Isolation of magnet-responsive bacteria from the tropical marine environment of Singapore

Abstract

Magnetotactic Bacteria (MTB) are a group of unique, diverse and motile prokaryotes that can be found in most aquatic environment. Through the synthesis of magnetosomes, MTB are able to migrate along the geomagnetic and artificial magnetic field lines. Up to today, many isolation works have been carried out to unravel the biodiversity of MTB. Most isolation works are performed in the northern and southern hemisphere, but not in the tropical region near the geomagnetic equator where the geomagnetic field conditions are thought to be unfavourable to the growth of MTB. Therefore, this study aims to isolate MTB located found in the tropical marine environment of Singapore. A marine sediment sample was collected and enriched through the magnetic flow cell. The collected samples were isolated and cultured in semi-solid agar media under anaerobic and microaerophilic conditions. The isolated species were taxonomically classified through 16S rRNA gene sequencing and 9 new species out of all 28 isolates were discovered.