Avanthi Althuri
Indian Institute of Technology - Kharagpur, India
Title: Simultaneous delignification and saccharification of mixed lignocellulosics for improved ethanol production in a single bioreactor: An eco-friendly enzymatic venture
Biography
Biography: Avanthi Althuri
Abstract
Lignocellulosic ethanol is the energy of the future that has the potential to replace petro-fuels when driven by a simple and competent biomass processing technology[1,2]. In the midst of alarming environmental consequences of industrialization and excessive fossil fuel combustion, it is obligatory to seek for a greener and benign approach for 2G ethanol production[3]. The present study is one such attempt that deals with enzymatic processing of carbon neutral lignocellulosics. For this a blend of nonedible lignocellulosics namely, Ricinus communis, Saccharum officinarum tops and Saccharum spontaneum was taken as a substrate, since collection of a single type of biomass to feed a refinery is time consuming, laborious and cost intensive. Whereas mixed feedstocks are readily available, sustainable and moreover are tailor made to fit in the best biochemical composition[4]. Biomass blend considered showed high carbon% and energy density[5].
The present study involved simultaneous biomass pretreatment and hydrolysis using a cocktail of enzymes consisting of ligninolytic laccase from Pleurotus djamor and a complete holocellulolytic system from Trichoderma reseei RUT C30 consisting of endo-glucanase, exo-glucanase, β-glucosidase and xylanase for hydrolysis. This enzyme based simultaneous pretreatment-saccharification (SPS) of biomass was found to yield higher reducing sugars (633 mg/g) than sequential pretreatment-saccharification (SePS, 600 mg/g), chemical pretreatment-saccharification (CPS, 367 mg/g) and chemical pretreatment-enzymatic saccharification (CPES, 526 mg/g). Ethanol concentration from co-fermentation of sugars was observed to be 7.1% (v/v). Further improved ethanol concentration up to 7.65% (v/v) was observed when biomass was subjected to SPS for 2h and followed by co-fermentation in same vessel. Statistical model was used to evaluate and validate the performance of this partially consolidated bioprocessing (PCBP). Biomass to ethanol conversion was 26.5% (g/g) with 60.35 g/L ethanol. The adopted process has meagre allied waste streams and thus aids in safeguarding the environment for future generations.