Effects of synbiotic containing Lactobacillus plantarum 7-40 and galactooligosaccharide on the growth performance of white shrimp, Litopenaeus vannamei

This study aimed to develop a synbiotic combination with probiotic, Lactobacillus plantarum 7-40 and one of three prebiotics, fructooligosaccharide (FOS), galactooligosaccharide (GOS) and mannan oligosaccharide (MOS). The best invitro growth was observed when probiotic was cultured in the medium containing either FOS or GOS as the sole of carbon source. The analysis of enzyme activity revealed that GOS induced the highest activities of protease and -galactosidase of probiotic. Based on the findings, probiotic+GOS were selected as synbiotic to evaluate if it could promote the growth of white shrimp, Litopenaeus vannamei. For this, four diets, including a basal diet with no GOS or probiotic (control), 0.4% GOS (PRE), 10(8)CFUprobiotickg(-1) (PRO) and 0.4% GOS in combination with 10(8)CFUprobiotickg(-1) (SYN), were fed to shrimp for 60days, and then the growth performance, intestinal microbiota (including total Vibrio counts, VBCs; and lactic acid bacteria, LAB) and digestive enzyme (including protease, leu-aminopeptidase and -galactosidase) were evaluated. The weight gain (WG) of shrimp fed the PRO did not significantly differ from those of control (p>.05). Shrimp fed the SYN had significantly higher WG compared with the other treatments (p<.05). In addition, the SYN-fed shrimp had significantly higher LAB and protease, leu-aminopeptidase and -galactosidase activity (p<.05). The lowest presumptive Vibrio count (VBC) was also observed in intestines of SYN-fed shrimp. Therefore, we suggested that Lac.plantarum 7-40+ GOS can be used as a synergistic synbiotic for shrimp culture.