Ocean College, Hainan University, Haikou 570228, China; Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences & Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute of Tropical Agricultural Resources, Haikou 571101, China.
Hainan Provincial Key Laboratory for Functional Components Research and Utilization of Marine Bio-resources, Institute of Tropical Biosciences and Biotechnology, Chinese Academy of Tropical Agricultural Sciences & Key Laboratory for Biology and Genetic Resources of Tropical Crops of Hainan Province, Hainan Institute of Tropical Agricultural Resources, Haikou 571101, China; Ocean College, Hebei Agricultural University, Qinghuangdao 066003, China.
Fish Shellfish Immunol. 2024 Feb;145:109288. doi: 10.1016/j.fsi.2023.109288. Epub 2023 Dec 16.
This study aimed to evaluate the potential benefits of chitosan oligosaccharide (COS) on red claw crayfish (Cherax quadricarinatus) and explore its underlying mechanisms. The crayfish were randomly divided into six groups, and the diets were supplemented with COS at levels of 0 (C0), 0.2 (C1), 0.4 (C2), 0.6 (C3), 0.8 (C4), and 1 (C5) g kg. Treatment with COS significantly improved the growth performance of the crayfish with a higher weight gain rate (WGR) and specific growth rate (SGR) in the C2 group compared to the C0 group. Additionally, the content of crude protein in the crayfish muscles in the C1 group was significantly higher than that of the C0 group. Regarding non-specific immunity, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and alkaline phosphatase (AKP), and the levels of expression of the genes related to immunity (SOD; anti-lipopolysaccharide factor [ALF]; thioredoxin1 [Trx1]; C-type lysozyme, [C-LZM]; and GSH-Px) in the hepatopancreas and hemolymph increased significantly (P < 0.05) after supplementation with 0.4 g kg of COS, while the content of malondialdehyde (MDA) decreased (P < 0.05). The survival rate of C. quadricarinatus increased (P < 0.05) in the C2, C3, C4, and C5 groups after the challenge with Aeromonas hydrophila. This study found that COS has the potential to modulate the composition of the intestinal microbiota and significantly reduce the abundance of species of the phylum Proteobacteria and the genera Aeromonas and Vibrio in the gut of C. quadricarinatus, while the abundance of bacteria in the phylum Firmicutes and the genus Candidatus_Hepatoplasma improved significantly. This study suggests that the inclusion of COS in the diet of C. quadricarinatus can enhance growth, boost immunity, and increase resistance to infection with A. hydrophila, especially when supplemented at 0.4-0.8 g kg.
本研究旨在评估壳寡糖（COS）对红螯螯虾（Cherax quadricarinatus）的潜在益处，并探讨其潜在机制。将螯虾随机分为六组，日粮中分别添加 0（C0）、0.2（C1）、0.4（C2）、0.6（C3）、0.8（C4）和 1（C5）g/kg 的 COS。COS 处理显著提高了螯虾的生长性能，与 C0 组相比，C2 组的增重率（WGR）和特定生长率（SGR）更高。此外，C1 组螯虾肌肉中的粗蛋白含量显著高于 C0 组。关于非特异性免疫，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）和碱性磷酸酶（AKP）的活性以及与免疫相关的基因（SOD；抗脂多糖因子[ALF]；硫氧还蛋白 1 [Trx1]；C 型溶菌酶[C-LZM]；和 GSH-Px）在肝胰腺和血淋巴中的表达水平显著增加（P<0.05），而丙二醛（MDA）的含量降低（P<0.05）。添加 0.4g/kg COS 后，C. quadricarinatus 的存活率在 A. hydrophila 攻毒后增加（P<0.05）。本研究发现，COS 能够调节肠道微生物群落的组成，显著降低 C. quadricarinatus 肠道中厚壁菌门和气单胞菌属和弧菌属的丰度，而厚壁菌门和 Candida_Hepatoplasma 属的细菌丰度显著提高。本研究表明，在 C. quadricarinatus 的日粮中添加 COS 可以增强生长、提高免疫力，并提高对 A. hydrophila 的感染抵抗力，特别是在 0.4-0.8g/kg 时添加效果更佳。
