The effect of different dosage probiotic Bacillus cereus in fish diets on the growth and enzyme activities of coral trout grouper juvenile, Plectropomus leopardus

Coral trout grouper (Plectropomus leopardus) is one of the economically important marine fish. The feed nutrients and probiotics influence the digestive system of fish. This research aims to get an optimal dosage of the probiotic Bacillus cereus on the diet for enhanced growth and enzyme activity of coral trout grouper juveniles. The experiment was conducted with different treatments with four dosages of probiotics in the diet: 0%, 0.5%, 1.0, % and 1.5%, and repeated four times. The diet was formulated with 48.32%-49.25% protein and 11.97%-12.98% lipid—twelve juveniles of coral trout grouper with an average weight of 5.7±0,3 g and length of 7.3±0,3. The fish were reared in 30 L of 16 polycarbonate tanks with a flow-through system. The research was carried out for eight weeks. The Fish were fed two times a day. The observed parameters were carried out for specific growth rate, survival rate, feed efficiency, viability of bacteria in diet, and enzyme activity. The results showed that the probiotics Bacillus cereus diet increased growth, feed efficiency, viability of probiotic bacteria, protease enzyme activity, and lipase enzyme activity in the intestine. The dosage of probiotics 1.5% in feed showed better results than other diets (P <0.05).