The bacterial community characterization of biofloc in grow-out system of GIFT (Genetically Improved Farmed Tilapia) was carried out to ascertain the dynamics and community structure of the microbiome. GIFT (5.1 ± 0.05 g) were stocked for 180 days at the stocking density of 15/m³ in triplicates. Distillery spent wash as carbon source was used for maintaining the C:N ratio at 10:1. Recorded water quality parameters revealed no significant difference among the replicates. The microscopic characterisation of the floc observed to be of uniform size (5–30 µm) but varied in shape throughout the culture period. Metagenomic profile of the floc was done through shotgun sequencing using Illumina NextSeq500 platform. High-quality data of 9.36 GB were obtained consisting 911,255 genes. The kingdom-level abundance was found in the order of 70.80% of Bacteria, 23.35% of Unclassified, 5.08% Eukarya, 0.62% of Archaea and 0.16% of Viruses. At the generic level composition, Proteobacteria and Caldilinea aerophila were the most abundant genus identified. Gene ontology using KEGG and SEED classification revealed predominantly carbohydrate metabolism associated genes. The present study is the first of its kind to study the microbial composition in biofloc of outdoor GIFT Tilapia grow-out culture and to identify the functional attributes of the microbiome in the biofloc system.

中文翻译：

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遗传改良养殖罗非鱼 (GIFT) 养成养殖中生物絮团的宏基因组特征

进行了GIFT（遗传改良养殖罗非鱼）养成系统中生物絮团的细菌群落表征，以确定微生物群落的动态和群落结构。GIFT (5.1 ± 0.05 g) 以 15/m ³的饲养密度饲养 180 天一式三份。酒厂用过的洗涤液作为碳源用于将 C:N 比保持在 10:1。记录的水质参数显示重复之间没有显着差异。观察到絮体的微观特征具有均匀的大小 (5–30 µm)，但在整个培养期间形状各不相同。使用 Illumina NextSeq500 平台通过鸟枪法测序完成絮体的宏基因组分析。获得了 9.36 GB 的高质量数据，包含 911,255 个基因。发现界级丰度的顺序为细菌的 70.80%、未分类的 23.35%、真核生物的 5.08%、古细菌的 0.62% 和病毒的 0.16%。在一般级别的组成上，变形杆菌和嗜 气球藻是最丰富的属。使用 KEGG 和 SEED 分类的基因本体显示主要是碳水化合物代谢相关基因。本研究是同类研究中首次研究室外 GIFT 罗非鱼养成养殖生物絮团中的微生物组成，并确定生物絮团系统中微生物组的功能属性。