Validity of eucaryote inhibitors for assessing production and grazing mortality of marine bacterioplankton. [Cyclidium sp]

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6791696

Taylor, G T; Pace, M L

Application of eucaryote inhibitors to the estimation of production and grazing mortality of bacterioplankton was evaluated. Exposure to a range of concentrations of thiram, cycloheximide, and neutral red (0.4 to 210, 36 to 1777, 4 to 346 ..mu..M, respectively) was 98 to 100% effective at inhibiting growth of a chrysomonad in culture. Exposure to colchicine and griseofulvin (50 to 1000 ..mu..M for both) yielded only 24 to 94 and 53 to 79% inhibition, respectively. Exposures to thiram, neutral red, and griseofulvin were 90 to 100% effective at inhibiting the growth in culture of a ciliate, Cyclidium sp., and the responses to colchicine and cycloheximide were variable (64 to 100 and 0 to 100% inhibition, respectively). Thiram and neutral red inhibited field populations of nanozooplankton more effectively than cycloheximide and colchicine. Direct effects of eucaryote inhibitors on growing cultures of bacterioplankton varied with parameters measured and duration of exposure. After 3-day exposures, specific growth rates and instantaneous heterotrophic potential ((/sup 14/C)glucose uptake) were not consistently affected, but biosynthetic activity (RNA and DNA syntheses) was depressed. The degree of inhibition of isolates and field populations of phytoplankton depended upon type of inhibitor and phytoplankton species. In field experiments, it was possible to calculate rates of bacterioplankton production and grazing mortality for only 16 of 29 inhibitor experiments and for 4 of 10 size fractionation experiments. Because of the inconsistent results obtained in this investigation, the authors strongly recommend exercising caution in the application of inhibitor techniques to ecological problems, especially in phototrophically dominated systems.

• Research Organization: Univ. of Hawaii, Honolulu
• OSTI ID: 6791696
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 53:1; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ALKALOIDS
AMINES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIMITOTIC DRUGS
ANTIPYRETICS
AQUATIC ORGANISMS
AZINES
BACTERIA
BIOSYNTHESIS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
COLCHICINE
CYCLOHEXIMIDE
DNA
DRUGS
FUNGICIDES
GLUCOSE
HETEROCYCLIC COMPOUNDS
HEXOSES
INDICATORS
INHIBITION
LABELLED COMPOUNDS
MICROORGANISMS
MONOSACCHARIDES
MORTALITY
NEUTRAL RED
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PESTICIDES
PLANKTON
PRODUCTIVITY
PYRAZINES
RNA
SACCHARIDES
SYNTHESIS
TOXICITY
UPTAKE