Ecology, Environment and Conservation Paper

POTENTIAL OF SODIUM HYDROXIDE PRE TREATMENT OF PROSOPIS JULIFLORA FOR FERMENTABLE SUGAR PRODUCTION

Vijayakumar Palled, M. Anantachar, M. Veerangouda, K.V. Prakash, C.T. Ramachandra, Nagaraj M. Naik and R.V. Beladadhi

Abstract

The present study aimed at investigating the potential of sodium hydroxide (NaOH) as a viable alkaline reagent for lignocellulosic pre treatment considering its various benefits of pre treatment. Prosopis juliflora was pre treated with different NaOH concentrations of 1–3 % for varying treatment times of 15-60 min at temperatures of 100, 120 and 140 °C in an autoclave. Maximum lignin reductions at different temperatures were all obtained at the combinations of highest NaOH concentrations and longest treatment times, which indicated a close relationship between pre treatment severity and lignin reduction. The highest carbohydrate retention of 65.09 per cent was observed in the sample pre treated at 120 °C with 2% NaOH and 60 min. Three pre treatment conditions were selected for subsequent enzymatic hydrolysis with Cellic CTec2® enzyme complex for fermentable sugar production along with untreated biomass as control to study the soaking effect. The biomass pretreated with 2.0 % NaOH for 1 h at 120 °C and loaded with 30% enzyme was determined to be the most effective as it resulted in generation of 583.9 mg sugar/g biomass for a corresponding carbohydrate conversion of 90.86 %.