Abstract
Host-derived probiotics offer sustainable alternatives to the commercial nonaquatic formulations due to superior compatibility with the gastrointestinal environment of aquatic species. This study integrated: (i) isolation, identification (via 16S rRNA sequencing), and in vitro potentiality (pH and bile tolerance) of gut-derived bacteria from wild M. rosenbergii, and (ii) an in vivo 120-day aquarium trial to evaluate performance of these laboratory-isolated probiotics (T1) compared to a commercial probiotic formulation (T2), and a control group fed with no probiotics (T0). Nine bacterial isolates were identified, including Bacillus cereus, Enterococcus faecium, Glutamicibacter mysorens, and Staphylococcus succinus, which exhibited strong acid and bile tolerance. In vivo, probiotic treatments improved water quality by reducing ammonia and stabilizing pH, ammonia was significantly lower in T1 (0.28 ± 0.03 mg/L) than in T0 (0.36 ± 0.06 mg/L; p < 0.05). Growth performance was enhanced with probiotics: final average weights reached 3.92 ± 0.08 g in T1, 3.17 ± 0.06 g in T2, and 2.31 ± 0.13 g in T0. Specific growth rate (SGR) was significantly higher in T1 (2.87% ± 0.03%) compared to T0 (2.36% ± 0.05%). Feed conversion ratio (FCR) was lowest in T1 (0.32 ± 0.09) and highest in T0 (1.13 ± 0.14), while feed conversion efficiency (FCE) was highest in T1 (3.15 ± 0.50). Overall, laboratory-isolated/host-derived probiotics outperformed the commercial formulations by simultaneously enhancing growth, feed utilization, and water quality, emphasizing their usefulness as a species-specific, sustainable alternative for freshwater prawn aquaculture.