over plants grown in the absence of urea (C-). However, P treated plants did not have enhanced growth in all the parameters in comparison to plants treated with S and B+F. Rice grown in presence of B+F was found to exhibit better growth over plants grown in presence of P and S. Rice grown in presence of urea (C+) and B+F showed similar levels of growth promotion.

Characterization of Protein-Rich Hydrolysates Produced Through Microbial Conversion of Waste Feathers

The poultry industry generates huge amounts of feather waste, which needs appropriate management to avoid environmental harm. Keratinolytic potential of Chryseobacterium sp. kr6 and Bacillus sp. kr16 was exploited for feathers bioconversion to produce protein hydrolysates. Increasing feather concentrations (10, 20, or 50 g/L) had minor effects on feather degradation by strain kr6, although the performance of strain kr16 was diminished as the feather concentration increased in culture media. At 50 g/L, strain kr6 degraded 75 % of the feathers after 96 h, and strain kr16 degraded 21 %. The feather-degrading efficiency of Chryseobacterium sp. kr6 was corroborated by a direct relationship between feather concentration and the content of released soluble protein and free amino acids, in comparison to Bacillus sp. kr16. In vitro analyses were performed to postulate feather hydrolysates as animal feed supplements. Digestibility of the hydrolysates was lower when compared to controls (soy protein and casein), but higher than feather meal (FM), which is a usual ingredient of animal feed. Methionine was the first limiting essential amino acid in the hydrolysates and FM; however, the protein digestibility-corrected amino acid scoring was higher for the hydrolysates. Predicted protein efficiency ratio and biological value of kr6 hydrolysates were higher than kr16 hydrolysates and FM. Hydrolysates produced through feathers bioprocessing could be considered as interesting protein-rich resources for animal feed, thus representing an alternative for the valorization of waste feathers.

Production of Thermostable Organic Solvent Tolerant Keratinolytic Protease from Thermoactinomyces sp. RM4: IAA Production and Plant Growth Promotion

There are several reports about the optimization of protease production, but only few have optimized the production of organic solvent tolerant keratinolytic proteases that show remarkable exploitation in the development of the non-polluting processes in biotechnological industries. The present study was carried with aim to optimize the production of a thermostable organic solvent tolerant keratinolytic protease Thermoactinomyces sp. RM4 utilizing chicken feathers. Thermoactinomyces sp. RM4 isolated from the soil sample collected from a rice mill wasteyard site near Kashipur, Uttrakhand was identified on the basis of 16S rDNA analysis. The production of organic solvent tolerant keratinolytic protease enzyme by Thermoactinomyces sp. RM4 was optimized by varying physical culture conditions such as pH (10.0), temperature (60°C), inoculum percentage (2%), feather concentration (2%) and agitation rate (2 g) for feather degradation. The result showed that Thermoactinomyces sp. RM4 potentially produces extra-cellular thermostable organic solvent tolerant keratinolytic protease in the culture medium. Further, the feather hydrolysate from keratinase production media showed plant growth promoting activity by producing indole-3-acetic acid itself. The present findings suggest that keratinolytic protease from Thermoactinomyces sp. RM4 offers enormous industrial applications due to its organic solvent tolerant property in peptide synthesis, practical role in feather degradation and potential function in plant growth promoting activity, which might be a superior candidate to keep ecosystem healthy and functional.

Biological Pretreatment of Chicken Feather and Biogas Production from Total Broth.

