Feather Hydrolysate Research Articles

Effect of Chicken Feather Hydrolysate on Growth of Spinach through Soil Amendment Method: Unraveling A Potential Liquid Biofertilizer

The study aims to investigate the effectiveness of chicken feather hydrolysate for promoting the growth of Spinacia oleracea L., a commonly consumed leafy green vegetable. An earlier isolated and identified keratinolytic bacterial species Bacillus tropicus was utilized for the preparation of chicken feather hydrolysate through submerged fermentation. Minimal media which was supplemented with chicken feather was used for the preparation of hydrolysate. The bacterial strain degraded chicken feather within 4 days of incubation after which the feather hydrolysate was collected and tested to check plant growth promoting activity through the seed germination trials and greenhouse study. Upon characterization of feather hydrolysate, it was found that the hydrolysate was a cocktail of Nitrogen, Phosphorus and Potassium (NPK) as well as other micro elements needed for plant growth. Four different concentrations of feather hydrolysate were employed for both the seed germination and greenhouse study which ranged from 25% (v/v), 30% (v/v), 35% (v/v) and 40% (v/v) including a control group (CN) which was not supplemented with feather hydrolysate. The hydrolysate supplementation brought about plant growth in all the four test concentrations with 35% (v/v) giving the highest result of 14 cm and 27.6 mg/g for tested parameters like plumule length and total chlorophyll content, respectively. The same concentration supported maximum seed germination and highest radicle extension for the germination studies as well. This study investigates the efficacy of chicken feather hydrolysate in promoting spinach growth, elucidating its potential as a fertilizer.

Effect of Chicken Feather Hydrolysate on Growth and Yield of French Bean

Effect of Chicken Feather Hydrolysate on Growth and Yield of French Bean

Bioenergy production from chicken feather waste by anaerobic digestion and bioelectrochemical systems

BackgroundPoultry feather waste has a potential for bioenergy production because of its high protein content. This research explored the use of chicken feather hydrolysate for methane and hydrogen production via anaerobic digestion and bioelectrochemical systems, respectively. Solid state fermentation of chicken waste was conducted using a recombinant strain of Bacillus subtilis DB100 (p5.2).ResultsIn the anaerobic digestion, feather hydrolysate produced maximally 0.67 Nm3 CH4/kg feathers and 0.85 mmol H2/day.L concomitant to COD removal of 86% and 93%, respectively. The bioelectrochemical systems used were microbial fuel and electrolysis cells. In the first using a microbial fuel cell, feather hydrolysate produced electricity with a maximum cell potential of 375 mV and a current of 0.52 mA. In the microbial electrolysis cell, the hydrolysate enhanced the hydrogen production rate to 7.5 mmol/day.L, with a current density of 11.5 A/m2 and a power density of 9.26 W/m2.ConclusionsThe data indicated that the sustainable utilization of keratin hydrolysate to produce electricity and biohydrogen via bioelectrical chemical systems is feasible. Keratin hydrolysate can produce electricity and biofuels through an integrated aerobic-anaerobic fermentation system.Graphical

Effects of Feather Hydrolysates Generated by Probiotic Bacillus licheniformis WHU on Gut Microbiota of Broiler and Common carp.

Due to the ever-increasing demand for meat, it has become necessary to identify cheap and sustainable sources of protein for animal feed. Feathers are the major byproduct of poultry industry, which are rich in hard-to-degrade keratin protein. Previously we found that intact feathers can be digested into free amino acids, short peptides, and nano-/micro-keratin particles by the strain Bacillus licheniformis WHU in water, and the resulting feather hydrolysates exhibit prebiotic effects on mice. To explore the potential utilization of feather hydrolysate in the feed industry, we investigated its effects on the gut microbiota of broilers and fish. Our results suggest that feather hydrolysates significantly decrease and increase the diversity of gut microbial communities in broilers and fish, respectively. The composition of the gut microbiota was markedly altered in both of the animals. The abundance of bacteria with potentially pathogenic phenotypes in the gut microbial community of the fish significantly decreased. Staphylococcus spp., Pseudomonas spp., Neisseria spp., Achromobacter spp. were significantly inhibited by the feather hydrolysates. In addition, feather hydrolysates significantly improved proteolytic activity in the guts of broilers and fish. In fish, the expression levels of ZO-1 and TGF-α significantly improved after administration of feather hydrolysates. The results presented here suggest that feather hydrolysates generated by B. licheniformis WHU could be an alternative protein source in aquaculture and could exert beneficial effects on fish.

