Depth distribution of bacterial production in a stratified lake with an anoxic hypolimnion

Journal Article · Sat Nov 01 04:00:00 EST 1986 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6847909

McDonough, R J; Sanders, R W; Porter, K G; Kirchman, D L

The purpose of this study was to determine the depth distribution of bacterial biomass and production in a stratified lake and to test techniques to measure bacterial production in anaerobic waters. Bacterial abundance and incorporation of both (/sup 3/H)thymidine and (/sup 3/H)leucine into protein were highest in the metalimnion, at the depth at which oxygen first became unmeasurable. In contrast, (/sup 3/H)thymidine incorporation into DNA was highest in the epilimnion. Recovery of added (/sup 3/H)DNA was about 90% in waters in which the portion of (/sup 3/H)thymidine incorporation into DNA was about 40%. At least some obligate anaerobic bacteria were capable of assimilating thymidine since aeration of anaerobic hypolimnion waters substantially inhibited thymidine incorporation. The depth profile of bacterial production estimated from total thymidine and leucine incorporation and the frequency of dividing cells were all similar, with maximal rates in the metalimnion. However, estimates of bacterial production based on frequency of dividing cells and leucine incorporation were usually significantly higher than estimates based on thymidine incorporation (using conversion factors from the literature), especially in anaerobic hypolimnion waters. These data indicate that the thymidine approach must be examined carefully if it is to be applied to aquatic systems with low oxygen concentrations. The results also indicate that the interface between the aerobic epilimnion and anaerobic hypolimnion is the site of intense bacterial mineralization and biomass production which deserves further study.

• Research Organization: Univ. of Georgia, Athens
• OSTI ID: 6847909
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 52:5; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
550701* -- Microbiology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANAEROBIC CONDITIONS
AZINES
BACTERIA
BIOCHEMICAL REACTION KINETICS
CARBOXYLIC ACIDS
DEPTH
DIMENSIONS
DISTRIBUTION
DNA
HETEROCYCLIC COMPOUNDS
INHIBITION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LAKES
LEUCINE
MICROORGANISMS
MINERALIZATION
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
POPULATION DYNAMICS
PRODUCTIVITY
PYRIMIDINES
REACTION KINETICS
RIBOSIDES
SPATIAL DISTRIBUTION
SURFACE WATERS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS