Enzymatic hydrolysis of the horn and hoof of cow and buffalo

Enzymolysis of walnut (Juglans regia L.) meal protein: Ultrasonication-assisted alkaline pretreatment impact on kinetics and thermodynamics

To improve the utility of walnut meal protein, influences of ultrasonication on the kinetic and thermodynamic constraints of enzyme (trypsin) hydrolysis were assessed using a multi-frequency counter current S-type ultrasound machine. Results revealed that both the ultrasonication treatment and control hydrolysis obeyed the first-order kinetics within the study constraints. After 90 min hydrolysis time, the uppermost percentage conversion rate (57.5%) of substrate to product and the percentage increase (25.42%) in hydrolyzed protein concentration were obtained at 323 K and 10% substrate concentration, respectively. The Michaelis constant (K_M ) in ultrasonic enzymolysis declined by 58.66% over the control. The reaction rate coefficient (k) for the proteolysis improved by 84.75%, 52.43%, 48.25%, and 37.79% at 219, 303, 313, and 323 K, correspondingly. Generally, the bond energy (E_a ), enthalpy change (ΔH), entropy change (ΔS), and Gibbs free energy (ΔG) were reduced by the ultrasound pretreatment with 36.61%, 28.05%, 18.22%, and 5.24%, respectively. PRACTICAL APPLICATIONS: Walnut meal protein has a well-balanced amino acid profile and its economic utilization could be increased practicably as a food ingredient via production of hydrolysates/peptides for the production of improved food ingredients instead of being cast off as animal feed. This study demonstrated a positive bearing of ultrasonication-assisted alkaline pretreatment on proteolytic reaction characteristics and its energy efficiency for walnut meal protein, which makes this technique applicable to the enhancement of plant proteins for inclusion in food products, especially tree nut and oil seed waste products from the oil industry.

Enzymolysis reaction kinetics and thermodynamics of defatted wheat germ protein with ultrasonic pretreatment

This research explores the mechanism of ultrasonic pretreatment on enzymolysis of defatted wheat germ protein (DWGP). The enzymolysis reaction kinetics and thermodynamics were studied after ultrasonic pretreatments using a probe-type sonicator and an ultrasonic cleaning bath, and the results were compared with traditional enzymolysis. The results showed that both the traditional and ultrasonic pretreated enzymolysis fit well to first-order kinetics. Both the temperature and ultrasound had a positive effect on the enzymolysis of DWGP, with temperature playing a dominant role. Under the optimized conditions of DWGP concentration of 1% (w/v), Alcalase concentration of 2000 U/g, time of 10 min and temperature of 50 °C, both the probe and cleaning bath ultrasonic pretreated enzymolysis showed high polypeptide concentrations (231.019 and 231.320 μg/mL) and low energy requirements. In comparison with traditional enzymolysis, these methods significantly increased the reaction rate constant (k) by 166.7% and 144.4%, 92.9% and 85.7%, 28.0% and 28.0%, 16.1% and 12.9% at 20, 30, 40 and 50 °C, and decreased the activation energy (Ea), enthalpy of activation (ΔH), Gibbs free energy of activation (ΔG) and entropy of activation (ΔS) by 68.6% and 62.4%, 74.1% and 67.5%, 34.3% and 31.2%, 1.4% and 1.3%. It can be concluded that ultrasonic pretreatment of DWGP can remarkably improve the enzymolysis efficiency and consequently leads to the production of higher polypeptide yield.

Effect of pretreatment on enzymatic hydrolysis of bovine collagen and formation of ACE-inhibitory peptides

Bovine collagen was pre-treated (boiled or high pressure (HP)-treated) and then hydrolysed by 6 proteases. The degree of hydrolysis (DH) and the angiotensin-converting enzyme (ACE)-inhibitory activity of hydrolysates were measured. All enzymes used were able to partly degrade collagen and release ACE-inhibitory peptides. The highest ACE-inhibitory activity was obtained with Alcalase. Pretreatment significantly influenced the DH and ACE-inhibition. For most enzymes, boiling for 5 min resulted in a significantly higher DH and ACE-inhibitory activity. With Alcalase and collagenase, hydrolysis and release of ACE-inhibitory peptides occurred without any pretreatment, but HP-treatment significantly improved the DH and ACE-inhibitory activity. HP did not markedly affect the hydrolysis with the other enzymes. The major peptides obtained with Alcalase were identified; all were released from the triple helix structure of collagen. Many of these peptides had C-terminal sequences similar to known ACE-inhibitory peptides. The present results suggest that collagen-rich food materials are good substrates for the release of potent ACE-inhibitory peptides, when proper pre-treatment and enzymatic treatment is applied.