<i>Exiguobacterium acetylicum</i> transformed poultry feathers into amino acids through an extracellular secretion of keratinolytic enzymes

<p>The transition from a traditional linear economy to a circular model aims to create a more sustainable future by reducing the adverse effects of agro-waste on the environment. The present study evaluated the metabolic diversity of bacterial isolates from municipal dumpsites for keratinase production and poultry feather valorization. The bacterium with the highest keratinolytic activity was identified through 16S ribosomal ribonucleic acid (rRNA) gene sequencing. The exo-keratinase production by the bacterium was optimized, and the feather hydrolysate obtained from the fermentation process was analyzed for amino acids. Among the twelve bacteria isolated from the dumpsite's sample, three showed significant feather degradation and keratinase production of 89% (744.5 ± 9.19 U/mL), 58% (269 ± 15.55 U/mL), and 46% (195 ± 7.07 U/mL) for SSB-03, SSB-02, and HSB-02, respectively. Analysis of the 16S rRNA gene sequence revealed that SSB-03 has high sequence homology with <italic>Exiguobacterium acetylicum</italic>, and thus, it was identified as <italic>Exiguobacterium acetylicum</italic> FHBD (accession number MW165834). Strain FHBD fermentation medium exhibited the maximum keratinase activity (2934.54 ± 38.56 U/mL) and sulfhydryl group content (3.09 ± 0.02 mM) at 72 h under optimal process conditions of pH 5.0, temperature (35 °C), inoculum size (2% v/v), and feather (15 g/L). Amino acid analysis of the feather hydrolysate showed significant levels of glutamic acid, aspartic acid, glycine, arginine, serine, and proline, with respective concentrations of 1.58, 1.34, 1.29, 1.20, 1.12, and 0.93 (g/100 g of sample). The study's findings emphasize the potential of <italic>E. acetylicum</italic> FHBD in poultry feather valorization and keratinase production.</p>

Poly(ε‑caprolactone) nanofibers functionalized with poultry feather hydrolysate as a novel antioxidant material

Bioactive keratin hydrolysates obtained from microbial treatment of poultry feathers were incorporated into polycaprolactone (PCL) nanofibers using the electrospinning method. The nanofiber mats were characterized by scanning electron microscopy (SEM),...

Keratinases produced by Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx liberated amino acids from poultry feathers

AbstractThe agro-industrial sector generates diverse waste that requires effective handling to mitigate economic loss and pollution. Consequently, this study assessed bacterial isolates from poultry dumpsites for feather decomposition and keratinase production capacity. The protein hydrolysates generated from feather dismemberment by two bacteria identified as Chryseobacterium proteolyticum FGNn (accession no. MW165478) and Pseudomonas aeruginosa GNFx (accession no. MW165479) were profiled for amino acids composition. The biochemical properties of the bacteria-associated keratinases were determined. Initial keratinase production (with percentage feather degradation), demonstrated by the isolates, was 693.63 ± 62.99 U/mL (81%) and 619.09 ± 37.28 (76%) against FGNn and GNFx, respectively. At optimized process conditions, C. proteolyticum and P. aeruginosa extracellular keratinase production was 1756.36 ± 2.57 U/mL at 72 h and 2055.45 ± 50.14 U/mL at 96 h, respectively. Analysis of the feather hydrolysates showed a relatively high abundance of arginine (3.18%) and glycine (3.26%) for FGNn and glutamic acid (6.05%), serine (3.31%), aspartic acid (4.74%), glycine (3.71%), alanine (3.43%), valine (3.09%), and leucine (3.23%) for GNFx. The keratinolytic proteases showed pH and temperature optima of 8.0 and 50°C against FGNn, and 8.0 and 60°C against GNFx. GNFx keratinase was thermostable, displaying a half-life time of more than 60 min at 80°C. In addition, GNFx keratinolytic enzyme was chemical agent tolerant post-treatment. The findings underlined the significance of C. proteolyticum FGNn and P. aeruginosa GNFx as suitable in the valorisation of keratinous biomass. Also, the robust stability profile of GNFx keratinase highlights its prospects in green technology.