Chicken feathers are available in large quantities around the world causing environmental challenges. The feathers are composed of keratin that is a recalcitrant protein and is hard to degrade. In this work, chicken feathers were aerobically pretreated for 2-8days at total solid concentrations of 5, 10, and 20% by Bacillus sp. C4, a bacterium that produces both α- and β-keratinases. Then, the liquid fraction (feather hydrolysate) as well as the total broth (liquid and solid fraction of pretreated feathers) was used as substrates for biogas production using anaerobic sludge or bacteria granules as inoculum. The biological pretreatment of feather waste was productive; about 75% of feather was converted to soluble crude protein after 8days of degradation at initial feather concentration of 5%. Bacteria granules performed better during anaerobic digestion of untreated feathers, resulting in approximately two times more methane yield (i.e., 199mlCH4/gVS compared to 105mlCH4/gVS when sludge was used). Pretreatment improved methane yield by 292 and 105% when sludge and granules were used on the hydrolysate. Bacteria granules worked effectively on the total broth, yielded 445mlCH4/gVS methane, which is 124% more than that obtained with the same type of inoculum from untreated feather.

Feather hydrolysate from Streptomyces sampsonii GS 1322: A potential low cost soil amendment

Process parameters for obtaining hydrolysate from hen feathers, i.e., initial pH (5.0-9.0) and incubation period (1-6 day), were set and studied, using Streptomyces sampsonii GS 1322 in submerged and solid state conditions. Under submerged conditions, complete hydrolysis of feathers was observed on fifth day [initial pH 8.0, 28±2°C, shaking (150rpm)] with release of soluble protein (2985μgml(-1)) and amino acids (2407μgml(-1)). Cell free hydrolysate showed hydrolysis of casein (18mm), gelatin (26mm), collagen (31mm), hemoglobin (23mm) and Tween 80 (35mm) while 445U keratinase activity. Total soluble protein reached 5mgml(-1) in solid state conditions. During Pot experimentation using barren agriculture soil the effect of feather hydrolysate on wheat crop were recorded. Significant increase (p<0.01) in wheat seed germination was observed in treated soils as compared to untreated. Treatment significantly increased plant height from 30 to 60 days and 30-90 days (p<0.001). Treated soil showed an increase in total microbial count, proteolytic activity, phosphate solubilizing bacteria and ammonifying bacteria, whereas pathogenic fungi load was reduced. S.sampsonii GS 1322 can be used for bio-processing of poultry wastes yielding feather hydrolysate rich in proteins and amino acids for development of low-cost organic amendment to accelerate wheat crop growth in barren agricultural land.

Identification and characterization of a novel antioxidant peptide from feather keratin hydrolysate.

To improve the potential value of feather, which is a valuable protein resource, we have separated and identified antioxidant peptide(s) from feather hydrolysate. Feather hydrolysate was prepared by fermentation with Bacillus subtilis S1-4. Antioxidative peptides were separated by sequential acid precipitation, cation exchange, and reversed-phase fast performance liquid chromatography. Finally, a peptide with antioxidative activity was identified as Ser-Asn-Leu-Cys-Arg-Pro-Cys-Gly by MALDI time-of-flight (TOF)/TOF analysis, and determined to represent a portion of feather keratin near its N-terminal. A synthesized peptide with the same sequence was used to characterize its antioxidative properties, including scavenging free radicals, reducing power, and Fe(2+) chelation. In terms of the peptide's amino acid composition, the antioxidative activity might be mainly attributed to Cys and other amino acid residues. Feather keratin is a good source for the quantitative preparation of antioxidative peptides.

A Statistical-Mathematical Model to Optimize Chicken Feather Waste Bioconversion via Bacillus licheniformis SHG10: A Low Cost Effective and Ecologically Safe Approach

