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.
Highlights
Ocherous deposits or floats in neutral waters of lakes, ponds, swamps, drainage ditches, and springs are seen all over the world [1,2,3]
After small pieces pieces of the sheath clump were suspended in SGP and shake-cultured for two days, small, fluffy of the sheath clump were suspended in SGP and shake-cultured for two days, small, fluffy clumps clumps comprised loosely tangled sheath-looking structures (Figure 1B, right inset), and single and comprised loosely tangled sheath-looking structures (Figure 1B, right inset), and single and double/triple chained cells cells were moving theclump clump periphery (Figure double/triple chained were movingoutside outside the periphery (Figure images of the sheath clump comprising tangled immature sheaths; (b) numerous motile cells images ofand themulticell-ensheathed sheath clump comprising tangled immature sheaths (b) numerous motile cells fragments near the sheath clump; (B)
The present observations illustrate that the rapid fragmentation of sheaths, ready aggregation of the ensheathed fragments, and subsequent recovery of sheath elongation contribute significantly to the initial stage of sheath clump formation
Summary
Ocherous deposits or floats in neutral waters of lakes, ponds, swamps, drainage ditches, and springs are seen all over the world [1,2,3] In most cases, these deposits are iron- or manganese-containing materials produced by Fe-/Mn-oxidizing bacteria, biomineralizing organisms that inhabit the groundwater-outwelling hydrosphere. Species of Leptothrix are such bacteria, which characteristically produce copious extracellular and microtubular sheaths encrusted with ocherous iron oxyhydroxides [1,2,3]. This sheath formation by Leptothrix cells is proposed to protect them. According to careful successive phase-contrast observations, cells of Leptothrix cholodnii divide regardless of their position in the sheath at
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
