Intakte polare Lipide : Möglichkeit und Grenzen ihrer Verwendung zur Analyse mikrobieller Gemeinschaften.

Im Rahmen dieser Doktorarbeit wurde grundlegenden Fragen zur Analytik und Verwendung von intakten polaren Lipiden (IPL) als Biomarker für lebende Mikroorganismen nachgegangen. Die Arbeit besteht aus vier Teilen, in denen jeweils unterschiedliche Aspekte der Verwendung von IPL behandelt werden. Zunächstwerdendie zur Analyse von IPL genutzten Methoden überprüft und Untersuchungen zu ihrer Verbesserung vorgenommen. Der zweite Teil der Arbeit beschäftigt sich mit der grundsätzlichen Frage der Stabilität von intakten polaren Lipiden nach dem Absterbenvon Mikroorganismen.Im sich anschließenden Kapitel werden die Membrananpassungsstrategien des Tiefseebakteriums Desulfovibrioindonensiensis an verschiedene Inkubationsbedingungen untersucht. Schließlich wird eine Studie der mikrobiologischen Gemeinschaft deshypersalinen Sees Lake Tyrrell (Victoria, Australien) undihrerFettsäure- und IPL-Zusammensetzungdargestellt

Metagenomic and lipid analyses reveal a diel cycle in a hypersaline microbial ecosystem.

Marine microbial communities experience daily fluctuations in light and temperature that can have important ramifications for carbon and nutrient cycling. Elucidation of such short time scale community-wide dynamics is hindered by system complexity. Hypersaline aquatic environments have lower species richness than marine environments and can be well-defined spatially, hence they provide a model system for diel cycle analysis. We conducted a 3-day time series experiment in a well-defined pool in hypersaline Lake Tyrrell, Australia. Microbial communities were tracked by combining cultivation-independent lipidomic, metagenomic and microscopy methods. The ratio of total bacterial to archaeal core lipids in the planktonic community increased by up to 58% during daylight hours and decreased by up to 32% overnight. However, total organism abundances remained relatively consistent over 3 days. Metagenomic analysis of the planktonic community composition, resolved at the genome level, showed dominance by Haloquadratum species and six uncultured members of the Halobacteriaceae. The post 0.8 μm filtrate contained six different nanohaloarchaeal types, three of which have not been identified previously, and cryo-transmission electron microscopy imaging confirmed the presence of small cells. Notably, these nano-sized archaea showed a strong diel cycle, with a pronounced increase in relative abundance over the night periods. We detected no eukaryotic algae or other photosynthetic primary producers, suggesting that carbon resources may derive from patchily distributed microbial mats at the sediment-water interface or from surrounding land. Results show the operation of a strong community-level diel cycle, probably driven by interconnected temperature, light abundance, dissolved oxygen concentration and nutrient flux effects

Determination of Age and Vectorial Capacity of Anopheles Maculipennis Sensu Lato in the Central Plateau of Iran

Background and Purpose: Islamic Republic of Iran has greatly reduced its malaria burden and has a national goal to eliminate malaria by 2025. The aim of this study was to determine the population dynamics of Anopheles maculipennis sensu lato, in relation to probable malaria transmission. For this purpose, the study was conducted in three villages in Isfahan Province of Iran, from April to March 2014. Materials and Methods: Two mosquitoes sampling methods were conducted, comprises human landing catch and human bed net collection. The results of this investigation were subjected to one-way ANOVA using SPSS. Results: A. maculipennis s.l. was found as a dominant vector with exophagic and endophilic behavior. Two peaks of blood feeding were observed, 9.00-10.00 p.m and 1.00-2.00 a.m. The gonotrophic cycle, survival rate, and life expectancy of the species were 4, 0.82, and 5 days, respectively. Malaria vectorial capacity of A. maculipennis was measured 0.0128 and 0.059 for Plasmodium vivax and Plasmodium Falciparum, respectively. Conclusion: The findings indicate that there is a negative correlation between the temperature and daily age of A. maculipennis s.l. The method described can be used as a standard method to determine the daily age of Anopheles, as well as of other mosquito species since it is fast and precise and needs small samples. Survey on the age structure of vectors is very important as it is useful in monitoring the success of large-scale vector control measures