Bacterial community analysis of zebrafish larvae and rearing water: Effects of feeding regimes on microbial contamination in germ-free systems

This study characterizes bacterial contamination in germ-free zebrafish (Danio rerio) larvae rearing systems using 16S rRNA gene amplicon sequencing targeting the V3-V4 hypervariable region. Samples were collected from both zebrafish larvae bodies and their rearing water across three feeding treatment groups: commercial feed (1 group), egg yolk (3 groups), and egg yolk supplemented with vitamins (1 group). The primary objective is to identify the composition and sources of bacterial contamination in germ-free zebrafish cultures and to evaluate how different nutritional regimes influence microbial colonization patterns.