Characterisation of the intestinal microbial communities of rainbow trout (Oncorhynchus mykiss) fed with Hermetia illucens (black soldier fly) partially defatted larva meal as partial dietary protein source

• Published in: Aquaculture 2018-02, Vol.487, p.56-63
• Main Authors: Bruni, Leonardo, Pastorelli, Roberta, Viti, Carlo, Gasco, Laura, Parisi, Giuliana
• Format: Article
• Language: English
• Subjects: Black soldier fly; DGGE; Insect; Intestinal microbial community; Rainbow trout; Sustainable aquaculture
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2018.01.006

Scientific research has examined the possibility of replacing fishmeal with alternative protein sources in feed for fish. The literature indicates that insects are an eco-friendly nutrient-rich alternative to fishmeal. The purpose of this study was to investigate the effects of including insects in a diet for rainbow trout (Oncorhynchus mykiss), by analysing organosomatic parameters, fillet yield and intestinal bacterial communities. Three experimental diets were formulated: a control diet with fishmeal as main protein source, and diets Hi25 and Hi50 where 25% and 50% of fishmeal, respectively, was replaced with partially defatted meal of larvae of Hermetia illucens (Hi; Diptera: Stratiomydae). At the end of the trial, organosomatic parameters and fillet yield were recorded. To profile the complex intestinal mucosa- and digesta-associated bacterial communities (MAB and DAB), denaturing gradient gel electrophoresis was performed on bacterial DNA extracted from intestinal mucosa and digesta, followed by sequencing of selected bands. Rainbow trout fed the alternative diets showed the same organosomatic indices and fillet yields as the control group, but increased bacterial community biodiversity, structure and composition, with ANOSIM p