NIFS announced that it developed the eco-friendly feed additive (aquatic probiotics*) through the research on olive flounder intestinal microorganisms (microbiome**). 

*Probiotics are live microorganisms. They have beneficial effects to the host when consumed in appropriate amounts. **Microbiome, a compound word of microbiota and genome, is the collection of all microbes such as bacteria, viruses, and their genes. 

To respond to the regulations on misuse of feed antibiotics and to supply safe seafoods through expanding the usage of formulated feed, NIFS developed microorganism feed additive producing digestive enzyme and natural substitute materials for antibiotics. 

The intestinal microbiome is known to play a critical role in the health, growth, and digestion of organisms. NIFS clarified that as olive flounder grows, intestinal microorganism diversity decreases. 

In particular, the decrease of beneficial bacteria, such as lactic acid bacteria and microorganism belonging to Bacillus sp., was outstanding. The result revealed the necessity of microorganism feed additive containing Bacillus and lactic acid bacteria for securing intestinal microorganism balance of olive flounder and promoting feed efficiency. 

Against this backdrop, NIFS secured microorganisms in the various aquaculture environments as well as intestines of olive flounder. After assessing characteristics of the microorganisms, NIFS lastly selected B. Pumilus and Pediococcus acidilactici, producing antimicrobial agents and digestive enzyme. 

Then, it tested the possibility for industrial utilization by adding the two microorganisms to olive flounder feed, and found the effects of accelerating growth (weight gain), improving immunity (increase of immune factors expression), and heightening resistance (mortality rate reduction) in the olive flounder fed by the mix-probiotics combining the Bacillus strain and Pediococcus acidilactici. 

As of now, NIFS registered its patent; Bacillus species having antimicrobial activity and uses thereof (Patent Registration No.102454000), and it launched aquatic probiotics through technical transfer to the industry based on the result verifying the efficacy of feed additive to olive flounder.