Effects of nutrients on specific growth rate of bacterioplankton in oligotrophic lake water cultures

Journal Article · Wed Jan 01 04:00:00 UTC 1992 · Applied and Environmental Microbiology; (United States)

OSTI ID:5689578

Coveney, M F; Wetzel, R G ^[1]

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1. Michigan State Univ., Hickory Corners (United States)

The effects of organic and inorganic nutrient additions on the specific growth rates of bacterioplankton in oligotrophic lake water cultures were investigated. Lake water was first passed through 0.8-{mu}m-pore-size filters (prescreening) to remove bacterivores and to minimize confounding effects of algae. Specific growth rates were calculated from changes in both bacterial cell numbers and biovolumes over 36 h. Gross specific growth rates in unmanipulated control samples were estimated through separate measurements of grazing losses by use of penicillin. The addition of mixed organic substrates alone to prescreened water did not significantly increase bacterioplankton specific growth rates. The addition of inorganic phosphorus alone significantly increased one or both specific growth rates in three of four experiments, and one experiment showed a secondary stimulation by organic substrates. The stimulatory effects of phosphorus addition were greatest concurrently with the highest alkaline phosphatase activity in the lake water. Because bacteria have been shown to dominate inorganic phosphorus uptake in other P-deficient systems, the demonstration that phosphorus, rather than organic carbon, can limit bacterioplankton growth suggests direct competition between phytoplankton and bacterioplankton for inorganic phosphorus.

• DOE Contract Number: FG02-87ER60515
• OSTI ID: 5689578
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 58:1; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540310* -- Environment
Aquatic-- Basic Studies-- (1990-)
ALKALINE PHOSPHATASE
AQUATIC ORGANISMS
BIOLOGICAL EFFECTS
ELEMENTS
ENZYMES
ESTERASES
GROWTH
HYDROLASES
LAKES
NONMETALS
NUTRIENTS
ORGANIC COMPOUNDS
PHOSPHATASES
PHOSPHORUS
PLANKTON
PROTEINS
SURFACE WATERS