Department of Aquaculture, College of Marine Sciences, Hainan University, Haikou, 570228, Hainan, China; School of Life Sciences, East China Normal University, Shanghai, 200241, China.
Department of Aquaculture, College of Marine Sciences, Hainan University, Haikou, 570228, Hainan, China.
Fish Shellfish Immunol. 2019 Aug;91:315-324. doi: 10.1016/j.fsi.2019.05.052. Epub 2019 May 23.
An 8-week trial was conducted to evaluate the effect of dietary β-glucan supplement (0, 0.01%, 0.02%, or 0.04%) on growth and health of Pacific white shrimp Litopenaeus vannamei at low salinity of 3 practical salinity unit (psu). The L. vannamei fed 0.02% and 0.04% β-glucan gained more weight and showed higher activities of protease, amylase, superoxide dismutase, and glutathione peroxidase in the intestine than in the control (0% β-glucan). The L. vannamei fed 0.04% β-glucan had a higher condition factor than those fed the control diet. Amylase activity in the hepatopancreas of L. vannamei fed 0.02% β-glucan was higher than those fed the control diet. Dietary β-glucan supplement increased the mRNA expressions of Toll-like receptor, myostatin, immune deficiency or heat shock protein 70, but decreased the mRNA expressions of tumor necrosis factor-α and C-type lectin 3 in both hepatopancreas and intestine. The response of intestine microbiota in L. vannamei fed 0.04% β-glucan was further compared to the control. The 0.04% β-glucan supplement reduced richness and diversity of the intestinal microbial community as indicated by the low values of Chao1 estimator, ACE estimator, Simpson index and Shannon diversity index. Abundances of Bacillus, Chitinibacter, Geobacillus and Vibrio in the intestine increased, while Flavobacterium, Microbacterium and Mycobacterium decreased significantly in L. vannamei fed 0.04% β-glucan compared to the control. This study indicates that dietary β-glucan supplement at 0.02%-0.04% can significantly improve digestibility, antioxidant capacity and immunity in L. vannamei, and thus improve growth performance and survival at low salinity. These beneficial effects of β-glucan probably are related to the dominance of probiotics over potential pathogens in the intestine.
进行了一项为期 8 周的试验，以评估膳食 β-葡聚糖补充剂（0、0.01%、0.02%或 0.04%）对低盐度 3 实用盐度单位（psu）下凡纳滨对虾生长和健康的影响。与对照组（0%β-葡聚糖）相比，摄食 0.02%和 0.04%β-葡聚糖的凡纳滨对虾体重增加更多，肠道中蛋白酶、淀粉酶、超氧化物歧化酶和谷胱甘肽过氧化物酶活性更高。摄食 0.04%β-葡聚糖的凡纳滨对虾的条件系数高于对照组。摄食 0.02%β-葡聚糖的凡纳滨对虾肝胰腺中淀粉酶活性高于对照组。膳食β-葡聚糖补充剂增加了肝胰腺和肠道中 Toll 样受体、肌肉生长抑制素、免疫缺陷或热休克蛋白 70 的 mRNA 表达，但降低了肿瘤坏死因子-α和 C 型凝集素 3 的 mRNA 表达。进一步比较了摄食 0.04%β-葡聚糖的凡纳滨对虾肠道微生物群的反应。与对照组相比，0.04%β-葡聚糖补充剂降低了肠道微生物群落的丰富度和多样性，Chao1 估计值、ACE 估计值、辛普森指数和香农多样性指数较低。摄食 0.04%β-葡聚糖的凡纳滨对虾肠道中芽孢杆菌、奇希比克菌、地杆菌和弧菌的丰度增加，而黄杆菌、微杆菌和分枝杆菌的丰度显著降低。本研究表明，膳食β-葡聚糖补充剂在 0.02%-0.04%的范围内可显著提高低盐度下凡纳滨对虾的消化率、抗氧化能力和免疫力，从而提高生长性能和存活率。β-葡聚糖的这些有益作用可能与肠道中益生菌对潜在病原体的优势有关。
