University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Large-area 3D chiral plasmonic structures.

Abstract: We manufacture large-area plasmonic structures featuring 3-dimensional chirality by colloidal nanohole lithography. By varying the polar rotating speed of the samples during gold evaporation, we can fabricate spiral-type ramp nanostructures. The optical properties show chiroptical resonances in the 100 to 400 THz frequency region (750 to 3000 nm), with circular dichroism values of up to 13%. Our method offers a simple low-cost manufacturing method of cm2-sized chiral plasmonic templates for chiroptical applications such as stereochemical enantiomer sensors.

Basic knowledge and perspectives on biodegradation of 2,4,6-trinitrotoluene and related nitroaromatic compounds in contaminated soil

Abstract: Although a few aromatic compounds bearing one nitro group as a substituent are produced as secondary metabolites by microorganisms (31, 44, 45, 49) the majority of nitroaromatic compounds in the environment are due to anthropogenic activities. Nitrations are important reactions for the large-scale production of aminoaromatic structures that are synthons for pesticides, dyes, polymers, and pharmaceuticals. Nitroaromatic compounds such as nitrobenzene are used as solvents, whereas polynitroaromatic compounds serve as explosives. According to Hartter (16) 2,4,6-trinitrotoluene (TNT) is produced in amounts of 2 million pounds per year. Nitroaromatic compounds are therefore abundantly present in industrial waste streams and surface waters. 2,4,6-Trinitrotoluene is commonly found as the main contaminant of soil and ground water originating from facilities for manufacturing, processing, and disposing of explosives. Often these contaminants have leached from disposal lagoons into the surrounding soil, and in the case of military burdens of World War I and II, have contaminated the groundwater (13). Consequently, in Germany large areas of highly contaminated soils at former production plants must be remediated. TNT, its metabolites, and related compounds represent an environmental hazard because they exhibit considerable toxicity to humans, fish, algae, and microorganisms (39, 43, 50). Since incineration, the only proven technology for the destruction of explosives, is prohibitively costly, bioremediation represents an important alternative approach, which deserves to be considered.

Effect of the soil type on the microbiome in the rhizosphere of field-grown lettuce.

Abstract: The complex and enormous diversity of microorganisms associated with plant roots is important for plant health and growth and is shaped by numerous factors. This study aimed to unravel the effects of the soil type on bacterial communities in the rhizosphere of field-grown lettuce. We used an experimental plot system with three different soil types that were stored at the same site for 10 years under the same agricultural management to reveal differences directly linked to the soil type and not influenced by other factors such as climate or cropping history. Bulk soil and rhizosphere samples were collected 3 and 7 weeks after planting. The analysis of 16S rRNA gene fragments amplified from total community DNA by denaturing gradient gel electrophoresis and pyrosequencing revealed soil type dependent differences in the bacterial community structure of the bulk soils and the corresponding rhizospheres. The rhizosphere effect differed depending on the soil type and the plant growth developmental stage. Despite the soil type dependent differences in the bacterial community composition several genera such as Sphingomonas, Rhizobium, Pseudomonas, and Variovorax were significantly increased in the rhizosphere of lettuce grown in all three soils. The number of rhizosphere responders was highest 3 weeks after planting. Interestingly, in the soil with the highest numbers of responders the highest shoot dry weights were observed. Heatmap analysis revealed that many dominant operational taxonomic units were shared among rhizosphere samples of lettuce grown in diluvial sand, alluvial loam, and loess loam and that only a subset was increased in relative abundance in the rhizosphere compared to the corresponding bulk soil. The findings of the study provide insights into the effect of soil types on the rhizosphere microbiome of lettuce.