Nocardiopsis sp. SD5: A potent feather degrading rare actinobacterium isolated from feather waste in Tamil Nadu, India

Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is nearly pure keratin protein, and keratin in its native state is not degradable by common proteolytic enzymes. The aim of the study was to find a potent feather degrading actinobacteria from feather waste soil. Out of 91 actinobacterial isolates recorded from feather waste soil in Tiruchirappalli and Nammakkal District, Tamil Nadu, India, isolate SD5 was selected for characterization because it exhibited significant keratinolytic activity. On the basis of the phenotypic, biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as Nocardiopsis sp. SD5. Protease and keratinase activity of Nocardiopsis sp. SD5 were analyzed. The enzyme was more stable over the neutral pH and the temperature of 40 °C. The optimum temperature and pH for both proteolytic and keratinolytic activity was determined at 50 °C and pH 9, respectively. Enzyme inhibitors, detergents and chelator declined the enzyme activity with increasing concentration. Non denaturing poly acrylamide gel electrophoresis and zymogram elucidated the presence of 30 kda and 60 kda protease enzymes. These findings indicated that thermo alkaliphilic feather degrading strain Nocardiopsis sp. SD5 could be used to control the feather waste pollution and to convert keratin rich feather waste into useful feedstock for poultry industry. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

Study of saiga horn using high-performance liquid chromatography with mass spectrometry

The saiga horns have been investigated the using of modern analytic methods. High-performance liquid chromatography (HPLC) with mass-spectrometric (MS and MS/MS) detection and polyacrylamide gel electrophoresis (PAGE) were used. It could be concluded that basic proteins of the saiga horns are keratins and collagen. The basic representation protein in all samples is keratin type I microfibrillar (from sheep), keratin type II microfibrillar (from sheep), collagen type I (α(1)) (from bovine) and collagen type I (α(2)) (from bovine). Free amino acids we determined in all samples are nontreated by enzyme.

New Protein Hydrolysates from Collagen Wastes Used as Peptone for Bacterial Growth

A simple and low-cost procedure was developed for the effective processing of native calf skin and blood wastes to produce protein hydrolysates. The method includes extraction of high-molecular-weight protein from the raw material, followed by enzymatic hydrolysis of the extracted residue. The enzymatic hydrolysis was performed by inexpensive commercial subtilisin DY, produced by Bacillus subtilis strain DY possessing high specific activity. The contents of protein, nitrogen, ash, and amino acids of the obtained hydrolysates were determined and compared with those of the commonly used commercial casein hydrolysate (Fluka Biochemica, Switzerland). The newly obtained calf skin hydrolysate, called Eladin, was found to be suitable as a low-cost alternative peptone in growth media of different microorganisms, such as Escherichia coli, Pseudomonas aeruginosa, Salmonella dublin, and Staphylococcus aureus. The method allows utilization of waste materials by converting them into valuable protein products that could find widespread application in microbiologic practice.

Microbial alkaline proteases: from a bioindustrial viewpoint

Alkaline proteases are of considerable interest in view of their activity and stability at alkaline pH. This review describes the proteases that can resist extreme alkaline environments produced by a wide range of alkalophilic microorganisms. Different isolation methods are discussed which enable the screening and selection of promising organisms for industrial production. Further, strain improvement using mutagenesis and/or recombinant DNA technology can be applied to augment the efficiency of the producer strain to a commercial status. The various nutritional and environmental parameters affecting the production of alkaline proteases are delineated. The purification and properties of these proteases is discussed, and the use of alkaline proteases in diverse industrial applications is highlighted.