Potency of mangrove Rhizophora mucronata as bactericide for vibrio causing tiger shrimp disease

Abstract

Tiger shrimp diseases have been occurred in Indonesian brackishwater ponds for two decades and considered as one of the factors causing mass mortality of the cultured shrimp and making big loss for the farmers. Vibrio harveyi is considered as the main causative agent of this disease. The natural substance is proposed to kill or inhibit the growth of pathogenic vibrios. In order to know the potency of mangrove Rhizophora mucronata as a bactericide for V. harveyi, research had been conducted at the Research Institute for Coastal Aquaculture (BPPBAP) from February to May 2013. This research consists of several steps, i.e. 1) collection of plant; 2) drying of the plant; 3) making powder of plant; 4) extraction of plant/herb; 5) qualitative bioassay; and 6) quantitative bioassay. The results showed that qualitatively all part of the R. mucronata collected from Bone regency had activity against V. harveyi, but the leaf part of this mangrove collected from Maros regency did not have this activity, and neither the leaf or bark part of this mangrove collected from Pangkep regency. The values of Minimum Inhibition Concentration (MIC) on V. harveyi were ranged between 1-10.000 mg/L depending on which part of the plant and the origin of the mangrove. The root part of the plant had higher activity against V. harveyi than other parts of the plant. Rhizophora mucronata collected from Bone regency had the highest activity against V. harveyi than that collected from Maros and Pangkep regencies.