Biobased Industrial Products Priorities for Research and Commercialization (2000) / Chapter Skim
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2 Raw Material Resource Base
2 Raw Material Resource Base
Pages 26-54
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From page 26... ...
The land and other agricultural resources of the United States are sufficient to satisfy current domestic and export demands for food, feed, and fiber and still produce ample raw materials for biobased industrial products except for massive fuel production. SILVICULTURE CROPS Forests are a major source of raw materials for the production of wood products.
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have field tested several short-rotation woody crop species (harvested on a cycle of 3 to 10 years) , including hybrid poplar, black locust, eucalyptus, silver maple, sweet gum, and sycamore.
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From page 28... ...
At the current rate of growth, another 19 million metric tons of corn could become available by the turn of the century. Perennial grasses and legumes are being evaluated as potential energy crops (Hohenstein and Wright, 1994)
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These reserves may provide the best odds for competitive production of biobased industrial products. Waste Materials The United States produces abundant wastes that are potential raw materials for biobased products.
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Sufficient biological wastes exist to supply the carbon for all 100 million metric tons of organic carbon-based chemicals consumed annually in the United States as well as to provide part of the nation's fuel requirements (Morris and Ahmed, 1992)
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From page 31... ...
Judicious harvesting on a fraction of CRP lands might be consistent with wildlife and wetlands preservation. Field-scale studies are under way to quantify changes in soil and water quality and native biodiversity due to production of biomass energy crops on former agricultural lands (Tolbert et al., 1997; Tolbert and Schiller, 1996)
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From page 32... ...
Introduction of new crops for biobased production will be limited without an adequate infrastructure for cultivar research, development, and commercialization. Satisfying the raw material needs of expanding biobased industries will require crops with the following characteristics: contain biomolecules and biochemical systems with potential industrial applications; can be manipulated to produce desirable molecules; can sustain a high level of predictable raw material production; and are supported by an infrastructure for biomass harvesting, transfer, storage, and industrial processing.
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From page 33... ...
Accessing these vast carbohydrate reserves will be key to maintaining a renewable source of raw materials that can substitute for petrochemicals. Cellulose Cellulose is a carbohydrate polymer composed of glucose and constitutes about 45 percent of woody plant parts.
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Because of its dominating abundance in plants, cellulose will always be a primary feedstock of any biobased industry. Hemicelluloses Hemicelluloses are composed of carbohydrates based on pentose sugars (mainly xylose)
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Approximately 600 million bushels of corn went into production of industrial products during the marketing year 1995 to 1996; of that total, 395 million bushels were used to produce fuel ethanol (ERS, 1996b)
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From page 36... ...
Plant Oils Many crops can serve as sources of plant oils; currently soybeans account for 75 percent of the vegetable oil produced in the United States.
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. Fatty acids derived from soybean oil are being converted into surfactants, emulsifiers, and alkyd resins for paints.
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Up to 5 percent of the total fatty acids in the modified tobacco's cells was petrose lenic acid. Introducing the thioesterase and elongase genes along with the desat uration gene might yield greater quantities of petroselenic acid.
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From page 39... ...
Improving Plant Raw Materials The discoveries occurring in plant and microbial genomics will advance the fundamental biological research needed to support a biobased industry. Scientific investigations are under way to decipher the genetic code of a flowering plant, Arabidopsis thaliana; the genetic map is complete for the microbial organisms Saccharomyces cerevisiae (common yeast)
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From page 40... ...
Thus, researchers could grow whole plants from individual transformed plant cells and select the plants that passed T-DNA to their progeny in a Mendelian-dominant manner. Various dicotyledon plants have been transformed using the Agrobacte rium technology, including tomato, hybrid poplar, potato, soybean, cotton, rape, and sunflower.
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From page 41... ...
Similarly, transcription of plant DNA and the processing and stability of mRNA in various plant species are far from being well understood. Research in this area will be critical for harnessing the full power of biotechnology.
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The present approach is to transform varieties most amenable to the process and then transfer the transgenes to elite germplasm by plant breeding. This is an inefficient process because evaluation and selection phases of research and development are prolonged, creating delays in the commercialization phase.
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. Resistance to Plant Pathogens Plant breeding will continue to be a predominant tool of defense against many plant diseases.
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It is expected that in the near term weed management will be dominated by pesticides and by use of genetically engineered or classically bred crop varieties. Research leading to development of new herbicides and transgenic crops will involve efforts of scientists from industry and academe.
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From page 45... ...
If dwarf corn plants could produce two to three ears instead of one or two, harvested biomass and grain yields might double from 150 to 250 bushels per acre up to 300 to 500 bushels per acre. While this scenario is unlikely in the near term, such yield enhancement could lower the costs of biobased production and enhance the competitiveness of biobased industrial raw materials.
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From page 46... ...
The availability of genetic mutants in Arabidopsis, corn, and other plants will accelerate this research. A complete understanding of plant carbohydrate metabolism in unmodified and modified plant tissues will promote application of these sophisticated engineering technologies to other applications.
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From page 47... ...
These plant species will provide a gene source for creating cultivars of major agronomic crops that produce fats and oils of value to the chemical industry as lubricants, fuels, and detergents. Introduction of additional functionalities, such as hydroxy or epoxy groups or double- and triple-carbon bonds, into plant fatty acids will enable synthesis of new molecules in major oilseed crops.
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From page 48... ...
, starch synthase, and branching enzyme. These enzymes Proteins Little genetic engineering research has focused on proteins other than enzymes, although there are several advantages to using protein polymers for biobased production: • Plant proteins generally are more diverse than other plant poly mers.
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From page 49... ...
The ADPglucose subsequently serves as the substrate for starch synthase. Plant cells tightly regulate the activity of ADPGPP, turning the enzyme "on" when excess carbohydrates are present and shutting it "off" when starch biosynthesis is not needed.
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This affects cash flow, almost 90% of the oil makes corporate planning difficult, and is ricinoleic acid) a discourages investment in new products.
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liquid fuel needs. Silviculture crops 130,500g Biomass Fermentable sugars, 30 to 40 million acres may supply 10 to (short rotation, liquid fuels, 20% of U.S.
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Plant breeding may be necessary to introduce new biomolecules or enhance total biomass production. Sugar cane provides a useful example.
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Genetic engineering offers unprecedented opportunities to manipulate the biochemical content of specific plant tissues and design a raw material for easier processing -- an advantage not enjoyed by fossil feedstocks. However, much more remains to be done to provide the raw materials for expanding biobased industries.
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From page 54... ...
Making the transition to a competitive biobased industry will require close coordination between plant scientists and process engineers to develop cost-effective biological and industrial processes for the conversion of raw materials into value-added products.
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