Articles

Special Issue from the NSERC Bioconversion network workshop: pretreatment and fractionation of biomass for biorefinery/biofuels

Authors: Jack Saddler and Linoj Kumar

Bioconversion of lignocellulose: inhibitors and detoxification

Bioconversion of lignocellulose by microbial fermentation is typically preceded by an acidic thermochemical pretreatment step designed to facilitate enzymatic hydrolysis of cellulose. Substances formed during ...

Authors: Leif J Jönsson, Björn Alriksson and Nils-Olof Nilvebrant

Assessing the molecular structure basis for biomass recalcitrance during dilute acid and hydrothermal pretreatments

The production of cellulosic ethanol from biomass is considered a promising alternative to reliance on diminishing supplies of fossil fuels, providing a sustainable option for fuels production in an environmen...

Authors: Yunqiao Pu, Fan Hu, Fang Huang, Brian H Davison and Arthur J Ragauskas

Survey of renewable chemicals produced from lignocellulosic biomass during ionic liquid pretreatment

Lignin is often overlooked in the valorization of lignocellulosic biomass, but lignin-based materials and chemicals represent potential value-added products for biorefineries that could significantly improve t...

Authors: Patanjali Varanasi, Priyanka Singh, Manfred Auer, Paul D Adams, Blake A Simmons and Seema Singh

Integration of pulp and paper technology with bioethanol production

Despite decades of work and billions of dollars of investments in laboratory and pilot plant projects, commercial production of cellulosic ethanol is only now beginning to emerge. Because of: (1)high technical...

Authors: Richard B Phillips, Hasan Jameel and Hou Min Chang

Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam

Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or chemical pulping. However, there is a lack of high-value applications f...

Authors: Xuejun Pan and Jack N Saddler

Ethanol and biogas production after steam pretreatment of corn stover with or without the addition of sulphuric acid

Lignocellulosic biomass, such as corn stover, is a potential raw material for ethanol production. One step in the process of producing ethanol from lignocellulose is enzymatic hydrolysis, which produces fermen...

Authors: Pia-Maria Bondesson, Mats Galbe and Guido Zacchi

Saccharification of recalcitrant biomass and integration options for lignocellulosic sugars from Catchlight Energy’s sugar process (CLE Sugar)

Woody biomass is one of the most abundant biomass feedstocks, besides agriculture residuals in the United States. The sustainable harvest residuals and thinnings alone are estimated at about 75 million tons/ye...

Authors: Johnway Gao, Dwight Anderson and Benjamin Levie

Lignosulfonate and elevated pH can enhance enzymatic saccharification of lignocelluloses

Nonspecific (nonproductive) binding (adsorption) of cellulase by lignin has been identified as a key barrier to reduce cellulase loading for economical sugar and biofuel production from lignocellulosic biomass...

Authors: ZJ Wang, TQ Lan and JY Zhu

Understanding of alkaline pretreatment parameters for corn stover enzymatic saccharification

Previous research on alkaline pretreatment has mainly focused on optimization of the process parameters to improve substrate digestibility. To achieve satisfactory sugar yield, extremely high chemical loading ...

Authors: Ye Chen, Mark A Stevens, Yongming Zhu, Jason Holmes and Hui Xu

Cofactor engineering through heterologous expression of an NADH oxidase and its impact on metabolic flux redistribution in Klebsiella pneumoniae

Acetoin is an important bio-based platform chemical. However, it is usually existed as a minor byproduct of 2,3-butanediol fermentation in bacteria.

Authors: Xiao-Jun Ji, Zhi-Fang Xia, Ning-Hua Fu, Zhi-Kui Nie, Meng-Qiu Shen, Qian-Qian Tian and He Huang

Using a model filamentous fungus to unravel mechanisms of lignocellulose deconstruction

Filamentous fungi are the main source of enzymes used to degrade lignocellulose to fermentable sugars for the production of biofuels. While the most commonly used organism for the production of cellulases in a...

