Archives par mot-clé : Biology

biology+acidification, climate-debate

When Exposed To Natural, Long-Term Extreme ‘Ocean Acidification’, Coral And Urchin ‘Persist’ And Even ‘Thrive’

by K. Richard, June 29, 2020 in NoTricksZone

Marine species subjected to high CO2 extremes – 8,891 to 95,000 ppm – in their natural environments may not be adversely affected. They may even “thrive”.

Earlier this year we highlighted a study that says coral reefs “thrive” near seafloor volcanic vents where CO2 concentrations reach 60,000 to 95,000 ppm.

Urchins basking in volcanic vent streams of 8,891 ppm CO2 and daily CO2 variations of more than 2,000 ppm as well as day-to-day pH fluctuations ranging from 6.9 (“acidification”) to 8.1…grow more than two times faster than nearby control (stable 394 ppm CO2, 8.1 pH) urchins (Uthicke et al., 2016).

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only geology, sciences-general

Impact-induced amino acid formation on Hadean Earth and Noachian Mars

by Takeuchi et al., June8, 2020 in SciReports Open Access

Abstract

Abiotic synthesis of biomolecules is an essential step for the chemical origin of life. Many attempts have succeeded in synthesizing biomolecules, including amino acids and nucleobases (e.g., via spark discharge, impact shock, and hydrothermal heating), from reduced compounds that may have been limited in their availabilities on Hadean Earth and Noachian Mars. On the other hand, formation of amino-acids and nucleobases from CO2 and N2 (i.e., the most abundant C and N sources on Earth during the Hadean) has been limited via spark discharge. Here, we demonstrate the synthesis of amino acids by laboratory impact-induced reactions among simple inorganic mixtures: Fe, Ni, Mg2SiO4, H2O, CO2, and N2, by coupling the reduction of CO2, N2, and H2O with the oxidation of metallic Fe and Ni. These chemical processes simulated the possible reactions at impacts of Fe-bearing meteorites/asteroids on oceans with a CO2 and N2 atmosphere. The results indicate that hypervelocity impact was a source of amino acids on the Earth during the Hadean and potentially on Mars during the Noachian. Amino acids formed during such events could more readily polymerize in the next step of the chemical evolution, as impact events locally form amino acids at the impact sites.

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biology+acidification, sciences-general

Scientists identify two new species of fungi in retreating Arctic glacier

by Research Organization of Information and Systems, January 15, 2019 in ScienceDaily

Two new species of fungi have made an appearance in a rapidly melting glacier on Ellesmere Island in the Canadian Arctic, just west of Greenland. A collaborative team of researchers from Japan’s National Institute of Polar Research, The Graduate University for Advanced Studies in Tokyo, Japan, and Laval University in Québec, Canada made the discovery.

The scientists published their results on DATE in two separate papers, one for each new species, in the International Journal of Systematic and Evolutionary Microbiology.

“The knowledge of fungi inhabiting the Arctic is still fragmentary. We set out to survey the fungal diversity in the Canadian High Arctic,” said Masaharu Tsuji, a project researcher at the National Institute of Polar Research in Japan and first author on both papers. “We found two new fungal species in the same investigation on Ellesmere Island.”

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only geology, sciences-general

Bacterial origin of the red pigmentation of Phanerozoic carbonate rocks: an integrated study of geology-biology-chemistry

by A. Préat et  al., December 2018 in GeologicaBelgica (with .pdf)

Abstract

Explaining the color of rocks is still a complex problem. This question was raised long ago in the community of geologists, particularly for the pigmentation of the ‘red marbles’ of the Frasnian of Belgium at the beginning of the last century, with many unsatisfactory hypotheses. Our recent analysis of different red carbonate rocks in Europe and North Africa (Morocco) may provide an alternative explanation for the color of these rocks. For this it was necessary to bring together diverse and complementary skills involving geologists, microbiologists and chemists. We present here a synthesis of these works. It is suggested that the red pigmentation of our studied Phanerozoic carbonate rocks, encompassing a time range from Pragian to Oxfordian, may be related to the activity of iron bacteria living in microaerophilic environments. A major conclusion is that this red color is only related to particular microenvironments and has no paleogeographic or climatic significance. All red carbonates have not necessarily acquired their pigmentation through the process established in this review. Each geological series must be analyzed in the light of a possible contribution of iron bacteria and Fungi.

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biology+acidification

Les coraux blanchissent depuis très longtemps

by Prof. Dr. Paul Berth, 5  septembre 2018, in ScienceClimatEnergie

Le blanchissement des coraux est un phénomène dont on entend souvent parler dans les médias. Il s’agirait d’un grave problème environnemental, dont la fréquence augmente, et qui pourrait mener à la perte totale des récifs coralliens. Le réchauffement climatique global, qui serait causé par l’augmentation de la concentration atmosphérique en CO2 est, bien entendu, pointé du doigt. Cependant, le blanchissement des coraux n’est-il pas un phénomène très ancien? Est-il seulement causé par des variations de température? Quel recul avons-nous à ce sujet? Une récente publication de Nicholas Kamenos et Sebastian Hennige, deux chercheurs anglais des Universités de Glasgow et d’Édimbourg, apporte de nouveaux éléments.

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