This study investigated the effects of fermented Chinese herb (FCH) on the growth indices, leukocyte activity, and biochemical indices of carp (Cyprinus carpio). Astragalus membranaceus (AM), Pericarpium Citri Reticulatae (PCR), and Glycyrrhizae Radix et Rhizoma (GRR) as feed additives enhance immune function, promote growth, and exert anti-inflammatory effects, respectively. Therefore, this study investigated the effects of co-fermented blends of these three herbs on growth performance and related parameters in common carp. By adding 2%, 5%, and 10% of the FCH to co-incubate with carp leukocytes, the results show that all three experimental treatments could enhance the respiratory burst activity and phagocytic activity of carp leukocytes. After 28 days of feeding with basal feed supplemented with 2%, 5%, and 10% (w/v) of the FCH, the weight gain rate and specific growth rate of carp were significantly higher than those of the control treatment without additives (ANOVA, p < 0.05), with the 5% treatment showing the highest. The activities of intestinal digestive enzymes were significantly increased (ANOVA, p < 0.05). On the 21st day, the activities of amylase (AMS), lipase (LPS), and chymotrypsin were increased compared to the control treatment. The 5% and 10% treatments showed significantly higher intestinal digestive enzyme activities compared to the 2% treatment. The serum superoxide dismutase (SOD) levels in both the control and experimental treatments initially increased and then decreased, with all three experimental treatments having higher levels than the control treatment. The activities of liver glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) in the experimental treatments showed no significant changes compared to the control treatment (ANOVA, p > 0.05). However, the serum GPT activity in the 5% treatment was significantly lower than that of the control treatment (ANOVA, p < 0.05), while no significant differences were observed in the other treatments. The results indicate that adding 2~10% of FCH to carp feed can improve intestinal digestion, enhance phagocytic activity and the body’s antioxidant defense capabilities, and effectively promote the growth of carp. It can significantly improve farming efficiency and economic benefits, reduce dependence on chemical drugs, and lower environmental pollution, showing good application prospects in production.

A fluorescent biosensor based on a cell-free RNA transcription system was developed for species-specific DNA sequence detection and seahorse product identification.

Pathogenic Vibrio species are a major cause of disease outbreaks in aquaculture, leading to substantial economic losses and posing risks to food safety. The increasing prevalence of antibiotic resistance among these pathogens has created an urgent need for alternative antimicrobial strategies. Phage-derived endolysins, which specifically degrade bacterial peptidoglycan, have emerged as promising candidates to replace or supplement conventional antibiotics. In this study, we systematically characterized the endolysin LysV039C from the Vibrio alginolyticus phage phiV039C. Whole-genome analysis identified a 462 bp endolysin gene, which was cloned into the pET-28a vector, expressed in E. coli BL21, and purified. The lytic activity of the recombinant enzyme was evaluated using a turbidity reduction assay. LysV039C showed the strongest activity (58.9%) against host bacteria in the logarithmic phase, with peak activity (60.7–64.1%) achieved at 53 μg/mL, 35 °C, and neutral pH. The addition of 2.5 mM EDTA enhanced activity to 63.8%, whereas 10 mM divalent metal ions strongly inhibited the enzyme (<6.5%). Lytic spectrum analysis demonstrated that LysV039C exhibited a broader lytic spectrum against six Vibrio species than its parent phage phiV039C. Overall, LysV039C combines high environmental adaptability (alkaline tolerance, suitability for aquaculture temperature ranges) with efficient and broadened lytic activity against multiple Vibrio species. These findings provide a foundation for developing eco-friendly agents for the prevention and control of pathogenic Vibrio and offer a valuable reference for the mining of other phage-derived antibacterials against aquatic pathogens.