2000 Volume 1 Issue 1 Pages 41-45
The growth characteristics of the marine diatom, Chaeroceros ceratosporum OSTENFELD were examined using a photobioreactor(capacity: 1801)in order to develop a continuous culture system with deep seawater collected from off Namerikawa City in Toyama Prefecture at a depth of 300m. Ch. ceratosporum is a very important microalgal species, preyed on bivalves and other invertebrates. Continuos culture was conducted under optimum temperatures(15-20°C). Long term culture for 131 days including 129 days of stable continuous culture, was successfully carried out using the culture system we developed. Specific growth rate(μ)was 1.08/day under batch culture conditions. The cell yield at 1.0/day dilution rate was similar to that at 1.2/day dilution rate. The maximum cell yield was 791 × 108cells/day at a 1.2/day dilution rate. It is generally known that cells wash out from continuous culture system, if the dilution rate is higher than the specific growth rate.
Therefore this system should be operated below a 1.2/day dilution rate.
