Characterization of amino acid transport in the dairy strain Leuconostoc mesenteroides subsp. mesenteroides CNRZ 1273.
OBJECTIVE
To identify and characterize amino acid transport in Leuconostoc mesenteroides.


RESULTS
The transport of labelled amino acids was measured in whole cells of Leuc. mesenteroides CNRZ 1273. Systems were operative under physiological conditions of growth, energy dependent and differed from peptide transport. Some of the systems were shared by several amino acids. Kinetic analysis indicated the presence of three transport systems with very high (VH), high (H) and low affinity (H) for the 11 amino acids studied. The K(t) values (micromol l(-1)) ranged from 0.088 to 0.815 (VH), 6-390 (H) and 320-4500 (L) and the V(max) values [nmol s(-1) (g dry weight)(-1)] from 0.015 to 0.8 (VH), 15-95 (H) and 90-470 (L).


CONCLUSIONS
The study showed the presence of three transport systems in Leuc. mesenteroides for all amino acids tested, some of them being shared by several amino acids.


CONCLUSIONS
The findings are discussed with reference to the growth of Leuc. mesenteroides in milk as pure or in mixed-strain culture with Lactococcus lactis.
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D003470:Culture Media; D007700:Kinetics; D007934:Leuconostoc / Q000378:metabolism*; D008892:Milk / Q000382:microbiology*; D021381:Protein Transport; D014633:Valine / Q000378:metabolism
D000596:Amino Acids; D003470:Culture Media; D014633:Valine