Effects of full replacement of dietary fishmeal with insect meal from Tenebrio molitor on rainbow trout gut and skin microbiota

• DOI: 10.1186/s40104-021-00551-9
• Publication Date: 2021-02-03T18:04:14Z
• Authors: Genciana Terova; Elisabetta Gini; Laura Gasco; Federico Moroni; Micaela Antonini; Simona Rimoldi
• Keywords: Feather meal

Abstract Background Aquaculture must continue to reduce dependence on fishmeal (FM) and fishoil in feeds ensure sustainable sector growth. Therefore, the use of novel aquaculture feed ingredients is growing. In this regard, insects can represent a new world protein-rich for farmed fish feeds. Accordingly, we investigated effects full replacement FM with Tenebrio molitor (TM) larvae meal diet rainbow trout ( Oncorhynchus mykiss ) gut skin microbiota. Methods A feeding trial was conducted 126 about 80 g mean initial weight that were fed 22 weeks two isonitrogenous, isolipidic, isoenergetic extruded experimental diets. Partially defatted TM included one diets replace 100% (TM 100) FM, whereas other 0) without TM. To analyse microbial communities, Illumina MiSeq platform sequencing 16S rRNA gene Qiime pipeline used identify bacteria mucosa, Results The data showed no major substitution bacterial species richness diversity both, mucosa- mucus-associated microbiome. Skin microbiome dominated by phylum Proteobacteria especially Gammaproteobacteria class constituted approximately half taxa found. dietary groups did not display distinctive features, except decrease relative abundance Deefgea genus (family Neisseriaceae) insect meal. metagenomic analysis mucosa indicated Tenericutes most abundant phylum, regardless diet. Specifically, within Mollicutes, mainly represented Mycoplasmataceae family, dominant class. However, observed only weak modulation intestinal communities. changes due decreased number reduced assigned Ruminococcaceae Neisseriaceae families. Conclusions demonstrated valid alternative animal protein aquafeeds. Only slight microbiota occurred after total mapping represents contribution present study. Indeed, contrast increasing knowledge microbiota, remains largely unmapped but it deserves thorough consideration.