Effects of the Probiotic Psychrobacter sp. B6 on the Growth, Digestive Enzymes, Antioxidant Capacity, Immunity, and Resistance of Exopalaemon carinicauda to Aeromonas hydrophila

Isolation and characterization of the actinomycete, Nocardiopsis, from Haizhou Bay, and its application as a probiotic for Exopalaemon carinicauda (Holthuis, 1950) (Caridea, Palaemonidae)

“…Detection of antimicrobial activity was carried out using the agar spot method following a modification of the technique used by Lai et al (2022). A. veronii and A. hydrophila were spread on TSA plates and V. parahaemolyticus and V. anguillarum were spread on TSA after adding an extra 10 g/l NaCl to the plates separately.…”

“…All groups were fed twice (8:00 and 20:00) with total daily diets at 2% body weight. The cultures lasted 30 days with conditions of 25 ± 1°C, pH 8.0 ± 0.2, salinity 27 ± 0.5 and water changed every 3 days by 50% of the volume (Lai et al, 2022).…”

“…So, hormones, antibiotics and pesticides, which might improve the growth, disease resistance, and flesh quality of aquaculture species (Saleh et al, 2015), but which could also lead to consequences of drug resistance, chemical residues, and environmental pollution, were banned from aquaculture. In this context, probiotics are beneficial microorganisms that can protect the host from diseases, promote the growth of farmed animals, or improve water quality, and these are, consequently, studied increasingly (Lai et al, 2022). Several gram-positive and gram-negative beneficial bacterial strains such as Bacillus species (Jamali et al, 2015;Guzmán-Villanueva et al, 2020), Vibrio species (Abdel-Tawwab et al, 2020), lactic acid bacteria (Adel et al, 2017), Leuconostoc mesenteroides (Tsenkovskii, 1878) van Tieghem, 1878(cf.…”

“…Selim et al, 2019, and Psychrobacter sp. (Lai et al, 2022), have been used as probiotics in aquaculture in recent years. Actinomycetes are also greatly important in aquaculture, such as the marine actinomycetes Streptomyces sp.…”

“…However, the natural germplasm resources of E. carinicauda have decreased, various breeding diseases have occurred more frequently, and the aquaculture environment has been polluted in recent years (Gao et al, 2021). In addition, the antibiotics and chemotherapeutics that could have prevented the serious consequences of those deteriorations, were explicitly prohibited in aquaculture in 2019 (Lai et al, 2022). Together, these developments constitute great challenges for the culture of E. carinicauda.…”