Production Optimization of Feather Hydrolysate and Use as a Promising Nitogen-Rich Fertilizer for Rice (Oryza Sativa) Production

Present agriculture sector mostly depend on synthetic fertilizer for better crop. Feather is a rich source of protein and nitrogen. It was degraded by Keratinolytic bacteria Bacillus wiedmanni SAB10 in poultry litter sole media. Feather hydrolysate was produce from solid state fermentation process and fermentation condition was optimized through OVAT (One Variable At A Time) system. In this process feather (1.25%w/v) was fully degraded in poultry litter(1%w/v) with in 48 hrs at pH 10.After the fermentation cell free feather hydrolysate use in rice plant in different concentration and different mode. Liquid feather hydrolysate produced from solid state fermentation contain important amount of protein (3.12mg/ml) and amino acid(792µg/ml) that enhances the rice plant growth in pot trial condition. After application Group D Plants leaves have been reported to have higher levels of total chlorophyll (5.25mg/g of dry wt), IAA (17.23µg/ml)..Carbohydrate contain of rice has increased 1.6 fold than control Following the spraying of feather hydrolysate (300 µl/ml), the phenolic (1.71 fold) and flavonoid (1.52 fold) contents significantly increased.. The novelty of our investigation is we use here two wasted products and convert them a valuable product.

Effective biodegradation on chicken feather by the recombinant KerJY-23 Bacillus subtilis WB600: A synergistic process coupled by disulfide reductase and keratinase

Keratin wastes are abundantly available but rich in hard-degrading fibrous proteins, and the keratinase-producing microorganisms have gained significant attention due to their biodegradation ability against keratinous materials. In order to improve the degradation efficiency of feather keratins, the keratinase gene (kerJY-23) from our previously isolated feather-degrading Ectobacillus sp. JY-23 was overexpressed in Bacillus subtilis WB600 strain. The recombinant KerJY-23 strain degraded chicken feathers rapidly within 48 h, during which the activities of disulfide reductase and keratinase KerJY-23 were sharply increased, and the free amino acids especially the essential phenylalanine and tyrosine were significantly accumulated in feather hydrolysate. The results of structural characterizations including scanning electron microscopy, Fourier transform infrared spectrum, X-ray diffraction, and X-ray photoelectron spectroscopy, demonstrated that the feather microstructure together with the polypeptide bonds and SS bonds in feather keratins were attacked and destroyed by the recombinant KerJY-23 strain. Therefore, the recombinant KerJY-23 strain contributed to feather degradation through the synergistic action of the secreted disulfide reductase to break the SS bonds and keratinase (KerJY-23) to hydrolyze the polypeptide bonds in keratins. This study offers a new insight into the underlying mechanism of keratin degradation, and provides a potential recombinant strain for the valorization of keratin wastes.

