Summary

The buoyancy regulation in light-limited cultures of the gas vacuolate cyanobacterium Microcystis aeruginosa AK1 was studied at three temperatures, 15, 20 and 28°C. At the two highest temperatures the organism remained buoyant during the entire light period, whereas at the lowest temperature the buoyancy was reduced at the start of the light period. With this temperature the buoyancy was lost during the light period. This reduced buoyancy was caused by an increase in ballast and a decrease in the gas vesicle volume. Buoyancy changes during a transient state with slow changes in temperatures, i.e., 1°C per day, were caused by changes in polysaccharide ballast. The gas vesicle volume showed no significant change during the transient state.

The maximal photosynthetic rate was dependent upon the growth and incubation temperature, whereas the light harvesting efficiency was independent of the temperature. The results are discussed in an ecological context.

References

[1]

Reynolds
C.S.
Walsby
A.E.
(
1975
)
Water blooms
Biol. Rev.
,
50
,
437
481
.

[2]

Dinsdale
M.T.
Walsby
A.E.
(
1972
)
The interrelationships of cell turgor pressure, gas vacuolation, and buoyancy in a blue-green alga
J. Exp. Bot.
,
23
,
561
570
.

[3]

Oliver
R.L.
Walsby
A.E.
(
1984
)
Direct evidence for the role of light-mediated gas-vesicle collapse in the buoyancy regulation of Anabaena flos-aquae (cyanobacteria)
Limnol. Oceanogr.
,
29
,
(4)
,
879
886
.

[4]

Kromkamp
J.C.
Mur
L.R.
(
1984
)
Buoyant density changes in the cyanobacterium Microcystis aeruginosa due to changes in the cellular carbohydrate content
FEMS Microbiol. Lett.
,
25
,
105
109
.

[5]

Thomas
R.H.
Walsby
A.E.
(
1985
)
Buoyancy regulation in a strain of Microcystis
J. Gen. Microbiol.
,
131
,
799
809
.

[6]

Utkilen
H.C.
Oliver
R.L.
Walsby
A.E.
(
1985
)
Buoyancy regulation in a red Oscillatoria unable to collapse gas vacuoles by turgor pressure
Arch. Hydrobiol.
,
102
,
319
329
.

[7]

Konopka
A.
Kromkamp
J.
Mur
L.R.
(
1987
)
Regulation of gas vesicle content and buoyancy in light- or phosphate-limited cultures of Aphanizomenon flos-aquae (Cyanophyceae)
J. Phycol.
,
23
,
70
78
.

[8]

Konopka
A.
Kromkamp
J.C.
Mur
L.R.
(
1987
)
Buoyancy regulation in phosphate-limited cultures of Microcystis aeruginosa
FEMS Microbiol. Ecol.
,
45
,
135
142
.

[9]

Kromkamp
J.
Konopka
A.
Mur
L.R.
(
1986
)
Buoyancy regulation in a strain of Aphanizomenon flos-aquae (Cyanophyceae): the importance of carbohydrate accumulation and gas vesicle collapse
J. Gen. Microbiol.
,
132
,
2113
2121
.

[10]

Kromkamp
J.
Konopka
A.
(
1988
)
Buoyancy regulation in cyanobacteria
, In
Proc. IV Int. Symp. Microbiol. Ecol.
in press.

[11]

Thomas
R.H.
Walsby
A.E.
(
1986
)
The effect of temperature on recovery of buoyancy by Microcystis
J. Gen. Microbiol.
,
132
,
1665
1672
.

[12]

Reynolds
C.S.
Rogers
D.A.
(
1976
)
Seasonal variations in the vertical distributions and buoyancy of Microcystis aeruginosa Kütz. emend. Elenkin in Rostherne Mere, England
Hydrobiologia
,
48
,
17
23
.

[13]

Kromkamp
J.
Konopka
A.
Mur
L.R.
(
1988
)
Buoyancy regulation in light-limited continuous cultures of Microcystis aeruginosa
J. Plankton Res.
,
10
,
171
183
.

[14]

Van Liere
Mur
L.R.
(
1978
)
Light-limited cultures of the blue-green alga Oscillatoria agardhii
Mitt. Int. Verein. Limnol.
,
21
,
158
167
.

[15]

Walsby
A.E.
(
1973
)
A portable apparatus for measuring relative gas vacuolation, the strength of gas vacuoles and turgor pressure in planktonic blue-green alga and bacteria
Limnol. Oceanogr.
,
18
,
653
658
.

[16]

Walsby
A.E.
(
1982
)
The elastic compressibility of gas vesicles
,
216
, In
Proc. A. Soc. Lond. B
, pp
335
368
.

[17]

Herbert
D.
Phipps
P.J.
Strange
R.W.
(
1971
)
Chemical analyses of microbial cells
In
Methods of Microbiology
(
Norris
J.R.
Ribbons
D.W.
, Eds)
Vol. 5B
, pp
209
344
Academic Press
, New York, NY.

[18]

Dubinsky
Z.
Falkowski
P.G.
Post
A.F.
Van Hes
U.
(
1987
)
A system for measuring phytoplankton photosynthesis in a defined light field with an oxygen electrode
J. Plankton Res.
,
9
,
607
612
.

[19]

Foy
R.H.
(
1983
)
Interaction of temperature and light on the growth rates of two planktonic Oscillatoria species under a short photoperiod regime
Br. Phycol. J.
,
18
,
273
276
.

[20]

Post
A.F.
De Wit
R.
Mur
L.R.
(
1985
)
Interactions between temperature and light intensity on growth and photosynthesis of the cyanobacterium Oscillatoria agardhii
J. Plankton Res.
,
7
,
487
495
.

[21]

Robarts
R.D.
Zohary
T.
(
1987
)
Temperature effects on photosynthetic capacity, respiration, and growth rates of bloom-forming cyanobacteria
N.Z.J. Mar. Freshwater Res.
,
21
,
391
400
.

This content is only available as a PDF.