2001 Volume 85 Issue 8 Pages 571-575
The culturing of micro-algae is important to the production of seeds for shellfish. We have developed an economical method of doing this that uses step-style light control to reduce the production cost, and appeared light environment of the culture chamber. The light intensity is increased 10% to 30% on the 3rd day (1.5×106cells·ml-1), from 30% to 60% on the 6th day (6.0×106cells·ml-1) and from 60% to 100% on the 9th day (1.4×107cells·ml-1) of cultivation. We cultivated P. lutheri using step-style light control in a 200-l chamber; the other factors were same as for conventional 100% stable light intensity cultivation. The dark zone of the chamber, which was less initially than 1μumol·m-2·s-1, increased with the cell density. It occupied 50% of the chamber at 1.5×107cells·ml-1 and 60% at 2.2×107cells·ml-1. The growth curve was identical to that for stable 100% light intensity. Then it is possible that the consumption of electrical power was 40% lower with step-style light control.
