Microbiological activities in moonmilk monitored using isothermal microcalorimetry (cave of Vers Chez le Brandt, Neuchatel, Switzerland)

Détails

ID Serval
serval:BIB_3A749DEE13B9
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Microbiological activities in moonmilk monitored using isothermal microcalorimetry (cave of Vers Chez le Brandt, Neuchatel, Switzerland)
Périodique
Journal of Cave and Karst Studies
Auteur(s)
Braissant O., Bindschedler S., Daniels A.U., Verrecchia E.P., Cailleau G.
ISSN-L
1090-6924
Statut éditorial
Publié
Date de publication
2012
Peer-reviewed
Oui
Volume
74
Pages
116-126
Langue
anglais
Résumé
Studies of the influence of microbial communities on calcium carbonate
deposits mostly rely on classical or molecular microbiology, isotopic analyses, and
microscopy. Using these techniques, it is difficult to infer microbial activities in such
deposits. In this context, we used isothermal microcalorimetry, a sensitive and nondestructive
tool, to measure microbial activities associated with moonmilk ex-situ. Upon
the addition of diluted LB medium and other carbon sources to fresh moonmilk samples,
we estimated the number of colony forming units per gram of moonmilk to be 4.8 3 105
6 0.2 3 105. This number was close to the classical plate counts, but one cannot assume
that all active cells producing metabolic heat were culturable. Using a similar approach,
we estimated the overall growth rate and generation time of the microbial community
associated with the moonmilk upon addition of various carbon sources. The range of
apparent growth rates of the chemoheterotrophic microbial community observed was
between 0.025 and 0.067 h21 and generation times were between 10 and 27 hours. The
highest growth rates were observed for citrate and diluted LB medium, while the highest
carbon-source consumption rates were observed for low molecular weight organic acids
(oxalate and acetate) and glycerol. Considering the rapid degradation of organic acids,
glucose, and other carbon sources observed in the moonmilk, it is obvious that upon
addition of nutrients during snow melting or rainfall these communities can have high
overall activities comparable to those observed in some soils. Such communities can
influence the physico-chemical conditions and participate directly or indirectly to the
formation of moonmilk.
Open Access
Oui
Création de la notice
07/01/2013 11:48
Dernière modification de la notice
20/08/2019 14:30
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