Feather waste is highly accumulated recalcitrant and non-efficiently utilized protein wastage of poultry processing. Present study highlights a cheap eco-friendly approach towards its valorization into efficiently utilized form (feather hydrolysate (SHG10 FH)) through Bacillus licheniformis SHG10 within 48 hrs. A statistical-mathematical model (Plackett-Burman Design (PBD), Central Composite Design (CCD), Canonical Analysis (CA) and Steepest Rising Ridge (SRR)) was anticipated to optimize feather bioconversion. PBD addressed three key determinants out of eight tested factors imposing significant influence (P≤0.006) on soluble proteins productivity. Optimal levels of the key determinants, localized by CCD, CA and SRR, were 1.55% (w/v) feather, 0.45% (w/v) yeast extract and 10.8% (v/v) inoculum size in basal medium II to attain 402 mg/Liter soluble proteins and 104,000 μmole leucine/Liter NH2-free amino groups. SHG10 FH was rich in phenylalanine, tyrosine, methionine and histidine. MALDI-TOF-MS showed proteins spectrum of SHG10 FH ranged from 140 Da m/z. to 733 Da m/z. The composition of SHG10 FH along with the ecologically safe low cost effective approach involved in its preparation might underpin its great potential in several industries (e.g., amino acids, soluble proteins, cosmetics and animal feed livestock).

Production of feather hydrolysates with antioxidant, angiotensin-I converting enzyme- and dipeptidyl peptidase-IV-inhibitory activities

The antioxidant and antihypertensive activities of feather hydrolysates obtained with the bacterium Chryseobacterium sp. kr6 were investigated. Keratin hydrolysates were produced with different concentrations of thermally denatured feathers (10-75 g l(-1)) and initial pH values (6.0-9.0). Soluble proteins accumulated in high amounts in media with 50 and 75 g l(-1) of feathers, reaching values of 18.5 and 22 mg ml(-1), respectively, after 48 hours of cultivation. In media with 50 g l(-1) of feathers, initial pH had minimal effect after 48 hours. Maximal protease production was observed after 24 hours of cultivation, and feather concentration and initial pH values showed no significant effect on enzyme yields at this time. Feather hydrolysates displayed in vitro antioxidant properties, and optimal antioxidant activities were observed in cultures with 50 g l(-1) feathers, at initial pH 8.0, after 48 hours growth at 30°C. Also, feather hydrolysates were demonstrated to inhibit the angiotesin I-converting enzyme by 65% and dipeptidyl peptidase-IV by 44%. The bioconversion of an abundant agroindustrial waste such as chicken feathers can be utilized as a strategy to obtain hydrolysates with antioxidant and antihypertensive activities. Feather hydrolysates might be employed as supplements in animal feed, and also as a potential source of bioactive molecules for feed, food and drug development.

가금폐기물 처리를 위한 세균유래 케라틴 분해효소의 특성

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were 40℃-45℃ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at 10℃-40℃. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.

Surface Display of a Bifunctional Glutathione Synthetase on Saccharomyces cerevisiae for Converting Chicken Feather Hydrolysate into Glutathione

The low economic profits of feather recycling lead that the large amount of feathers is currently discarded in China. To convert feather hydrolysates into GSH with high values, surface display of the bifunctional glutathione synthetase encoded by gcsgs from Streptococcus thermophilus on Saccharomyces cerevisiae and the potential in glutathione (GSH) production from feather hydrolysates were studied. The surface-displayed GCSGS could be used to convert feather hydrolysates into GSH. Results showed that 10 g/l of feather was converted into 321.8 mg/l GSH by the Trichoderma atroviride F6 and surface-displayed GCSGS in the study. Compared with production of intracellular GSH by S. cerevisiae from amino acids or feather hydrolysate, the concentration of GSH in the study was higher, and purification of GSH was more feasible. Due to the glycolytic pathway, the S. cerevisiae was used to generate ATP and cheap feather hydrolysate as precursors, the process for GSH production based on surface-displayed GCSGS is cheap and feasible. The process showed the potential to convert feather hydrolysates into GSH on an industrial scale.

