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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.


(A) colonies of OUMS1 on seven-day-old SGP (silicon-glucose-peptone) agar plate. (a) DIC images of the sheath clump comprising tangled immature sheaths (inset); (b) numerous motile cells and multicell-ensheathed fragments near the sheath clump; (B) visible sheath clumps formed within two days culture (left inset) and comprised tangled immature sheaths (right inset) and motile cells and multicell-ensheathed fragments outside the sheath clump periphery.
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biology-05-00032-f001: (A) colonies of OUMS1 on seven-day-old SGP (silicon-glucose-peptone) agar plate. (a) DIC images of the sheath clump comprising tangled immature sheaths (inset); (b) numerous motile cells and multicell-ensheathed fragments near the sheath clump; (B) visible sheath clumps formed within two days culture (left inset) and comprised tangled immature sheaths (right inset) and motile cells and multicell-ensheathed fragments outside the sheath clump periphery.

Mentions: On SGP agar plates, colonies consisted of a raised, fluffy center and a rough, flat margin. In SGP, large clumps of ensheathed cells and sheaths (hereafter referred to as sheath clumps), that comprised loosely tangled sheath-like structures (Figure 1A (a), inset), and numerous single and double/triple chained cells were seen outside the clump periphery by DIC (Figure 1A (b)). Numerous slender, sheath-like filaments extended outward from the clump periphery (Figure 1A (a)). After small pieces of the sheath clump were suspended in SGP and shake-cultured for two days, small, fluffy clumps comprised loosely tangled sheath-looking structures (Figure 1B, right inset), and single and double/triple chained cells were moving outside the clump periphery (Figure 1B).


Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths
(A) colonies of OUMS1 on seven-day-old SGP (silicon-glucose-peptone) agar plate. (a) DIC images of the sheath clump comprising tangled immature sheaths (inset); (b) numerous motile cells and multicell-ensheathed fragments near the sheath clump; (B) visible sheath clumps formed within two days culture (left inset) and comprised tangled immature sheaths (right inset) and motile cells and multicell-ensheathed fragments outside the sheath clump periphery.
© Copyright Policy
Related In: Results  -  Collection

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

biology-05-00032-f001: (A) colonies of OUMS1 on seven-day-old SGP (silicon-glucose-peptone) agar plate. (a) DIC images of the sheath clump comprising tangled immature sheaths (inset); (b) numerous motile cells and multicell-ensheathed fragments near the sheath clump; (B) visible sheath clumps formed within two days culture (left inset) and comprised tangled immature sheaths (right inset) and motile cells and multicell-ensheathed fragments outside the sheath clump periphery.
Mentions: On SGP agar plates, colonies consisted of a raised, fluffy center and a rough, flat margin. In SGP, large clumps of ensheathed cells and sheaths (hereafter referred to as sheath clumps), that comprised loosely tangled sheath-like structures (Figure 1A (a), inset), and numerous single and double/triple chained cells were seen outside the clump periphery by DIC (Figure 1A (b)). Numerous slender, sheath-like filaments extended outward from the clump periphery (Figure 1A (a)). After small pieces of the sheath clump were suspended in SGP and shake-cultured for two days, small, fluffy clumps comprised loosely tangled sheath-looking structures (Figure 1B, right inset), and single and double/triple chained cells were moving outside the clump periphery (Figure 1B).

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.