Lipids from microorganisms, and especially lipids from Archaea, are used as taxonomic markers. Unfortunately, knowledge is very limited due to the uncultivability of most Archaea, which greatly reduces the importance of the diversity of lipids and their ecological role. One possible solution is to use lipidomic analysis. Six radioactive sources were investigated, two of which are surface (Wettinquelle and Radonka) and four deep from the Svornost mine (Agricola, Behounek, C1, and Curie). A total of 15 core lipids and 82 intact polar lipids were identified from the membranes of microorganisms in six radioactive springs. Using shotgun lipidomics, typical Archaea lipids were identified in spring water, namely dialkyl glycerol tetraethers, archaeol, hydroxyarchaeol and dihydroxyarchaeol. Diverse groups of polar heads were formed in archaeal IPLs, whose polar heads are formed mainly by hexose, deoxyhexose, and phosphoglycerol. The analysis was performed using shotgun lipidomics and the structure of all molecular species was confirmed by tandem mass spectrometry. After acid hydrolysis, a mixture of polar compounds was obtained from the polar head. Further analysis by GC-MS confirmed that the carbohydrates were glucose and rhamnose. Analysis by HPLC-MS of diastereoisomers of 2-(polyhydroxyalkyl)-3-(O-tolylthiocarbamoyl)thiazolidine-4(R)-carboxylates revealed that both L-rhamnose and D-glucose are present in spring samples only in varying amounts. The glycoside composition depends on the type of spring, that is, Wettinquelle and Radonka springs are basically shallow groundwater, while the samples from the Svornost mine are deep groundwater and do not contain glycosides with rhamnose. This method enables quick screening for characteristic Archaea lipids, allowing decisions on whether to pursue further analyses, such as metagenomic analysis, to directly confirm the presence of Archaea.

• Klíčová slova
• d-glucose, l-rhamnose, Archaea, Glycerol dialkyl glycerol tetraethers, Intact polar lipids, Radioactive springs,
• MeSH
• Archaea * chemie   metabolismus   MeSH
• horké prameny * mikrobiologie   chemie   MeSH
• lipidomika * metody   MeSH
• membránové lipidy * chemie   analýza   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• tandemová hmotnostní spektrometrie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• membránové lipidy * MeSH

Finding solutions for the remediation and restoration of abandoned mining areas is of great environmental importance as they pose a risk to ecosystem health. In this study, our aim was to determine how remediation strategies with (i) compost amendment, (ii) planting a metal-tolerant grass Bouteloua curtipendula, and (iii) its inoculation with beneficial endophytes influenced the microbiome of metal-contaminated tailings originating from the abandoned Blue Nose Mine, SE Arizona, near Patagonia (USA). We conducted an indoor microcosm experiment followed by a metataxonomic analysis of the mine tailings, compost, and root samples. Our results showed that each remediation strategy promoted a distinct pattern of microbial community structure in the mine tailings, which correlated with changes in their chemical properties. The combination of compost amendment and endophyte inoculation led to the highest prokaryotic diversity and total nitrogen and organic carbon, but also induced shifts in microbial community structure that significantly correlated with an enhanced potential for mobilization of Cu and Sb. Our findings show that soil health metrics (total nitrogen, organic carbon and pH) improved, and microbial community changed, due to organic matter input and endophyte inoculation, which enhanced metal leaching from the mine waste and potentially increased environmental risks posed by Cu and Sb. We further emphasize that because the initial choice of remediation strategy can significantly impact trace element mobility via modulation of both soil chemistry and microbial communities, site specific, bench-scale preliminary tests, as reported here, can help determine the potential risk of a chosen strategy.

• Klíčová slova
• Compost, Endophyte, Microbial communities, Mine tailings, Restoration, Trace elements,
• Publikační typ
• časopisecké články MeSH

In terms of the number and diversity of living units, the prokaryotic empire is the most represented form of life on Earth, and yet it is still to a significant degree shrouded in darkness. This microbial "dark matter" hides a great deal of potential in terms of phylogenetically or metabolically diverse microorganisms, and thus it is important to acquire them in pure culture. However, do we know what microorganisms really need for their growth, and what the obstacles are to the cultivation of previously unidentified taxa? Here we review common and sometimes unexpected requirements of environmental microorganisms, especially soil-harbored bacteria, needed for their replication and cultivation. These requirements include resuscitation stimuli, physical and chemical factors aiding cultivation, growth factors, and co-cultivation in a laboratory and natural microbial neighborhood.

• Klíčová slova
• VBNC, cultivation techniques, difficult-to-culture microorganisms, dormancy, environmental microbiome, growth factors, improved cultivation, microbial ecology,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH