Comparative efficiency of different pretreatment methods on enzymatic digestibility of Parthenium sp.

The potential of Parthenium sp. as a feedstock for enzymatic saccharification was investigated by using chemical and biological pretreatment methods. Mainly chemical pretreatments (acid and alkali) were compared with biological pretreatment with lignolytic fungi Marasmiellus palmivorus PK-27. Structural and chemical changes as well as crystallinity of cellulose were examined through scanning electron microscopy, fourier transform infra red and X-ray diffraction analysis, respectively after pretreatment. Total reducing sugar released during enzymatic saccharification of pretreated substrates was also evaluated. Among the pretreatment methods, alkali (1 % NaOH) treated substrate showed high recovery of acid perceptible polymerised lignin (7.53 +/- A 0.5 mg/g) and significantly higher amount of reducing sugar (513.1 +/- A 41.0 mg/gds) compared to uninoculated Parthenium (163.4 +/- A 21.2) after 48 h of hydrolysis. This is the first report of lignolytic enzyme production from M. palmivorus, prevalent in oil palm plantations in Malaysia and its application in biological delignification of Parthenium sp. Alkali (1 % NaOH) treatment proves to be the suitable method of pretreatment for lignin recovery and enhanced yield of reducing sugar which may be used for bioethanol production from Parthenium sp.