Selection and molecular characterization of cellulolytic–xylanolytic fungi from surface soil-biomass mixtures from Black Belt sites

Publication date: Available online 10 March 2015 Source:Microbiological Research Author(s): Benedict C. Okeke , Rosine W. Hall , Ananda Nanjundaswamy , M. Sue Thomson , Yasaman Deravi , Leah Sawyer , Andrew Prescott Plant biomass is an abundant renewable natural resource that can be transformed into chemical feedstocks. Enzymes used in saccharification of lignocellulosic biomass are a major part of biofuel production costs. A cocktail of cellulolytic and xylanolytic enzymes are required for optimal saccharification of biomass. Accordingly, thirty-two fungal pure cultures were obtained from surface soil-biomass mixtures collected from Black Belt sites in Alabama by culturing on lignocellulosic biomass medium. The fungal strains were screened for the coproduction of cellulolytic and xylanolytic enzymes. Strains that displayed promising levels of cellulolytic and xylanolytic enzymes were characterized by molecular analysis of DNA sequences from the large subunit and internal transcribed spacer (ITS) of their ribosomal RNA gene. Nucleotide sequence analysis revealed that two most promising isolates FS22A and FS5A were most similar to Penicillium janthinellum and Trichoderma virens. Production dynamics of cellulolytic and xylanolytic enzymes from these two strains were explored in submerged fermentation. Volumetric productivity after 120h incubation was 121.08units/L/h and 348units/L/h for the filter paper cellulase and xylanase of strain FS22A, and 90.83units/L/h and 3...
Source: Microbiological Research - Category: Infectious Diseases Source Type: research