A Cellulolytic Streptomyces Sp. Isolated from a Highly Oligotrophic Niche Shows Potential for Hydrolyzing Agricultural Wastes

Cellulases fromStreptomycesspecies can be used as auxiliary agents in the pretreatment of lignocellulosic materials, but little work has been done on this topic. Besides,Streptomycesstrains have been identified from Cuatro Cienegas basin, but their potential in the treatment of agricultural wastes has not been demonstrated. In this work aStreptomycessp., strain CC48 isolated from the oligotrophic environment, shows high levels of cellulolytic activity (0.76 U/ mL at pH 7.0, 60 degrees C) in minimum medium supplemented with carboxymethyl cellulose compared with otherStreptomycesstrains and isolates in a bacterial collection. At least three putative cellulases (similar to 30, 40, and 45 kDa) were identified inStreptomycessp. CC48 extracts. The addition of Mg(2+)increased cellulase activity by 23%, whereas other cations resulted in decreased catalysis. Residual cellulolytic activities after 4 and 8 h of incubation at 60 degrees C were similar to 73 and 65%, respectively, and similar to 98% at 50 degrees C after 8 h. Corn cob and wheat straw pretreated with an alkaline method showed saccharification values of 320 and 330 mg/g of reducing sugars per gram of dry substrate, respectively. The significance of this work lies in the fact that data provided here show thatStreptomycessp. strain CC48 is capable of hydrolyzing both maize and wheat substrates, suggesting the potential of this bacterium to hydrolyze agricultural wastes. Also, Cuatro Cienegas Basin may represent a source for efficient cellulolytic microorganisms.

Automated summary

Streptomyces sp. strain CC48 isolated from an oligotrophic environment exhibits high cellulolytic activity and potential for hydrolyzing maize and wheat substrates. Additionally, the study suggests that the Cuatro Cienegas Basin could be a potential source of efficient cellulolytic microorganisms.