Chicken feather waste degradation by Malbranchea cinnamomea and its application on plant growth and metabolites of Vicia faba plant

Keratinase are proteolytic enzymes that have received a lot of interest for their ability to transform the keratinous wastes that are a major source of environmental pollution. The most effective isolate that produced more keratinase was Malbranchea cinnamomea CBS 343.55. The enzyme activity was higher at 37 °C, pH 5.6; the incubation period was 7 days; and 1.0 ml was found to be the best inoculum size for keratinase production. Under solid substrate cultivation, the best substrate loadage for maximal keratinase production was 3.0 g/500 ml conical flask for M. cinnamomea CBS 343.55. The purified keratinase was stable between pH 3 and 8 and stable at temperatures ranging from 40 to 90 °C, with optimal activity at 45 °C and pH 8. The relative activity of keratinase was raised in the presence of the ions Na+, Mg2+, Mn2+, Ca2+, Co2+, Fe2+, Fe3+, and mercaptoethanol, but decreased in the presence of Hg2+, Zn2+, Cu2+, Ag2+, pb2+, ethylenediaminetetraacetic acid, and phenylmethylsulfonyfluoride. Chicken feather hydrolysate of M. cinnamomea produced total amino acids (329.0 mg/100 mL). In soil treated with feather compost and a fungus strain, there was a rise in the level of N, P, and K. However, the feather compost had a favorable impact on the growth, relative water content, photosynthetic pigments, antioxidant activity, total phenol and proline content of Vicia faba plant. In conclusion, the present study revealed that M. cinnamomea CBS 343.55O has potential applications in the biodegradation of chicken feathers and the value-addition of poultry waste as a biofertilizer.

Bioconversion of feather waste into bioactive nutrients in water by Bacillus licheniformis WHU.

Feathers become hazardous pollutants when deposited directly into the environment. The rapid expansion of the poultry industry has significantly increased feather waste, necessitating the development of new ways to degrade and utilize feathers. This study investigated the ability of Bacillus licheniformis WHU to digest intact chicken feathers in water. The results indicated that yields of free amino acids, bioactive peptides, and keratin-derived nano-/micro-particles were improved in bacteria- versus purified keratinase-derived feather hydrolysate. Bacteria-derived feather hydrolysate supplementation induced health benefits in mice, including significantly increased intestinal villus height and zonula occludens-1 protein expression, as well as increased secretory immunoglobulin A levels in the intestinal mucosa and superoxide dismutase activity in serum. Additionally, feather hydrolysate supplementation modulated the mouse gut microbiota, reflected by increased relative abundance of probiotics such as Lactobacillus spp., decreased relative abundance of Proteobacteria at the phylum level and pathogens such as Staphylococcus spp., and increased Bacteroidota/Firmicutes ratio. This study developed a simple, cost-effective method to degrade feathers by B. licheniformis WHU digestion, yielding a hydrolysate that can be directly used as a bioactive nutrient resource. The study findings have applications in the livestock, poultry, and aquaculture industries, which have high demands for cheap protein. KEY POINTS: • Bacillus licheniformis could degrade intact feather in water. • The resulting feather hydrolysate shows prebiotic effects on mouse.

Thermostable keratinase from Bacillus cereus L10: optimization and some potential biotechnological applications

The accumulation of feather waste is a critical problem in solid waste management; therefore, microbial management of waste is highly significant. Consequently, the keratinolytic capacity of some bacteria isolated from the keratinous waste area was evaluated. The most promising isolate coded as L10 showed the highest feather degradation efficiency 72.7% was identified as Bacillus cereus L10 using 16S rRNA gene sequencing. The effect and contribution of independent process variables were studied by Plackett–Burman design. The optimal values of the independent variables obtained from the Plackett–Burman design were chicken feather, 1%; K2HPO4, 0.3%; KH2PO4, 0.05%; MgSO4 7H2O, 0.01%; yeast extract, 0.05%; inoculum size 4% with pH 7 and incubation period 5 days at 35 °C. The optimal parameters were validated resulting in the enhancement of keratinase production (9.602 U/ml), protein concentration (521.17 µg/ml), and feather degradation (94%) along with a 4.56-fold increased of keratinase production. The enzyme is relatively thermostable, completely stable between 30 and 80 °C for 1 h and retained 97.66% of its activity at 100 °C. B. cereus L10 was able to degrade different types of keratins. Interestingly, the feather hydrolysate from optimized keratinase production medium showed plant growth promoting activity by producing indole-3-acetic acid (IAA). The feathers hydrolysate produced a great benefit by its use as a soil biofertilizer through enhancing the germination of Triticum aestivum. The important implication of keratinase in laundry detergent and leather industry was examined. Results revealed that the enzyme achieved great efficiency in removing protein and blood-rich stains within 30 min at 36 °C in addition to its thoroughly dehairing of cow-hide after 40 h incubation without any damage. The dehaired pelt exhibited a smooth, velvety, and white color surface, good flexibility. Therefore, our study presents an effective method to turn waste into wealth.Graphical

