Oxiglutatione

The investigation of geographical feed raw materials is crucial to maintain the sustainable development of aquaculture. Ensuring the intestinal health of aquatic animals is the key to improving the absorption and utilization rate of new protein sources. In the present study, a composite protein source derived from the sargassum enzyme-hydrolysate compound fish protein hydrolysate ("SFPH" in the experiment) was utilized to replace 0 %, 5 %, 10 %, 20 %, 30 %, and 40 % of fish meal protein, respectively. Pacific white shrimp (Penaeus vannamei) with an initial weight of 0.9 g was used as experimental model for an 8-week feeding trial. The results revealed that SFPH replacement reduced the width of intestinal microvilli, but the 5%SFPH group significantly increased intestinal wall thickness and microvilli height. Antioxidant indicators analysis revealed that when over 10 % of fish meal protein was substituted with SFPH, the total antioxidant capacity dramatically decreased. When SFPH replaced 40 % of fish meal protein, the mRNA expression levels of endoplasmic reticulum stress-related indicators (bip and atf4) significantly increased, as well as the genes associated with apoptosis (jnk, caspase 8 and caspase 3). The analysis of intestinal microbiota showed that the 5%SFPH group significantly increased the richness of intestinal microbiota and significantly increased the abundance of beneficial bacteria (Campilobacter, Patescibacter, Deferribacter and Halobacter). The 40%SFPH group significantly increased the abundance of pathogenic bacteria (Pseudomonas, Serratia, Rickettsia, Edwardsiella, and Veillonella). A total of 201 differential relative abundance metabolites were detected by metabolomics, among which the contents of succinate, oxidized glutathione and reduced glutathione were reduced in the 40%SFPH group. The differential metabolites were mainly enriched in cysteine and methionine metabolism, biosynthesis of amino acid and glutathione metabolism. Based on the integrated analysis of metabolomics and intestinal microbiota, changes in signal pathways such as amino acid metabolism and glutathione synthesis may be the main reasons for the high proportion of SFPH disrupting intestinal health. This study provides in-depth data on the reaction mechanisms of shrimp to seaweed protein, and also provides new directions for the improvement of seaweed protein in the future.

Litopenaeus vannamei is an important aquaculture species and faces complex stress challenges in saline-alkali water, such as high pH and alkalinity. In this study, the immune and metabolic responses of L.vannamei under acute interactive stress (pH 9.2, alkalinity 350 mg / L) were investigated by multi-omics analysis. The results showed that significant changes in antioxidant enzyme activity (e.g., increased SOD, decreased GSH-Px) and immune-related pathways (lysosomes, TGF-β, glutathione metabolism) were affected. Transcriptome analysis identified 1968 DEGs, which were mainly enriched in apoptosis, immune defense, and energy metabolism pathways. Metabolomics revealed the disorder of lipid, amino acid, and nucleotide metabolism, and key metabolites (such as arachidonic acid and sphingomyelin) were related to oxidative stress and membrane stability. Multi-omics integration showed that PI3K-AKT and TGF-β signaling pathways were coordinated and regulated under stress conditions. WGCNA analysis obtained a total of 19 co-expression modules. Among them, 13 hub genes related to saline-alkali stress were screened out in the turquoise and brown modules, and a transcriptional regulatory network was constructed. The expression patterns of five pairs of genes in four hot pathways under saline-alkali stress were verified. In summary, high pH and alkalinity interaction stress induces oxidative damage, disrupts metabolic homeostasis, and triggers adaptive responses through immune activation and energy redistribution. This study provides clues for exploring the molecular response mechanism of L. vannamei under saline-alkali stress and provides a theoretical basis for optimizing shrimp culture in saline-alkali waters.