Isolation and characterization of bacteria from two species of horseshore crabs

Abstract

An experiment was conducted to isolate and to identify the bacteria found on the gills and carapace of two species of horseshoe crab namely Tachypleus gigas and Carcinoscorpius rotundicauda. Samples of horseshoe crabs are collected from Pantai Cherating, Kuantan. Bacterial cultures were characterized with series of morphological and biochemical tests. A total of 27 isolates were obtained and all were characterized up to genus and species level through the guide from key-book for identification. The genus of bacteria which were characterized includes Serratia sp., Aeromonas sp., Pseudomonas sp., Enterobacter sp., Staphylococcus sp., Streptococcus sp., Corynebacterium sp. and Lactobaci/lus sp. Isolate 01 was Serratia fonticola, 04 as subspecies of Aeromonas, A. smithia, 13 as Enterobacter intermedius, and both isolates 18 and 24 in the same genus, which is Corynebacterium kutsceri. Six strains were found to produce agent that reduces sulfur into H2S as end product. All of the strains were cultured again in AMS cultivation method to be supervised if they produce active compounds. Test that was conducted to screen the compound was DDT test which was based on the application of inhibition zones on other cultured bacterial strains. Results from DDT test were determined through the inhibition zones found around the disc implemented with compounds produced by the bacteria.