Exploring cellulolytic microorganisms from coffee industry by-products and their enzyme properties

Abstract

Cellulolytic microorganism has immense potential due to their cellulase production, enzyme complexity and widespread habitat of life. This study was conducted to obtain microbial cellulase with vast industrial applicability from the coffee industry by-product in East Java, Indonesia. Fifty-four isolates with significant clear zone formation were obtained by Congo red staining in CMC agar plates. Eighteen bacteria, two yeasts and two moulds with high cellulolytic index were subjected to protein content determination as well as reducing sugar analysis in various conditions such as pH, temperature, addition of metal ions, surfactant and inhibitor agent. The specific activity measurements of all the crude enzymes result in the highest value of cellulase activity produced by isolate C12 which was 0.401 ± 0.018 U/mg. This enzyme activity was known to be optimum at 50°C and pH 9. It was also stimulated by K+, Na+, Mg2+, Fe3+, and SDS. However, the enzyme activity was inhibited by EDTA at 10 mM concentration. The use of coffee industry by-products as the source of cellulolytic microorganisms offers a promising approach for its various types of indigenous microorganisms and their unique property of cellulase produced that is useful for industrial application.