131
of energy from phycoerythrin to chlorophyll is undetectable (Yentsch
and Phinney, 1984).
Table 1 shows the possible spectral interpretations for marine
species using two excitation wavelengths, measuring two wavelengths
of emission. All algae, with the exception of the cyanobacteria,
Table l.
Chlorophyll-accessory pigment relationships.
F = fluorescence by chI a at 680 nm
E
wavelength of excitation for chI a fluorescence
Organism
Dinoflagellates
Diatoms
Coccolithophores
Green flagellates
Cryptomonads
Cyanobacteria
Primary accessory pigments
Carotenoids, ChI a
Carotenoids, ChI a
Carotenoids, ChI a
ChI b
Phycobilins
Phycobilins
ChI a F (E530:E450)
0.8 - 0.9
0.7 - 0.8
0.3 - 0.4
0.1 - 0.2
0.7
will emit fluorescence when excited by light at 450 nm.
Organisms
with carotenoid proteins, such as diatoms and dinoflagellates, will
fluoresce at 680 nm. Cryptomonads will also fluoresce at 680 nm when
excited by wavelengths of 530 nm, however, in this case, the accessory pigmentation is the phycobilin, phycoerythrin and not a carotenoid protein.
Both cyanobacteria and cryptomonads will fluroesce at
580 nm, which is the primary band for phycoerythrin fluorescence,
when excited by 450 or 530 nm.
FLUORESCENCE SIGNATURE EXTREMES IN OPEN OCEANIC POPULATIONS
For the past five years, we have measured spectral fluorescence
in particulate matter collected from the world's oceans.
Since the
number of fluorescent cells in the particulate matter is generally
low, we have had to concentrate particles on membrane filters (0.45
ll) and mount these in the light path of the conventional spectrofluorometer.
The details of this method can be found in Yentsch and
Phinney (1984).
The use of membrane filters in this manner also
alleviates spurious signals that occur from cells settling or being
moved about in cuvettes.
The extremes in spectral signatures that we have observed are
shown in Fig. 2.
These extremes illustrate the spectral differences
observed in populations taken in eutrophic waters as opposed to those
populations taken in oligotrophic waters. In these two examples, the
of energy from phycoerythrin to chlorophyll is undetectable (Yentsch
and Phinney, 1984).
Table 1 shows the possible spectral interpretations for marine
species using two excitation wavelengths, measuring two wavelengths
of emission. All algae, with the exception of the cyanobacteria,
Table l.
Chlorophyll-accessory pigment relationships.
F = fluorescence by chI a at 680 nm
E
wavelength of excitation for chI a fluorescence
Organism
Dinoflagellates
Diatoms
Coccolithophores
Green flagellates
Cryptomonads
Cyanobacteria
Primary accessory pigments
Carotenoids, ChI a
Carotenoids, ChI a
Carotenoids, ChI a
ChI b
Phycobilins
Phycobilins
ChI a F (E530:E450)
0.8 - 0.9
0.7 - 0.8
0.3 - 0.4
0.1 - 0.2
0.7
will emit fluorescence when excited by light at 450 nm.
Organisms
with carotenoid proteins, such as diatoms and dinoflagellates, will
fluoresce at 680 nm. Cryptomonads will also fluoresce at 680 nm when
excited by wavelengths of 530 nm, however, in this case, the accessory pigmentation is the phycobilin, phycoerythrin and not a carotenoid protein.
Both cyanobacteria and cryptomonads will fluroesce at
580 nm, which is the primary band for phycoerythrin fluorescence,
when excited by 450 or 530 nm.
FLUORESCENCE SIGNATURE EXTREMES IN OPEN OCEANIC POPULATIONS
For the past five years, we have measured spectral fluorescence
in particulate matter collected from the world's oceans.
Since the
number of fluorescent cells in the particulate matter is generally
low, we have had to concentrate particles on membrane filters (0.45
ll) and mount these in the light path of the conventional spectrofluorometer.
The details of this method can be found in Yentsch and
Phinney (1984).
The use of membrane filters in this manner also
alleviates spurious signals that occur from cells settling or being
moved about in cuvettes.
The extremes in spectral signatures that we have observed are
shown in Fig. 2.
These extremes illustrate the spectral differences
observed in populations taken in eutrophic waters as opposed to those
populations taken in oligotrophic waters. In these two examples, the