Microbial Life. Second Edition. By James T. Staley, Robert P. Gunsalus, Stephen Lory, and, Jerome J. Perry. Sunderland (Massachusetts): Sinauer Associates. $139.95. xxviii + 1066 p. + A‐1–A‐9 + G‐1–G‐16 + N‐1–N‐2 + I‐1–I‐31; ill.; index. 978‐0‐87893‐685‐4. 2007.

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of Laminaria hyperborea. Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg−1 of dry weight, respectively, were found in L. hyperborea blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in L. hyperborea, thus improving the product’s safety for consumers.

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Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield

Communications Earth & Environment ◽

10.1038/s43247-021-00170-2 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Henrik Drake ◽

Nick M. W. Roberts ◽

Manuel Reinhardt ◽

Martin Whitehouse ◽

Magnus Ivarsson ◽

...

Keyword(s):

Fennoscandian Shield ◽

Stable Carbon ◽

Deep Biosphere ◽

Isotopic Signatures ◽

Microbial Life ◽

Carbon Isotopic ◽

Terrestrial Life ◽

Vein Mineral ◽

Methyl Branched Fatty Acids

AbstractEarth’s crust contains a substantial proportion of global biomass, hosting microbial life up to several kilometers depth. Yet, knowledge of the evolution and extent of life in this environment remains elusive and patchy. Here we present isotopic, molecular and morphological signatures for deep ancient life in vein mineral specimens from mines distributed across the Precambrian Fennoscandian shield. Stable carbon isotopic signatures of calcite indicate microbial methanogenesis. In addition, sulfur isotope variability in pyrite, supported by stable carbon isotopic signatures of methyl-branched fatty acids, suggest subsequent bacterial sulfate reduction. Carbonate geochronology constrains the timing of these processes to the Cenozoic. We suggest that signatures of an ancient deep biosphere and long-term microbial activity are present throughout this shield. We suggest that microbes may have been active in the continental igneous crust over geological timescales, and that subsurface investigations may be valuable in the search for extra-terrestrial life.

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Production of nonulosonic acids in the extracellular polymeric substances of “Candidatus Accumulibacter phosphatis”

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11249-3 ◽

2021 ◽

Author(s):

Sergio Tomás-Martínez ◽

Hugo B.C. Kleikamp ◽

Thomas R. Neu ◽

Martin Pabst ◽

David G. Weissbrodt ◽

...

Keyword(s):

Mass Spectrometry ◽

Pathogenic Bacteria ◽

Extracellular Polymeric Substances ◽

Lectin Binding ◽

Wide Distribution ◽

Sialic Acids ◽

Animal Cells ◽

Microbial Life ◽

Proteomic Data ◽

Accumulibacter Phosphatis

Abstract Nonulosonic acids (NulOs) are a family of acidic carbohydrates with a nine-carbon backbone, which include different related structures, such as sialic acids. They have mainly been studied for their relevance in animal cells and pathogenic bacteria. Recently, sialic acids have been discovered as an important compound in the extracellular matrix of virtually all microbial life and in “Candidatus Accumulibacter phosphatis”, a well-studied polyphosphate-accumulating organism, in particular. Here, bioaggregates highly enriched with these bacteria (approx. 95% based on proteomic data) were used to study the production of NulOs in an enrichment of this microorganism. Fluorescence lectin-binding analysis, enzymatic quantification, and mass spectrometry were used to analyze the different NulOs present, showing a wide distribution and variety of these carbohydrates, such as sialic acids and bacterial NulOs, in the bioaggregates. Phylogenetic analysis confirmed the potential of “Ca. Accumulibacter” to produce different types of NulOs. Proteomic analysis showed the ability of “Ca. Accumulibacter” to reutilize and reincorporate these carbohydrates. This investigation points out the importance of diverse NulOs in non-pathogenic bacteria, which are normally overlooked. Sialic acids and other NulOs should be further investigated for their role in the ecology of “Ca. Accumulibacter” in particular, and biofilms in general. Key Points •“Ca. Accumulibacter” has the potential to produce a range of nonulosonic acids. •Mass spectrometry and lectin binding can reveal the presence and location of nonulosonic acids. •The role of nonulosonic acid in non-pathogenic bacteria needs to be studied in detail.

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