ALBERT

Description: During the Antarctica 2000 Expedition samples of rocks and ice bubbles entrained in ice were collected from the blue ice fields near the Moulton Escarpment of the Thiel Mountains (85S, 94W) and the Morris Moraine of the Patriot Hills (80S, 8 1 W) Ellsworth Mountains of Antarctica. Investigation of the microbiota of these cryoconite and ice bubble ecosystems are now being conducted to help refine chemical and morphological biomarkers of potential significance to Astrobiology. The Antarctica 2000 Expedition will be discussed and the preliminary results of the studies of the ice bubble and cryoconite microbial ecosystems discussed. Recent ESEM images of the Antarctic microbiota will be presented a the relevance of ice ecosystems to Astrobiology will be discussed.

Description: The study of communities of microbial extremophiles from anaerobic sediments of Owens Lake and Mono Lake in California has established the presence of active microbial cellulolytic processes in both lakes. The prior study of the microbial diversity in Mono Lake showed that the trophic chain of organic decomposition includes secondary anaerobes that were found to be previously unknown species (Spirochaeta americana, Tindallia californiensis, and Desulfonatronum thiodismutans). And as we published earlier, the secondary anaerobes of Owens Lakes were morphologically very similar to those of Mono Lake. However, continuing comparison of the physiology and genetics has led to the conclusion that some links of organic decomposition in the trophic chain of Owens Lake are represented by different unknown species. A new isolate of a sugarlytic spirochete from Owens Lake, which was morphologically very similar to S. americana isolated from Mono Lake, was found to have different metabolic capacity such as the lack of capability to produce hydrogen during glucose fermentation. Furthermore, from the same bacterial community (from Owens Lake) another sugarlytic spore-forming alkaliphile (strain SCA) was isolated in pure culture. Here we discuss the geology and chemistry of Owens Lake as a unique ecosystem of Astrobiological significance. This paper also presents some of the characteristics for the novel isolates and describes their participation in the process of cellulose degradation.

Description: We have previously outlined a strategy for the detection of fossils [Storrie-Lombardi and Hoover, 2004] and extant microbial life [Storrie-Lombaudi and Hoover, 20051 during robotic missions to Mars using co-registered structural and chemical signatures. Data inputs included image lossless compression indices to estimate relative textural complexity and elemental abundance distributions. Two exploratory classification algorithms (principal component analysis and hierarchical cluster analysis) provide an initial tentative classification of all targets. Nonlinear stochastic neural networks are then trained to produce a Bayesian estimate of algorithm classification accuracy. The strategy previously has been successful in distinguishing regions of biotic and abiotic alteration of basalt glass from unaltered samples. [Storrie-Lombardi and Fisk, 2004; Storrie-Lombardi and Fisk, 2004] Such investigations of abiotic versus biotic alteration of terrestrial mineralogy on Earth are compromised by .the difficulty finding mineralogy completely unaffected by the ubiquitous presence of microbial life on the planet. The renewed interest in lunar exploration offers an opportunity to investigate geological materials that may exhibit signs of aqueous alteration, but are highly unlikely to contain contaminating biological weathering signatures. We here present an extension of our earlier data set to include lunar dust samples obtained during the Apollo 17 mission. Apollo 17 landed in the Taurus-Littrow Valley in Mare Serenitatis. Most of the rock samples from this region of the lunar highlands are basalts comprised primarily of plagioclase and pyroxene and selected examples of orange and black volcanic glass. SEM images and elemental abundances (C6, N7, O8, Na11, Mg12, Al13, Si14, P15, S16, Cll7, K19, Ca20, Fe26) for a series of targets in the lunar dust samples are compared to the extant cyanobacteria, fossil trilobites, Orgueil meteorite, and terrestrial basalt targets previously discussed. The data set provides a first step in producing a quantitative probabilistic methodology for geobiological analysis of returned lunar samples or in situ exploration.

Description: The Orgueil CII meteorite, which fell in southern France on the evening of May 14, 1864, has been one of the most extensively studied of all known carbonaceous meteorites. Field Emission Scanning Electron Microscopy (FESEM) studies of freshly fractured interior surfaces of the Orgueil meteorite have resulted in the detection of the fossilized remains of a large and diverse population of filamentous prokaryotic microorganisms. The taphonomy and the diverse modes of the preservation of these remains ,are diverse. Some of the remains exhibit carbonization of a hollow sheath and in other cases the remains are permineralized with water-soluble evaporite minerals, such as magnesium sulfate or ammonium salts. After the sample is fractured and the interior surfaces are exposed to the atmospheric moisture, some of these friable remains have been observed to exhibit significant alterations in appearance with time. Images are presented to document the changes that have been observed in some forms within the past two years. Images and EDS spectral data will also be presented to document the studies carried out on abiotic forms to search for possible nonbiological interpretations of the indigenous filamentous microstructures that have been found in the Orgueil meteorite. Images and EDS data will be presented showing the size, size range, morphology and chemical compositions of abiotic microstructures found in native crystalline and fibrous Epsomites from Poison Lake, Washington, USA and Catalayud, Zaragoza, Aragon, Spain. Many of these embedded forms are consistent in size and microstructure with cyanobacteria morphotypes. Some of the forms are exhibit known characteristics differentiation of cells, and reproductive structures of filamentous trichomic prokaryotes (bacteria and cyanobacteria) and the degraded remains of microfibrils associated with sheaths of cyanobacteria. In this paper, recently obtained comparative images and EDS data will be presented for the mineralized remains found in the Orgueil meteorite and these forms will be compared with known cyanobacteria of the family Oscillatoriaceae. Many of the indigenous filamentous microstructures found in Orgueil filaments are dramatically different from the abiotic microstructures found in the fibrous epsomites and these forms are interpreted as the molds, casts and the well preserved permineralized remains (microfossils) of filamentous prokaryotes that are embedded in and indigenous to the matrix of the Orgueil CI1 carbonaceous meteorite.

Description: Microfossils of large filamentous trichomic prokaryotes have been detected during in-situ investigations of carbonaceous meteorites. This research has been carried out using the Field Emission Scanning Electron Microscope (FESEM) to examine freshly fractured interior surfaces of the meteorites. The images obtained reveal that many of these remains are embedded in the meteorite rock matrix. Energy Dispersive X-Ray Spectroscopy (EDS) studies establish that the filamentous microstructures have elemental compositions consistent with the meteorite matrix, but are often encased within carbon-rich electron transparent sheath-like structures infilled with magnesium sulfate. This is consistent with the taphonomic modes of fossilization of cyanobacteria and sulphur bacteria, since the life habits and processes of these microorganisms frequently result in distinctive chemical biosignatures associated with the properties of their cell-walls, trichomes, and the extracellular polymeric substances (EPS) of the sheath. In this paper the evidence for biogenicity presented includes detailed morphological and morphometric data consistent with known characteristics of uniseriate and multiseriate cyanobacteria. Evidence for indigeneity includes the embedded nature of the fossils and elemental compositions inconsistent with modern biocontaminants.