Consolidated bioprocessing for biofuel‐ethanol production from pine needle biomass

Abstract

Lignocellulosic‐bioethanol‐fuel (LBF) technology faces challenges due to cost/energy intensive nature of lignocellulosic biomass (LB) pretreatment and saccharification. Ionic liquid (IL) based pretreatment of LB has recently emerged as an environmentally friendly approach. However, for saccharification of IL pretreated LB, IL stable enzymes must be used else the latter may be inhibited. Furthermore, availability of IL stable enzymes may help designing novel consolidated process by in situ coupling of IL mediated pretreatment of LB and enzymatic saccharification processes in a single vessel, that is, one pot consolidated bioprocess (OPCB). OPCB may potentially offer new avenues for technoeconomic feasibility of LBF. In this study, an OPCB was developed and optimized for the first time for bioethanol production from pine needle biomass (PNB) using in situ IL pretreatment and enzymatic saccharification in a single pot. Various process parameters, namely, biomass loading, reaction time, and cellulase/xylanase enzyme dose were optimized, and sugar yield of 1.88 g per five gram of PNB was obtained. The sugar hydrolysate obtained was subjected to ethanol fermentation using dual yeast culture, that is, Saccharomyces cerevisiae and Pichia stipitis. The maximum ethanol yield of 0.148 g/g PNB was obtained after 72 h of fermentation representing an efficiency of 41.39%. The study shows that consolidated processing of PNB may be an efficient, sustainable, and feasible approach for valorization of PNB for industrial production of second generation ethanol‐biofuel. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 546–552, 2018

Recent advances in bioethanol production from lignocelluloses: a comprehensive review with a focus on enzyme engineering and designer biocatalysts

“…In another study, pine needle biomass was pretreated using IL followed by fermentation using S. cerevisiae and P. stipitis in a CBP system. The ethanol yield of 0.148 g/g was obtained after 72 h, and the fermentation efficiency of system was found at 41.39% (Vaid et al, 2018). Recently, recombinant S. cerevisiae ER T12 and M2n T1 strains (harboring integrated temA and temG Opt gene cassettes) simultaneously expressing αamylase and glucoamylase, produced 89.35 g/L and 98.13 g/L ethanol from starchy biomass in a single step CBP system at 30℃ after 192 h with carbon conversion of 87% and 94%, respectively (Cripwell et al, 2019).…”

Underutilized Lignocellulosic Waste as Sources of Feedstock for Biofuel Production in Developing Countries

“…Recently, a study (Cunha et al, 2020) reported the use of engineered industrial Saccharomyces cerevisiae strains (whole-cell biocatalysts) as a promising commercial enzymatic cocktail for the production of ethanol from corn cob biomass. Other authors have also documented a one-pot CBP as a potential means for techno-economic feasibility of lignocellulosic-bioethanol-fuel production (Vaid et al, 2018). The authors optimized bioethanol production from pine needle biomass via single pot in-situ ionic liquid-based pretreatment and enzymatic saccharification.…”

Valorization of mushroom by‐products: a review

“…Consolidated processing, a bio-manufacturing concept, was first implemented in the field of bio-fuel preparation from cellulose and lignin. 95 The industrial yeast strains with high enzyme activity and strong adverse environment tolerance are used to integrate fermentation enzyme production, cellulase hydrolysis and sugar fermentation in one reaction system, where agricultural/industrial by-products are used as raw materials to produce ethanol. Mushroom by-products are rich in fiber components, especially SMS, which is mainly composed of lignin similar to straw, sawdust, and corncob.…”