Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Uji Metoda Pemeliharaan Larva Axenic Sebagai Metoda Untuk Uji In-vivo Bakteri Pada Larva Ikan Sea Bass (Dicentrarchus Labrax)

Penyakit adalah hambatan utama pada akuakultur sehingga upaya pengendaliannya haruss direncanakan. Strategi eksperimental adalah untuk mempelajari fungsi ikan sebagai inang tanpa kehadiran bakteri dan mengevaluasi kehadiran populasi bakteri mikroba pada ikan axenic (di bawah kondisi gnotobiotik). Tujuan utama adalah untuk mempelajari pengaruh penambahan bakteri tertentu terhadap kelangsungan hidup larva sea bass (Dicentrarchus labrax). Pengaruh bakteri L. anguillarum (HI-610, diisolasi di Bergh, Norway) dan Aeromonas hydrophila (LVS 3) terhadap larva sea bass axenic dipelajari.

Metoda untuk memproduksi larva aksenik diawali dengan disinfeksi telur ikan dengan glutaraldehyde dan mengaplikasikan antibiotik. Perendaman telur selama 3 menit terhadap 100 mg/L glutaraldehyde di bawah kondisi steril dilakukan untuk memperoleh telur axenic. Media inkubasi telur berupa air laut yang sebelumnya telah diautoclave ditambahkan 10 mg/L ampicillin dan 10 mg/L rifampicin, dan metoda ini cukup efektif untuk mempertahankan kondisi axenic. Penambahan bakteri Aeromonas hydrophila (LVS3) tidak berpengaruh terhadap kelangsungan hidup larva aksenik, akan tetapi strain HI-610 dari L. anguillarum ternyata patogenik terhadap laarva ikan sea bass sehingga menyebabkan kelangsungan hidup ikan yang rendah. Bakteri diintroduksi pada media kultur aksenik pada hari ke-3 dan menyebabkan kematian pada hari ke-7 dan hari ke-11.

Disease is the main constraint to aquaculture therefore the disease controlling strategies must be used. An experimental strategy is to study the functioning of the host in the absence of bacteria and then to evaluate the effects of adding a single or defined population of microbes, or certain compounds (under gnotobiotic conditions). The main purpose of this study was to investigate the effect of the addition of selebacteria strains on the survival of axenic ea bass cted s(Dicentrarchus labrax) larvae. The influence of selected bacteria strains of L. anguillarum (HI610, initially isolated by Bergh, Norway) and Aeromonas hydrophila (LVS 3) upon axenic sea bass larvae was examined.

The method to produce axenic larvae starting with disinfection of eggs with glutaraldehyde and application of incubation methods with antibiotics was investigated. A 3-minute exposure of eggs to 100 mg/L of glutaraldehyde under sterile conditions resulted in axenic eggs. Incubation of eggs in autoclaved sea water containing 10 mg/L of ampicillin and 10 mg/L of rifampicin, was successful to keep the sea bass eggs axenic. The hatching and hatching rate of axenic eggs was significantly lower compared to the xenic eggs in several experiments of this study. Addition of Aeromonas hydrophila (LVS3) did not significantly affect the survival compared to the survival of axenic larvae. However, the strain HI-610 of L. anguillarum was pathogenic to sea bass larvae causing a significantly lower survival. Bacteria were introduced to the axenic culture medium on DAH 3 and caused significant mortality on DAH 7 and DAH 11.