Plant cell walls to ethanol

2012 ◽  
Vol 442 (2) ◽  
pp. 241-252 ◽  
Author(s):  
Douglas B. Jordan ◽  
Michael J. Bowman ◽  
Jay D. Braker ◽  
Bruce S. Dien ◽  
Ronald E. Hector ◽  
...  
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Second Generation ◽  
Consolidated Bioprocessing ◽  
Enzymatic Saccharification ◽  
Crystalline Cellulose ◽  
Plant Cell Walls ◽  
Second Generation Bioethanol ◽  
Single Organism ◽  
The Cost

Conversion of plant cell walls to ethanol constitutes second generation bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation and separation. Ultimately, it is desirable to combine as many of the biochemical steps as possible in a single organism to achieve CBP (consolidated bioprocessing). A commercially ready CBP organism is currently unreported. Production of second generation bioethanol is hindered by economics, particularly in the cost of pretreatment (including waste management and solvent recovery), the cost of saccharification enzymes (particularly exocellulases and endocellulases displaying kcat ~1 s−1 on crystalline cellulose), and the inefficiency of co-fermentation of 5- and 6-carbon monosaccharides (owing in part to redox cofactor imbalances in Saccharomyces cerevisiae).

Selective Detection of Crystalline Cellulose in Plant Cell Walls with Sum-Frequency-Generation (SFG) Vibration Spectroscopy

2011 ◽  
Vol 12 (7) ◽  
pp. 2434-2439 ◽  
Author(s):  
Anna L. Barnette ◽  
Laura C. Bradley ◽  
Brandon D. Veres ◽  
Edward P. Schreiner ◽  
Yong Bum Park ◽  
...  
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Sum Frequency Generation ◽  
Crystalline Cellulose ◽  
Selective Detection ◽  
Plant Cell Walls ◽  
Sum Frequency ◽  
Vibration Spectroscopy ◽  
Frequency Generation

The chemical composition of glochids from Opuntia

1976 ◽  
Vol 54 (1-2) ◽  
pp. 173-176 ◽  
Author(s):  
Hayden N. Pritchard ◽  
James A. Hall
Keyword(s):  
Chemical Composition ◽  
Calcium Oxalate ◽  
Plant Cell ◽  
Cell Walls ◽  
Crystalline Cellulose ◽  
Plant Cell Walls ◽  
Infrared Spectrophotometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Cellulose

Glochids of two species of cactus were analyzed using infrared spectrophotometry and x-ray diffraction to determine their chemical constituency. The results were compared with calcium oxalate, a known constituent of many plant crystals, and with pure cellulose, the major component of plant cell walls. The analysis showed the glochids to be pure crystalline cellulose.

scholarly journals Bioethanol Production From Pineapple Wastes

2014 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Alessia Tropea ◽  
David Wilson ◽  
Loredana G. La Torre ◽  
Rosario B. Lo Curto ◽  
Peter Saugman ◽  
...  
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Yield ◽  
Enzymatic Saccharification ◽  
Plant Cell Walls ◽  
Theoretical Yield ◽  
Cellulosic Sugars ◽  
Separate Hydrolysis And Fermentation ◽  
Simultaneous Saccharification

<p>There is great interest in producing bioethanol from biomass and there is much emphasis on exploiting lignocellulose sources, from crop wastes through to energy-rich crops. Some waste streams, however, contain both cellulosic and non-cellulosic sugars. These include wastes from pineapple processing.</p> <p>Pineapple wastes are produced in large amounts throughout the world by canning industries. These wastes are rich in intracellular sugars and plant cell walls which are composed mainly of cellulose, pectic substances and hemicelluloses. The purpose of this study was to investigate the potential to transform such residues into ethanol after enzymatic saccharification of plant cell walls, and fermentation of the resulting simple sugars using the <em>Saccharomyces cerevisiae</em> NCYC 2826 strain. Three different fermentation modes, direct fermentation, separate hydrolysis and fermentation, and simultaneous saccharification and fermentation of the biomass were tested and compared. The results show that the main sugars obtained from pineapple waste were: glucose, uronic acid, xylose, galactose, arabinose and mannose. The highest ethanol yield was achieved after 30 hours of simultaneous saccharification and fermentation, and reached up to 3.9% (v/v), corresponding to the 96% of the theoretical yield.</p>

