Characterization of large, autotrophic Beggiatoa spp. abundant at hydrothermal vents of the Guaymas Basin

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Applied and Environmental Microbiology; (USA)

OSTI ID:5950250

Nelson, D C ^[1]; Wirsen, C O; Jannasch, H W ^[2]

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1. Univ. of California, Davis (USA)
2. Woods Hole Oceanographic Institution, MA (USA)

Filamentous bacteria, identified as members of the genus Beggiatoa by gliding motility and internal globules of elemental sulfur, occur in massive aggregations at the deep-sea hydrothermal vents of the Guaymas Basin, Gulf of California. Cell aggregates covering the surface of sulfide-emanating sediments and rock chimneys were collected by DS R/V Alvin and subjected to shipboard and laboratory experiments. Each sample collected contained one to three discrete width classes of this organism usually accompanied by a small number of flexibacteria (width, 1.5 to 4 {mu}m). The average widths of the Beggiatoa classes were 24 to 32, 40 to 42, and 116 to 122 {mu}m. As indicated by electron microscopy and cell volume/protein ratios, the dominant bacteria are hollow cells, i.e., a thin layer of cytoplasm surrounding a large central liquid vacuole. Activities of Calvin-cycle enzymes indicated that at least two of the classes collected possess autotrophic potential. Judging from temperature dependence of enzyme activities and whole-cell CO{sub 2} incorporation, the widest cells were mesophiles. The narrowest Beggiatoa sp. was either moderately thermophilic or mesophilic with unusually thermotolerant enzymes. This was consistent with its occurrence on the flanks of hot smoker chimneys with highly variable exit temperatures. In situ CO{sub 2} fixation rates, sulfide stimulation of incorporation, and autoradiographic studies suggest that these Beggiatoa spp. contribute significantly as lithoautrophic primary producers to the Guaymas Basin vent ecosystems.

• OSTI ID: 5950250
• Journal Information: Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 55:11; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310* -- Environment
Aquatic-- Basic Studies-- (1990-)
BACTERIA
CALVIN CYCLE SPECIES
CARBON DIOXIDE FIXATION
ECOLOGY
ENZYME ACTIVITY
FUMAROLES
GULF OF CALIFORNIA
MICROORGANISMS
PACIFIC OCEAN
PLANTS
SEAS
SULFUR-OXIDIZING BACTERIA
SURFACE WATERS
TEMPERATURE DEPENDENCE
THERMAL WATERS