Feather protein lysate optimization and feather meal formation using YNDH protease with keratinolytic activity afterward enzyme partial purification and characterization

• Published in: Scientific reports 2021-07, Vol.11 (1), p.14543-15, Article 14543
• Main Authors: Goda, Doaa A., Bassiouny, Ahmad R., Abdel Monem, Nihad M., Soliman, Nadia A., Abdel-Fattah, Yasser R.
• Format: Article
• Language: English
• Subjects: 631/326; 631/61; Amino acids; Amino Acids - analysis; Animals; Bacillales - enzymology; Casein; Chickens; Column chromatography; Detergents - chemistry; Enzymatic activity; Enzyme Stability; Enzymes; Feathers; Feathers - chemistry; Feathers - metabolism; Humanities and Social Sciences; Hydrogen-Ion Concentration; Keratin; Keratinase; Keratinocytes; multidisciplinary; Peptide Hydrolases - isolation & purification; Peptide Hydrolases - metabolism; pH effects; Protease Inhibitors - chemistry; Protease Inhibitors - pharmacology; Protein purification; Proteinase; Proteins; Proteins - chemistry; Proteins - metabolism; Regression Analysis; Science; Science (multidisciplinary); Serine; Solvents - chemistry; Temperature; Waste Products
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-93279-5

Incubation parameters used for the creation of a protein lysate from enzymatically degraded waste feathers using crude keratinase produced by the Laceyella sacchari strain YNDH were optimized using the Response Surface Methodology (RSM); amino acids quantification was also estimated. The optimization elevated the total protein to 2089.5 µg/ml through the application of the following optimal conditions: a time of 20.2 h, a feather concentration (conc.) of 3 g%, a keratinase activity of 24.5 U/100 ml, a pH of 10, and a cultivation temperature of 50 °C. The produced Feather Protein Lysate (FPL) was found to be enriched with essential and rare amino acids. Additionally, this YNDH enzyme group was partially purified, and some of its characteristics were studied. Crude enzymes were first concentrated with an Amicon Ultra 10-k centrifugal filter, and then concentrated proteins were applied to a "Q FF" strong anion column chromatography. The partially purified enzyme has an estimated molecular masses ranging from 6 to 10 kDa. The maximum enzyme activity was observed at 70 °C and for a pH of 10.4. Most characteristics of this protease/keratinase group were found to be nearly the same when the activity was measured with both casein and keratin-azure as substrates, suggesting that these three protein bands work together in order to degrade the keratin macromolecule. Interestingly, the keratinolytic activity of this group was not inhibited by ethylenediamine tetraacetic acid (EDTA), phenylmethanesulfonyl fluoride (PMSF), or iron-caused activation, indicating the presence of a mixed serine – metallo  enzyme type.