On-line monitoring of marine cyanobacterial cultivation based on phycocyanin fluorescence.
A novel on-line fluorescence monitoring system for marine cyanobacterial cultivation was developed. This method is based on the measurement of intracellular phycocyanin content, which is the major light harvesting protein. A fluorescence spectrophotometer, equipped with a flow cell connected with a culture liquid recycling tube was used. Experiments were carried out using a marine unicellular cyanobacteria Synechococcus sp. NKBG 042902 isolated from Japanese coastal sea water. We have optimized excitation wavelength to avoid the light scattering, using non-pigmented old cells which no longer contained phycocyanin. At an excitation wavelength of 590 nm, light scattering was minimized. Viable cell concentration could be measured in the range of 2 x 10(6) to 2 x 10(8) cells per ml, without pronounced light scattering. Continuous monitoring of marine cyanobacteria cultivation was performed. Cell concentrations were determined by both culture fluorescence and by using a hemacytometer. A good linear correlation was obtained. We conclude that on-line monitoring of cyanobacterial culture fluorescence based on phycocyanin is a rapid, efficient and also versatile method for determining viable cell concentration.
Department of Biotechnology, Faculty of Technology, Tokyo University of Agriculture and Technology, Japan.
K
K
Sode
K
K
Horikoshi
H
H
Takeyama
N
N
Nakamura
T
T
Matsunaga
D001709:Biotechnology / Q000379:methods*; D015169:Colony Count, Microbial; D000458:Cyanobacteria / Q000254:growth & development* / Q000378:metabolism; D005434:Flow Cytometry; D005453:Fluorescence; D007700:Kinetics; D010798:Phycocyanin / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation
D010798:Phycocyanin