Evaluation of active versus passive uptake of metabolites by Rhizobium japonicum bacteroids.
Rhizobium japonicum bacteroids were isolated anaerobically from soybean [Glycine max (L.) Merr] nodules. The bacteroids, which were capable of acetylene reduction and respiration, were used to study the uptake of metabolites by a method which permits correction for nonspecific adsorption of metabolites and estimation of total cell volume. These determinations permit active uptake to be assessed from metabolite accumulation against a concentration gradient. Succinate, malate, alpha-ketoglutarate, and glutamate were absorbed via an active mechanism. Plots of 1/V versus 1/[S] for succinate and malate indicated the presence of two uptake components: a saturable and presumably active or carrier-mediated component and a nonsaturable and presumably passive component. The uptake of glucose, malonate, D-pinitol, myo-inositol, and glucose 6-phosphate was slow and not active.
D000114:Acetylene / Q000378:metabolism; D001692:Biological Transport; D001693:Biological Transport, Active; D002250:Carbon Radioisotopes; D002264:Carboxylic Acids / Q000378:metabolism; D003911:Dextrans / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007294:Inositol / Q000031:analogs & derivatives / Q000378:metabolism; D007306:Insecticides / Q000378:metabolism; D007700:Kinetics; D008293:Malates / Q000378:metabolism; D010944:Plants; D012231:Rhizobium / Q000378:metabolism*
D002250:Carbon Radioisotopes; D002264:Carboxylic Acids; D003911:Dextrans; D005971:Glutamates; D007306:Insecticides; D008293:Malates; D018698:Glutamic Acid; C021730:pinitol; D007294:Inositol; C030298:malic acid; D005947:Glucose; D000114:Acetylene