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Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths

View Article: PubMed Central - PubMed

ABSTRACT

Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales.

No MeSH data available.


Time-lapse images of multicell-ensheathed fragments found moving around the periphery of the sheath clump. Fragments marked by red arrowheads did not move during the observations; fragment marked by yellow arrowhead moved. Time elapsed is shown at the bottom right of each image.
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biology-05-00032-f003: Time-lapse images of multicell-ensheathed fragments found moving around the periphery of the sheath clump. Fragments marked by red arrowheads did not move during the observations; fragment marked by yellow arrowhead moved. Time elapsed is shown at the bottom right of each image.

Mentions: Many single cells and multicell-ensheathed fragments moved near the periphery of sheath clumps as shown above (Figure 1). To monitor the behavior of these structures in more detail, the cells in SGP were observed with time-lapse at 0.5 s intervals. Although almost half of the cells and the multicell-ensheathed fragments remained at their original positions even at the end of the 4-min observation, others moved rapidly with intermittent short breaks and out of the field of view as summarized (Figure 3). Although OUMS1 cells were reported to have a single polar flagellum [17], the presence of a flagellum within a sheath fragment has not been confirmed, so the driving force of the rapid movement of multicell-ensheathed fragments is an issue to be elucidated.


Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths
Time-lapse images of multicell-ensheathed fragments found moving around the periphery of the sheath clump. Fragments marked by red arrowheads did not move during the observations; fragment marked by yellow arrowhead moved. Time elapsed is shown at the bottom right of each image.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037351&req=5

biology-05-00032-f003: Time-lapse images of multicell-ensheathed fragments found moving around the periphery of the sheath clump. Fragments marked by red arrowheads did not move during the observations; fragment marked by yellow arrowhead moved. Time elapsed is shown at the bottom right of each image.
Mentions: Many single cells and multicell-ensheathed fragments moved near the periphery of sheath clumps as shown above (Figure 1). To monitor the behavior of these structures in more detail, the cells in SGP were observed with time-lapse at 0.5 s intervals. Although almost half of the cells and the multicell-ensheathed fragments remained at their original positions even at the end of the 4-min observation, others moved rapidly with intermittent short breaks and out of the field of view as summarized (Figure 3). Although OUMS1 cells were reported to have a single polar flagellum [17], the presence of a flagellum within a sheath fragment has not been confirmed, so the driving force of the rapid movement of multicell-ensheathed fragments is an issue to be elucidated.

View Article: PubMed Central - PubMed

ABSTRACT

Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales.

No MeSH data available.