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. 2013 May 21;8(5):e63091. doi: 10.1371/journal.pone.0063091

Table 5. Summary of the environmental conditions used to culture phytoplankton species and strains in the present study.

Protocol
Organism Laboratory A. B. C. D. E. F. G. H.
Trichodesmium spp.,Crocosphaera spp. Hutchins/Fu Yes Yes (6 replicates) Yes Yes (150) Yes Yes Yes No15
Thalassiosira pseudonana Litchman Yes Yes (6 replicates) Yes Yes (100) Yes6 No8 No12 No15
Proboscia inermis Boyd/Strzepek Yes Yes (6 replicates) Yes Yes (90) Yes Yes9 No12 Yes
Prorocentrum donghaiense; Synechococcus Mulholland No1 Yes Yes4 Yes (35;100) Yes No10 Yes13 Yes
Akashiwo sanguinea Kudela No2 Yes (5 replicates) Yes Yes (125) Yes Yes Yes14 Yes
Thalassiosira weissflogii Passow No1 Yes (4 replicates) Yes5 No (35) Yes7 Yes Yes14 Yes
Thalassiosira rotula Rynearson No3 Yes (3–5 replicates) Yes No (112) Yes No11 Yes 14 Yes

A. Growth rates were determined at a minimum of six temperature conditions. B. A minimum of three replicate growth rates were determined. C. All other environmental variables were held constant within each individual experiment, other than temperature. These include day length, culture medium, and culture protocols. Saturating nutrients were used to avoid nutrient-induced growth limitation. D. Isolates grown at saturating light intensity (µmol quanta m−2 s−1). E. Semi-continuous cultures were diluted using media that was previously adjusted to the appropriate temperature. Dilution frequencies were set so that cells were maintained in constant exponential growth phase and growth rates were reported when cultures were fully acclimated to the experimental conditions, after statistically invariant growth rates were recorded for at least 3–5 generations [98] F. Upper and lower thermal limits were tested repeatedly (at least 3 times) G. Multiple biomass parameter/proxies were used to determine daily abundance and included cell counts, extracted chlorophyll a, and in vivo chlorophyll a fluorescence. Each method could be used reliably to determine steady-state acclimation. H. At each temperature, the maximum acclimated specific growth rate (d−1) for each isolate was determined by regressing the change in the log of fluorescence, cell count or chlorophyll a over time and testing the equality of slopes from at least three serial cultures (α = 0.05) [99]. If slopes of serial growth curves were not significantly different, the average regression coefficient was used to estimate the common slope, which represented the average acclimated growth rate and the standard error.

Footnotes:

1

Growth rates were determined at five temperatures.

2

Growth rates were determined at 4 temperatures. Cells failed to grow at 35°C and reliable growth estimates could not be obtained at 10°C.

3

Growth rates were determined for 4 temperatures, cells exhibited no growth at 35°C.

4

Isolates also grown in 4 different nitrogen species (nitrate, ammonium, urea, and glutamate).

5

Carbonate system also held within a specific range at ambient conditions.

6

Recorded growth for 5 days after acclimation (not necessarily 3–5 generations).

7

After >8 generations.

8

This was performed for upper limit only.

9

Upper limited tested repeatedly. Lower limit was below 0°C, the lowest temperature tested.

10

Upper and lower limits were tested for P. donghaiense, however only lower limit was tested for Synechococcus. Upper and lower limit tests were performed twice, not three times.

11

This was performed for upper limit in all isolates, and in one isolate for the lower limit.

12

Fluorescence alone was used.

13

In vivo fluorescence reported, but Chl measured at the first and last culture days, as well as PN and PC.

14

Growth rates were determined using in vivo fluorescence, but were not significantly different from growth rates determined using cell counts.

15

Significant differences between slopes of replicate cultures were not tested. Instead, the mean slope was used. Variation within a temperature treatment was much smaller than variation between temperatures.