Properties of tetragenococcus halophilus strains isolated from myeolchi (anchovy)-jeotgal

Abstract

Halophilic lactic acid bacteria (LAB) were isolated from myeolchi-jeotgal (23% NaCl, w/v) fermented in jangdok (Korean earthenware) located outside a house. They were identified as Tetragenococcus halophilus by 16S rRNA and recA gene sequencing. Four T. halophilus isolates showing high protease activities were selected for further studies. Four strains grew well, reaching OD 600 values of 0.75?0.92 at 18% NaCl content (w/v) and 0.28?0.44 at 23% salt. They showed rapid growth, attaining OD 600 values of 1.1?1.2 at 20?30℃, but did not grow at 4℃. At 15℃, the highest OD 600 values, which exceeded 0.6, were observed at 20 days, and were higher than those of cultures at 37℃ and 42℃ (approximately 0.5). Four isolates grew best in broth where the initial pH was adjusted to 8 and did not grow at pH ≤ 4. T. halophilus BS2-36 showed the highest survival ratio of 18.7% after 2 hours of exposure at pH 3. BS2-36 showed the highest survival ratio (1.29%) in presence of 0.3% bile salts. T. halophilus BS2-36 seems a promising candidate as a starter for jeotgal and other fermented foods with high salinities. ? 2018, The Korean Society for Microbiology and Biotechnology.