Purification and characterization of an efficient poultry feather degrading-protease from Myrothecium verrucaria

Abstract

The purpose of this work was to characterize an alkaline protease from the filamentous fungus Myrothecium verrucaria and to explore its capability to degrade native poultry feathers. The enzyme was purified to homogeneity using a single chromatographic step. Recovery was high, 62%, with a specific activity of 12,851.8 U/mg protein. The enzyme is a small monomeric protein with a molecular mass of 22 +/- 1.5 kDa. It presented pH optimum of 8.3 and was stable over a broad pH range (5.0-12.0). The temperature optimum was 37 degrees C, with thermal stability at temperatures up to 45 degrees C. The enzyme presented an efficiency of 80.3% in the degradation of poultry feather meal, releasing amino acids and soluble peptides. It was able to hydrolyze beta-keratin without necessity of chemical or enzymatic reduction of the disulphide bonds. Considering that, everyday, poultry-processing plants produce feathers as a waste products, this protease can be useful in biotechnological processes aiming to improve the transformation of poultry feathers through solubilization of beta-keratin into usable peptides. Furthermore, it can also be useful in processes aiming to reduce the environmental pollution caused by the accumulation of feathers.

Microbial keratinases: characteristics, biotechnological applications and potential.

“…A suitable redox environment may be necessary for effective degradation of keratin. The presence of reducing agents (Böckle et al 1995;Gradisar et al 2005;Cao et al 2008) or a cell-bound redox system (Ramnani et al 2005;Ramnani and Gupta 2007;Moreira-Gasparin et al 2009) stimulate keratin hydrolysis by purified keratinase. In a cell-bound redox system, the bacterial cells probably provide a continuous supply of reductant (e.g.…”

Chicken Feather Waste Valorization Into Nutritive Protein Hydrolysate: Role of Novel Thermostable Keratinase From Bacillus pacificus RSA27

“…(Gupta and Singh, 2013 ; Gupta et al, 2015 ; Dong et al, 2017 ; Hamiche et al, 2019 ; Nnolim et al, 2020b ; Almahasheer et al, 2022 ; Devi et al, 2022 ; Mazotto et al, 2022 ), Aspergillus oryzae (Farag and Hassan, 2004 ), Paecilomyces marquandii and Doratomyces microsporum (Gradisar et al, 2005 ), Streptomyces sp. (Tatineni et al, 2008 ), Stenotrophomonas maltophilia (Cao et al, 2009 ), Myrothecium verrucaria (Moreira-Gasparin et al, 2009 ), Thermoactinomyces sp. RM4 (Verma et al, 2016 ), and Fusarium sp.…”

Queratinasas microbianas: microorganismos, producción y caracterización

“…Trichoderma (Cao et al, 2008), Doratomyces (Gradišar et al, 2000), Myrothecium (Moreira-Gasparin et al, 2009), Paecilomyces Cavello et al, 2012)y también Acremonium, Alternaria, Beauveria, Curvularia y Penicillium (Marcondes et al, 2008;Elíades et al, 2010).…”

“…AH-101, entre pH 11.0 y 12.0 (Takami et al, 1989;. La mayoría de las queratinasas poseen una estabilidad relativamente buena dentro de un rango de pHs entre 7.0-9.0 como por ejemplo, la queratinasa de Streptomyces gulbargensis que posee su máxima estabilidad dentro de este rango , o la queratinasa de Myrothecium verrucaria (Moreira-Gasparin et al, 2009) cuya máxima estabilidad se encuentra en un rango de entre 5.0 y 9.0. En cambio, hay queratinasas cuyo rango de estabilidad al pH es aún mucho menor como sucede en el caso de la queratinasa de Trichophyton mentagrophytes var.…”

“…Por lo general la mayoría de las queratinasas reportadas presentan un pH óptimo ligeramente alcalino, por ejemplo, las queratinasas de P. marquandii y Doratomyces microsporus presentan ambas pH óptimo cercano a 8.0 , la queratinasa de Microbacterium sp. un pH óptimo de 7.5 ) y, la de B. cereus DCUW de 8.5 (Ghosh et al, 2008 , queratinasas que presentan moderada estabilidad como la purificada en esta tesis y queratinasas que presentan una estabilidad más baja, como por ejemplo, la queratinasa purificada de cultivos de M. verrucaria que sólo presenta estabilidad hasta los 45 ºC (Moreira-Gasparin et al, 2009) o la queratinasa de Bacillus sp. P7 que presenta una vida media de 53 min a 50 ºC y menos de 10 min a 55 ºC .…”