Over 2000-Fold Increased Production of the Leaderless Bacteriocin Garvicin KS by Increasing Gene Dose and Optimization of Culture Conditions

• Published in: Frontiers in microbiology Vol. 10; p. 389
• Main Authors: Telke, Amar A, Ovchinnikov, Kirill V, Vuoristo, Kiira S, Mathiesen, Geir, Thorstensen, Tage, Diep, Dzung B
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 05-03-2019
• Subjects: antimicrobial production; bacteriocin production; garvicin KS; lactic acid bacteria; Lactococcus garviae; leaderless bacteriocins; Microbiology; bacteriocin production; antimicrobial production; leaderless bacteriocins; Lactococcus garviae; growth media; lactic acid bacteria; garvicin KS
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2019.00389

The leaderless bacteriocin Garvicin KS (GarKS) is a potent antimicrobial, being active against a wide range of important pathogens. GarKS production by the native producer
KS1546 is, however, relatively low (80 BU/ml) under standard laboratory growth conditions (batch culture in GM17 at 30°C). To improve the production, we systematically evaluated the impact of different media and media components on bacteriocin production. Based on the outcomes, a new medium formulation was made that increased GarKS production about 60-fold compared to that achieved in GM17. The new medium was composed of pasteurized milk and tryptone (PM-T). GarKS production was increased further 4-fold (i.e., to 20,000 BU/ml) by increasing the gene dose of the bacteriocin gene cluster (
) in the native producer. Finally, a combination of the newly composed medium (PM-T), an increased gene dose and cultivation at a constant pH 6 and a 50-60% dissolved oxygen level in growth medium, gave rise to a GarKS production of 164,000 BU/ml. This high production, which is about 2000-fold higher compared to that initially achieved in GM17, corresponds to a GarKS production of 1.2 g/L. To our knowledge, this is one of the highest bacteriocin production reported hitherto.