Competition for sulfide among colorless and purple sulfur bacteria in cyanobacterial mats

Jorgensen, B.B.; Des Marais, D.J.; Des Marais, D.J.

Fems Microbiology Ecology 38: 179-186

1986


ISSN/ISBN: 0168-6496
PMID: 11542103
DOI: 10.1111/j.1574-6968.1986.tb01727.x
Accession: 005018350

Download citation:  
Text
  |  
BibTeX
  |  
RIS

Article/Abstract emailed within 0-6 h
Payments are secure & encrypted
Powered by Stripe
Powered by PayPal

Abstract
The vertical zonation of light, O2, H2S, pH, and sulfur bacteria was studied in two benthic cyanobacterial mats from hypersaline ponds at Guerrero Negro, Baja California, Mexico. The physical-chemical gradients were analyzed in the upper few mm at .ltoreq. 100 .mu.m spatial resolution by microelectrodes and by a fiber optic microprobe. In mats, where oxygen produced by photosynthesis diffused far below the depth of the photic zone, colorless sulfur bacteria (Beggiatoa sp.) were the dominant sulfide oxidizing organisms. In a mat, where the O2-H2S interface was close to the photic zone, but yet received no significant visible light, purple sulfur bacteria (Chromatium sp.) were the dominant sulfide oxidizers. Analysis of the spectral light distribution here showed that the penetration of only 1% of the incident near-IR light (800-900 nm) into the sulfide zone was sufficient for the mass development of Chromatium in a narrow band of 300 .mu.m thickness. The balance between O2 and light penetration down into the sulfide zone thus determined in micro-scale which type of sulfur bacteria became dominant.

Competition for sulfide among colorless and purple sulfur bacteria in cyanobacterial mats