Authors: Elizabeth A Znameroski and N Louise Glass

Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

It is necessary to develop efficient methods to produce renewable fuels from lignocellulosic biomass. One of the main challenges to the industrialization of lignocellulose conversion processes is the large amo...

Authors: Noah Weiss, Johan Börjesson, Lars Saaby Pedersen and Anne S Meyer

Ultra-structural mapping of sugarcane bagasse after oxalic acid fiber expansion (OAFEX) and ethanol production by Candida shehatae and Saccharomyces cerevisiae

Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources of energy that can be produced from non-food/feed-based substrates. Due to its abundance, sugarcane bagasse (S...

Authors: Anuj K Chandel, Felipe F A Antunes, Virgilio Anjos, Maria J V Bell, Leonarde N Rodrigues, Om V Singh, Carlos A Rosa, Fernando C Pagnocca and Silvio S da Silva

A pyrosequencing-based metagenomic study of methane-producing microbial community in solid-state biogas reactor

A solid-state anaerobic digestion method is used to produce biogas from various solid wastes in China but the efficiency of methane production requires constant improvement. The diversity and abundance of rele...

Authors: An Li, Ya’nan Chu, Xumin Wang, Lufeng Ren, Jun Yu, Xiaoling Liu, Jianbin Yan, Lei Zhang, Shuangxiu Wu and Shizhong Li

Simultaneous saccharification and co-fermentation for bioethanol production using corncobs at lab, PDU and demo scales

While simultaneous saccharification and co-fermentation (SSCF) is considered to be a promising process for bioconversion of lignocellulosic materials to ethanol, there are still relatively little demo-plant da...

Authors: Rakesh Koppram, Fredrik Nielsen, Eva Albers, Annika Lambert, Sune Wännström, Lars Welin, Guido Zacchi and Lisbeth Olsson

Characterization and genomic analysis of kraft lignin biodegradation by the beta-proteobacterium Cupriavidus basilensis B-8

Lignin materials are abundant and among the most important potential sources for biofuel production. Development of an efficient lignin degradation process has considerable potential for the production of a va...

Authors: Yan Shi, Liyuan Chai, Chongjian Tang, Zhihui Yang, Huan Zhang, Runhua Chen, Yuehui Chen and Yu Zheng

RNA-seq based identification and mutant validation of gene targets related to ethanol resistance in cyanobacterial Synechocystis sp. PCC 6803

Fermentation production of biofuel ethanol consumes agricultural crops, which will compete directly with the food supply. As an alternative, photosynthetic cyanobacteria have been proposed as microbial factori...

Authors: Jiangxin Wang, Lei Chen, Siqiang Huang, Jie Liu, Xiaoyue Ren, Xiaoxu Tian, Jianjun Qiao and Weiwen Zhang

Thermophilic fermentation of acetoin and 2,3-butanediol by a novel Geobacillus strain

Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination.

Authors: Zijun Xiao, Xiangming Wang, Yunling Huang, Fangfang Huo, Xiankun Zhu, Lijun Xi and Jian R Lu

Comparative study of sulfite pretreatments for robust enzymatic saccharification of corn cob residue

Corn cob residue (CCR) is a kind of waste lignocellulosic material with enormous potential for bioethanol production. The moderated sulphite processes were used to enhance the hydrophily of the material by sul...

Authors: Lingxi Bu, Yang Xing, Hailong Yu, Yuxia Gao and Jianxin Jiang

Biogas from Macroalgae: is it time to revisit the idea?

The economic and environmental viability of dedicated terrestrial energy crops is in doubt. The production of large scale biomass (macroalgae) for biofuels in the marine environment was first tested in the lat...

Authors: Adam D Hughes, Maeve S Kelly, Kenneth D Black and Michele S Stanley

Carbon catabolite repression in Thermoanaerobacterium saccharolyticum

The thermophilic anaerobe Thermoanaerobacterium saccharolyticum is capable of directly fermenting xylan and the biomass-derived sugars glucose, cellobiose, xylose, mannose, galactose and arabinose. It has been me...

