13 research outputs found
Proteotyping of microbial isolates from the Atacama Desert
Background
❖Out of up to one trillion (1012) microbial species
only 104 species have been cultured and less than
105 species are well presented by categorized
sequences [1]
➢99.999 % of microbial taxa remain undiscovered
➢enormous knowledge gap in genetic repertoire for
diverse biotechnological applications
❖However: sampling changes environmental
parameters-> MultiKulti Bioreacto
Cultivation of high-altitude lakes in Atacama Desert as extraterrestrial analogous habitats for astrobiological research
Background: Out of up to one trillion (10¹²) microbial species only 10⁴ species have been cultured and
less than 10⁵ species are well presented by categorized sequences [1]. According to this numbers,
99.999 % of microbial taxa remain undiscovered [1] which indicates an enormous knowledge gap in the
genetic repertoire for diverse biotechnological applications. Especially extreme habitats which are hard
to access are poorly microbial investigated. A special interest from astrobiologists is layed on the
research of extreme extraterrestrial analogous habitats. An example are the highest lakes on Earth,
located in the Andes in south America, which are classified as model systems for extraterrestrial life [2].
They are characterized by low oxygen, high UV-radiation, and chemical extremes like high dissolved
salt contents including high arsenic salts with up to 234 ppm as well as alkalinity [3]. Extremophilic
organisms often exhibit resistance genes, such as for pigmentation, which can protect against radiation,
cold or other stress factors. Microbial pigments therefore offer a wide range of biotechnological uses
such as radiation protection in space missions or as food additives and medical products like vitamin
precursors. The goal of this study is to describe yet unwell described extraterrestrial habitats and access
the microbial life here to extend the list of previously uncultivated organisms and expand the genetic
knowledge.
Material and Methods: In this work five different high-altitude lakes from Atacama Desert were
analyzed and identified according to cultivable organisms. First of all, chemical analysis of salt, pH,
temperature and UV irradiation was measured and revealed partly high salt concentration of up to 27 %
and alkaline pH in some places. Cultivation was performed by using standard media for aquatic
ecosystems (R2A and Marine Broth) and was complemented by individual environmental-close
cultivation. Results show that especially modifying the pH according to the initial environmental
conditions results in higher cultivability. To select especially astrobiology-relevant isolates, cultivation
was also performed after stress treatment with X-rays. Over 100 different isolates were generated and
will be identified via 16S rRNA Sequencing. Besides single species characterization, the overall
cultivation strategies will contribute to the recently BMBF founded project “MultiKulti”. The vision of
this project is to develop a bioreactor system that simulates habitat conditions as closely as possible for
systematic isolation experiments of target- and yet uncultivated organisms in the long term