A Bacillus Strain Able to Hydrolyze Alpha- and Beta-Keratin

The ability to hydrolyze keratin, a rigid and strongly cross-linked protein in the waste of poultry feather and sheep wool, has made keratinase production by microorganisms highly important to the biotechnological industry. A proteindegrading bacterium (C4) was isolated from compost. Based on morphology and biochemical tests, along with 16S rRNA sequencing, the isolated C4 was tentatively identified as Bacillus sp. C4 (2008). The proteolytic activity of the Bacillus sp. C4 strain was broadly specific; it degraded keratinous and non-keratinous proteins to different degrees. Pea pods as substrate generated the highest protease production, followed by soybean meal and sheep wool. Notwithstanding, using wool keratin as a sole source of carbon and nitrogen yielded the highest level of soluble proteins. Furthermore, the C4 bacterium grew well, and produced a significant level of keratinase when using wool and feather as substrates. Supplementing the medium with yeast extract and peptone shortened the time required for feather degradation, but delayed the onset of the wool keratin hydrolysis with two days. The predominant amino acids released in feather hydrolysate were tyrosine, phenylalanine, and histidine. In contrast, the wool lysate was rich in aspartic acid, methionine, tyrosine, phenylalanine, histidine, and lysine. Results established that utilizing the C4 strain for keratin degradation in waste management holds considerable potential.

Keratinolytic Protease Production by Bacillus amyloliquefaciens 6B Using Feather Meal as Substrate and Application of Feather Hydrolysate as Organic Nitrogen Input for Agricultural Soil

Feather waste, a by-product of poultry processing sectors, contains a large quantity of hard to degrade keratin that pose great threat to the environment and mankind. Thus, development of a biotechnological approach to use such waste as substrate for enzyme production with its subsequent conversion to nitrogenous soil input is the main aim of the present investigation. Thirteen proteolytic bacteria were isolated from feather dump soil, amongst which Bacillus amyloliquefaciens 6B (JQ904625) was found to completely degrade native feather in shortest time period (24 h) and thus selected for further investigation. Upon optimization of process parameters, the maximum enzyme yield (610.13 U/ml) was obtained after 12 h of fermentation at 37 °C using a medium containing 0.5 % (w/v) feather meal and 0.5 % (w/v) xylose at pH 8.0. The keratinolytic protease 6B exhibited optimum activity at 50 °C and pH 8.0. The enzyme exhibited significant stability in presence of solvents, surfactants and bleach-oxidant, suggesting its potential use in industries. Furthermore, the strain could produce antifungal metabolites which could inhibit the growth of fungal phytopathogens in the same conditions observed for keratinolytic enzyme production. Consequently, feather hydrolysates resulting from the microbial conversion of feather keratin might be utilized as a bioactive agricultural nitrogen input. Thus, degradation of bird feather using a soil bacterial isolate with simultaneous production of solvent and detergent tolerant keratinolytic protease, offers a cost-effective technology for industrial protease production, while adding value to poultry feather waste.

Production of Extremely Alkaliphilic, Halotolerent, Detergent, and Thermostable Mannanase by the Free and Immobilized Cells of Bacillus halodurans PPKS-2. Purification and Characterization

The alkaliphilic Bacillus halodurans strain PPKS-2 was shown to produce extracellular extreme alkaliphilic, halotolerent, detergent, and thermostable mannanase activity. The cultural conditions for the maximum enzyme production were optimized with respect to pH, temperature, NaCl, and inexpensive agro wastes as substrates. Mannanase production was enhanced more than 4-fold in the presence of 1% defatted copra meal and 0.5% peptone or feather hydrolysate at pH11 and 40°C. Mannanase was purified to 10.3-fold with 34.6% yield by ion exchange and gel filtration chromatography methods. Its molecular mass was estimated to be 22kDa by SDS-PAGE. The mannanase had maximal activity at pH11 and 70°C. This enzyme was active over a broad range of NaCl (0-16%) and thermostable retaining 100% of the original activity at 70°C for 3h. Immobilization of whole cells proved to be effective for continuous production of mannanase. Since the strain PPKS-2 grows on cheaper agro wastes such as defatted copra meal, corn husk, jowar bagasse, and wheat bran, these can be exploited for mannanase production on an industrial scale.

