Dietary Klebsormidium sp. Supplementation Improves Growth Performance, Antioxidant and Anti-Inflammatory Status, Metabolism, and Mid-Intestine Morphology of Litopenaeus Vannamei

Abstract

Filamentous microalga <i>Klebsormidium</i> sp. has huge potential to become a natural and healthy additive in aquatic feed since it contains various bioactive nutrients, such as linoleic acid (LA), carotenoids, and chlorophylls. Therefore, an eight-week feeding experiment was performed to evaluate the effects of dietary <i>Klebsormidium</i> sp. on the growth performance, antioxidant and anti-inflammatory status, metabolism, and mid-intestine morphology of <i>Litopenaeus vannamei</i>. Two isonitrogenous and isolipid diets supplemented with and without 5% <i>Klebsormidium</i> sp. were prepared. Results showed that <i>L. vannamei</i> fed with <i>Klebsormidium</i> sp. had better growth performance and feed utilization by optimizing mid-intestine morphology and improving the carbohydrate metabolism. In addition, <i>Klebsormidium</i> sp. also enhanced the antioxidant capacity of <i>L. vannamei</i> by downregulating antioxidant parameters (hepatopancreas T-SOD, hepatopancreas GSH-PX, hemolymph T-SOD, hemolymph MDA) and RNA expression levels of antioxidant genes (<i>gsh-px</i> and <i>cat</i>). Furthermore, the supplementations of dietary <i>Klebsormidium</i> sp. significantly improved hepatopancreas health by downregulating RNA expression levels of pro-inflammatory related genes (<i>relish</i> and <i>rho</i>). Therefore, a dose of 5% <i>Klebsormidium</i> sp. is recommended for the daily diet of <i>L. vannamei</i> to improve the growth performance, antioxidant and anti-inflammatory status, metabolism, and mid-intestine morphology of shrimp.