Selection and Characterization of Staphylococcushominis subsp. hominis WiKim0113 Isolated fromKimchi as a Starter Culture for the Production of Natural Pre-convertedNitrite

摘要

Synthetic nitrite is considered an undesirable preservative for meat products;thus, controlling synthetic nitrite concentrations is important from thestandpoint of food safety. We investigated 1,000 species of microorganisms fromvarious kimchi preparations for their potential use as a starter culture for theproduction of nitrites. We used 16S rRNA gene sequence analysis to select astarter culture with excellent nitrite and nitric oxide productivity, which wesubsequently identified as subspecies WiKim0113. That starter culture was grown in NaCl(up to 9%; w/v) at 10°C–40°C; its optimum growth wasobserved at 30°C at pH 4.0–10.0. It exhibited nonproteolyticactivity and antibacterial activity against , a bacterium that causes food poisoning symptoms.Analysis of subspecies WiKim0113 with an API ZYM system did not reveal thepresence of β-glucuronidase, and tests of the starter culture on5% (v/v) sheep blood agar showed no hemolytic activity. Our resultsdemonstrated the remarkable stability of coagulase-negative subspecies WiKim0113, especially in strain negative for staphylococcal enterotoxins andsensitive to clinically relevant antibiotics. Moreover, subspecies WiKim0113 exhibited a45.5% conversion rate of nitrate to nitrite, with nitrate levels reducedto 25% after 36 h of culturing in the minimal medium supplemented withnitrate (200 ppm). The results clearly demonstrated the safety and utility of subspecies WiKim0113, and therefore its suitability as a starter culture.