Exopolysaccharide from Porphyridium cruentum (purpureum) is Not Toxic and Stimulates Immune Response against Vibriosis: The Assessment Using Zebrafish and White Shrimp Litopenaeus vannamei.

Yenny Risjani,Praprianita Manurung,Nurul Mutmainnah,Yunianta Yunianta,Siti Narsito Wulan

doi:10.3390/md19030133

Abstract

Exopolysaccharides, or extracellular polysaccharides (EPS, sPS), represent a valuable metabolite compound synthesized from red microalgae. It is a non-toxic natural agent and can be applied as an immunostimulant. The toxicity test of exopolysaccharides from Porphyridium has been done in vivo using zebrafish (Danio rerio) embryonic model, or the ZET (zebrafish embryotoxicity test). The administration of extracellular polysaccharides or exopolysaccharides (EPS) from microalgae Porphyridium cruentum (synonym: P. purpureum) to shrimps Litopenaeus vannamei was investigated to determine the effect of this immunostimulant on their non-specific immune response and to test if this compound can be used as a protective agent for shrimps in relation to Vibrio infection. For immune response, exopolysaccharides were given to shrimps via the immersion method on day 1 and booster on day 8. Shrimp hemocytes were taken on day 1 (EPS administration), day 7 (no treatment), day 8 (EPS booster) and day 9 (Vibrio infection) and tested for their immune response on each treatment. The result shows that the EPS is not toxic, as represented by the normal embryonic development and the mortality data. In the Pacific white shrimps, an increase in the values of all immune parameters was shown, in line with the increasing EPS concentration, except for the differential hemocyte count (DHC). In detail, an increase was noted in total hemocytes (THC) value, phagocytotic activity (PA) and respiratory burst (RB) in line with the EPS concentration increase. These results and other previous studies indicate that EPS from Porphyridium is safe, enhances immune parameters in shrimp rapidly, and has the ability to act as an immunostimulant or an immunomodulator. It is a good modulator for the non-specific immune cells of Pacific white shrimps, and it can be used as a preventive agent against vibriosis.

Highlights

Vaname, the white shrimp (Litopenaeus vannamei), is one type of the more popular and cultivated shrimps
We revealed that the EPS from Porphyridium cruentum (P. purpureum) modulates all immune cells rapidly, as shown by the total hemocyte count (THC), the
We revealed that the EPS from Porphyridium cruentum (P. purpureum) has been carried out to test if the exopolysaccharides of red microalgae are a toxic commodulates all immune cells rapidly, as shown by the total hemocyte count (THC), the pound or not

Summary

Introduction

The white shrimp (Litopenaeus vannamei), is one type of the more popular and cultivated shrimps. It is able to live in a wide range of salinities (euryhaline), between 5 and 30 ppt, as well as being adaptable to high stocking densities, and growing well at low protein feeding levels It entered Indonesia, according to the Decree of the Minister of Marine and Fisheries of Republic of Indonesia Number 41 of 2001, as a substitute for the tiger shrimp commodity, whose production declined due to disease attacks [1]. The pathogenic bacteria often attack shrimp during the nauplii, zoea, and mysis stages, and this sometimes occurs in the post-larval stage, even during maintenance in ponds at the age of 1 to 1.5 months This disease can spread directly through the waters, as well as through direct contact between shrimps, killing the population shortly after 1 to 3 days from the initial infection [4]

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