García-Márquez Jorge, Díaz Alba Galafat, Molina-Roque Luis, Domínguez-Maqueda Marta, de Las Heras Verónica, Simó-Mirabet Paula, Vizcaíno Antonio J, Martos-Sitcha Juan Antonio, Alarcón-López Francisco Javier, Moriñigo Miguel Ángel, Balebona María Carmen
Departamento de Microbiología, Facultad de Ciencias, Instituto Andaluz de Biotecnología y Desarrollo Azul (IBYDA), Universidad de Málaga, CEI⋅MAR-Universidad de Málaga, 29071, Málaga, Spain.
Departamento de Biología y Geología, Universidad de Almería, CEI⋅MAR-Universidad de Almería, 04120, Almería, Spain.
Probiotics Antimicrob Proteins. 2024 Sep 11. doi: 10.1007/s12602-024-10350-z.
This study investigates the postbiotic potential of extracellular products (ECPs) from Bacillus pumilus strains cultivated on microalgae-supplemented media. We assessed enzymatic and antimicrobial activities to select ECPs that enhance the digestive processes in gilthead seabream. Additionally, we explored the in vitro enzymatic capacity of the chosen postbiotics to hydrolyze macromolecules in microalgae. Finally, a feeding trial was conducted to determine the in vivo effects of the ECPs on Sparus aurata. In vitro enzymatic assays demonstrated diverse hydrolytic capacities among ECPs. All conditions exhibited antimicrobial activity against Photobacterium damselae subsp. piscicida, with variation in inhibitory effects against Vibrio harveyi and Tenacibaculum maritimum. Furthermore, in vitro assays revealed differences in protein hydrolysis and soluble protein concentration, influencing amino acid and reducing sugar release from microalgal biomass. These analyses facilitated a selection to test ECPs in vivo. Lastly, the in vivo experiment revealed no differences in the growth performance, nutrient utilization, and general metabolism of S. aurata fed the experimental diets. Dietary inclusion of postbiotics increased the activity of key digestive enzymes in fish compared to the control group, and particularly, values increased significantly when the fish were fed with the ECP-nanoparticulate-supplemented diet. In conclusion, the inclusion of microalgae in the culture media significantly influences the activity of extracellular products from B. pumilus strains, as evidenced in both in vitro and in vivo assays.
本研究调查了在添加微藻的培养基上培养的短小芽孢杆菌菌株的胞外产物（ECPs）的益生元潜力。我们评估了酶活性和抗菌活性，以选择能够增强金头鲷消化过程的ECPs。此外，我们还探索了所选益生元在体外水解微藻中大分子的酶促能力。最后，进行了一项饲养试验，以确定ECPs对金头鲷的体内影响。体外酶活性测定表明，ECPs具有不同的水解能力。所有条件下均对美人鱼发光杆菌亚种表现出抗菌活性，对哈维氏弧菌和海生黄杆菌的抑制效果存在差异。此外，体外试验揭示了蛋白质水解和可溶性蛋白质浓度的差异，影响了微藻生物质中氨基酸和还原糖的释放。这些分析有助于选择在体内测试ECPs。最后，体内实验表明，喂食实验饲料的金头鲷在生长性能、营养利用和一般代谢方面没有差异。与对照组相比，日粮中添加益生元可提高鱼体内关键消化酶的活性，特别是当鱼喂食添加ECP纳米颗粒的日粮时，酶活性值显著增加。总之，在培养基中添加微藻显著影响了短小芽孢杆菌菌株胞外产物的活性，这在体外和体内试验中均得到了证实。
