Selection and Characterization of Subsp. WiKim0113 Isolated from Kimchi As a Starter Culture for the Production of Natural Pre-converted Nitrite

Synthetic nitrite is considered an undesirable preservative for meat products; thus, controlling synthetic nitrite concentrations is important from the standpoint of food safety. We investigated 1,000 species of microorganisms from various kimchi preparations for their potential use as a starter culture for the production of nitrites. We used 16S rRNA gene sequence analysis to select a starter culture with excellent nitrite and nitric oxide productivity, which we subsequently identified as subspecies WiKim0113. That starter culture was grown in NaCl (up to 9%; w/v) at 10°C-40°C; its optimum growth was observed at 30°C at pH 4.0-10.0. It exhibited nonproteolytic activity and antibacterial activity against , a bacterium that causes food poisoning symptoms. Analysis of subspecies WiKim0113 with an API ZYM system did not reveal the presence of β-glucuronidase, and tests of the starter culture on 5% (v/v) sheep blood agar showed no hemolytic activity. Our results demonstrated the remarkable stability of coagulase-negative subspecies WiKim0113, especially in strain negative for staphylococcal enterotoxins and sensitive to clinically relevant antibiotics. Moreover, subspecies WiKim0113 exhibited a 45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced to 25% after 36 h of culturing in the minimal medium supplemented with nitrate (200 ppm). The results clearly demonstrated the safety and utility of subspecies WiKim0113, and therefore its suitability as a starter culture.