Microelectrode studies of interstitial water chemistry and photosynthetic activity in a hot spring microbial mat

Journal Article · Wed Aug 01 00:00:00 EDT 1984 · Appl. Environ. Microbiol.; (United States)

OSTI ID:5314849

Revsbech, N P; Ward, D M

Microelectrodes were used to measure oxygen, pH, and oxygenic photosynthetic activity in a hot spring microbial mat (Octopus Spring, Yellowstone National Park), where the cyanobacterium Synechoccus lividus and the filamentous bacteria Chloroflexus aurantiacus are the only known phototrophs. The data showed very high biological activities in the topmost layers of the microbial mat, resulting in extreme values for oxygen and pH. At a 1-mm depth at a 55 C site, oxygen and pH reached 900 micro M and 9.4, respectively, just after solar noon, whereas anoxic conditions with pH of 7.2 were measured before sunrise. Although diurnal changes between these extremes occurred over hours during a diurnal cycle microbial activity was great enough to give the same response in 1 to 2 mm after artificial shading. Oxygenic photosynthesis was confined to a 0.5- to 1.1-mm layer at sites with temperatures at or above about 50 C, with maximum activities in the 55 to 60 C region. The data suggest that S. lividus is the dominant primary producer of the mat. 30 references, 5 figures.

• Research Organization: Montana State Univ., Bozeman
• OSTI ID: 5314849
• Journal Information: Appl. Environ. Microbiol.; (United States), Vol. 48:2
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BACTERIA
PHOTOSYNTHESIS
HOT SPRINGS
WATER CHEMISTRY
AQUATIC ECOSYSTEMS
DAILY VARIATIONS
OXYGEN
PH VALUE
CHEMICAL REACTIONS
CHEMISTRY
ECOSYSTEMS
ELEMENTS
MICROORGANISMS
NONMETALS
PHOTOCHEMICAL REACTIONS
SYNTHESIS
THERMAL SPRINGS
VARIATIONS
WATER SPRINGS
520100* - Environment
Aquatic- Basic Studies- (-1989)