Abbas Eman M, Al-Souti Ahmed Said, Sharawy Zaki Z, El-Haroun Ehab, Ashour Mohamed
National Institute of Oceanography and Fisheries (NIOF), Cairo 11516, Egypt.
Head AL Hail Aquaculture Unit, Department of Marine Science and Fisheries, College of Agriculture and Marine Science, Sultan Qaboos University, Muscat 123, Oman.
Life (Basel). 2023 Jan 27;13(2):344. doi: 10.3390/life13020344.
This work aims to determine the impact of dietary supplementation of polysaccharide, extracted from brown seaweeds on growth indices, feed utilization, biochemical compositions, microbial abundance, expressions of growth and immunity-related genes, and stress genes of the Pacific Whiteleg shrimp . A total of 360 post-larvae of were randomly distributed into a 12-glass aquarium (40 L of each) at a stocking density of 30 shrimp with an initial weight of (0.0017 ± 0.001 g). During the 90-day experiment trial, all shrimp larvae were fed their respective diets at 10% of total body weight, three times a day. Three experimental diets were prepared with different seaweed polysaccharide (SWP) levels. The basal control diet had no polysaccharide level (SWP), while SWP, SWP, and SWP contained polysaccharides at concentrations of 1, 2, and 3 g kg diet, respectively. Diets supplemented with polysaccharide levels showed significant improvements in weight gain and survival rate, compared to the control diet. Whole-body biochemical composition and the microbial abundance (the total count of heterotrophic bacteria and spp.) of showed significant differences among polysaccharide-treated diets compared to the control. At the end of the feeding experiment, the dietary supplementation of polysaccharide levels enhanced the expression of growth-related genes (Insulin-like growth factors (), immune-related genes ( -Glucan-binding protein (), Prophenoloxidase (), Lysozyme (), and ), and stress genes (Superoxide dismutase () and Glutathione peroxidase () in the muscle tissue of . However, the current study concluded that the inclusion rate of 2 g kg of polysaccharide as a dietary additive administration enhanced both weight gain and survival rate of , while the incorporation level of 3 g kg reduces the abundance of pathogenic microbes and enhances the growth-, immunity- and stress-related gene expressions of .
本研究旨在确定从褐藻中提取的多糖进行日粮添加对凡纳滨对虾生长指标、饲料利用率、生化组成、微生物丰度、生长和免疫相关基因以及应激基因表达的影响。总共360尾凡纳滨对虾幼体，初始体重为（0.0017±0.001 g），以30尾虾的放养密度随机分配到12个玻璃水族箱（每个40 L）中。在为期90天的实验期间，所有对虾幼体均按体重的10%投喂各自的日粮，每天投喂三次。制备了三种不同海藻多糖（SWP）水平的实验日粮。基础对照日粮不含多糖（SWP），而SWP1、SWP2和SWP3日粮分别含有浓度为1、2和3 g/kg日粮的多糖。与对照日粮相比，添加多糖水平的日粮在增重和存活率方面有显著改善。凡纳滨对虾的全身生化组成和微生物丰度（异养细菌总数和弧菌属）在多糖处理日粮与对照日粮之间存在显著差异。在投喂实验结束时，日粮添加多糖水平增强了凡纳滨对虾肌肉组织中生长相关基因（胰岛素样生长因子（IGFs））、免疫相关基因（β-葡聚糖结合蛋白（βGBP）、酚氧化酶原（PPO）、溶菌酶（LYZ）和免疫球蛋白M（IgM））以及应激基因（超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GPx））的表达。然而，当前研究得出结论，日粮中添加2 g/kg的多糖作为添加剂可提高凡纳滨对虾的增重和存活率，而添加水平为3 g/kg时可降低致病微生物的丰度并增强凡纳滨对虾生长、免疫和应激相关基因的表达。
