Binding to lipid II is an important step in the mode of action of most lantibiotics targeting the bacterial cell wall. We applied the Bacillus subtilis two-component system, LiaRS, that is known to respond to antibiotics interfering with lipid II cycle, in order to evaluate lipid II binding activity of known bacteriocins and also to identify lipid II binding moieties in lantibiotic nukacin ISK-1. Using this method, we confirmed that the methyllanthionine ring in nukacin ISK-1 is crucial for lipid II binding as previously indicated.
View Article and Find Full Text PDFDegradation of phenolics by members of soil microflora is an important means by which these substances are removed from the environment thus reducing environmental pollution. Biodegradation by microorganisms offers unique opportunities to destroy or render phenolic compounds. A bacterium, PU1, identified as Pseudomonas fluorescens PU1, was investigated for its ability to grow on and degrade phenols as sole carbon sources in aerobic shaking batch culture.
View Article and Find Full Text PDFThe effects of nisin-induced dnaK expression in Lactococcus lactis were examined, and this expression was shown to improve stress tolerance and lactic acid fermentation efficiency. Using a nisin-inducible expression system, DnaK proteins from L. lactis (DnaK(Lla)) and Escherichia coli (DnaK(Eco)) were produced in L.
View Article and Find Full Text PDFRecently, lactic acid bacteria (LAB) have attracted much attention because of their potential application to probiotics and industrial applications as starters for dairy products or lactic acid fermentation. Additional emphasis is also being paid to them as commensal bacteria in gastrointestinal tract. Since LAB exhibit a stress response, insight into the relationship between stress proteins such as molecular chaperones and stress tolerance or adaptation is increasing gradually along with current research examining these important bacteria.
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