Novel Protease from &amp;lt;i&amp;gt;Aspergillus tamarii&amp;lt;/i&amp;gt; URM4634: Production and Characterization Using Inexpensive Agroindustrial Substrates by Solid-State Fermentation

Osmar Soares Da Silva,Ana Lúcia Figueiredo Porto,Cristina Maria Souza-Motta,Rodrigo Lira De Oliveira,Tatiana Souza Porto

doi:10.4236/aer.2016.44012

Abstract

This study reports the protease production from Aspergillus tamarii using agroindustrial residues as substrate for solid-state fermentation (SSF) and biochemical characterization. The highest protease production was obtained using wheat bran as substrate at 72 h fermentation with maximum proteolytic activity of 401.42 U/mL, collagenase of 243.0 U/mL and keratinase of 19.1 U/mL. The protease exhibited KM = 18.7 mg/mL and Vmax = 28.5 mg/mL/min. The optimal pH was 8.0 and stable in a wide pH range (5.0 - 11.0) during 24 h. The optimum temperature was 40°C. The proteolytic activity was inhibited by Cu2+ (33.98%) and Hg2+ (22.69%). The enzyme was also inhibited by PMSF (65.11%), indicating that is a Serine Protease. These properties suggest that alkaline protease from A. tamarii URM4634 is suitable for application in food industries and leather processing. Additionally, the present findings opened new vistas in the utilization of wheat bran and other effective agroindustrial wastes as substrates for SSF.

Highlights

IntroductionEven though a wide variety of microbial proteases are available, the use of these enzymes on industrial scale is still limited by their high production costs and the fact that their activity is often limited to a restricted range of biochemical characteristics [5]
We evaluated the inexpensive production of proteases from several Generally Recognized as Safe (GRAS) fungal strains, using agroindustrial waste: wheat grains, Canadian lentils, amaranth flakes, soybean grains, nuggets sunflower, oat bran and wheat bran
The enzyme extract from Aspergillus tamarii URM4634 was selected

Summary

Introduction

Even though a wide variety of microbial proteases are available, the use of these enzymes on industrial scale is still limited by their high production costs and the fact that their activity is often limited to a restricted range of biochemical characteristics [5]. The Solid State Fermentation (SSF) is especially suitable for the fungi growth because their moisture requirements are lower compared to the bacteria. In this technique, the enzymes produced are more concentrated than those in submerged fermentation. Development of novel processes to increase the yield of proteases with respect to their industrial requirements coupled with lowering down the production cost is highly appreciable from the commercial point of view [6]

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