Unexpected trapping of swimming microalgae in foam
Type de document :
Pré-publication ou Document de travail
Titre :
Unexpected trapping of swimming microalgae in foam
Auteur(s) :
Roveillo, Quentin [Auteur]
Matière et Systèmes Complexes [MSC]
Dervaux, Julien [Auteur]
Laboratoire de Physique Statistique de l'ENS [LPS]
Matière et Systèmes Complexes [MSC]
Wang, Yuxuan [Auteur]
Tsinghua University [Beijing] [THU]
Rouyer, Florence [Auteur]
Laboratoire Navier [NAVIER UMR 8205]
Zanchi, Drazen [Auteur]
Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) [PASTEUR]
Matière et Systèmes Complexes [MSC]
Seuront, Laurent [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Elias, Florence [Auteur]
Matière et Systèmes Complexes [MSC]
Matière et Systèmes Complexes [MSC]
Dervaux, Julien [Auteur]
Laboratoire de Physique Statistique de l'ENS [LPS]
Matière et Systèmes Complexes [MSC]
Wang, Yuxuan [Auteur]
Tsinghua University [Beijing] [THU]
Rouyer, Florence [Auteur]
Laboratoire Navier [NAVIER UMR 8205]
Zanchi, Drazen [Auteur]
Processus d'Activation Sélective par Transfert d'Energie Uni-électronique ou Radiatif (UMR 8640) [PASTEUR]
Matière et Systèmes Complexes [MSC]
Seuront, Laurent [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Elias, Florence [Auteur]
Matière et Systèmes Complexes [MSC]
Discipline(s) HAL :
Physique [physics]/Matière Condensée [cond-mat]/Matière Molle [cond-mat.soft]
Physique [physics]
Physique [physics]
Résumé en anglais : [en]
Massive foam formation in aquatic environments is a seasonal threat that drastically impacts the stability of marine ecosystems. Because liquid foams are known to filter passive solid particles, with large particles remaining ...
Lire la suite >Massive foam formation in aquatic environments is a seasonal threat that drastically impacts the stability of marine ecosystems. Because liquid foams are known to filter passive solid particles, with large particles remaining trapped by confinement in the network of liquid channels and small particles being freely advected by the gravity-driven flow, we hypothesized that a similar e↵ect could explain the major shifts in phytoplankton populations observed during foaming episodes. The model unicellular motile algae Chlamydomonas reinhardtii (CR) was incorporated in a bio-compatible foam, and the number of cells escaping the foam at the bottom was measured in time. Comparing the escape dynamics of living and dead CR cells, we found that dead cells are totally advected by the liquid flow towards the bottom of the foam, as expected since the CR diameter remains smaller than the typical foam channel diameter. In contrast, living motile CR cells escape the foam at a significantly lower rate: after two hours, up to 60 % of the injected cells may remain blocked in the foam, while 95 % of the initial liquid volume in the foam has been drained out of the foam. Microscopic observation of the swimming CR cells in a chamber mimicking the cross-section of foam internal channels revealed that swimming CR cells accumulate near channels corners. A theoretical analysis based on the probability density measurements in the micro chambers have shown that this trapping at the microscopic scale contributes to explain the macroscopic retention of the microswimmers in the foam.Lire moins >
Lire la suite >Massive foam formation in aquatic environments is a seasonal threat that drastically impacts the stability of marine ecosystems. Because liquid foams are known to filter passive solid particles, with large particles remaining trapped by confinement in the network of liquid channels and small particles being freely advected by the gravity-driven flow, we hypothesized that a similar e↵ect could explain the major shifts in phytoplankton populations observed during foaming episodes. The model unicellular motile algae Chlamydomonas reinhardtii (CR) was incorporated in a bio-compatible foam, and the number of cells escaping the foam at the bottom was measured in time. Comparing the escape dynamics of living and dead CR cells, we found that dead cells are totally advected by the liquid flow towards the bottom of the foam, as expected since the CR diameter remains smaller than the typical foam channel diameter. In contrast, living motile CR cells escape the foam at a significantly lower rate: after two hours, up to 60 % of the injected cells may remain blocked in the foam, while 95 % of the initial liquid volume in the foam has been drained out of the foam. Microscopic observation of the swimming CR cells in a chamber mimicking the cross-section of foam internal channels revealed that swimming CR cells accumulate near channels corners. A theoretical analysis based on the probability density measurements in the micro chambers have shown that this trapping at the microscopic scale contributes to explain the macroscopic retention of the microswimmers in the foam.Lire moins >
Langue :
Anglais
Source :
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- Trapping_preprint_full.pdf
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