Authors: Vasiliki Tsakraklides, A Joe Shaw, Bethany B Miller, David A Hogsett and Christopher D Herring

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitr...

Authors: Pia Damm Petersen, Jane Lau, Berit Ebert, Fan Yang, Yves Verhertbruggen, Jin Sun Kim, Patanjali Varanasi, Anongpat Suttangkakul, Manfred Auer, Dominique Loqué and Henrik Vibe Scheller

Reaction wood – a key cause of variation in cell wall recalcitrance in willow

The recalcitrance of lignocellulosic cell wall biomass to deconstruction varies greatly in angiosperms, yet the source of this variation remains unclear. Here, in eight genotypes of short rotation coppice will...

Authors: Nicholas JB Brereton, Michael J Ray, Ian Shield, Peter Martin, Angela Karp and Richard J Murphy

Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and ...

Authors: Elda I España-Gamboa, Javier O Mijangos-Cortés, Galdy Hernández-Zárate, Jorge A Domínguez Maldonado and Liliana M Alzate-Gaviria

Evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation and a consolidated bioprocessing approach

The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact...

Authors: Kelsey L Yee, Miguel Rodriguez Jr, Timothy J Tschaplinski, Nancy L Engle, Madhavi Z Martin, Chunxiang Fu, Zeng-Yu Wang, Scott D Hamilton-Brehm and Jonathan R Mielenz

Bioenergy grass feedstock: current options and prospects for trait improvement using emerging genetic, genomic, and systems biology toolkits

For lignocellulosic bioenergy to become a viable alternative to traditional energy production methods, rapid increases in conversion efficiency and biomass yield must be achieved. Increased productivity in bio...

Authors: Frank Alex Feltus and Joshua P Vandenbrink

Production of four Neurospora crassa lytic polysaccharide monooxygenases in Pichia pastoris monitored by a fluorimetric assay

Recent studies demonstrate that enzymes from the glycosyl hydrolase family 61 (GH61) show lytic polysaccharide monooxygenase (PMO) activity. Together with cellobiose dehydrogenase (CDH) an enzymatic system cap...

Authors: Roman Kittl, Daniel Kracher, Daniel Burgstaller, Dietmar Haltrich and Roland Ludwig

Paradigmatic status of an endo- and exoglucanase and its effect on crystalline cellulose degradation

Microorganisms employ a multiplicity of enzymes to efficiently degrade the composite structure of plant cell wall cellulosic polysaccharides. These remarkable enzyme systems include glycoside hydrolases (cellu...

Authors: Sarah Moraïs, Yoav Barak, Raphael Lamed, David B Wilson, Qi Xu, Michael E Himmel and Edward A Bayer

Derivatization-free gel permeation chromatography elucidates enzymatic cellulose hydrolysis

The analysis of cellulose molecular weight distributions by gel permeation chromatography (GPC) is a powerful tool to obtain detailed information on enzymatic cellulose hydrolysis, supporting the development o...

Authors: Philip Engel, Lea Hein and Antje C Spiess

Boosting the free fatty acid synthesis of Escherichia coli by expression of a cytosolic Acinetobacter baylyi thioesterase

Thioesterases remove the fatty acyl moiety from the fatty acyl-acyl carrier proteins (ACPs), releasing them as free fatty acids (FFAs), which can be further used to produce a variety of fatty acid-based biofue...

Authors: Yanning Zheng, Lingling Li, Qiang Liu, Wen Qin, Jianming Yang, Yujin Cao, Xinglin Jiang, Guang Zhao and Mo Xian

Transcriptome profiling of Zymomonas mobilis under ethanol stress

High tolerance to ethanol is a desirable characteristics for ethanologenic strains used in industrial ethanol fermentation. A deeper understanding of the molecular mechanisms underlying ethanologenic strains t...

