Streptomyces sp. K47 alkaline proteases: partial purification and analysis by zymography

Cengiz Çorbacı,Kadriye Özcan

doi:10.4025/actascitechnol.v43i1.51486

Abstract

Microbial enzymes are used as organic catalysts in different industrial processes. In this study, we aimed to produce and investigate alkaline proteases from a novel actinobacterium strain isolated from a Black Sea marine sediment. The optimal production conditions for Streptomyces sp. K47 alkaline proteases was 4-days incubation at 28ºC in a salt-free medium buffered with 50 mM Tris-HCl buffer (pH 9.0) and containing glucose (1.0%, w v-1) and yeast extract (0.5%, w v-1). The enzyme solution was partially purified using (NH4)2SO4 precipitation (40-70%). After desalting, it was purified 1-84 fold with a recovery of 19.42%. Zymogram analyses revealed the presence of more than one protease enzyme. The enzyme solution exhibited maximum activity at pH 9.0 and 37ºC, remaining stable after a 2-hour incubation at all tested conditions. Streptomyces sp. K47 has the potential to be used in industrial processes because of its ability to produce multiple protease enzymes displaying stability in a broad pH and temperature range.

Highlights

The aim of our research was to investigate the production of alkaline proteases from actinobacterium strain K47 from a marine sediment from Black Sea
A phylogenetic tree based on the neighbor-joining method confirmed the evolutionary relationship of the strain with the other Streptomyces species (Figure 1)
Due to its ability to produce more than one protease enzyme and their stability in a broad pH and temperature range, Streptomyces sp

Summary

Introduction

Enzymes are proteins used in medical, agricultural, chemical, biofuel, food and beverage industries. They are important low-cost catalysts because of their specific properties such as substrate specificity and minimum production of by-product arising from their chemo-, regio-, and stereo-selectivity. They are biodegradable and non-toxic compounds requiring moderate conditions to catalyze reactions and are an alternative to harmful chemical counterparts (Singh, Kumar, Mittal, & Mehta, 2016; Sanchez & Demain, 2017; Prasad & Roy, 2018). The global enzyme market amounted to $1.5 billion in 2000, $3.1 billion in 2009 and $5.01 billion in 2016 and this value is guessed to be $6.32 billion in 2021 (Kirk & Borchert, 2002; Chapman, Ismail, & Dinu, 2018)

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