Effect of aqueous moringa (Moringa oleifera) leaf extract as a prebiotic on growth of the whiteleg shrimp, Penaeus vannamei Boone, 1931 (Decapoda, Penaeidae)

Abstract

This study evaluated the potential of the aqueous moringa (Moringa oleifera) leaf extract (ME) as a prebiotic and its effect on the growth performance of the whiteleg shrimp, Penaeus vannamei Boone, 1931. The growth trial of probiotics in the broth containing ME showed that Lactobacillus acidophilus growth rate was significantly higher () than that of Lactobacillus plantarum and Lactobacillus reuteri. Furthermore, L. acidophilus exhibited also better growth () than Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio harveyi in the broth containing ME. The minimum inhibitory concentration of ME (MIC) and minimum bactericidal concentration (MBC) were the same against V. alginolyticus, V. parahaemolyticus, and V. harveyi at concentrations of 10, 7.5, and 7.5 mg/ml, respectively. By contrast, ME’s MIC and MBC against L. acidophilus were 50 and >100 mg/ml, respectively. The prebiotic scores of L. acidophilus against V. parahaemolyticus and V. harveyi were significantly higher () than that against V. alginolyticus. The MIC, MBC, and prebiotic scores indicated that ME enhanced the growth of L. acidophilus more than that of Vibrio bacteria. Six diets were formulated for the feeding trial; 3 diets contained ME at 0 (ME0), 2.5 (ME2.5) and 5.0 g/kg (ME5.0), respectively, and the same 3 diets were also prepared with L. acidophilus (ME0 + P, ME2.5 + P, and ME5.0 + P, respectively). After the feeding trial, the number of lactic acid bacteria in the gut was higher () in the ME2.5 + P group than in the control and ME2.5 groups, but no differences were found in the vibrio-like bacterial count among the treatments. The ME2.5 + P group had a higher () final weight, weight gain, and specific growth rate than did the ME or L. acidophilus alone and the control groups. Therefore, ME exhibits a prebiotic function and exerts a symbiotic effect with L. acidophilus, thus increasing the growth performance of P. vannamei.