Authors: Ming-xiong He, Bo Wu, Zong-xia Shui, Qi-chun Hu, Wen-guo Wang, Fu-rong Tan, Xiao-yu Tang, Qi-li Zhu, Ke Pan, Qing Li and Xiao-hong Su

Transcriptomic analysis of the oleaginous microalga Neochloris oleoabundans reveals metabolic insights into triacylglyceride accumulation

The lack of sequenced genomes for oleaginous microalgae limits our understanding of the mechanisms these organisms utilize to become enriched in triglycerides. Here we report the de novo transcriptome assembly an...

Authors: Hamid Rismani-Yazdi, Berat Z Haznedaroglu, Carol Hsin and Jordan Peccia

Microbial β-glucosidases from cow rumen metagenome enhance the saccharification of lignocellulose in combination with commercial cellulase cocktail

A complete saccharification of plant polymers is the critical step in the efficient production of bio-alcohols. Beta-glucosidases acting in the degradation of intermediate gluco-oligosaccharides produced by ce...

Authors: Mercedes V Del Pozo, Lucía Fernández-Arrojo, Jorge Gil-Martínez, Alejandro Montesinos, Tatyana N Chernikova, Taras Y Nechitaylo, Agnes Waliszek, Marta Tortajada, Antonia Rojas, Sharon A Huws, Olga V Golyshina, Charles J Newbold, Julio Polaina, Manuel Ferrer and Peter N Golyshin

A constraint-based model of Scheffersomyces stipitis for improved ethanol production

As one of the best xylose utilization microorganisms, Scheffersomyces stipitis exhibits great potential for the efficient lignocellulosic biomass fermentation. Therefore, a comprehensive understanding of its uniq...

Authors: Ting Liu, Wei Zou, Liming Liu and Jian Chen

Down-regulation of the caffeic acid O-methyltransferase gene in switchgrass reveals a novel monolignol analog

Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more co...

Authors: Timothy J Tschaplinski, Robert F Standaert, Nancy L Engle, Madhavi Z Martin, Amandeep K Sangha, Jerry M Parks, Jeremy C Smith, Reichel Samuel, Nan Jiang, Yunqiao Pu, Arthur J Ragauskas, Choo Y Hamilton, Chunxiang Fu, Zeng-Yu Wang, Brian H Davison, Richard A Dixon…

The flat-plate plant-microbial fuel cell: the effect of a new design on internal resistances

Due to a growing world population and increasing welfare, energy demand worldwide is increasing. To meet the increasing energy demand in a sustainable way, new technologies are needed. The Plant-Microbial Fuel...

Authors: Marjolein Helder, David PBTB Strik, Hubertus VM Hamelers and Cees JN Buisman

Improved ethanol yield and reduced minimum ethanol selling price (MESP) by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 2) Techno-economic analysis

Our companion paper discussed the yield benefits achieved by integrating deacetylation, mechanical refining, and washing with low acid and low temperature pretreatment. To evaluate the impact of the modified p...

Authors: Ling Tao, Xiaowen Chen, Andy Aden, Eric Kuhn, Michael E Himmel, Melvin Tucker, Mary Ann A Franden, Min Zhang, David K Johnson, Nancy Dowe and Richard T Elander

Proteomic analysis reveals resistance mechanism against biofuel hexane in Synechocystis sp. PCC 6803

Recent studies have demonstrated that photosynthetic cyanobacteria could be an excellent cell factory to produce renewable biofuels and chemicals due to their capability to utilize solar energy and CO₂ as the sol...

Authors: Jie Liu, Lei Chen, Jiangxin Wang, Jianjun Qiao and Weiwen Zhang

Elucidation of the effect of ionic liquid pretreatment on rice husk via structural analyses

In the present study, three ionic liquids, namely 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), and 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM]DEP)...