Attractiveness and palatability of feather protein hydrolysate for juvenile Nile tilapia (Oreochromis niloticus)

The objective of the study was to determine the attractiveness and palatability of feather hydrolysate for juvenile Nile tilapia. Twelve Nile tilapia (Oreochromis niloticus) fingerlings with an average weight of 9.63 ± 0.9 g were used, distributed in 12 aquariums with a useful volume of 20 liters. Six diets were formulated, as follows: T0: Control, T1: 1% feather hydrolysate, T2: 2% feather hydrolysate, T3: 3% feather hydrolysate, T4: 4% feather hydrolysate and T5: 5% feather hydrolysate. The fish went through an adaptation period to record their feeding behavior in which they were fed twice a day, for six days, with 20 pellets per aquarium. The experimental design used was completely randomized. To assess attractiveness and palatability, the following eating behaviors were observed: time taken to capture the first pellet (seconds), number of rejections after capture, number of approaches without capture and number of pellets consumed. These values were used to calculate the attractiveness and palatability index. Data were submitted to parametric analysis of variance (ANOVA), and Tukey's multiple comparison test was also performed, with a significance level of 5%. All diets containing the hydrolysate showed a positive palatability index when compared to the control treatment. Treatment T3 had the best palatability index of 6.66%, followed by T2 4.66%, T5 4.30%, T1 3.92% and T4 0.20%. Feather protein hydrolysate can be used to replace fish meal in diets for Nile tilapia, without altering palatability and feeding behavior.

Adsorption kinetics, isotherms and thermodynamics of aromatic amino acids in feather hydrolysate onto modified activated carbon

AbstractThe main objective of this study was to produce low cost activated carbons for the adsorption of aromatic amino acids (AA) from feather hydrolysate. By optimizing the static adsorption conditions (time, pH and concentration) of amino acids, the adsorption amounts of tyrosine and phenylalanine reached 15.2 and 20.1 mg/g, respectively, under optimal conditions. Furthermore, it exhibits excellent reusability as it maintains a removal efficiency of 82.0% and 82.8% for tyrosine and phenylalanine after being reused 4 times. The effects of NaOH modified activated carbon (NA‐AC) on the adsorption capacity of AA in feather hydrolysate at different temperatures (298.15, 308.15, 318.15 K) were investigated, and the static adsorption kinetics curves were plotted. The adsorption isotherm (Langmuir, Freundlich model), kinetics (pseudo‐first‐order‐mode, pseudo‐second‐order‐mode, particle diffusion model) and thermodynamics were studied. The results shown that the adsorption process of AA onto NA‐AC accorded with the pseudo‐second‐order‐mode. The adsorption rate was mainly controlled by the liquid film diffusion and the particle diffusion. The adsorption isotherm accorded with the Langmuir adsorption isothermal model. Adsorption was an endothermic process, and increasing temperature was conducive to adsorption. Gibbs energy ΔG indicated that the adsorption process was spontaneous, and enthalpy △H indicated that the adsorption process was mainly physical adsorption. The proposed adsorption mechanisms provide a theoretical basis for the optimization of AA separation and purification process in feather hydrolysate by NA‐AC, which may further improve the separation and purification efficiency of other amino acids in feather hydrolysate.

