Simultaneous enzymatic saccharification and comminution for the valorization of lignocellulosic biomass toward natural products

Abstract

BackgroundLarge-scale processing of lignocellulosics for glucose production generally relies on high temperature and acidic or alkaline conditions. However, extreme conditions produce chemical contaminants that complicate downstream processing. A method that mainly rely on mechanical and enzymatic reaction completely averts such problem and generates unmodified lignin. Products from this process could find novel applications in the chemicals, feed and food industry. But a large-scale system suitable for this purpose is yet to be developed. In this study we applied simultaneous enzymatic saccharification and communition (SESC) for the pre-treatment of a representative lignocellulosic biomass, cedar softwood, under both laboratory and large-scale conditions.ResultsLaboratory-scale comminution achieved a maximum saccharification efficiency of 80% at the optimum pH of 6. It was possible to recycle the supernatant to concentrate the glucose without affecting the efficiency. During the direct alcohol fermentation of SESC slurry, a high yield of ethanol was attained. The mild reaction conditions prevented the generation of undesired chemical inhibitors. Large-scale SESC treatment using a commercial beads mill system achieved a saccharification efficiency of 60% at an energy consumption of 50 MJ/kg biomass.ConclusionSESC is very promising for the mild and clean processing of lignocellulose to generate glucose and unmodified lignin in a large scale. Economic feasibility is highly dependent on its potential to generate high value natural products for energy, specialty chemicals, feed and food application.

Functional Materials from Plant Biomass Obtained by Simultaneous Enzymatic Saccharification and Communition

“…Copyright 2016, The Royal Society of Chemistry. Reproduced with permission from [95]. Copyright 2018, BMC.…”

“…In this part, we show some example for cost down of SESC process to achieve their industrial application (95).…”

“…However, solution recycling also concentrates other chemicals that may inhibit enzymatic activity (96,97). Hence, we compared the saccharification efficiencies of recycled and nonrecycled systems (95). For this test, instead of using a fresh batch of buffer and enzyme during the second milling stage, the supernatant from the first milling was directly used.…”

“…Here, we present the simultaneous enzymatic saccharification and comminution (SESC) process to create a mild and environmentally-friendly process for the treatment of lignocellulosic biomass for its utilization for a wide variety of novel applications (37,106). Solution recycling resulted in higher product concentration without affecting overall sugar recovery (95). The direct alcohol fermentation of SESC-generated slurry allows for the complete conversion of glucose to ethanol (95).…”

“…Solution recycling resulted in higher product concentration without affecting overall sugar recovery (95). The direct alcohol fermentation of SESC-generated slurry allows for the complete conversion of glucose to ethanol (95). Furthermore, the obtained SESC lignin also use as functional polymer according to its radical scavenging property (61,70,82) and its stiff polyphenolic main chain (77).…”