Effect of Lactobacillus salivarius Dietary Supplementation on the Antioxidant Biomarkers of the Freshwater Shrimp Macrobrachium rosenbergii

The shrimp aquaculture is one of the most important livelihoods in the Philippines. Although there is an observed boost in the production of shrimps in the Philippines, there are remaining problems that are needed to be resolved. Bacterial and viral infections in shrimps have significantly affected its mortality, resulting in lower production and yield. In order to prevent or lessen this effect, various researches have been made to increase the resistance of shrimps against infections. In this study, a probiotic microorganism, Lactobacillus salivarius was used as a dietary supplementation for Macrobrachium rosenbergii and see its influence on the antioxidant biomarkers and temperature stress tolerance of the shrimp. Three concentrations of L. salivarius (1.0x107, 1.0x108, and 1.0x109 cells/g) were initially tested for its effect towards the oxidative stress tolerance and the oxygen consumption of the shrimp. The study involved the use of various antioxidant biomarkers including total glutathione (tGSH), catalase enzyme activity, and lipid peroxidation. Results showed that 1.0x108 cell/g of L. salivarius was the most effective concentration of probiotic microorganism per weight of feeds in improving the metabolic rate of the shrimp. Oxidative stress tolerance levels were observed to be increasing in terms of the catalase reaction (12.46 and 21.74 nmole/min) and lipid peroxidation (1.4X10-7 and 1.49X10-7 nmole MDA/mg protein) on both hepatopancreas and muscles tissues when the shrimp was fed with supplemented feeds. Also, high oxidant stress biomarkers were more evident on the hepatopancreas than the muscles.