Modifications ultrastructurales des parois végétales dans le tube digestif d'une larve xylophage Oryctes nasicornis (Coleoptera, Scarabaeidae): rôle des bactéries

1981 ◽  
Vol 59 (10) ◽  
pp. 2020-2029 ◽  
Author(s):  
Colette Bayon
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Gut Contents ◽  
Crystalline Cellulose ◽  
Natural Food ◽  
Plant Cell Walls ◽  
Tube Digestif ◽  
Ultrastructural Modifications

The ultrastructural modifications of plant cell walls have been studied in the food and gut contents from the xylophagous larvae of Oryctes nasicornis. Before ingestion the natural food undergoes a large amount of degradation by fungus-rich microflora of the soil. The break-down of α-cellulose, and amorphous and crystalline cellulose of the secondary walls occurs in the mesenteron and later in the proctodeal dilation where it is greatest. The role of bacteria is recognised and the successive stages of degradation are characterised.

scholarly journals Down-regulation of OsMYB103L distinctively alters beta-1,4-glucan polymerization and cellulose microfibers assembly for enhanced biomass enzymatic saccharification in rice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Leiming Wu ◽  
Mingliang Zhang ◽  
Ran Zhang ◽  
Haizhong Yu ◽  
Hailang Wang ◽  
...  
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cellulose Nanofibers ◽  
Enzymatic Saccharification ◽  
Bioenergy Crops ◽  
Cellulose Biosynthesis ◽  
Plant Cell Walls ◽  
Down Regulation ◽  
Rnai Line ◽  
Rice Mutant

Abstract Background As a major component of plant cell walls, cellulose provides the most abundant biomass resource convertible for biofuels. Since cellulose crystallinity and polymerization have been characterized as two major features accounting for lignocellulose recalcitrance against biomass enzymatic saccharification, genetic engineering of cellulose biosynthesis is increasingly considered as a promising solution in bioenergy crops. Although several transcription factors have been identified to regulate cellulose biosynthesis and plant cell wall formation, much remains unknown about its potential roles for genetic improvement of lignocellulose recalcitrance. Results In this study, we identified a novel rice mutant (Osfc9/myb103) encoded a R2R3-MYB transcription factor, and meanwhile generated OsMYB103L-RNAi-silenced transgenic lines. We determined significantly reduced cellulose levels with other major wall polymers (hemicellulose, lignin) slightly altered in mature rice straws of the myb103 mutant and RNAi line, compared to their wild type (NPB). Notably, the rice mutant and RNAi line were of significantly reduced cellulose features (crystalline index/CrI, degree of polymerization/DP) and distinct cellulose nanofibers assembly. These alterations consequently improved lignocellulose recalcitrance for significantly enhanced biomass enzymatic saccharification by 10–28% at p < 0.01 levels (n = 3) after liquid hot water and chemical (1% H2SO4, 1% NaOH) pretreatments with mature rice straws. In addition, integrated RNA sequencing with DNA affinity purification sequencing (DAP-seq) analyses revealed that the OsMYB103L might specifically mediate cellulose biosynthesis and deposition by regulating OsCesAs and other genes associated with microfibril assembly. Conclusions This study has demonstrated that down-regulation of OsMYB103L could specifically improve cellulose features and cellulose nanofibers assembly to significantly enhance biomass enzymatic saccharification under green-like and mild chemical pretreatments in rice. It has not only indicated a powerful strategy for genetic modification of plant cell walls in bioenergy crops, but also provided insights into transcriptional regulation of cellulose biosynthesis in plants.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Sign in / Sign up

Export Citation Format

Share Document