Abstract Along with the intensification of culture systems to meet the increasing global demands, there is an elevated risk of disease outbreak and substantial loss for shrimp farmers. Probiotics, e.g., Lactobacillus plantarum, are among the most promising feed supplements for controlling or treating microbial diseases in shrimp aquaculture. The maintenance of live and viable probiotic bacterial culture during storage is, however, quite challenging. This study investigated the paraprobiotic potential of L. plantarum on whiteleg shrimp (Penaeus vannamei), specifically on the intestinal microbiota. Four different experimental diet preparations of L. plantarum (fermentation supernatant (FS), live bacteria (LB), dead bacteria (DB), and cell-free extract (CE)) were used in the 15-day feeding trial. Subsequently, 16S rDNA gene sequencing technology was applied to analyze and characterize the whiteleg shrimp intestinal microbiota. Results showed that Proteobacteria was the most prevalent phylum in whiteleg shrimp gut microbiota, independent of the diet. Other phyla, including Bacteroidetes, Verrucomicrobia, Tenericutes, and Euryarchaeota were also recorded and independent of the diet. The microbiota of the whiteleg shrimp fed with the L. plantarum CE diet showed the highest abundance of Acidobacteria, with a 70-fold increase compared to that of the animals on the control diet. The abundance of Verrucomicrobia was the highest in the whiteleg shrimp fed with L. plantarum DB diet. Moreover, the abundance of Cyanobacteria, Crenarcheota, and Euryarchaeota in the microbiota of animals fed with L. plantarum FS diet were more than 10-fold higher, compared to that of the whiteleg shrimp fed with the control diet. An increased number of the potential beneficial bacteria from the genera Demequina, Rubritalea, Tenacibaculum, Marinicella and Phaeobacter versus a significantly decreased amount of the potential pathogenic genus Synechococcus were encountered in the microbiota of the CE diet-fed animals. There were 382 operational taxonomic units (OTUs) shared among all gut samples. The microbiota of the shrimps on the CE diet had the most unique OTUs, followed by those included in the FS and DB diet groups. These results demonstrated that P. vannamei fed with L. plantarum CE and FS diets had a significantly altered gastrointestinal microbiota. In conclusion, L. plantarum CE and FS diets have the potential to be used as paraprobiotics, due to the capacity to positively modulate the gastrointestinal microbiota in P. vannamei.

中文翻译：

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植物乳杆菌给药对南美白对虾肠道菌群的影响

摘要 随着养殖系统的集约化以满足日益增长的全球需求，疾病爆发和对虾养殖者的重大损失的风险也在增加。益生菌，例如植物乳杆菌，是最有前途的饲料添加剂，用于控制或治疗对虾养殖中的微生物疾病。然而，在储存期间维持活的和有活力的益生菌细菌培养物是相当具有挑战性的。本研究调查了植物乳杆菌对南美白对虾（Penaeus vannamei），特别是肠道微生物群的副益生菌潜力。在为期 15 天的喂养试验中使用了四种不同的植物乳杆菌实验饮食制剂（发酵上清液 (FS)、活细菌 (LB)、死细菌 (DB) 和无细胞提取物 (CE)）。随后，应用16S rDNA基因测序技术对白脚虾肠道微生物群进行分析和表征。结果表明，变形杆菌是白腿虾肠道微生物群中最普遍的门，与饮食无关。还记录了其他门，包括拟杆菌门、疣微菌门、Tenericutes 和 Euryarchaeota，并且与饮食无关。用植物乳杆菌 CE 饮食喂养的白腿虾的微生物群显示出最高的酸杆菌丰度，与对照组饮食的动物相比增加了 70 倍。在用植物乳杆菌 DB 饲料喂养的白腿虾中，疣微菌的丰度最高。此外，用植物乳杆菌 FS 饮食喂养的动物微生物群中蓝藻、Crenarchaeota 和 Euryarchaeota 的丰度高出 10 倍以上，与用对照饲料喂养的白腿虾相比。在 CE 饮食喂养的动物的微生物群中，来自 Demequina、Rubritalea、Tenacibaculum、Marinicella 和 Phaeobacter 的潜在有益细菌数量增加，而潜在致病性聚球藻属的数量显着减少。所有肠道样本共有 382 个操作分类单位 (OTU)。CE 饮食中虾的微生物群具有最独特的 OTU，其次是 FS 和 DB 饮食组中的虾。这些结果表明，用植物乳杆菌 CE 和 FS 饲料喂养的南美白对虾具有显着改变的胃肠道微生物群。总之，植物乳杆菌 CE 和 FS 饮食有可能用作副益生菌，