LABORATORY SCALE STUDIES TO IMPROVE THE PRODUCTION OF XYLANASES BY Paenibacillus sp. AR247

DI MARCO, ENZO; SORAIRE, PABLO MARTÍN; PEROTTI, NORA INÉS; BRU, ELENA; MARTINEZ, M. ALEJANDRA

Rosario

Congreso; IX Congreso Argentino de Microbiología General SAMIGE; 2013

SAMIGE (Sociedad Argentina de MIcrobiología)

Microbial xylanases and cellulases play a main role in the growing demand for fuels fromlignocellulosic biomass, from which the hemicellulose represents 20% to 30% being the xylan its main polymer. Thus, xylan degradation through several glycosyl hydrolases, xylanases as a whole, is a significant factor towards substantial improvements in biofuel production. In addition, the xylanases act in a complementary and often synergistic manner with cellulases, allowing to a more efficient utilization lignocellulosic biomass and other agro-industrial residues.In this study, the production of xylanases from a bacterial isolate from sugarcane bagasse, designated AR247, was evaluated and improved. This strain, selected from several xylanase producing bacteria and was taxonomically identified as a member of Paenibacillus spp. according to sequence analyses of the 16S and 23S rRNA, gyrB and rpoB genes.In order to improve the extracellular xylanases production by Paenibacillus sp. AR247, the medium components were studied using a 29-4 fractional factorial design type. The experimental design and data analysis were performed using the Design Expert 7.0.3 software. The medium components evaluated were xylan, as sole carbon source and as inducer of the enzyme of interest, organic and inorganic nitrogen sources, phosphates, Ca II, Mg II and Tween 80 as nutrient uptake enhancer.As a result, we defined a culture medium for the production of xylanases that allowed us to reach an increase of 9.93 times the enzyme production at laboratory scale. This medium contained theminimum levels of xylan and yeast extract assayed, 5.0 g/L and 0.5 g/L, respectively, while theconcentration of Mg II, phosphate and ammonium sulfate were of 0.5 g/L, 1.0 g/L and 0.5 g/L,respectively, which were the highest levels assayed.Finally, analyses of variance of the response evaluated, enzymatic activity, showed that a systematicanalysis of the components of the culture medium by factorial design, as we performed, is a valuable tool for assessing and optimizing the influence of culture medium components for xylanase production.