Organ bacteriological dynamics in Heterobranchus bidorsalis juveniles fed diets fortified with Lactobacillus fermentum, Saccharomyces cerevisiae and their combination

Abstract

The effect of dietary intake of Lactobacillus fermentum, Saccharomyces cerevisiae and their combination on selected tissue bacteriology of Heterobranchus bidorsalis juveniles was investigated. Ten experimental diets at 41.0% crude protein were prepared to include Lf1 (basal diet + 10¹cfu/mL Lactobacillus fermentum), Lf2 (basal diet + 10²cfu/mL Lactobacillus fermentum), Lf3 (basal diet + 10³cfu/mL Lactobacillus fermentum), Sc1 (basal diet + 10¹cfu/mL Saccharomyces cerevisiae), Sc2 (basal diet + 10²cfu/mL Saccharomyces cerevisiae), Sc3 (basal diet + 10³cfu/mL Saccharomyces cerevisiae), LfSc1 (basal diet + 10¹cfu/mL Lactobacillus fermentum and 10¹cfu/mL Saccharomyces cerevisiae) LfSc2 (basal diet + 10²cfu/mL Lactobacillus fermentum and 10²cfu/mL Saccharomyces cerevisiae) LfSc3 (basal diet + 10³cfu/mL Lactobacillus fermentum and 10³cfu/mL Saccharomyces cerevisiae) and control (basal diet). The experiment was replicated thrice with the fish (initial mean weight 22.76±0.83g) fed twice daily at 3% body weight for twelve weeks. Microbial analyses of experimental water, fish organs and organ index of the experimental fish were investigated. Data were statistically analyzed using descriptive statistics and one-way analysis of variance (ANOVA) at p ∞ 0.05. Results of enterobacteria counts and total viable counts from this study showed that bacterial loads in water and experimental fish were significantly affected by L. fermentum and S. cerevisiae than the control group at 4th, 8th and 12th weeks. Furthermore, higher values for the skin (somatic index) than other organs were observed, since it is the area of first contact, which received most of the microorganisms than other organs in all the treatments. The result of organ indices further revealed that the spleen, liver, gill, intestine and kidney were insignificantly increased in both the treated and the control groups. Therefore, Lactobacillus fermentum and Saccharomyces cerevisiae inclusion in the diet of Heterobranchus bidorsalis could be a promising dietary additive which could positively influence growth, reduce and prevent any bacterial infection in fish culture.

Keywords: Lactobacillus fermentum, Saccharomyces cerevisiae, Heterobranchus bidorsalis, Enterobacteriacea.