ADHERENCE OF ASPERGILLUS AWAMORI K-1 AND TRICHODERMA VIRIDE SL-45 ON LOOFA SPONGE FOR PRODUCTION OF HYDROLASES

D. Nikolova, M. Yordanova, Y. Evstatieva, M. Badalova, E. Velichkova

Abstract: In nature, filamentous fungi of the genus Aspergillus and Trichoderma are able to secrete a wide range of different enzymes into their environment. In recent years, one of the most important large-scale biotechnological applications of these fungi is the use as producers of xylanases and cellulases for pulp and paper industry. The cost of the enzymatic hydrolysis by microbial cells is one of the main factors limiting the economic feasibility of biotechnological manufacturers. In this context, the adaptation of cell immobilization techniques to an industrial scale and the use of cheap carriers would simplify the fermentation processes. Loofa (Luffa cylindrical) sponge appears to be an excellent carrier because it is biodegradable, does not require the use of chemical products and the immobilization method is very simple. In comparison with other carriers used for immobilization by cell adhesion, the density of loofa sponge is very low while the porosity and specific pore volume are very high. Furthermore, loofa sponge is stable over the whole range of pH and can be autoclaved many times without any visible change in the shape, structure and texture. The purpose of the present investigation was to study the hydrolase activities immobilized cells of Aspergillus awamori K-1 and Trichoderma viride SL-45 on loofa sponge. Xylanase and cellulase production by immobilized cultures were evaluated during batch fermentation processes and compared with enzyme activities of free cell cultures. Immobilization technique used in the present study resulted in complete adherence of the cells and also provides higher hydrolase production.

Keywords: Aspergillus; cellulose; immobilization; loofa; Trichoderma; xylanase

Date published: 2017-10-20