Poster Presentation 2-17

Fungal and Streptomyces Cellulase Production: Evaluation of Non-repressible Carbon Sources

K. Wilkist,¹ D.M.C. Nery,² R.R.R. Coelho² and E.P.S. Bon^{* 3}

¹Lund Institute of Technology – Lund University

²Soil Microbiology Lab. - Institute of Microbiology Prof. Paulo de Goes

Federal University of Rio de Janeiro

³ Enzyme Technology Lab. - Institute of Chemistry

Instituto de Química – UFRJ

CT, Bloco A, Ilhas do Fundão

21949-900 – Rio de Janeiro, RJ, Brazil

Phone: (+55 21) 25627358

E-mail: elba1996@iq.ufrj.br

Present and prospective industrial uses of cellulases cover a range of applications including food and textile processing, detergent formulation, and lignocellulose materials treatment for pulp and paper and fermentable sugar production. Cellulase availability, activity levels and profiles, formulation and, most importantly, cost play a central role in green chemistry processes based on renewable biomass utilization. Cellulase production costs are affected by the cellulase fermentation substrates. This work evaluated cellulase production using the selected microbial strains, Aspergillus awamori and Streptomyces sp., strain M23. Submerged and solid phase fermentation were performed using as carbon source lactose, soluble starch, carboxymethyl cellulose (CMC), and the industrial substrates wheat bran and dried distillers grain (DDG) that was obtained from a dry grind corn ethanol plant in the U.S. Mid-West. This industrial residue, used as cattle feed, called our attention for its overall suitable composition as a cellulase fermentation substrate: proteins (35%), fibres, including cellulose (20%), and starch (6%), besides not presenting free repressible sugars. Furthermore, its high availability as a residue from the corn ethanol industry implies a low cost.

According to our endoglucanase activity data, the use of wheat bran favoured cellulase production by the streptomycete, whereas DDG was the best carbon source for the fungal enzyme.