The Z-ring should only be formed at midcell in between the newly formed daughter chromosomes, and this process is carefully regulated. Cytokinesis in most bacteria is initiated by the polymerization of the tubulin homolog FtsZ into a ring-like structure (the Z-ring) onto which the cytokinesis apparatus assembles ( 1). Indications that the pmf might be important emerged when we were studying the cell division regulator MinD in Bacillus subtilis. Despite this proximity, nothing was known about the potential role of this force in the regulation of complex protein structures. These structures are therefore in the vicinity of another fundamental energy source the proton motive force (pmf). However, the cell division apparatus ( 1), and bacterial cytoskeletal elements such as MreB ( 2), are essentially membrane anchored structures, and membrane attachment also plays a critical role in chromosome segregation ( 3) and regulation of cell division by the Min system ( 4, 5). Maintenance of this order requires energy, and it is not surprising that proteins that form cytoskeletal structures, or the cell division machinery, consume ATP or GTP. Thus, we fully characterized the antibacterial activity of medical-grade honey.The bacterial cell has a well organized cytoplasm, and the correct localization of proteins is essential for their function, particularly for those involved in morphogenetic processes. Activity against all other bacteria tested depended on sugar, H(2)O(2), MGO, and bee defensin-1. After combined neutralization of H(2)O(2), MGO, and bee defensin-1, 20% honey had only minimal activity left, and subsequent adjustment of the pH of this honey from 3.3 to 7.0 reduced the activity to that of sugar alone. subtilis for activity-guided isolation of the additional antimicrobial factors, we discovered bee defensin-1 in honey. After enzymatic neutralization of these two compounds, honey retained substantial activity. Honey accumulated up to 5.62 +/- 0.54 mM H(2)O(2) and contained 0.25 +/- 0.01 mM methylglyoxal (MGO). All bacteria tested, including Bacillus subtilis, methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase producing Escherichia coli, ciprofloxacin-resistant Pseudomonas aeruginosa, and vancomycin-resistant Enterococcus faecium, were killed by 10-20% (v/v) honey, whereas > or = 40% (v/v) of a honey-equivalent sugar solution was required for similar activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors.
With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity.
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