The increased knowledge of functional foods has led to the development of a new generation of health products, including those containing probiotics and products derived from them. Shewanella putrefaciens Pdp11 (SpPdp11) is a strain described as a probiotic that exerts important beneficial effects on several farmed fish. However, the use of live probiotic cells in aquaculture has limitations such as uncertain survival and shelf life, which can limit their efficacy. In addition, its efficacy can vary across species and hosts. When probiotics are administered orally, their activity can be affected by the environment present in the host and by interactions with the intestinal microbiota. Furthermore, live cells can also produce undesired substances that may negatively impact the host as well as the risk of potential virulence reversion acquired such as antibiotic resistance. Therefore, new alternatives emerged such as postbiotics. Currently, there is no knowledge about the postbiotic potential of SpPdp11 in the aquaculture industry. Postbiotic refers to the use of bacterial metabolites, including extracellular products (ECPs), to improve host physiology. However, the production of postbiotic metabolites can be affected by various factors such as cultivation conditions, which can affect bacterial metabolism. Thus, the objective of this study was to evaluate the postbiotic potential of ECPs from SpPdp11 under different cultivation conditions, including culture media, temperature, growth phase, and salinity. We analyzed their hydrolytic, antibacterial, antiviral, and cytotoxic capacity on several fish cell lines. The results obtained have demonstrated how each ECP condition can exert a different hydrolytic profile, reduce the biofilm formation by bacterial pathogens relevant to fish, lower the titer of nervous necrosis virus (NNV), and exert a cytotoxic effect on different fish cell lines. In conclusion, the ECPs obtained from SpPdp11 have different capacities depending on the cultivation conditions used. These conditions must be considered in order to recover the maximum number of beneficial capacities or to choose the appropriate conditions for specific activities.

对功能性食品的了解不断增加，促进了新一代保健产品的开发，包括含有益生菌的产品及其衍生产品。腐败希瓦氏菌Pdp11 (SpPdp11) 是一种被描述为益生菌的菌株，对多种养殖鱼类产生重要的有益作用。然而，在水产养殖中使用活益生菌细胞存在一些局限性，例如不确定的存活率和保质期，这可能会限制其功效。此外，其功效因物种和宿主而异。当口服益生菌时，其活性可能会受到宿主环境以及与肠道微生物群相互作用的影响。此外，活细胞还会产生不需要的物质，这些物质可能对宿主产生负面影响，并存在潜在毒力回复的风险，例如抗生素耐药性。因此，出现了新的替代品，例如后生元。目前，尚不清楚 SpPdp11 在水产养殖业中的后生潜力。后生元是指利用细菌代谢物，包括细胞外产物（ECP）来改善宿主生理机能。然而，生后代谢物的产生可能受到多种因素的影响，例如培养条件，这会影响细菌的代谢。因此，本研究的目的是评估 SpPdp11 的 ECP 在不同培养条件下（包括培养基、温度、生长期和盐度）的生后潜力。我们分析了它们对几种鱼细胞系的水解、抗菌、抗病毒和细胞毒性能力。获得的结果证明了每种 ECP 条件如何发挥不同的水解特性，减少与鱼类相关的细菌病原体的生物膜形成，降低神经坏死病毒 (NNV) 的滴度，并对不同的鱼类细胞系发挥细胞毒性作用。总之，从 SpPdp11 获得的 ECP 具有不同的容量，具体取决于所使用的培养条件。必须考虑这些条件，以便恢复最大数量的有益能力或为特定活动选择适当的条件。