닭털 단백질로부터 가수분해물 제조 및 철분 결합 펩타이드의 분리

닭털 단백질로부터 가수분해물 제조 및 철분 결합 펩타이드의 분리

Exploitation of chicken feather waste as a plant growth promoting agent using keratinase producing novel isolate Paenibacillus woosongensis TKB2

Abstract A potent feather degrading bacterium was isolated from soil and it was identified as Paenibacillus woosongensis TKB2 on the basis of morphological, biochemical and as well as 16S rDNA sequence characteristics. The physico-chemical cultural condition for keratinase (principal feather degrading enzyme) production by the isolate was optimized following OVAT (one variable at a time) protocol. It was found that the bacterium produced highest amount of keratinase at 0.75% (w/v) raw feather as sole substrate, 2% (v/v) inoculums, pH 8.5, incubation temperature 30 °C, 5% (w/v) sodium chloride and other mineral components like 0.05% K 2 HPO 4 , 0.025% MgSO 4 and 0.02% CaCO 3 (w/v). The filter sterilized fermented hydrolysate has the ability to promote significantly the germination of seeds (germination rate 87.5%) and growth of Bengal gram ( Cicer arietinum ) seedlings. It induces the nodule formation (3 fold) and increased soil fertility by altering N, P, K and the C/N ratio by 1.2 fold. This also enhanced the quantity of free living nitrogen fixers (2 fold) and phosphate solubilizers (5.8 fold) in comparison to the control soil. Thus the enzymatic feather hydrolysate can be exploited as a useful biological fertilizer in future.

Utilization of chicken feather hydrolysate as a novel fermentation substrate for production of exopolysaccharide and mycelial biomass from edible mushroom Morchella esculenta

This study was performed to investigate the usability of chicken feather hydrolysate (Chicken feather peptone (CFP)) as substrate for mycelial biomass and extracellular polysaccharides (EPS) production from edible mushroom Morchella esculenta. The ability of CFP to support biomass and EPS production in edible mushroom M. esculenta was compared to those of two commercial peptones (Tryptone peptone (TP) and Fish peptone (FP)). The maximum biomass (16.3 g/l) and EPS (4.8 g/l) concentrations were achieved with TP. Second, high biomass (15.9 g/l) and EPS (4.6 g/l) concentrations were obtained with CFP. Also, biomass and EPS concentrations in CFP medium were statistically near to those in the TP medium. CFP and TP resulted in not only uniform pellets with smaller size (5 mm) but also faster mycelial growth compared to FP. This study showed for the first time that CFP could be effectively used as a novel EPS production substrate.

Assessment of Feather Hydrolysate From Thermophilic Actinomycetes for Soil Amendment and Biological Control Application

Protein-rich hydrolysate from feather waste was obtained using a mixed culture of selected thermophilic actinomycete strains, and was tested for possible application as soil amendment and biological control agent. For this purpose, a 4 months laboratory experiment was carried out using two types of urban soils (Sofia, Bulgaria): native park soil and anthropogenic soil. The effect of the obtained hydrolysate on some soil parameters (pH, some enzyme activities and microbial activity), seed germination and ryegrass growth, and activity against some plant pathogenic fungi was studied. The results demonstrated that soil enrichment with the organic solution in low concentrations exerted a positive effect on soil urease and microbial activity, seed germination and ryegrass growth, and this trend was better expressed in the anthropogenic soils. Feather hydrolysate showed good activity against plant pathogenic fungi Fusarium solani, Fusarium oxysporum, Mucor sp. and Aspergillus niger. Produced antifungal compounds were isolated and partially characterized as amphiphilic peptides. To the best of our knowledge, antifungal peptides produced by Thermoactinomyces sp. have not been reported. Therefore, the feather hydrolysate obtained by means of the mixed culture of Thermoactinomyces strains has potential to be used as alternative organic amendment for restoration of contaminated soils and for accelerating ryegrass growth. It could successfully used also for as biocontrol agent applicable to crop plant soil.