Effect of Dietary Supplementation of Diatom Melosira nummuloides and Lactic Acid Bacteria Lactobacillus plantarum on the Growth and Immune Stimulation Responses of Olive Flounder Paralichthys olivaceus

摘要

The diatom Melosira nummuloides is a microalga that is widely distributed in freshwater and seawater is used is used in the production of silicon and fucoxanthin. The objective of this experimental study was to determine the effects of diatom powder on the physiology of olive flounder Paralichthys olivaceus. In four feeding groups consuming 0%, 1%, 2% and 3% diatom powder. After 8 weeks of feeding, we investigated P. olivaceus growth rate, feed efficiency rate, survival rate, anti-oxidant enzyme rate, non-specific immune activity and immune gene expression. The rates of growth rate, feed efficiency rate and survival were significantly higher for olive flounder in all diatom groups than in the control. The results for anti-oxidant enzyme, superoxidedismutase and catalase showed no significance, but glutathione was significant, depending on the concentration of diatom addition. The galectin and lysozymes of immune genes were increased in the control group. Galectin and lysozymes were thought to haveincreased due to infections by from pathogens during the experiment period. These results suggest that the addition of diatoms to olive flounder diets is effective in enhancing growth rate and innate immunity.