Cellulose is an organic compound with the formula (C
6H
10O
5)
n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%.
Cellulase is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides. The name is also used for any naturally occurring mixture or complex of various such enzymes, that act serially or synergistically to decompose cellulosic material.
Ethanol fuel is ethyl alcohol, the same type of alcohol found in alcoholic beverages, used as fuel. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. The first production car running entirely on ethanol was the Fiat 147, introduced in 1978 in Brazil by Fiat. Ethanol is commonly made from biomass such as corn or sugarcane. World ethanol production for transport fuel tripled between 2000 and 2007 from 17×109 liters (4.5×10^9 U.S. gal; 3.7×10^9 imp gal) to more than 52×109 liters (14×10^9 U.S. gal; 11×10^9 imp gal). From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%. In 2011 worldwide ethanol fuel production reached 8.46×109 liters (2.23×10^9 U.S. gal; 1.86×10^9 imp gal) with the United States of America and Brazil being the top producers, accounting for 62.2% and 25% of global production, respectively. US ethanol production reached 57.54×109 liters (15.20×10^9 U.S. gal; 12.66×10^9 imp gal) in May 2017.
Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico. Switchgrass is one of the dominant species of the central North American tallgrass prairie and can be found in remnant prairies, in native grass pastures, and naturalized along roadsides. It is used primarily for soil conservation, forage production, game cover, as an ornamental grass, in phytoremediation projects, fiber, electricity, heat production, for biosequestration of atmospheric carbon dioxide, and more recently as a biomass crop for ethanol and butanol.
Cellulosic ethanol is ethanol produced from cellulose rather than from the plant's seeds or fruit. It can be produced from grasses, wood, algae, or other plants. It is generally discussed for use as a biofuel. The carbon dioxide that plants absorb as they grow offsets some of the carbon dioxide emitted when ethanol made from them is burned, so cellulosic ethanol fuel has the potential to have a lower carbon footprint than fossil fuels.
Various alcohols are used as fuel for internal combustion engines. The first four aliphatic alcohols are of interest as fuels because they can be synthesized chemically or biologically, and they have characteristics which allow them to be used in internal combustion engines. The general chemical formula for alcohol fuel is CnH2n+1OH.
Bioconversion, also known as biotransformation, is the conversion of organic materials, such as plant or animal waste, into usable products or energy sources by biological processes or agents, such as certain microorganisms. One example is the industrial production of cortisone, which one step is the bioconversion of progesterone to 11-alpha-Hydroxyprogesterone by Rhizopus nigricans. Another example is the bioconversion of glycerol to 1,3-propanediol, which is part of scientific research for many decades.
Cellulosomes are multi-enzyme extracellular complexes. Cellulosomes are associated with the cell surface and mediate cell attachment to insoluble substrates and degrade them to soluble products which are then absorbed. Cellulosome complexes are intricate, multi-enzyme machines, produced by many cellulolytic microorganisms. They are produced by microorganisms for efficient degradation of plant cell wall polysaccharides, notably cellulose, the most abundant organic polymer on Earth. The multiple subunits of cellulosomes are composed of numerous functional domains that interact with each other and with the cellulosic substrate. One of these subunits, a large glycoprotein "scaffoldin", is a distinctive class of non-catalytic scaffolding polypeptides. The scaffoldin subunit selectively integrates the various cellulases and xylanase subunits into the cohesive complex, by combining its cohesin domains with a typical dockerin domain present on each of the subunit enzymes. The scaffoldin of some cellulosomes, an example being that of Clostridium thermocellum, contains a carbohydrate-binding module that adheres cellulose to the cellulosomal complex.
Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Each has distinct chemical behavior. Being a composite of three very different components makes the processing of lignocellulose challenging. The evolved resistance to degradation or even separation is referred to as recalcitrance. Overcoming this recalcitrance to produce useful, high value products requires a combination of heat, chemicals, enzymes, and microorganisms. These carbohydrate-containing polymers contain different sugar monomers and they are covalently bound to lignin.
The United States produces mainly biodiesel and ethanol fuel, which uses corn as the main feedstock. The US is the world's largest producer of ethanol, having produced nearly 16 billion gallons in 2017 alone. The United States, together with Brazil accounted for 85 percent of all ethanol production, with total world production of 27.05 billion gallons. Biodiesel is commercially available in most oilseed-producing states. As of 2005, it was somewhat more expensive than fossil diesel, though it is still commonly produced in relatively small quantities.
Butanol may be used as a fuel in an internal combustion engine. It is more similar to gasoline than it is to ethanol. A C4-hydrocarbon, butanol is a drop-in fuel and thus works in vehicles designed for use with gasoline without modification. Both n-butanol and isobutanol have been studied as possible fuels. Both can be produced from biomass as well as from fossil fuels. The chemical properties depend on the isomer, not on the production method.
Renewable Fuels are fuels produced from renewable resources. Examples include: biofuels and Hydrogen fuel. This is in contrast to non-renewable fuels such as natural gas, LPG (propane), petroleum and other fossil fuels and nuclear energy. Renewable fuels can include fuels that are synthesized from renewable energy sources, such as wind and solar. Renewable fuels have gained in popularity due to their sustainability, low contributions to the carbon cycle, and in some cases lower amounts of greenhouse gases. The geo-political ramifications of these fuels are also of interest, particularly to industrialized economies which desire independence from Middle Eastern oil.
Trichoderma reesei is a mesophilic and filamentous fungus. It is an anamorph of the fungus Hypocrea jecorina. T. reesei can secrete large amounts of cellulolytic enzymes. Microbial cellulases have industrial application in the conversion of cellulose, a major component of plant biomass, into glucose.
2,5-Dimethylfuran is a heterocyclic compound with the formula (CH3)2C4H2O. Although often abbreviated DMF, it should not be confused with dimethylformamide. A derivative of furan, this simple compound is a potential biofuel, being derivable from cellulose.
Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass in this context means plant materials and animal waste used especially as a source of fuel.
Mascoma Corporation was a U.S. biofuel company founded to produce cellulosic ethanol made from wood and switchgrass. Headquartered in Lebanon, New Hampshire, the company was founded in 2005 by Robert Johnsen (CEO), Lee Lynd and Charles Wyman, two professors from Dartmouth College. The company was named after Mascoma Lake, which is near Lebanon. In November 2014, the yeast-related business assets including the Mascoma name were purchased by Lallemand, Inc. of Montreal, Canada. The R&D facility in Lebanon, NH was renamed Mascoma LLC which is now a subsidiary of Lallemand. The remaining business assets of the former Mascoma Corp. including the thermophilic bacteria technology, pilot plant in Rome, NY, and former headquarters in Waltham, MA were renamed Enchi Corporation.
Caldicellulosiruptor bescii is a species of thermophilic, anaerobic cellulolytic bacteria. It was isolated from a geothermally heated freshwater pool in the Valley of Geysers on the Kamchatka Peninsula in Russia in 1990. The species was originally named Anaerocellum thermophilum, but reclassified in 2010, based on genomic data.
Cellulose 1,4-beta-cellobiosidase is an enzyme of interest for its capability of converting cellulose to useful chemicals, particularly cellulosic ethanol.
Acetivibrio straminisolvens is a moderately thermophilic, aerotolerant and cellulolytic bacterium. It is non-motile, spore-forming, straight or slightly curved rod, with type strain CSK1T. Its genome has been sequenced.
Edward A. Bayer is an American-Israeli scientist.