Bioconversion of chicken feather waste into feather hydrolysate by multifaceted keratinolytic Bacillus tropicus LS27 and new insights into its antioxidant and plant growth-promoting properties

Bioconversion of chicken feather waste into feather hydrolysate by multifaceted keratinolytic Bacillus tropicus LS27 and new insights into its antioxidant and plant growth-promoting properties

Isolation of a novel feather-degrading Ectobacillus sp. JY-23 strain and characterization of a new keratinase in the M4 metalloprotease family

Microbial keratinases have prominent potential in biotransformation of recalcitrant keratin substrates to value-added products which has made keratinases a research focus in the past decades. In this study, an efficient feather-degrading bacterium was isolated and identified as a novel species in Ectobacillus genus and designated as Ectobacillus sp. JY-23. The degradation characteristics analysis revealed that Ectobacillus sp. JY-23 could utilize chicken feathers (0.4% w/v) as the sole nutrient source and degraded 92.95% of feathers in 72 h. A significant increase in sulfite and free sulfydryl group content detected in the feather hydrolysate (culture supernatant) indicated efficient reduction of disulfide bonds, which inferred that the degradation mechanism of isolated strain was a synergetic action of sulfitolysis and proteolysis. Moreover, abundant amino acids were also detected, among which proline and glycine were the predominant free amino acids. Then, the keratinase of Ectobacillus sp. JY-23 was mined and Y1_15990 was identified as the keratinase encoding gene of Ectobacillus sp. JY-23 and designated as kerJY-23. Escherichia coli strain overexpressing kerJY-23 degraded chicken feathers in 48 h. Finally, bioinformatics prediction of KerJY-23 demonstrated that it belonged to the M4 metalloprotease family, which was a third keratinase member in this family. KerJY-23 showed low sequence identity to the other two keratinase members, indicating the novelty of KerJY-23. Overall, this study presents a novel feather-degrading bacterium and a new keratinase in the M4 metalloprotease family with remarkable potential in feather keratin valorization.

Application of bacterial feather hydrolysates as biofertilizers in growing leafy vegetables: yield, nutritional, phytochemical, antioxidant and hepatoprotective profiles

Application of bacterial feather hydrolysates as biofertilizers in growing leafy vegetables: yield, nutritional, phytochemical, antioxidant and hepatoprotective profiles

Production of Enriched Biomass by Carotenogenic Yeasts Cultivated on by-Products of Poultry Processing—A Screening Study

Carotenogenic yeasts are a group of microorganisms producing valuable metabolites such as carotenoids, ergosterol, ubiquinone or fatty acids. Their exceptional adaptability allows them to grow in diverse conditions. Owing to their extracellular lipase activity, they are capable of processing many lipid-type waste substrates. This study discusses the processing of poultry waste, specifically fat and feathers by using carotenogenic yeasts. Poultry fat does not require any pre-treatment to be utilized by yeast, but hydrolytic pre-treatment is required for the utilization of the nitrogen contained in feathers. Glycerol was used as a supplementary substrate to support the culture in the early stages of growth. Seven yeast strains were used for the experiments, of which the strain Rhodotorula mucilaginosa CCY19-4-25 achieved exceptional results of biomass production: 29.5 g/L on poultry fat + 10% glycerol at C/N ratio 25 and 28.3 g/L on media containing poultry fat + 25% glycerol at C/N 50. The bioreactor cultivation of the Rhodosporidium toruloides strain in media containing glycerol and feather hydrolysate as a nitrogen substrate achieved a biomass yield of 34.92 g/L after 144 h of cultivation. The produced enriched yeast biomass can be used as a component for poultry feeding; thus, the study is performed under the biorefinery concept.

