Production of Alkaline Protease Using Industrial Waste Effluent as Low-cost Fermentation Substrate

H Zare,G D Najafpour,F Meiguni

doi:10.5829/ijee.2021.12.03.11

Abstract

Alkaline proteases are the most important groups of commercial enzymes, which have been broadly used in industrial processes. In this study, Bacillus sp. PTCC 1538 was selected as a biological agent to produce alkaline protease. Enzyme production under submerge fermentation using industrial waste effluent was investigated. Since the costs of the raw material plays an important role in the cost of enzyme production, corn steep liquor (CSL) was selected as a low-cost substrate to reduce the cost of enzyme production. Various carbon sources were used as the auxiliary substrates to enhance enzyme production. Results showed that maximum enzyme activity was obtained when wheat bran was used as an auxiliary substrate. Optimal media composition and growth conditions for alkaline protease production were defined. The optimum conditions were found to be pH 8, incubation temperature of 37 °C, CSL inoculum size of 5 v/v %, yeast extract and wheat bran concentrations of 2 and 6 g/l, respectively. CaCl2 was used as an activator to enhance proteolytic activity of the enzyme. Under optimum condition, enzyme activity of 100.7 U/ml was obtained at CaCl2 concentration of 1.5 g/l.

Highlights

Proteases represent one of the most important groups of enzymes, which have found a wide application in various industries such as pharmaceutical, detergents, X-ray films, animal feed stocks and food [1,2,3,4,5,6]
Bacillus species are the most important microorganisms which have been commercially used for the production alkaline proteases [18,19,20]
In submerged fermentation up to 40% of the cost of enzyme production is due to the media component and substrate [29, 30]; optimization of the medium composition is essential in microbial protease production [3]

Summary

Introduction

Proteases represent one of the most important groups of enzymes, which have found a wide application in various industries such as pharmaceutical, detergents, X-ray films, animal feed stocks and food [1,2,3,4,5,6]. For commercial production of alkaline protease, microbial cells should ensure high yield using low cost methods [17]. Bacillus species are the most important microorganisms which have been commercially used for the production alkaline proteases [18,19,20]. Are generally aerobic and gram positive microorganisms that grow well in simple media These species are able to produce hydrolytic enzymes such as glucanase, mannanase and protease using various media [11, 21]. In submerged fermentation up to 40% of the cost of enzyme production is due to the media component and substrate [29, 30]; optimization of the medium composition is essential in microbial protease production [3]

Objectives

Methods

Results

Conclusion