Production of cellulose-degrading enzyme on sisal and other agro-industrial residues using a new Brazilian actinobacteria strain Streptomyces sp. SLBA-08

Several types of lignocellulosic raw materials including wheat straw, sisal bagasse and sugarcane bagasse have different contents of cellulosic components. In our studies, aimed at isolating cellulose-degrading actinobacteria from Brazilian soils, a promising strain was selected and identified as Streptomyces sp. SLBA-08. This strain was tested for cellulase production under submerged fermentation in a mineral medium using different carbon sources (sisal bagasse, sugarcane bagasse and straw), as well as ammonium sulphate in different concentrations as nitrogen source. The results showed that medium containing 2.4% (w/v) sisal bagasse and 0.3% (w/v) ammonium sulphate resulted in the highest production of carboxymethylcellulase (1.11 U mL-1), after 48 hours. The pH and temperature profile showed optimal activity at pH 6.0 and 50 °C. As for thermostability, carboxymethylcellulases were tolerant at 50 °C, retaining 70% of the maximal activity even after 2h of incubation. The results obtained indicate that Streptomyces sp. SLBA-08 was capable of producing CMCase using lignocellulosic residues, especially sisal bagasse