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Bernal, Cristobal; Vidal, Luis; Valdivieso, Elizabeth; Coello, Nereida

doi:10.1023/a:1023685621215

Cited by 35 publications

(3 citation statements)

References 18 publications

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“…Also, a lack of curvature, with points moving towards higher keratinase production, suggests the need for higher glucose and peptone concentrations for maximum enzyme production. The enzyme production in this case did not show a decrease in the presence of glucose in contrast with previous studies [12,24].…”

Section: Resultscontrasting

confidence: 99%

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Ramnani

Gupta

2004

Biotech and App Biochem

111

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A 3.5-fold increase in keratinase production by Bacillus licheniformis RG1 was achieved by using statistical methods involving Plackett-Burman design and response surface methodology. Eight variables were screened using Plackett-Burman design. Of these, glucose, peptone and glutathione were found to affect the response signal positively, whereas CaCl(2) had a negative effect. Further interaction of these factors, along with phosphate and incubation time, was studied using response surface methodology. An optimum keratinase production of 1295 units/mg dry weight was obtained with the following medium composition: 1% glucose, 1% peptone, 1% phosphate, 0.05% glutathione, 0.5% feather and 2% inoculum under shaking at 250 rev./min with an incubation period of 72 h at 37 degrees C. Keratinase production was found to be a function of biomass and maximum production occurred during the stationary phase.

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Section: Resultscontrasting

confidence: 99%

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Ramnani

Gupta

2004

Biotech and App Biochem

111

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“…The molecular masses of the known keratinases vary in a wild range. For example, Streptomyces albidoflavus produces an 18 kDa keratinases (22), while the alkaline extracellular keratinase secreted by Kocuria rosea has a molecular mass of >200 kDa (23, 24). The optimal pH and temperature for keratinase activity from different sources show a great discrepancy (2).…”

Section: Discussionmentioning

confidence: 99%

Feather degradation inStenotrophomonas maltophiliarelies on conversion and internalization of keratin monomer

Cao,

Song,

Xue

et al. 2024

Preprint

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Feather keratin is the most abundant nitrogen source waste in nature. This insoluble material cannot be directly utilized as nutrition by most organisms, especially animals and plants. While feathers are naturally decomposed by some microorganisms through keratinase-based degradation which remains mechanistically not fully understood. In this study, we find that when feathers serve as the only nutrient source for Stenotrophomonas maltophilia culture, keratin monomer of about 10 kDa is present in the medium as a predominant hydrolyzed product. We further show that keratin monomers bind to cells and in turn enter cells via an undetermined pathway. The cell entry of keratin monomer elicits keratinase activity to promote the forward reaction in keratin hydrolysis. This study highlights the importance of keratin monomer production as the first step in feather biodegradation, in which the insoluble feather is converted into soluble intermediate to facilitate its internalization and complete hydrolysis.

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“…For zymogram analysis, SDS‐PAGE using 10% polyacrylamide containing 0.1% gelatin was performed according to the method of Bernal et al with slight modification. After electrophoresis, the gel was rinsed with 0.25% Triton X‐100 and incubated for 1 H at 37°C in Tris–HCl buffer (0.05 mol/L, pH 8.0).…”

Section: Methodsmentioning

confidence: 99%

Isolation and characterization of a novel oxidant‐ and surfactant‐stable extracellular alkaline protease from Exiguobacterium profundumBK‐P23

Anbu

Hur

Lee

2013

Biotech and App Biochem

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The novel protease from Exiguobacterium profundum BK-P23 was partially purified by ammonium sulfate precipitation and further purified Mono Q 5/50 and Superdex 200 10/300 column chromatography. The enzyme was purified 10.23-fold with a yield of 14%. The molecular weight was estimated to be 52 kDa by SDS-PAGE. The enzyme was most active at a pH of 8.0 and temperature of 40°C and the enzyme was stable between a pH of 7 and 10 and up to a temperature of 50°C. The enzyme activity was enhanced by CaCl2 but was slightly inhibited by CoCl2 , MgSO4 , and AgNO3 . In addition, this enzyme was completely inhibited by phenylmethylsulfonyl fluoride, indicating that this enzyme was a serine protease. Furthermore, the alkaline protease was more stable in the presence of surfactants such as Triton X-100, which was followed by Tween 80 and SDS. Moreover, the enzyme was highly stable in the presence of 1% oxidizing agent (H2 O2 ). The enzyme also has significant stability (70%-80%) in a few organic solvents. Thus, the increased stability of the enzyme in the presence of oxidizing agent, surfactants, and organic solvents may find potential applications in the detergent industry and peptide synthesis in nonaqueous media.

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Untitled

Cited by 35 publications

References 18 publications

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Optimization of medium composition for keratinase production on feather by Bacillus licheniformis RG1 using statistical methods involving response surface methodology

Feather degradation inStenotrophomonas maltophiliarelies on conversion and internalization of keratin monomer

Isolation and characterization of a novel oxidant‐ and surfactant‐stable extracellular alkaline protease from Exiguobacterium profundumBK‐P23

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