Open AccessIsolation and identification of nitrifying bacteria from tilapia (Oreochromis sp.) pond in Sleman Yogyakarta Indonesia
Author(s) -
I Aswiyanti,
Indah Istiqomah,
Alim Isnansetyo
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/919/1/012054
Subject(s) - nitrifying bacteria , biology , bacteria , tilapia , microbiology and biotechnology , 16s ribosomal rna , oreochromis , nitrification , oreochromis mossambicus , veterinary medicine , chemistry , fishery , fish <actinopterygii> , medicine , organic chemistry , nitrogen , genetics
This research aims to isolate and identify autochtonous nitrifying bacteria from tilapia pond in Sleman Yogyakarta Indonesia for future application in aquaculture practices in the region. Bacteria were isolated using a nitrification medium. Bacterial characterization was carried out by non-pathogenic test to tilapia ( Oreochromis sp.), and nitrification activity test in a single bacterial fermentation medium for 9 days. Bacterial identification was carried out based on the colony and cell morphologies, biochemical tests, and molecular analysis using the 16S rRNA and gyrB genes. A total of 15 isolates of nitrifying bacteria were obtained. Four non-pathogenic isolates obtained the highest nitrification activity on the sixth day of incubation, with nitrate production of 17.26-21.54 ppm. Two selected bacteria, isolates A2 and A3, have colony morphology that is milky white, smooth surface, circular shape, entire edge, and convex elevation. Both bacteria are short rods, Gram-negative, non-motile, produce catalase, fermenting glucose, sucrose, and lactose, and do not produce oxidase, ornithine decarboxylase, indole, and H 2 S. Molecular analysis showed that the two isolates had the highest similarity (99.28% and 99.34%) to Klebsiella spp.