Figure 2 : The survival of mannitolytic Vibrio
wild type (▲—▲) and Vibrio mtl mutant 1
(•
•) during starvation.
Figure 3 : Mannitol uptake by Vibrio wild type
(■
— ■) and Pseudomonas was grown in 1/10
SW broth either with (▲—▲) or without
(• — •) the addition of 1 % D-mannitol. Relative uptake refers to the percentage of mannitol
available which is taken up by the cells.
The Pseudomonas strain used here does not maintain detectable basal levels of mannitol
uptake during starvation survival, (C. Davis, unpublished results) and is thus less able to
respond rapidly to a pulse of exogenous mannitol.
There is a far higher maximal rate of mannitol uptake in the Vibrio strain isolated from a
kelp frond, compared with the Pseudomonas from the water column, as shown in Figure
3. In addition, the mannitol uptake system is inducible by growth in the presence of 1%
mannitol in the case of the Pseudomonas strain. The Vibrio strain used here is constitutive
for mannitol uptake, in common with all the mannitolytic Vibrio strains we have tested
(C. Davis, unpublished results).
The effects of long term starvation on several active uptake systems in the strains used
here are shown in Table 2. This confirms the result that mannitol uptake is maintained in
Vibrio strains during starvation, and also indicates that glucose, glutamate, alanine and
aspartate uptake systems are present in starved cells. The recent work of Faquin and
Oliver (1984) showed that arginine transport was maintained during starvation survival.
Substrate
Relative uptake
0 weeks
5 weeks
D-Mannitol
78
51
D-Glucose
84
50
L-Glutamate
73
81
L-Aspartate
55
46
L-Alanine
61
41
Table 2 : Relative uptake of several substrates by the Vibrio wild type strain at the beginning and end of a five
week starvation period. Uptake was measured as described in Materials and Methods, over a period of ten
minutes. The viable cell count was 6.3 x 10 e at t = 0 and 7.0 x 108 at t = 5 weeks. Relative uptake refers to the
pecentage of labelled compound available which is taken up by the cells in ten minutes.
188
wild type (▲—▲) and Vibrio mtl mutant 1
(•
•) during starvation.
Figure 3 : Mannitol uptake by Vibrio wild type
(■
— ■) and Pseudomonas was grown in 1/10
SW broth either with (▲—▲) or without
(• — •) the addition of 1 % D-mannitol. Relative uptake refers to the percentage of mannitol
available which is taken up by the cells.
The Pseudomonas strain used here does not maintain detectable basal levels of mannitol
uptake during starvation survival, (C. Davis, unpublished results) and is thus less able to
respond rapidly to a pulse of exogenous mannitol.
There is a far higher maximal rate of mannitol uptake in the Vibrio strain isolated from a
kelp frond, compared with the Pseudomonas from the water column, as shown in Figure
3. In addition, the mannitol uptake system is inducible by growth in the presence of 1%
mannitol in the case of the Pseudomonas strain. The Vibrio strain used here is constitutive
for mannitol uptake, in common with all the mannitolytic Vibrio strains we have tested
(C. Davis, unpublished results).
The effects of long term starvation on several active uptake systems in the strains used
here are shown in Table 2. This confirms the result that mannitol uptake is maintained in
Vibrio strains during starvation, and also indicates that glucose, glutamate, alanine and
aspartate uptake systems are present in starved cells. The recent work of Faquin and
Oliver (1984) showed that arginine transport was maintained during starvation survival.
Substrate
Relative uptake
0 weeks
5 weeks
D-Mannitol
78
51
D-Glucose
84
50
L-Glutamate
73
81
L-Aspartate
55
46
L-Alanine
61
41
Table 2 : Relative uptake of several substrates by the Vibrio wild type strain at the beginning and end of a five
week starvation period. Uptake was measured as described in Materials and Methods, over a period of ten
minutes. The viable cell count was 6.3 x 10 e at t = 0 and 7.0 x 108 at t = 5 weeks. Relative uptake refers to the
pecentage of labelled compound available which is taken up by the cells in ten minutes.
188