Utilization of Biosurfactants in common carp (Cyprinus carpio) Semi-Artificial Fish Reproduction: Toxicity, Antimicrobial Activity, and Broodstock condition

Biosurfactants have increasing attention as bioactive compounds with potential applications in aquaculture. The present study investigates the utilization of purified biosurfactants in semi-artificial fish reproduction, with particular emphasis on broodstock condition, toxicity, and antimicrobial activity. Healthy brood fish were conditioned under controlled environmental and nutritional regimes prior to induced spawning using a semi-artificial fertilization method. Reproductive performance was evaluated based on fertilization rate, hatching success, and larval survival. Purified biosurfactants were assessed for toxicological effects using early life stages of fish, where concentration-dependent responses were observed. Results indicated that lower concentrations exhibited minimal toxicity, while higher concentrations affected larval survival and development. In addition, the antimicrobial activity of the biosurfactants was evaluated against selected clinical and aquatic pathogens using standard in vitro assays. The biosurfactants demonstrated significant inhibitory effects against both Gram-positive and Gram-negative bacteria, suggesting their potential role in microbial control during fish breeding operations