This study is primarily focused on proving the potential of miniaturized Raman systems to detect any biomolecular and mineral signal in natural geobiological samples that are relevant for future application of the technique within astrobiologically aimed missions on Mars. A series of evaporites of varying composition and origin from two extremely dry deserts were studied, namely Atacama and Mojave. The samples represent both dry evaporitic deposits and recent evaporitic efflorescences from hypersaline brines. The samples comprise halite and different types of sulfates and carbonates. The samples were analysed in two different ways: (i) directly as untreated rocks and (ii) as homogenized powders. Two excitation wavelengths of miniaturized Raman spectrometers were compared: 532 and 785 nm. The potential to detect carotenoids as biomarkers on Mars compared with the potential detection of carbonaceous matter using miniaturized instrumentation is discussed.
- Klíčová slova
- algae, cyanobacteria, halophile, pigments, portable Raman, salt,
- Publikační typ
- časopisecké články MeSH
Laboratory cultures of a number of red extremely halophilic Archaea (Halobacterium salinarum strains NRC-1 and R1, Halorubrum sodomense, Haloarcula valismortis) and of Salinibacter ruber, a red extremely halophilic member of the Bacteria, have been investigated by Raman spectroscopy using 514.5nm excitation to characterize their carotenoids. The 50-carbon carotenoid α-bacterioruberin was detected as the major carotenoid in all archaeal strains. Raman spectroscopy also detected bacterioruberin as the main pigment in a red pellet of cells collected from a saltern crystallizer pond. Salinibacter contains the C40-carotenoid acyl glycoside salinixanthin (all-E, 2'S)-2'-hydroxy-1'-[6-O-(methyltetradecanoyl)-β-d-glycopyranosyloxy]-3',4'-didehydro-1',2'-dihydro-β,ψ-carotene-4-one), for which the Raman bands assignments of are given here for the first time.
- MeSH
- Bacteroidetes chemie MeSH
- glykosidy chemie izolace a purifikace MeSH
- Haloarcula chemie MeSH
- Halobacteriaceae chemie MeSH
- Halobacterium salinarum chemie MeSH
- Halorubrum chemie MeSH
- karotenoidy chemie izolace a purifikace MeSH
- Ramanova spektroskopie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bacterioruberin MeSH Prohlížeč
- glykosidy MeSH
- karotenoidy MeSH
- salinixanthin MeSH Prohlížeč
In this study the possibility to detect biomarkers in experimentally prepared evaporitic matrices using a portable Raman instrument was estimated. Testing of the instrument was carried-out under the Alpine conditions outdoors at a low ambient temperature of -10 °C and at an altitude of 2860 m (Pitztal, Austria). Amino acids glycine and l-alanine, nucleo bases thymine and adenine, and metabolite urea were the organics mixed with gypsum powder. In this step it was shown that portable Raman spectroscopic instrumentation is capable of detecting biomarkers in complex samples in a host geological matrix. Such detection is possible even when the laser beam was focussed through the gypsum crystals 3-9 mm thick. For exobiology areas, this is an important fact, because life and/or related biomolecules are likely to be found in cavities under the surface of partially transparent evaporitic minerals that provide them a shelter from the hostile surrounding environment. For influencing the intensity of Raman bands the thickness of covering crystals is not as important as is the actual concentration of the biomarkers. This work and similar experiments serve for better evaluation of Raman spectroscopy as a method for future planetary exploration mission adoption.
- MeSH
- adenin analýza MeSH
- alanin MeSH
- biologické markery analýza MeSH
- glycin analýza MeSH
- krystalizace MeSH
- močovina analýza MeSH
- prášky, zásypy, pudry analýza MeSH
- Ramanova spektroskopie přístrojové vybavení MeSH
- síran vápenatý chemie MeSH
- thymin analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenin MeSH
- alanin MeSH
- biologické markery MeSH
- glycin MeSH
- močovina MeSH
- prášky, zásypy, pudry MeSH
- síran vápenatý MeSH
- thymin MeSH
In this paper Raman spectra were obtained for a series of zeolites (thomsonite, stilbite, natrolite) and beryllium containing silicates (beryl, chrysoberyl, euclase, phenacite, bavenite, milarite) using a portable Raman specrometer with a 785 nm laser excitation to show the possibility to apply this setting for unambiguous detection and discrimination of these silicate minerals. Obtained spectra contain the most intense Raman bands at the same positions ±2-4 cm(-1) as reported in the literature. The use of these bands permits the unambiguous identification of these phases. Data show the possibility to discriminate individual species of similar whitish color and aspect. Measurements showed an excellent correspondence of Raman bands obtained using the portable system and a laboratory Raman microspectrometer (with the same excitation laser wavelenght). However, for several minerals of these groups (chrysoberyl, bertrandite, chiavennite) Raman spectra were not of sufficient quality to permit unambiguous identification. The reasons are discussed. Raman spectrum of chiavennite CaMnBe(2)Si(5)O(13)(OH)(2)·2(H(2)O) - a transformation product occurring together with bavenite on the surface of beryl crystals was obtained for the first time using the laboratory Raman spectrometer.
