Characterization of enzymatic activity of a Paenibacillus sp. xylanolytic strain isolated from soil

GHIO, S; PICCINI F.E:; INSANI M; PARMA, M; GRASSO D; CAMPOS E

Rosario

Congreso; L Reunión Anual Sociedad Argentina de Investigación en Bioquimica y Biología Molecular- SAIB 2014; 2014

SAIB

Improving xylan deconstruction is of high interest for increasing yields of fermentable sugars from lignocellulosic biomass, which is important in the second generation bioethanol production as well as for pulp and paper industry. Biodegradation of xylan requires the action of two main enzymes: xylanases and beta xylosidases. With the objective of prospecting hemicellulolytic environmental bacteria, a xylanolytic strain has been isolated from a forest soil sample and identified by 16S rRNA sequencing as Paenibacillus sp. Major cellular fatty acids were identified as: anteiso-C15:0 (38.53%), anteiso-C17:0 (38.53%), iso-C16:00 (17.8%) and C16:0 (3.67%), in accordance to the profile found for this genus. The effect of cultivation of the microorganism under different cellulosic substrates was evaluated and the maximum xylanase activity was obtained when growing on minimal medium supplied with xylan from birchwood, for 72 hours. Also, the best condition of reaction was achieved at pH 7 and 50 °C. HPLC analysis of hydrolysis products released from xylan by crude extracts showed four main peaks corresponding to xylotetraose, xylotriose, xylobiose and xylose, indicating that this microorganism has the set of enzymes to obtain a complete degradation of the xylan. Therefore, this strain results of high interest for potential industrial applications and to study its xylanolytic system.