Optimising a method for aragonite precipitation in simulated biogenic calcification media.

Resolving how factors such as temperature, pH, biomolecules and mineral growth rate influence the geochemistry and structure of biogenic CaCO3, is essential to the effective development of palaeoproxies. Here we optimise a method to precipitate the CaCO3 polymorph aragonite from seawater, under tigh...

Full description

Bibliographic Details
Main Authors: Celeste Kellock, Maria Cristina Castillo Alvarez, Adrian Finch, Kirsty Penkman, Roland Kröger, Matthieu Clog, Nicola Allison
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0278627
_version_ 1811177190900891648
author Celeste Kellock
Maria Cristina Castillo Alvarez
Adrian Finch
Kirsty Penkman
Roland Kröger
Matthieu Clog
Nicola Allison
author_facet Celeste Kellock
Maria Cristina Castillo Alvarez
Adrian Finch
Kirsty Penkman
Roland Kröger
Matthieu Clog
Nicola Allison
author_sort Celeste Kellock
collection DOAJ
description Resolving how factors such as temperature, pH, biomolecules and mineral growth rate influence the geochemistry and structure of biogenic CaCO3, is essential to the effective development of palaeoproxies. Here we optimise a method to precipitate the CaCO3 polymorph aragonite from seawater, under tightly controlled conditions that simulate the saturation state (Ω) of coral calcification fluids. We then use the method to explore the influence of aspartic acid (one of the most abundant amino acids in coral skeletons) on aragonite structure and morphology. Using ≥200 mg of aragonite seed (surface area 0.84 m2), to provide a surface for mineral growth, in a 330 mL seawater volume, generates reproducible estimates of precipitation rate over Ωaragonite = 6.9-19.2. However, unseeded precipitations are highly variable in duration and do not provide consistent estimates of precipitation rate. Low concentrations of aspartic acid (1-10 μM) promote aragonite formation, but high concentrations (≥ 1 mM) inhibit precipitation. The Raman spectra of aragonite precipitated in vitro can be separated from the signature of the starting seed by ensuring that at least 60% of the analysed aragonite is precipitated in vitro (equivalent to using a seed of 200 mg and precipitating 300 mg aragonite in vitro). Aspartic acid concentrations ≥ 1mM caused a significant increase in the full width half maxima of the Raman aragonite v1 peak, reflective of increased rotational disorder in the aragonite structure. Changes in the organic content of coral skeletons can drive variations in the FWHM of the Raman aragonite ν1 peak, and if not accounted for, may confuse the interpretation of calcification fluid saturation state from this parameter.
first_indexed 2024-04-10T22:58:36Z
format Article
id doaj.art-fd25586ba33b4846b776707ac75cba1e
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-04-10T22:58:36Z
publishDate 2022-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-fd25586ba33b4846b776707ac75cba1e2023-01-14T05:31:50ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-011712e027862710.1371/journal.pone.0278627Optimising a method for aragonite precipitation in simulated biogenic calcification media.Celeste KellockMaria Cristina Castillo AlvarezAdrian FinchKirsty PenkmanRoland KrögerMatthieu ClogNicola AllisonResolving how factors such as temperature, pH, biomolecules and mineral growth rate influence the geochemistry and structure of biogenic CaCO3, is essential to the effective development of palaeoproxies. Here we optimise a method to precipitate the CaCO3 polymorph aragonite from seawater, under tightly controlled conditions that simulate the saturation state (Ω) of coral calcification fluids. We then use the method to explore the influence of aspartic acid (one of the most abundant amino acids in coral skeletons) on aragonite structure and morphology. Using ≥200 mg of aragonite seed (surface area 0.84 m2), to provide a surface for mineral growth, in a 330 mL seawater volume, generates reproducible estimates of precipitation rate over Ωaragonite = 6.9-19.2. However, unseeded precipitations are highly variable in duration and do not provide consistent estimates of precipitation rate. Low concentrations of aspartic acid (1-10 μM) promote aragonite formation, but high concentrations (≥ 1 mM) inhibit precipitation. The Raman spectra of aragonite precipitated in vitro can be separated from the signature of the starting seed by ensuring that at least 60% of the analysed aragonite is precipitated in vitro (equivalent to using a seed of 200 mg and precipitating 300 mg aragonite in vitro). Aspartic acid concentrations ≥ 1mM caused a significant increase in the full width half maxima of the Raman aragonite v1 peak, reflective of increased rotational disorder in the aragonite structure. Changes in the organic content of coral skeletons can drive variations in the FWHM of the Raman aragonite ν1 peak, and if not accounted for, may confuse the interpretation of calcification fluid saturation state from this parameter.https://doi.org/10.1371/journal.pone.0278627
spellingShingle Celeste Kellock
Maria Cristina Castillo Alvarez
Adrian Finch
Kirsty Penkman
Roland Kröger
Matthieu Clog
Nicola Allison
Optimising a method for aragonite precipitation in simulated biogenic calcification media.
PLoS ONE
title Optimising a method for aragonite precipitation in simulated biogenic calcification media.
title_full Optimising a method for aragonite precipitation in simulated biogenic calcification media.
title_fullStr Optimising a method for aragonite precipitation in simulated biogenic calcification media.
title_full_unstemmed Optimising a method for aragonite precipitation in simulated biogenic calcification media.
title_short Optimising a method for aragonite precipitation in simulated biogenic calcification media.
title_sort optimising a method for aragonite precipitation in simulated biogenic calcification media
url https://doi.org/10.1371/journal.pone.0278627
work_keys_str_mv AT celestekellock optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT mariacristinacastilloalvarez optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT adrianfinch optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT kirstypenkman optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT rolandkroger optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT matthieuclog optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia
AT nicolaallison optimisingamethodforaragoniteprecipitationinsimulatedbiogeniccalcificationmedia