Jonathan Knight and Richard Gregory
MB 495
November 28, 2011

High concentrations of glucose in the LB
media are enabling biphasic growth.
2.0% Glucose (inoculum 10^-7 )
2.5% Glucose (inoculum 10^-5)
2.5
2.5
2
2
1.5
1.5
1
1
0.5
0.5
Well 107
Well 108
Well 109
Well 110
Well 111
Well 112
191
181
171
161
151
141
131
121
111
101
91
81
71
61
51
41
31
21
191
181
171
161
151
141
131
121
111
1
Well 106
101
91
81
71
61
51
41
31
11
1
21
Well 105
11
0
0
.5 and 2% Glucose (10^-5 inoculum)
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Well 201
Well 202
Well 203
Well 204
Note: the different lag times between .5 and 2% glucose
205
199
193
187
181
175
169
163
157
151
145
139
133
127
121
115
109
103
97
91
85
79
73
67
61
55
49
43
37
31
25
19
13
7
1
0
Varying Conc Glucose (While cutting down on LB)
1.4
1.2
1
0.8
0.6
0.4
0.2
Average (7.5%)
Average(8.5%)
Average(9.0%)
Average(9.37%)
Average(9.5%)
Average (control)
Average(9.25%)
Note: no biphasic growth, long lag times, and lower max OD’s with
higher conc. Of glucose and smaller concentrations of LB.
273
265
257
249
241
233
225
217
209
201
193
185
177
169
161
153
145
137
129
121
113
105
97
89
81
73
65
57
49
41
33
25
17
9
1
0
Max OD
Lag times
1.2
Max OD
1
0.8
0.6
Max OD
0.4
0.2
0
Lag times (15 minute units)
1.4
250
200
150
Lag times
100
Linear (Lag times)
50
0
7
8
9
Glucose %
6
7
8
Glucose %
9
10
10

Pseudomonas fluorescens can survive high
osmostic pressure from high glucose
concentrations, however, it must adjust
through regulation of it’s genes.
Lag Times versus Glucose
conc.
140
120
Varying Glucose
100
80
2
60
1.8
40
1.6
20
1.4
1.2
0
1
0.5
0.8
1
Glucose %
2
4
6
7
Max OD
0.6
0.4
1.72
0.2
1.7
267
253
239
225
211
197
183
169
155
141
127
113
99
85
71
57
43
29
15
1
0
1.68
1.66
Average .5%
Average 1.0%
Average 2.0%
1.64
Average 4.0%
Average 6.0%
Average 7.0%
1.62
1.6
1.58
1.56
0
2
4
6
8





Pseudomonas fluorescens can survive more osmotic
pressure than previously believed.
The biphasic growth was not reproducible.
High glucose concentrations increased lag times,
indicating some sort of regulatory changes that must
be done in order for the organism to survive.
Restricting LB media, decreased maximum
populations of organism, proving that the organism
cannot make it’s some amino acids and vitamins….
Continuing research should be done on the molecular
level to see what actually enables this organism to
live at such extreme osmotic pressure.