SUMMARY: -Arabinose is broken down by MNF300 via 2-oxoglutarate semialdehyde. Enzyme activities in cells grown on succinate, mannitol or arabinose indicated much greater modulation of arabinonate dehydratase, 2-keto-3-deoxyarabinonate dehydratase and 2-oxoglutarate semialdehyde dehydrogenase than of arabinose dehydrogenase or of arabinono-γ-lactonase. In cowpea NGR234, all the enzymes of -arabinose metabolism except -arabinono-γ-lactonase were inducible. Assays for such enzymes in snake bean bacteroids indicated that -arabinose did not reach the bacteroids in large quantities. The Tn-induced mutant MNF3045 of was unable to grow on -arabinose and accumulated -arabinono-γ-lactone and -arabinonate. Product accumulation and enzyme assays suggested that this mutant was defective in -arabinonate dehydratase. It nodulated peas and the nodules fixed N, indicating that the supply of -arabinose is not essential for bacteroid function. Another Tn-induced mutant of , MNF3041, lacked ribokinase and was unable to grow on -ribose; this mutant was also able to nodulate peas and fix N.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error