No abstract

No abstract

The aim of this study was to know antibacterial potency of ethanolic extract of drumstick leaf against Aeromonas hydrophila in vitro. Total flavonoid, alkaloid, tannin and saponin of the ethanolic drumstick leaf extract were analyzed using spectrophotometry. Antibacterial activity test was carried out by disk diffusion and tube dilution method. Ethanolic extract of drumstick leaf contained flavonoids total as 71.9 mg quercetine equivalent/g, alkaloids total as 3 mg quinine equivalent/g, tannin as 24.7 mg tannic acid equivalent/g and saponin as 44.4 mg/g. The result of antibacterial test showed significant inhibition of Aeromonas hydrophila by drumstick leaf extract (P<0.05). The highest inhibition zone was produced by drumstick leaf extract with concentration of 100% which is 9.9± 0,162 mm. The minimum inhibition concentration (MIC) of drumstick leaf extract is 3.125%, while the minimum bactericidal concentration (MBC) is 6.25%. Based on this study, it can be concluded that drumstick leaf can be used as an alternative natural product of antibacterial agent which can be applied especially in aquaculture.

Detergents are a chemical product that is commonly used in personal care and household product on a daily basis. Its huge consumption in human activities resulted in the increasing awareness of its toxicity in the aquatic environment due to their active ingredients. Daphnia is a planktonic invertebrate organism that usually found in freshwater ecosystems. It plays an essential part in the lower trophic level of food chains. Because of its sensitivity to various environmental changes, they are generally used as a model organism in toxicology. In the present study, we analyzed the toxic effect of household detergent exposure on Daphnia sp. Four different concentration of detergent (25, 50, 75, and 100 mg.L−1) were prepared and the aquadest was used as control. The mortality of Daphnia was observed for 24 hours. The result showed that the mortality of Daphnia increased along with the increasing concentration of detergent exposures. LC50-24 hours values obtained in this study was 28.89 mg.L−1. This result described that the higher level of detergent in a water body can be harmful to the aquatic organism, especially on Daphnia sp. as predominant food for planktivorous fish.

The freshwater aquaculture fishery sector in Indonesia has the potential to be developed through extensification and intensification. The problem in aquaculture is diseases that infects cultivated organisms, one of which is caused by bacterial infection. Bacterial infection can cause huge losses to cultivation activities, including death which results in economic losses. The purpose of this study is to identify the A. salmonicida and E. ictalury in live fish that will be exported from DI Yogyakarta. The method of examining bacteria used is conventional which consists of isolation, purification, presumptive test, biochemical test, and identification. The results showed that all live fish samples (koi, gouramy, goldfish, catfish, and eel) were not infected with A. salmonicida and E. ictalury. This shows that all live fish are in a healthy condition and suitable to be exported of DI Yogyakarta.