Aquaculture is responsible for more than 50% of global seafood consumption. Bacterial diseases are a major constraint to this sector and associated with misuse of antibiotics, pose serious threats to public health. Fish-symbionts, co-inhabitants of fish pathogens, might be a promising source of natural antimicrobial compounds (NACs) alternative to antibiotics, limiting bacterial diseases occurrence in aquafarms. In particular, sporeforming Bacillus spp. are known for their probiotic potential and production of NACs antagonistic of bacterial pathogens and are abundant in aquaculture fish guts. Harnessing the fish-gut microbial community potential, 172 sporeforming strains producing NACs were isolated from economically important aquaculture fish species, namely European seabass, gilthead seabream, and white seabream. We demonstrated that they possess anti-growth, anti-biofilm, or anti-quorum-sensing activities, to control bacterial infections and 52% of these isolates effectively antagonized important fish pathogens, including Aeromonas hydrophila, A. salmonicida, A. bivalvium, A. veronii, Vibrio anguillarum, V. harveyi, V. parahaemolyticus, V. vulnificus, Photobacterium damselae, Tenacibaculum maritimum, Edwardsiela tarda, and Shigella sonnei. By in vitro quantification of sporeformers’ capacity to suppress growth and biofilm formation of fish pathogens, and by assessing their potential to interfere with pathogens communication, we identified three promising candidates to become probiotics or source of bioactive molecules to be used in aquaculture against bacterial aquaculture diseases.

水产养殖占全球海产品消费量的 50% 以上。细菌性疾病是该部门的主要制约因素，与滥用抗生素有关，对公众健康构成严重威胁。鱼类共生体是鱼类病原体的共同居住者，可能是替代抗生素的天然抗菌化合物 (NAC) 的有希望的来源，从而限制了水产养殖场中细菌性疾病的发生。尤其是产芽孢杆菌属 以其益生菌潜力和对抗细菌病原体的 NAC 的产生而闻名，并且在水产养殖鱼的内脏中含量丰富。利用鱼肠道微生物群落的潜力，从经济上重要的水产养殖鱼类，即欧洲鲈鱼、银头鲷和白鲷中分离出 172 种产生 NAC 的孢子形成菌株。我们证明它们具有抗生长、抗生物膜或抗群体感应活性，以控制细菌感染，并且这些分离物中 52% 有效地拮抗重要的鱼类病原体，包括嗜水气单胞菌、A.salmonicida、A. bivalvium、A . veronii , Vibrio anguillarum , V. harveyi ,V. parahaemolyticus、V. vulnificus、Photobacterium damselae、Tenacibaculum maritimum、Edwardsiela tarda和Shigella Sonnei。通过体外量化孢子形成者抑制鱼类病原体生长和生物膜形成的能力，并通过评估它们干扰病原体传播的潜力，我们确定了三种有希望成为益生菌或生物活性分子来源的候选物，用于水产养殖对抗细菌水产养殖疾病。