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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Research » Publications at this Location » Publication #108496
Title: REGULATION OF B-GLUCANASE EXPRESSION IN THE RUMEN BACTERIUM, PREVOTELLA BRYANTTI B14

Author
item FIELDS, MATTHEW - CORNELL UNIVERSITY
item Russell, James

Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Prevotella bryantii B14 cultures provided with mannose produce large amounts of b-glucanase, but glucose represses b-glucanase synthesis. When cells were transferred from media containing mannose to glucose, b-glucanase mRNA declined, and this result indicated that the activity was transcriptionally regulated. When cells were provided with glucose and b-deoxy-glucose, b-glucanase activity increased, and this result indicated that mannose was not needed as an inducer. Cells incubated with glucose and 2DG catabolized glucose at a slower rate than those not provided with 2DG, and the rate of 14C-glucose transport was slower. 2DG was also a competitive inhibitor of glucokinase activity. Cells growing with glucose and 2DG had 50% lower ATP than untreated controls, but the glycolytic inhibitor iodoacetate did not increase b-glucanase activity even though ATP was 90% lower. This indicated that ATP itself was not regulating b-glucanase expression. Cell extracts that were supplemented with mannose ATP, phosphoglucose isomerase and phosphomannose isomerase synthesized glucose-6-phosphate, but the rate was slower than the conversion of glucose. Cell extracts provided with glucose and 2DG also produced glucose-6-phophate at a slower rate, and this result is consistent with the idea that the phosphorylation of glucose may be involved in regulating b-glucanase expression.