Our results indicate that HBD-1-3 and Phd-1-3 do not require PMF for their antibacterial activity. The absence of activity against E. coli in the presence of Na+ and Ca2+ ions is due to not only weakened electrostatic interactions with anionic membrane components, but also involvement of electrochemical

gradients. However, Mg2+ prevents electrostatic interaction of the peptides with the outer membrane resulting in loss of activity. “
“The purpose of this study was to investigate the feasibility of cultivating the biotechnologically important bacterium Streptomyces www.selleckchem.com/products/CP-690550.html griseus in single-species and mixed-species biofilms using a tubular biofilm reactor (TBR). Streptomyces griseus biofilm development was found to be cyclical, starting with the initial adhesion and subsequent development of a visible biofilm after 24 h growth, followed by the complete detachment of the biofilm as a single mass, and ending with the re-colonisation of the tube. Fluorescence microscopy revealed that the filamentous structure of the biofilm was lost upon treatment with protease, but not DNase or metaperiodate, indicating that the extracellular polymeric substance is predominantly protein. When the biofilm was cultivated in conjunction with Bacillus amyloliquefaciens, no detachment was observed after 96 h, although

once subjected to flow detachment. Electron microscopy confirmed the presence of both bacteria in the biofilm and revealed a network of fimbriae-like structures that were much less apparent in single-species biofilm and are likely to increase mechanical Palbociclib order stability when developing in a TBR. This study presents the very first attempt in engineering S. griseus biofilms for continuous bioprocess applications. “
“The diversity of a collection of 49

Lactococcus garvieae strains, including isolates of dairy, fish, meat, vegetable and cereal origin, was explored using a molecular polyphasic approach comprising PCR-ribotyping, REP and RAPD-PCR analyses and a multilocus restriction typing (MLRT) carried out on six partial genes (atpA, tuf, Florfenicol dltA, als, gapC, and galP). This approach allowed high-resolution cluster analysis in which two major groups were distinguishable: one group included dairy isolates, the other group meat isolates. Unexpectedly, of the 12 strains coming from fish, four grouped with dairy isolates, whereas the others with meat isolates. Likewise, strains isolated from vegetables allocated between the two main groups. These findings revealed high variability within the species at both gene and genome levels. The observed genetic heterogeneity among L. garvieae strains was not entirely coherent with the ecological niche of origin of the strains, but rather supports the idea of an early separation of L. garvieae population into two independent genomic lineages. In the last two decades, foodborne diseases have been emerging as an important and growing public health concern.