- MeSH
- beryllium analýza MeSH
- infračervené záření * MeSH
- mikrospektrofotometrie MeSH
- Ramanova spektroskopie přístrojové vybavení MeSH
- zeolity analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- beryllium MeSH
- zeolity MeSH
The detection of relatively low concentrations of the biomarkers in experimentally prepared evaporitic matrices using a portable Raman instrument (Ahura First Defender XL equipped with a 785 nm diode laser and fixed frontal probe) under Alpine conditions was tested. The instrument was able to detect nucleobases thymine (1673 and 984 cm(-1)) and adenine (722 and 536 cm(-1)) at concentrations of 1 wt% in the gypsum matrix outdoors at a low ambient temperature of -10°C and at an altitude of 2860 m(Pitztal, Austria). Amino acids glycine (1324 and 892 cm(-1)) and alanine (1357 and 851 cm(-1)) were unambiguously detected at 10 wt%. The main Raman features: strong, medium and partially weak intensity bands were observed in good agreement with the reference spectra for individual compounds (with a spectral resolution 7-10 cm(-1)) in the wavenumber range 200-1800 cm(-1). In the qualitative part of the experiment it was established that the portable instrument is able to detect the components in the mixture of three biomarkers (glycine, alanine and mellitic acid) and two evaporitic minerals unambiguously. It also detected the majority of the six similar amino acids in the mixture with gypsum and epsomite evaporitic minerals. The results obtained here demonstrate the possibility of a miniaturised Raman spectrometer to be able to cope with the various exobiologically related tasks that can be expected in the future planetary surface exploration missions. Within the payload designed by ESA and NASA for future missions, Raman spectroscopy will represent a unique research instrument.
- MeSH
- aminokyseliny analýza MeSH
- biologické markery analýza MeSH
- mimozemské prostředí chemie MeSH
- minerály chemie MeSH
- nadmořská výška * MeSH
- nízká teplota MeSH
- Ramanova spektroskopie přístrojové vybavení metody MeSH
- síran vápenatý chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- aminokyseliny MeSH
- biologické markery MeSH
- minerály MeSH
- síran vápenatý MeSH
Recently, portable Raman instrumentation has been in demand for geosciences and for future planetary exploration for the identification of both organic and inorganic compounds in situ on Earth and on other planetary bodies, especially on Mars. Here we present the results of the analysis of halite/β-carotene and halite/mellitic acid mixtures, performed by miniaturized Raman instrumentation equipped with 785 and 1064 nm excitation. Various proportions of organics in the halite matrix were examined. The lowest concentration of β-carotene detected using the 785 nm laser was 1 mg kg(-1), with slightly better signals observed with shorter exposure times compared with the bench instrument using the same excitation wavelength. Mellitic acid was identified at the concentration level 10 g kg(-1). The 1064 nm excitation provided a lower sensitivity towards low concentration when compared with the 785 nm excitation.
- MeSH
- benzoáty analýza MeSH
- beta-karoten analýza MeSH
- minerály analýza MeSH
- Ramanova spektroskopie přístrojové vybavení metody MeSH
- senzitivita a specificita MeSH
- výzkum přístrojové vybavení MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- benzoáty MeSH
- beta-karoten MeSH
- mellitic acid MeSH Prohlížeč
- minerály MeSH
Raman spectra of 13 amino acids: L-alanine, β-alanine, L-asparagine, L-aspartic acid, L-glutamic acid, L-glutamine, glycine, L-methionine, L-proline, L-serine, L-threonine, L-tryptophan and L-tyrosine were acquired outdoors using two portable Raman instruments from the Ahura and Delta Nu manufacturers, both with 785 nm laser excitation. Both instruments provide quality Raman spectra with nevertheless a variable dependence upon the prevailing experimental conditions. The data acquired in these experiments will inform the selection of suitable Raman spectrometers for the in-field detection of biomolecules of relevance to the search for life signatures spectroscopically in terrestrial extreme environments and in extraterrestrial exploration, especially of planetary surfaces and subsurfaces using robotic instrumentation.
