Effects of Mannan-oligosaccharides on Intestinal Microorganisms of Tilapia Larvae

Abstract:

The effects of mannan-oligosaccharides and flavomycin on the intestinal microorganisms of Tilapia larvae [(l.00 ± 0.04) g] were studied. The results showed that the number and ratio of Lactobacillus and E. coli in the intestinal tract of Tilapia larvae were obviously affected by three different additives including self-made yeast mannan-oligosaccharides, purchased mannan-oligosaccharides and flavomycin with different concentrations by plate count method. Among these additives, 0.5% self-made yeast mannan-oligosaccharides increased the Lactobacillus by 10.77% (P < 0.05), but reduce E. coli by 14.80% (P < 0.05), which increased the ratio of lactobacillus and E. coli to 0.9720. Furthermore, the Denatured Gradient Gel Electrophoresis (DGGE) fingerprints demonstrated that the original intestinal microbial microecology of Tilapia larvae was changed by all additives, among the three additives, self-made yeast mannan-oligosaccharides had the most significant influence on the intestinal microorganisms of Tilapia larvae.

Key words:Tilapia, Mannan-ligosaccharides, Flavomycin, Intestinal microorganisms, DGGE