ALGINATE FROM Padina sp. ENHANCES NON-SPECIFIC IMMUNE SYSTEM AND UP-REGULATES IMMUNES GENES IN WHITE SHRIMP (Litopenaeus vannamei)

Alim Isnansetyo*, Ayuningtyas, Ervia Yudiati,
Murwantoko, Ch. Retna Handayani
 
Department of Fisheries, Faculty of Agriculture, Gadjah Mada University, Jl. Flora, Bulaksumur, Yogyakarta 55281, Indonesia
E mail: isnansetyo@yahoo.com ; isnansetyo@ugm.ac.id

White shrimp (L. vannamei) is a global aquaculture commodity, which is cultured intensively in around the world including Indonesia. In Indonesia, the shrimp production now is dominated by this species. The shrimp aquaculture frequently faces diseases outbreak mainly caused viral and bacterial pathogens. Non-spesific immune system plays an important role in shrimp to counter measure the pathogen. Immunostimulant such as alginate may be administered orally to enhance the non-spscific immune system. This research aimed to evaluate the effects of alginate from Padina sp. on immune respons and expression of immune genes in White shrimp. White shrimp (20±2 g) was fed with diets containing alginate at 0, 2 and 4 g/kg feed for 15 days. Haemolymph was taken before treatment, on 5, 10, and 15 days post treatment. Total hemocyte count (THC), phagocytosis activity (PA) and phagocytosis indeks (PI) were measured directly by a microscope. Phenoloxidase activity (PO), superoxide dismutase activity (SOD) and total protein plasma (TPP) were measured by colorimetry method. LGBP, lectin, toll, and proPO genes expression were evaluated by qRT-PCR method.

Results indicated Phagocytosis indeks (PI) and TPP significantly increased at 10th day post treatment. Morever, total hemocyte count (THC), PA, PO, and SOD activity significantly increased at 15th day post treatment (P<0.05). However, oral administration of alginate did not affect on PI and TPP (P>0.05). The expressions of LGBP, toll, lectin, and proPO genes elevated. Toll gene expresion exhibited the highest up-regulating up to 13.9 fold comparing to the control treatment. Alginate also up-regulated expression of LGBP and C-type lectin genes up to 1.42 and 1.61 fold, respectively. The expression of ProPO gene was also up-regulated up to 4.52 fold. It was concluded that alginate from Padina sp. elevates immune respons and expression of immune genes in L. vannamei, so it might be applied as an immunostimulant to enhance the resistant of the shrimp to pathogens.

Challenge test with especially viral and bacterial pathogens is needed in the next experiment to know the effectiveness of alginate for preventing diseases in shrimp.