Insights in the antibacterial action of poly(methyloxazoline)s with a biocidal end group and varying satellite groups

The antimicrobial activity of poly(2-methyl-1,3-oxazoline)s (PMOX) with the antimicrobial N,N-dimethyldodecylammonium (DDA) end group is greatly dependent on the nature of the group at the distal end of the polymer, the satellite group. Three comparable PMOX with a DDA end group and different satellite groups (methyl, decyl, hexadecyl) were investigated with respect to the reasons for the huge differences in their biocidal behavior. Static light scattering (SLS) and pulsed field gradient diffusion NMR measurements revealed that the samples show comparable aggregation conduct, thus, not being responsible for the varying biological activity. Experiments using different liposomal systems as models for bacterial cell membranes have been performed. It was found that differential interactions between the respective polymers and the phospholipid membranes constitute the reason for the varying effectiveness observed in antimicrobial susceptibility determinations.     

Economic improvement of the fermentative production of gallidermin by Staphylococcus gallinarum

Gallidermin production by Staphylococcus gallinarum was optimal using a new developed medium consisting of 50 g yeast extract l^–1, 45 g CaCl₂ l^–1 and 5 g maltose l^–1. Medium optimisation led to the cost of the medium decreasing by 93% compared to the previously used medium and in addition gained a higher product yield. A scale-up of the process based on the new medium was successfully tested up to a working volume of 200 l.     

N-1 substituted pyrimidin-4-ones: novel, orally active inhibitors of lipoprotein-associated phospholipase A2

From two related series of 2-(alkylthio)-pyrimidones, a novel series of 1-((amidolinked)-alkyl)-pyrimidones has been designed as nanomolar inhibitors of human lipoprotein-associated phospholipase A2. These compounds show greatly enhanced activity in isolated plasma. Selected derivatives such as compounds 51 and 52 are orally active with a good duration of action.     

On universal common ancestry, sequence similarity, and phylogenetic structure: the sins of P-values and the virtues of Bayesian evidence

Life is a chemical reaction. Three major transitions in early evolution are considered without recourse to a tree of life. The origin of prokaryotes required a steady supply of energy and electrons, probably in the form of molecular hydrogen stemming from serpentinization. Microbial genome evolution is not a treelike process because of lateral gene transfer and the endosymbiotic origins of organelles. The lack of true intermediates in the prokaryote-to-eukaryote transition has a bioenergetic cause. This article was reviewed by Dan Graur, W. Ford Doolittle, Eugene V. Koonin and Christophe Malaterre.     

Correlation between the consumption of amino acids and the production of the antibiotic gallidermin by Staphylococcus gallinarum

The correlation between the consumption of amino acids and the production of the polypeptide antibiotic gallidermin by Staphylococcus gallinarum Tü 3928 was investigated by on-line determination of amino acids and pulse experiments. A prolonged production phase together with an increase in gallidermin formation of about 25% was obtained during pulse and fed-batch experiments with the amino acids glutamic acid, glycine, serine and threonine.