Isolasi, Karakterisasi dan Identifikasi Bakteri Asam Laktat (BAL) pada Usus dan Lambung Ikan Nila (Oreochromis niloticus) yang Dibudidayakan di Tambak Ikan Kota Medan Sumatera Utara

Abstract

Tilapia is a fish that has important economic value. This is because these fish are mostly caught for consumption. So it is necessary to carry out tests on bacteria and analyze bacterial growth in the media used. This study aims to determine the isolation, characterization, identification and growth rate of Lactic Acid Bacteria from the intestines and stomachs of fish and to determine the growth rate of Lactic Acid Bacteria that were successfully isolated from the intestines and stomachs of Tilapia (Oreochromis niloticus) taken from Medan City fish ponds. North Sumatra, namely Siombak, Sei Mati, Sei Canang. This research was carried out in May-June 2023. The research methods carried out included sampling stages, sample preparation, isolation of LAB purification, morphological analysis, physiological analysis and bacterial growth rate. The research results obtained were the discovery of 8 genera of bacteria, namely bacteria in the stomach of the genus Bacillus, Lactobacillus and Micrococcus, bacteria in the intestine were the genus Eubacterium, Weisella, Pseudomonas, Bifidobacterium, Staphylococcus. The Eubacterium genus with a growth rate of 0.682 – 0.786 bacteria/minute and a generation time of 0.88 – 1.91 generations/minute, in the Weisella genus with a growth rate of 0.481 – 0.682 bacteria/minute and a generation time of 1.015 – 1.438 generations/minute, in the genus Pseudomonas with a growth rate of 0.614 – 0.798 bacteria/minute and a generation time of 0.868 – 1.126 generations/minute, in the genus Bifidobacterium with a growth rate of 0.652 – 0.730 bacteria/minute and a generation time of 0.948 – 1.062 generations/minute, in the genus Staphylococcus with a growth rate of 0.566 – 0.682 bacteria/minute and a generation time of 1.015 – 1.222 generations/minute, in the genus Bacillus with a growth rate of 0.543 – 0.658 bacteria/minute and a generation time of 1.052 – 1.275 generations/minute, in the genus Micrococcus with a growth rate of 0.592 – 0.695 bacteria/minute and generation time 1.079 – 1.387 generations/minute and in the genus Lactobacillus with a growth rate of 0.730 – 0.913 bacteria/minute and generation time 0.758 – 0.948 generations/minute.