Authors: Teck Nam Ang, Gek Cheng Ngoh, Adeline Seak May Chua and Min Gyu Lee

Erratum to: Direct production of biodiesel from high-acid value Jatropha oil with solid acid catalyst derived from lignin

Authors: Fei-ling Pua, Zhen Fang, Sarani Zakaria, Feng Guo and Chin-hua Chia

Cytosolic re-localization and optimization of valine synthesis and catabolism enables increased isobutanol production with the yeast Saccharomyces cerevisiae

The branched chain alcohol isobutanol exhibits superior physicochemical properties as an alternative biofuel. The yeast Saccharomyces cerevisiae naturally produces low amounts of isobutanol as a by-product during...

Authors: Dawid Brat, Christian Weber, Wolfram Lorenzen, Helge B Bode and Eckhard Boles

One-pot bioethanol production from cellulose by co-culture of Acremonium cellulolyticus and Saccharomyces cerevisiae

While the ethanol production from biomass by consolidated bioprocess (CBP) is considered to be the most ideal process, simultaneous saccharification and fermentation (SSF) is the most appropriate strategy in p...

Authors: Enoch Y Park, Kazuya Naruse and Tatsuya Kato

Hyperthermophilic endoglucanase for in planta lignocellulose conversion

The enzymatic conversion of lignocellulosic plant biomass into fermentable sugars is a crucial step in the sustainable and environmentally friendly production of biofuels. However, a major drawback of enzymes ...

Authors: Holger Klose, Juliane Röder, Michele Girfoglio, Rainer Fischer and Ulrich Commandeur

Sugarcane bagasse pretreatment using three imidazolium-based ionic liquids; mass balances and enzyme kinetics

Effective pretreatment is key to achieving high enzymatic saccharification efficiency in processing lignocellulosic biomass to fermentable sugars, biofuels and value-added products. Ionic liquids (ILs), still ...

Authors: Sergios Kimon Karatzos, Leslie Alan Edye and William Orlando Sinclair Doherty

Very high gravity ethanol fermentation by flocculating yeast under redox potential-controlled conditions

Very high gravity (VHG) fermentation using medium in excess of 250 g/L sugars for more than 15% (v) ethanol can save energy consumption, not only for ethanol distillation, but also for distillage treatment; ho...

Authors: Chen-Guang Liu, Na Wang, Yen-Han Lin and Feng-Wu Bai

Improved ethanol yield and reduced Minimum Ethanol Selling Price (MESP) by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 1) Experimental

Historically, acid pretreatment technology for the production of bio-ethanol from corn stover has required severe conditions to overcome biomass recalcitrance. However, the high usage of acid and steam at seve...

Authors: Xiaowen Chen, Ling Tao, Joseph Shekiro, Ali Mohaghaghi, Steve Decker, Wei Wang, Holly Smith, Sunkyu Park, Michael E Himmel and Melvin Tucker

Epigallocatechin gallate incorporation into lignin enhances the alkaline delignification and enzymatic saccharification of cell walls

Lignin is an integral component of the plant cell wall matrix but impedes the conversion of biomass into biofuels. The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic m...

Authors: Sasikumar Elumalai, Yuki Tobimatsu, John H Grabber, Xuejun Pan and John Ralph

Hemicelluloses negatively affect lignocellulose crystallinity for high biomass digestibility under NaOH and H₂SO₄ pretreatments in Miscanthus

Lignocellulose is the most abundant biomass on earth. However, biomass recalcitrance has become a major factor affecting biofuel production. Although cellulose crystallinity significantly influences biomass sa...

Authors: Ning Xu, Wei Zhang, Shuangfeng Ren, Fei Liu, Chunqiao Zhao, Haofeng Liao, Zhengdan Xu, Jiangfeng Huang, Qing Li, Yuanyuan Tu, Bin Yu, Yanting Wang, Jianxiong Jiang, Jingping Qin and Liangcai Peng

Torque measurements reveal large process differences between materials during high solid enzymatic hydrolysis of pretreated lignocellulose

A common trend in the research on 2^nd generation bioethanol is the focus on intensifying the process and increasing the concentration of water insoluble solids (WIS) throughout the process. However, increasing th...

Authors: Benny Palmqvist and Gunnar Lidén