@article {734,
	title = {"Doubly selective" antimicrobial polymers: how do they differentiate between bacteria?},
	journal = {Chemistry},
	volume = {15},
	year = {2009},
	month = {2009 Nov 2},
	pages = {11710-4},
	abstract = {We have investigated how doubly selective synthetic mimics of antimicrobial peptides (SMAMPs), which can differentiate not only between bacteria and mammalian cells, but also between Gram-negative and Gram-positive bacteria, make the latter distinction. By dye-leakage experiments on model vesicles and complementary experiments on bacteria, we were able to relate the Gram selectivity to structural differences of these bacteria types. We showed that the double membrane of E. coli rather than the difference in lipid composition between E. coli and S. aureus was responsible for Gram selectivity. The molecular-weight-dependent antimicrobial activity of the SMAMPs was shown to be a sieving effect: while the 3000 g mol(-1) SMAMP was able to penetrate the peptidoglycan layer of the Gram-positive S. aureus bacteria, the 50000 g mol(-1) SMAMP got stuck and consequently did not have antimicrobial activity.},
	keywords = {Anti-Infective Agents, Biomimetic Materials, Escherichia coli, Microbial Sensitivity Tests, Peptidoglycan, Polymers, Staphylococcus aureus},
	issn = {1521-3765},
	doi = {10.1002/chem.200802558},
	author = {Lienkamp, Karen and Kumar, Kushi-Nidhi and Som, Abhigyan and N{\"u}sslein, Klaus and Tew, Gregory N}
}
@article {748,
	title = {Distribution of extensive nifH gene diversity across physical soil microenvironments.},
	journal = {Microb Ecol},
	volume = {51},
	year = {2006},
	month = {2006 May},
	pages = {441-52},
	abstract = {The diversity of nitrogen-fixing bacteria is well described for aquatic environments; however, terrestrial analyses remain mostly biased to rhizobial plant-microbe associations. We maximized the level of resolution for this study through the use of nucleotide sequence information extracted from a series of soil microenvironments, ranging from macroaggregates at 2000 microm to the clay fraction at < 75 microm in diameter. In addition, we attempted to create an overview of the distribution of terrestrial nitrogen fixers across such microenvironments by combining culture-independent techniques with a suite of natural soil environments from uniquely different origins. Soil diazotroph diversity was analyzed phylogenetically for 600 terrestrial nifH sequences from 12 midsized clone libraries based on microenvironments of three separate soils across a global scale. Statistical analyses of nifH gene clone libraries were used to estimate coverage, establish degrees of sequence overlap, and compare cluster distributions. These analyses revealed an extensive diversity in a tropical (19 phylotypes) and an arctic soil (17 phylotypes), and moderate diversity in a temperate soil (11 phylotypes). Within each soil, comparisons across aggregate size fractions delineated nifH gene cluster shifts within populations and degrees of sequence overlap that ranged from significantly different (arctic, tropical) to significantly similar (temperate). We suggest that this is due to population separation across aggregates of different size classes, which results from differences in the temporal stability of aggregates as niches for microbial communities. This study not only provides new knowledge of the arrangement of diazotrophic communities at the soil microscale, but it also contributes to the underrepresented knowledge of soil nifH sequences in the public databases.},
	keywords = {Bacteria, Base Sequence, DNA Primers, Genes, Bacterial, Multigene Family, Oxidoreductases, Phylogeny, Polymerase Chain Reaction, Soil Microbiology},
	issn = {0095-3628},
	doi = {10.1007/s00248-006-9044-x},
	author = {Izquierdo, Javier A and N{\"u}sslein, Klaus}
}
