Regulation of Catabolic Enzyme Biosynthesis in 'Thermomonospora curvata'

摘要

The research studied under this contract included determination of the mechanisms by which the thermophilic actinomycete, Thermomonospora curvata, regulates the biosynthesis of catabolic exoenzyme at the levels of transcription, secretion, post-translational modification, and substrate-specific catalysis. The major results of this research are as follows: 1) We have demonstrated that T. curvata produces multiple forms of cyclic AMP phosphodiesterase (PDE), the enzyme responsible for the degradation of cyclic AMP. 2) We have described the strong preference that T. curvata shows for the uptake of cellobiose over that of glucose, the preferred carbon and energy source for most other bacteria. 3) At the level of exoenzyme secretion, we have shown that the surfactant, Tween-80, effects a component-specific stimulation of cellulase release. 4) At the level of post-translational modification, we have shown that T. curvata cultures alter endoglucanase pattern during growth on cellulose. 5) We have published the first report to describe a polygalacturonate lyase (PL) in any thermophilic actinomycete. Keywords: Actinomycete, Cellulase, Cellulose, Cyclic AMP, Exoenzymes, Phosphodiesterase, Polygalacturonate lyase, Cellobiose, Beta-glucosidase, Thermophile, Thermonospora, Reaction kinetics, Biodeterioration, DD 1473 only. (kt)