Obtaining fermentable sugars from pine sawdust sequentially pretreated with acid-base

RODRÍGUEZ, MARÍA DANIELA; CASTRILLO, MARÍA LORENA; VELÁZQUEZ, JUAN ERNESTO; KRAMER, GUSTAVO RAÚL; SEDLER, CYNTIA; ZAPATA, PEDRO DARÍO; VILLALBA, LAURA

REVISTA INTERNACIONAL DE CONTAMINACIóN AMBIENTAL

CENTRO CIENCIAS ATMOSFERA UNAM

Año: 2017 vol. 33 p. 317 - 324

0188-4999

The use of lignocellulosic waste constitutes an abundant and inexpensive source; it also offers a solution to the problem of waste disposal. The aim of the study was to evaluate the effect of different conditions of a sequential acid-base pretreatment of pine sawdust, through the release of reducing sugars in the saccharification step. The lignocellulosic material was pretreated in two stages: acid pretreatment (PT1), using sulfuric acid and basic pretreatment (PT2), employing sodium hydroxide at three levels each one: 1, 2 and 3 [%] in a factorial design. Enzymatic hydrolysis was carried out at 50 ºC and 150 rpm in 50 mL vials. Samples were taken at 0.15, 24, 48, 72 and 96 h. The percentage of acid soluble lignin and the concentration of reducing sugars were determined. The optimum level of each factor favoring the highest delignification corresponded to 3 [%] sulfuric acid and 3 [%] sodium hydroxide. The production of reducing sugars was not affected by the PT2, but by the PT1, achieving a maximum for level 0 thereof (2 [%] of sulfuric acid). The sequential acid-base pretreatment was optimized and it was found that this pretreatment improves enzymatic hydrolysis of pine sawdust respect to unpretreated samples. The amount of reducing sugars obtained was comparable to that obtained by other authors.