Keratinases from Streptomyces netropsis and Bacillus subtilis and Their Potential Use in the Chicken Feather Degrading

Feathers are the most prevalent agricultural waste generated by chicken farms, polluting the environment and wasting protein resources as a result of the accumulation of large amounts of feathers. Therefore, keratinase-producing microorganisms represent a promising potential technique for the degradation of feather waste. Streptomyces netropsis A-ICA and Bacillus subtilis ALICA, previously isolated from the rhizosphere of desert plants (Larrea tridentata and Prosopis juliflora) respectively, were assessed for their feather-degradation ability. Keratinase activity was optimized using various parameters, including incubation time, pH, temperature, and feather concentration. The maximum keratinase activity of S. netropsis A-ICA and B. subtilis ALICA (113.6 ± 5.1 and 135.6 ± 4.1 U/mL) was obtained at the 5th and 3rd day of incubation with initial pH of 7.0 and 7.5 at 25 and 30 °C, and 1% (w/v) of chicken feather, respectively. Under the optimized conditions, the concentration of soluble protein in the feather hydrolysate reached 423.3 ± 25 and 565.3 ± 7.7 µg/mL, with feathers weight loss of 84 ± 2 and 86± 1.5% by S. netropsis A-ICA and B. subtilis ALICA, respectively. The highest disulphide bond reductase activity reached 10.7 ± 0.4 and 10.96 ± 1.1 U/mL, after five and three days of inoculation with S. netropsis A-ICA and B. subtilis ALICA, respectively. Furthermore, the antioxidant activity of feather protein hydrolysate obtained by S. netropsis A-ICA and B. subtilis ALICA was evaluated using DPPH radical-scavenging activity, which exhibited a significant antioxidant potential with an IC50 value of 0.8 and 0.6 mg/mL. The 3D models of detected keratinases in both strains showed high similarity with subtilisin family. Further, the docking results clarified the importance of GSG and VVVFTP domains in B. subtilis and beta-keratin, respectively. The present study revealed the keratinolytic potential of S. netropsis A-ICA and B. subtilis ALICA in chicken feather degradation, which have potential application value and may be exploited as supplementary protein and antioxidant in animal feed formulations.

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

The use of fertilizers based on organic waste as a result of microbial biodegradation and biotransformation is becoming increasingly common practice in plant cultivation. This is to limit the chemicals used in agriculture and thus protect the environment and consumer health. The aim of this study was to evaluate a hitherto unexplored effect of hydrolysates obtained after biodegradation of chicken feather waste by a soil strain of the keratinolytic fungus Trichophyton ajelloi on germination, early growth, and development of plants, in particular with high sulfur requirements, and to verify, in model conditions, their impact on soil biological activity and the total pool of soil DNA. Undiluted and diluted keratin hydrolysate generally stimulated seed germination as well as root and shoot growth of the Lepidium sativum L. (garden cress) and Brassica napus L. var. napus (oilseed rape) on sandy soil (Cambisol I), loamy soil (Cambisol II), and Chernozem. In the model experiment, in the variants with and without oilseed rape on sandy soil and Chernozem, the introduction of keratin hydrolysate generally increased the total abundance of microorganisms. In sandy soil, feather hydrolysate mostly increased respiratory activity, dehydrogenase activity, and alkaline phosphatase activity by an average of approx. 38% and the total DNA pool by 15% and 23% in the variant with and without plants. The activity of protease and acid phosphatase increased by an average of 4% and 6% only in the variant without oilseed rape. Respiratory and enzymatic activity in Chernozem, in the variants with and without oilseed rape, tended to show a downward trend, despite periodically recorded increases. The total DNA pool has increased by 8% in the oilseed rape variant. Oilseed rape biomass was almost two-fold higher after adding feather hydrolysate to both soils, and its yield was higher by 98% in Chernozem than in sandy soil. The results have demonstrated that keratin hydrolysate can be used as a biofertilizer.