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Title: Hydrocarbons and energy from plants: Final report, 1984-1987

Technical Report ·
DOI:https://doi.org/10.2172/6846970· OSTI ID:6846970

Plant hydrocarbon (isoprenoid) production was investigated as an alternative source to fossil fuels. Because of their high triterpenoid (hydrocarbon) content of 4--8%, Euphorbia lathyris plants were used as a model system for this study. The structure of the E. lathyris triterpenoids was determined, and triterpenoid biosynthesis studied to better understand the metabolic regulation of isoprenoid production. Triterpenoid biosynthesis occurs in two distinct tissue types in E. lathyris plants: in the latex of the laticifer cells; and in the mesophyll cells of the leaf and stem. The latex has been fractionated by centrifugation, and it has been determined that the later steps of isoprenoid biosynthesis, the conversion of mevalonic acid to the triterpenes, are compartmentized within a vacuole. Also identified was the conversion of hydroxymethyl glutaryl-CoA to mevalonic acid, catalyzed by the enzyme Hydroxymethyl glutaryl-CoA Reductase, as a key rate limiting step in isoprenoid biosynthesis. At least two isozymes of this enzyme, one in the latex and another in the leaf plastids, have been identified. Environmental stress has been applied to plants to study changes in carbon allocation. Salinity stress caused a large decrease in growth, smaller decreases in photosynthesis, resulting in a larger allocation of carbon to both hydrocarbon and sugar production. An increase in Hydroxymethyl glutaryl-CoA Reductase activity was also observed when isoprenoid production increased. Other species where also screened for the production of hydrogen rich products such as isoprenoids and glycerides, and their hydrocarbon composition was determined.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
6846970
Report Number(s):
ORNL/Sub-84-90435/1; ON: DE88015328
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English