Isolation and characterization of halophilic and alkaliphilic lactic acid bacteria from solar sea-salt

Abstract

Halophilic and alkaliphilic lactic acid bacteria (HALAB), such as Marinilactibacillus and Alkalibacterium, have been frequently isolated from marine environment affected by the physico-chemical features of sea water. On the other hand, although these HALAB also existed in fermented food containing salt, such as ripened cheeses, their derivation have not been revealed. Therefore, to elucidate HALAB diversity of isolation sources, we isolated HALAB from various sea-salts that may be used for fermented food production. Among the 23 kinds of solar sea-salts, the strains belonging to the genus Alkalibacterium were isolated from two kinds of French solar sea-salts by the enrichment culture. These isolates had halophilic and alkaliphilic properties, and were identified as Alkalibacterium putridalgicola originally isolated from marine environment. On the other hand, the isolates did not grow under 20% NaCl and required sugar compound for their growth, indicating that they may not stimulate growth but survive on the surface of solar salt. Based on these findings, it can be considered that HALAB existed in the marine environment will adhere and survive on the solar sea-salt and propagate to various salted food manufacturing environments.