Diel vertical movements of the cyanobacterium Oscillatoria terebriformis in a sulfide-rich hot spring microbial mat
Oscillatoria terebriformis, a thermophilic cyanobacterium, carried out a diel vertical movement pattern in Hunter's Hot Springs, Oregon. Throughout most daylight hours, populations of O. terebriformis covered the surface of microbial mats in the hot spring outflows below an upper temperature limit of 54/sup 0/C. Upon darkness trichomes moved downward by gliding motility into the substrate to a depth of 0.5 to 1.0 mm, where the population remained until dawn. At dawn the population rapidly returned to the top of the mats. Field studies with microelectrodes showed that the dense population of O. terebriformis moved each night across an oxygen-sulfide interface, entering a microenvironment which was anaerobic and reducing, a dramatic contrast to the daytime environment at the mat surface where oxygenic photosynthesis resulted in a supersaturated O/sub 2/. Laboratory experiments on motility with the use of sulfide gradients produced in agar revealed a negative response to sulfide at concentrations similar to those found in the natural mats. The motility response may help explain the presence of O. terebriformis below the mat surface at night. The movement back to the surface at dawn appears to be due to a combination of phototaxis, photokinesis, and the onset of oxygenic photosynthesis which consumes sulfide.
- Research Organization:
- Univ. of Oregon, Eugene
- OSTI ID:
- 5927182
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 53:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CYANOBACTERIA
PHOTOSYNTHESIS
TOLERANCE
SULFIDES
METABOLISM
HOT SPRINGS
OXYGEN
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
MICROORGANISMS
NONMETALS
PHOTOCHEMICAL REACTIONS
SULFUR COMPOUNDS
SYNTHESIS
THERMAL SPRINGS
WATER SPRINGS
560300* - Chemicals Metabolism & Toxicology