Cosmopolitan distribution of the large composite microbial mat spirochete, Spirosymplokos deltaeiberi

Authors

  • Lynn Margulis Department of Geosciences, University of Massachusetts, Amherst, USA
  • Antoni Navarrete Department of Microbiology, University of Barcelona, Spain
  • Mónica Solé Microbiology, Autonomous University of Madrid, Cantoblanco (Madrid), Spain

Keywords:

Spirosymplokos deltaeiberi, spirochete ultrastructure, spirochete round bodies, cytoplasmic granules, microbial mats

Abstract

Inocula from organic-rich black muds immediately underlying intertidal laminated microbial mats dominated by Microcoleus chthonoplastes yielded large, variable diameter spirochetes. These unusual spirochetes, previously reported only from the Alfacs Peninsula at the delta of the Ebro river in northeast Spain, contain striking arrays of cytoplasmic granules packed into their protoplasmic cylinders. On several occasions, both in summer and winter, the huge spirochetes were recognized in samples from mats growing in the Sippewissett salt marsh at Woods Hole Massachusetts. They were also seen in similar samples from microbial mats at North Pond, Laguna Figueroa, Baja California Norte, Mexico. The identity of these spirochetes was confirmed by electron microscopy: number and disposition of flagella, composite structure, measurements of their distinctive cytoplasmic granules. The granules, larger, more conspicuous and present in addition to ribosomes, are hypothesized to contain ATPases. As culture conditions worsen, these spirochetes retract into membrane-bounded round bodies in which they form refractile inclusions. From morphology and behavior we conclude the North American spirochetes from both Atlantic and Pacific intertidal microbial mats are indistinguishable from those at the delta of the Ebro river. We conclude a cosmopolitan distribution for Spirosymplokos deltaeiberi.

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Published

2010-03-18

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Section

Research Articles