Development of Synbiotic Feed Pellets Containing Lactobacillus rhamnosus GG with Kantawan (Jerusalem Artichoke) for Nile Tilapia

Abstract

Probiotics can help promoting growth and controlling infection in aquatic animals. Prebiotic from Kantawan (Jerusalem Artichoke, JA) can protect the probiotics from unsuitable conditions. The objectives of this study were to: 1) determine the effects of JA on survival of Lactobacillus rhamnosus GG (LGG) in alginate capsules after freeze drying process, in dried powders after spray drying process, and during exposure to stimulated in Nile tilapia gastrointestinal conditions; 2) develop synbiotic feed pellets containing encapsulated LGG with JA by using non-thermal pelleting process; and 3) evaluate the effects of synbiotic feed pellets containing encapsulated LGG with JA on growth performance, blood chemistry, and morphology of the Nile tilapia intestines. LGG was mixed with JA powder and encapsulated with alginate solution and milk powder (MP) using gel extrusion method prior to the freeze drying process to obtain LGG capsules and the spray drying process to obtain LGG powders. LGG capsules and LGG powders were analyzed for the number of viable cells after freeze drying process, after spray drying process and when they were under stimulated in Nile tilapia gastrointestinal tract (GT). After that, the samples that had the highest number of viable LGG were mixed with fish feed ingredients, and then pelleted at room temperature to produce synbiotic pelleted feed supplemented with LGG and JA for Nile tilapia. The synbiotic pellets were fed to Nile tilapia to evaluate the effects of LGG and JA on the fish growth performance, the blood chemistry values, and the morphology of the Nile tilapia intestines. The results indicated that: 1) JA could protect LGG from freeze-drying process and spray-drying process, and increase the survival of LGG under stimulated GT of Nile tilapia; 2) LGG could survive in the synbiotic pellets when the LGG powders were incorporated with fish feed ingredients, pelleted, and dried at 50 degree Celsius for 8 hours; and 3) the synbiotic pellets could increase weight gain and specific growth rate of the fish, as well as the villi height which was higher than that was fed with a basal diet. In addition, JA had no significant effects on glucose levels of the fish. Therefore, it could be concluded that JA could potentially protect LGG from unsuitable conditions and LGG with JA could improve the tilapia growth. The synbiotic pelleted feed containing LGG and JA could be potentially used for Nile tilaplia.