Purification and partial characterization of two extracellular keratinases of Scopulariopsis brevicaulis

Abstract

Two extracellular keratinases of Scopulariopsis brevicaulis were purified and partially characterized. The enzymes were isolated by the techniques of gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These keratinases (K I & K II) were purified approximately 33 and 29 fold, respectively. SDS-PAGE of the products of gel filtration chromatography (K I & II) produced only one band each, suggesting homogeneity. The optimum pH for both keratinases was 7.8, while the optimum temperatures were 40 degrees C (K I) and 35 degrees C (K II). Estimated molecular weights were 40-45 KDa and 24-29 KDa for K I & K II respectively. Both keratinases were inhibited by phenylmethylsulfonyl fluoride which suggests a serine residue at or near an active site.

Similarities and Specificities of Fungal Keratinolytic Proteases: Comparison of Keratinases of Paecilomyces marquandii and Doratomyces microsporus to Some Known Proteases

“…The best studied are keratinases from the dermatophytic genera Microsporum (26, 37) and Trichophyton (30, 38) as well as from bacteria of the genera Bacillus (4,14,20,24,34,35) and Streptomyces (2, 3, 27). There are relatively few reports on characterization of the keratinases from nondermatophytic fungi (5,7,12,25,32,33).Most keratinases have some common characteristics despite their different origins. They belong mainly to the extracellular serine proteases, with the exception of keratinases from yeasts, which belong to the aspartic proteases (23, 28).…”

“…The best studied are keratinases from the dermatophytic genera Microsporum (26,37) and Trichophyton (30,38) as well as from bacteria of the genera Bacillus (4,14,20,24,34,35) and Streptomyces (2,3,27). There are relatively few reports on characterization of the keratinases from nondermatophytic fungi (5,7,12,25,32,33).…”

Novel Keratinolytic Activity of Cyberlindnera fabianii Nrc3 Aza as A Plant Growth Promoting Agent (PGPA)

“…On the other hand, the partial pure enzyme showing a single Protein band in SDS-PAGE with a molecular weight of 45-50 kDa for KIII which is similar to the molecular weight of the enzymes from Trichophyton mentagrophytes (Malviya et al, 1992).…”

Queratinasas microbianas: microorganismos, producción y caracterización

“…La mayoría de las queratinasas reportadas son enzimas inducibles, con muy pocos reportes de queratinasas constitutivas como las reportadas por Gessesse et al (2003) y por Manczinger et al (2003). El aumento en la producción enzimática en presencia de glucosa es un hecho que ha sido observado por varios autores y ha sido atribuido al hecho de que estos microorganismos utilizan esta fuente de carbono (fácilmente asimilable) para crecer en biomasa sin producir enzimas y una vez agotada esta fuente comiencen a secretarlas (Malviya et al, 1992;Singh, 1997;Gioppo et al, 2009).…”

“…Con las restantes fuentes de nitrógeno (Urea y KNO 3 ) se observa una disminución de la producción enzimática. A diferencia de ciertos reportes en los cuales se señala que la adición de una fuente de carbono y una de nitrógeno externas producen una disminución en la producción enzimática (Malviya et al, 1992;Gioppo et al, 2009), en el presente trabajo de tesis se observó que la presencia de ambas fuentes en el medio de cultivo produjeron una influencia acumulativa positiva sobre la producción de enzimas queratinolíticas (U azoc /ml ~16). Similares resultados fueron reportados por Hossain et al El efecto del pH inicial sobre la producción enzimática se estudió en el rango de pHs comprendido entre 5.0-8.0.…”