Enumeration and biomass estimation of planktonic bacteria and viruses by transmission electron microscopy

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Applied and Environmental Microbiology; (USA)

OSTI ID:7025992

Borsheim, K Y; Bratbak, G; Heldal, M ^[1]

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1. Univ. of Bergen (Norway)

Bacteria and virus particles were harvested from water samples by ultracentrifugation directly onto Formvar-coated electron microscopy grids and counted in a transmission electron microscope. With this technique, we have counted and sized bacteria and viruses in marine water samples and during laboratory incubations. By X-ray microanalysis, we could determine the elemental composition and dry-matter content of individual bacteria. The dry weight/volume ratio for the bacteria was 600 fg of dry weight microns-3. The potassium content of the bacteria was normal compared with previous estimates from other bacterial assemblages; thus, this harvesting procedure did not disrupt the bacterial cells. Virus particles were, by an order of magnitude, more abundant than bacteria in marine coastal waters. During the first 5 to 7 days of incubation, the total number of viruses increased exponentially at a rate of 0.4 day-1 and thereafter declined. The high proliferation rate suggests that viral parasitism may affect mortality of bacteria in aquatic environments.

• OSTI ID: 7025992
• Journal Information: Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 56:2; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

550701* -- Microbiology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AQUATIC ORGANISMS
BACTERIA
CENTRIFUGATION
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
ELECTRON MICROPROBE ANALYSIS
ELECTRON MICROSCOPY
HYDROGEN COMPOUNDS
MICROANALYSIS
MICROORGANISMS
MICROSCOPY
OXYGEN COMPOUNDS
PARASITES
PHYTOPLANKTON
PLANKTON
SEAWATER
SEPARATION PROCESSES
TRANSMISSION ELECTRON MICROSCOPY
ULTRACENTRIFUGATION
VIRUSES
WATER