Isolation and characterization of lactic acid bacteria strains with ornithine producing capacity from natural sea salt

Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive, short rod-type bacteria, and able to grow anaerobically with CO₂ production. The isolates grew well on MRS broth at 30–37°C and a pH of 6.5–8.0. The optimum temperature and pH for growth are 37°C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose, sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1% arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0–6%. These results show for the first time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity.