Zebrafish Danio rerio exhibit positive growth profiles when fed dietary yeast and bacterial-based single-cell protein as a replacement for fish protein hydrolysate

Abstract

Objective: The value of Zebrafish Danio rerio as a preclinical biomedical model has increased as nutritionally complete diets are being developed. Consequently, nutrients and nutrient sources can be used in evaluating the health status of Zebrafish, providing information that can be translated to human health. We have investigated the impact of commercially produced bacterial (MRD-Pro) and yeast (DY-Pro) single-cell protein sources in formulated Zebrafish diets. Methods: Thirty-five days after fertilization Zebrafish were randomized to one of five dietary treatments including FPH100 (a control diet with primarily fish protein hydrolysate [FPH] as the protein source), MRD50 and MRD100 (diets that replaced half or all of the FPH with MRD, a bacterial protein), or DY50 and DY100 (diets that replaced half or all of the FPH with DY, a yeast protein) for 8 weeks (n = 8 tanks/diet treatment, 14 fish/tank). Result: Female terminal wet weight was the same among all diets; however, male terminal wet weight was increased in fish consuming MRD diets. In addition, carcass lipid content was significantly lower in females consuming the DY and MRD diets than those fed FPH. Male lipid content was the same among all diets. Conclusion: Results demonstrate that single-cell protein sources are suitable replacements for FPH and, in female populations, may impart health benefits related to lean matter production and reduced adiposity.