Roland Breves

rRNA-based profiling of bacteria in the axilla of healthy males suggests right–left asymmetry in bacterial activity

The activity of the human armpit microbiota triggers the formation of body odor. We used differential 16S rRNA gene (rDNA)- and rRNA-based terminal-restriction fragment length polymorphism fingerprinting in combination with cloning and sequencing to identify active members of the human armpit microbiota. DNA and RNA were isolated from skin scrub samples taken from both armpits of 10 preconditioned, healthy males. The fingerprint profiles indicated pronounced similarities between the armpit microbiota in the right and the left axillae of an individual test person, but larger differences between the axilla microbiota of different individuals. Using 16S rDNA and rRNA sequence data, the majority of peaks in the armpit profiles were assigned to bacteria affiliated with well-known genera of skin bacteria. The relative abundances of all groups were similar among the rDNA and rRNA samples, suggesting that all groups of armpit bacteria were active. Surprisingly, the relative abundance of sequences affiliated with Peptoniphilus sp. was by far and with statistical significance the highest in the rRNA samples of the right armpits. Thus, bacteria affiliated with Peptoniphilus sp. might have been particularly active in the right axillae of the test persons, possibly owing to the handedness of the test persons, which might cause different environmental conditions in the right axillae.

Influence of farnesol on the morphogenesis of Aspergillus niger.

Farnesol was the first quorum‐sensing regulator to be found in eukaryotic cells. In Candida albicans, a dimorphic fungal human pathogen, farnesol blocks the yeast‐to‐filamentous growth transition. Here we show that in Aspergillus niger farnesol acts as an inhibitor of conidiation: Colonies grown on media containing farnesol were unable to develop conidia. Although farnesol treated A. niger cultures exhibited a colony morphology resembling the “fluffy” phenotype of A. nidulans, which is caused by a hyperactive G‐protein/cAMP pathway, the intracellular level of cAMP in A. niger mycelia grown in presence of farnesol is greatly diminished. Furthermore, whereas inhibiting adenylyl cyclase led to a farnesol‐like effect, the addition of external cAMP inhibited conidiation without causing a “fluffy” phenotype. This suggests that the mechanisms regulating conidiation in A. niger and A. nidulans are different. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Star‐Shaped Poly(styrene)‐block‐Poly(4‐vinyl‐N‐methylpyridiniumiodide) for Semipermanent Antimicrobial Coatings

Goal of the present work is to develop an antimicrobial coating that can be applied from an aqueous solution and resists short washing cycles, but can be rinsed off by thorough washing. To this end, a series of star-shaped polystyrene-block-poly(4-vinyl-N-methylpyridinium iodide) polymers are synthesized by anionic polymerization using a core-first approach. The optimal resulting polymers are applied as coatings on glass slides, showing high antimicrobial efficiency against Staphylococcus aureus as well as Escherichia coli. The coatings, characterized by atomic force microscopy and transmission electron microscopy, stay at the surface even after at least 20 flush-like washings with water, and retain their antimicrobial activity.

Evaluation of the virucidal performance of domestic laundry procedures

Laundering is one of the most important means to ensure a sufficient hygiene standard in the household environment. To evaluate the performance of this process, it is desirable to have methods that mimic the real-life situation as closely as possible. Although methods for the evaluation of the antibacterial and antifungal efficacy of domestic laundry procedures are available, the effect of laundering on viruses is still rather unclear. As the influence of laundry process parameters such as mechanical actions, temperature dynamics or liquor ratio cannot be simulated in vitro by suspension assays, a new in situ test method allowing virus simulation tests in washing machines has been developed. Using this in situ method we could show that conventional household washing detergents have a full virucidal efficiency at 40 degrees C also against non-enveloped surrogate viruses.

A glimpse under the rim--the composition of microbial biofilm communities in domestic toilets.

Aim:  To determine the microbial composition of biofilms in domestic toilets by molecular means.

Identification of compounds inhibiting the C-S lyase activity of a cell extract from a Staphylococcus sp. isolated from human skin

The C‐S lyase activity of bacteria in the human armpit releases highly malodorous, volatile sulfur compounds from nonvolatile precursor molecules. Such compounds significantly contribute to human body odour. Hence, C‐S lyase represents an attractive target for anti‐body‐odour cosmetic products. Here, aiming at a final use in an ethanol‐based deodorant formulation, 267 compounds and compound mixtures were screened for their ability to inhibit the C‐S lyase activity of a Stapyhlococcus sp. crude extract. Staphylococcus sp. Isolate 128, closely related to Staphylococcus hominis, was chosen as the test bacterium, as it showed a reproducibly high specific C‐S lyase activity on three different culturing media. Using a photometric assay and benzylcysteine as substrate, six rather complex, plant‐derived compound mixtures and five well defined chemical compounds or compound mixtures were identified as inhibitors, leading to an inhibition of ≥70% at concentrations of ≤0·5% in the assay. The inhibition data have demonstrated that compounds with two vicinal hydroxyl groups or one hydroxyl and one keto group bound to an aryl residue are characteristic for the inhibition. The substances identified as C‐S lyase inhibitors have the potential to improve the performance of anti‐body‐odour cosmetic products, for example, ethanol‐based deodorants.

Modulation of Infectivity in Phage Display as a Tool to Determine the Substrate Specificity of Proteases

Proteases play an important role in human and animal diseases. Rapid determination of substrate specificity is possible through the use of substrate phage display; however, current methods possess several drawbacks. They require phage‐immobilization and cannot be used for infectivity‐destroying or affinity tag‐destroying proteases; this can make entire libraries useless. To overcome these limitations, here we introduce infectivity‐modulated phage display (IMOP). IMOP uses a protease‐resistant and infectivity‐reducing tag fused to substrate‐displaying polyvalent phages, and the specific cleavage of the substrate increases the infectivity of the phages by releasing the infectivity‐reducing tag. The resulting phages were first tested with the infectivity‐destroying detergent protease subtilisin; this resulted in a highly specific substrate at a 200‐fold enrichment. In a second example, the protease ompT was used and led to an enrichment of the known double‐arginine motif. The IMOP system thus substantially improves and simplifies previous systems.

How to capture the bioeconomy’s industrial and regional potential through professional cluster management

The bioeconomy transforms the fossil-based economy by forming new value chains and linking until now distinct industrial sectors. It provides an opportunity for rural as well as industrialized regions. The transformation process can be accelerated by building bioeconomy clusters comprising industries, academia and investors. Using the model of the German cluster CLIB2021 the role of cluster organisations and professional cluster management in moderating the transformation process and gaining a competetive advantage is discussed. In addition examples of how cluster management supports the formation of an industrial consortium and the analysis of regional options are presented.

In Deo veritas — Entstehung und Verhinderung humanen Körpergeruchs

For many customers underarm perspiration and body odor are important topics. The armpit microbiota metabolizes odorless sweat to malodorous compounds. A better understanding of composition and activity of the human armpit microbiota is crucial for a deeper understanding of the formation of human body odor. We provide an overview of the human armpit microbiota and its odor-releasing enzyme activities and discuss strategies supporting the development of innovative and more effective deodorants.

Alternative Wege zu schimmelresistenten Materialien

The equipment of construction and sealing materials with biocides represents an effective way to inhibit fungal growth. However, active agents in sanitary sealants are subjected to continuous leaching. In addition, the number of available biocides declines. Alternative strategies are discussed with sanitary silicones as an example: besides the enhanced leaching stability of the fungicide, non-biocidal agents shield the surface from spore adhesion and inhibit the production of new spores.