- MeSH
- alanin chemie MeSH
- aminokyseliny analýza chemie MeSH
- asparagin chemie MeSH
- beta-alanin chemie MeSH
- doprava * přístrojové vybavení metody MeSH
- glutamin chemie MeSH
- glycin chemie MeSH
- kyselina aspartová chemie MeSH
- kyselina glutamová chemie MeSH
- methionin chemie MeSH
- pracoviště MeSH
- prolin chemie MeSH
- Ramanova spektroskopie přístrojové vybavení metody MeSH
- robotika MeSH
- serin chemie MeSH
- tryptofan chemie MeSH
- tyrosin chemie MeSH
- výzkumný projekt MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- alanin MeSH
- aminokyseliny MeSH
- asparagin MeSH
- beta-alanin MeSH
- glutamin MeSH
- glycin MeSH
- kyselina aspartová MeSH
- kyselina glutamová MeSH
- methionin MeSH
- prolin MeSH
- serin MeSH
- tryptofan MeSH
- tyrosin MeSH
The hyper-arid core of the Atacama Desert (Chile) is the driest place on Earth and is considered a close analogue to the extremely arid conditions on the surface of Mars. Microbial life is very rare in soils of this hyper-arid region, and autotrophic micro-organisms are virtually absent. Instead, photosynthetic micro-organisms have successfully colonized the interior of halite crusts, which are widespread in the Atacama Desert. These endoevaporitic colonies are an example of life that has adapted to the extreme dryness by colonizing the interior of rocks that provide enhanced moisture conditions. As such, these colonies represent a novel example of potential life on Mars. Here, we present non-destructive Raman spectroscopical identification of these colonies and their organic remnants. Spectral signatures revealed the presence of UV-protective biomolecules as well as light-harvesting pigments pointing to photosynthetic activity. Compounds of biogenic origin identified within these rocks differed depending on the origins of specimens from particular areas in the desert, with differing environmental conditions. Our results also demonstrate the capability of Raman spectroscopy to identify biomarkers within rocks that have a strong astrobiological potential.
- MeSH
- chlorid sodný * MeSH
- difrakce rentgenového záření MeSH
- exobiologie MeSH
- mikrobiologie * MeSH
- minerály * MeSH
- pouštní klima * MeSH
- Ramanova spektroskopie * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Jižní Amerika MeSH
- Názvy látek
- chlorid sodný * MeSH
- minerály * MeSH
Organic minerals, organic acids and NH-containing organic molecules represent important target molecules for astrobiology. Here, we present the results of the evaluation of a portable hand-held Raman spectrometer to detect these organic compounds outdoors under field conditions. These measurements were carried out during the February-March 2009 winter period in Austrian Alpine sites at temperatures ranging between -5 and -25 degrees C. The compounds investigated were detected under field conditions and their main Raman spectral features were observed unambiguously at their correct reference wavenumber positions. The results obtained demonstrate that a miniaturized Raman spectrometer equipped with 785 nm excitation could be applied with advantage as a key instrument for investigating the presence of organic minerals, organic acids and nitrogen-containing organic compounds outdoors under terrestrial low-temperature conditions. Within the payload designed by ESA and NASA for several missions focusing on Mars, Titan, Europa and other extraterrestrial bodies, Raman spectroscopy can be proposed as an important non-destructive analytical tool for the in situ identification of organic compounds relevant to life detection on planetary and moon surfaces or near subsurfaces.
- MeSH
- exobiologie metody MeSH
- nadmořská výška * MeSH
- organické látky analýza MeSH
- Ramanova spektroskopie metody MeSH
- teplota * MeSH
- Země (planeta) MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- organické látky MeSH
Raman spectral signatures have been obtained in situ for a series of minerals using portable Raman instruments. Cerussite, anglesite, wulfenite, titanite, calcite, tremolite, andradite and quartz were detected using portable Raman spectrometer First Defender XL (Ahura). Baryte, almandine and realgar Raman spectra obtained by this instrument in the field were compared to the data measured by the other mobile Raman instrument Inspector Raman (DeltaNu). Bench Raman dispersive microspectrometer (InVia Reflex, Renishaw) was used for comparative purposes. All spectra were obtained using a 785nm diode excitation. Although displaying lower spectral resolution comparing with the laboratory confocal instrument both portable instruments permit unambiguous detection of minerals in the field. These possibilities designate portable Raman machines as excellent tools for field geological applications. Miniaturised Raman instrument combined with LIBS will be included in the payload of the EXO Mars mission and would open interesting research possibilities in other in situ field planetary studies.
- MeSH
- amfibolový azbest analýza MeSH
- arsenikové přípravky analýza MeSH
- křemen analýza MeSH
- minerály analýza MeSH
- Ramanova spektroskopie přístrojové vybavení metody MeSH
- sulfidy analýza MeSH
- uhličitan vápenatý analýza MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- amfibolový azbest MeSH
- arsenic disulfide MeSH Prohlížeč
- arsenikové přípravky MeSH
- křemen MeSH
- minerály MeSH
- sulfidy MeSH
- tremolite MeSH Prohlížeč
- uhličitan vápenatý MeSH
