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Determination of Cellulase Enzyme Produced by Bacillus cereus DU-1 Isolated from Soil, and Its Effects on Cotton Fiber

Abstract

A Cellulase enzyme is the enzyme synthesized by some bacterial and fungal species and breaks down the ß-1,4 glycoside bonds of cellulose. Cellulase enzyme has a wide range of uses such as food, paper, textile industry, animal feed and detergent production. In this study, which was designed to add a new cellulase enzyme with such a wide industrial use, cellulotic bacterium isolation, identification, partial purification, characterization and application on denim fabric of the cellulase enzyme synthesized by the identified bacterium was performed. Firstly, bacterium that can produce cellulase enzyme was isolated from soil samples containing hazelnut wastes. The enzyme-producing isolate was identified as Bacillus cereus strain DU-1 by morphological, biochemical and molecular techniques. The optimum conditions for enzyme production by B. cereus DU-1 was determined as pH 7.0, at 37°C and 24h. However, the activity of the enzyme (5.16 U/mL) was found to be optimum at 50°C and pH 6.0. The Vmax value of the enzyme was 3.18 U/mL and the Km value was 0.0019 mM. The enzyme was partially purified by ammonium sulfate precipitation. The molecular size of the partially purified enzyme was determined as approximately 40 kDa by SDS-PAGE and Zymogram analysis. Finally, enzyme was applied on the denim fabric and when the fabrics were viewed under the electron microscope, it was seen that they were suitable for textile use.

Keywords:
Bacillus cereus; Cellulase; Characterization; Enzyme kinetics; Purification

HIGHLIGHTS

A report showing was identified as Bacillus cereus DU-1 which is a cellulase-producing bacterium.

Optimum production conditions for Bacillus cereus DU-1 are 37°C, pH 7 and 24 h, respectively.

The Vmax value of the enzyme was 3.18 U/mL and the Km value was 0.0019 mM.

The performance of cellulase enzyme on denim fabrics was evaluated by electron microscopy.

GRAPHICAL ABSTRACT

Instituto de Tecnologia do Paraná - Tecpar Rua Prof. Algacyr Munhoz Mader, 3775 - CIC, 81350-010 Curitiba PR Brazil, Tel.: +55 41 3316-3052/3054, Fax: +55 41 3346-2872 - Curitiba - PR - Brazil
E-mail: babt@tecpar.br