Abstract
The rotifer Brachionus plicatilis requires vitamin B~12~. Freshwater Chlorella, which is produced by traditional culture, cannot support rotifer growth under bacteria‐free conditions. However, Chlorella enriched with vitamin B~12~ can support rotifer growth. To attain stable mass production of Brachionus, it is desirable to develop a food that can completely support growth of the rotifers. The authors cultured rotifers at experimental and mass culture scale with concentrated Chlorella vulgaris suspension enriched with vitamin B~12~ in their cells.
Chlorella suspensions were prepared containing different amounts of vitamin B~12~ in their cells, and rotifers were then cultured in 20 ml of the prepared suspensions. The highest rotifer yield was obtained from the group cultured with Chlorella containing more vitamin B~12~ in their cells. The suitable content of vitamin B~12~ in the concentrated Chlorella suspension commercially available for mass culture of the rotifer is considered to be 200 ~μg~ per 100 g dry matter of Chlorella. The amount of vitamin B~12~ necessary to produce one individual rotifer is calculated at 0.32 pg.
The authors conducted mass production of the rotifer with baker's yeast and refrigerated concentrated Chlorella containing vitamin B~12~ Rotifer culture with vitamin B~12~ was more stable and showed 1.3 times higher production than with normal Chlorella.