Tritiated thymidine incorporation as a measure of microbial activity in lake sediments

Tobin, R.S.; Anthony, D. H. J.

doi:10.4319/lo.1978.23.1.0161

Cited by 47 publications

(25 citation statements)

References 7 publications

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“…Sediment was dispensed into control tubes a n d treated with NaOH prior to isotope addition. Normally milder conditions for the extraction of DNA have been used (Thomas et al, 1974;Tobin and Anthony, 1978). We found, however, that the more rigorous conditions described here extracted more DNA from these sediments.…”

Section: Methodsmentioning

confidence: 91%

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DNA Synthesis as a Measure of Bacterial Productivity in Seagrass Sediments

Moriarty¹,

Pollard²

1981

Mar. Ecol. Prog. Ser.

178

113

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B a c t e r~a l growth rates In sedlments have been calculated fiom measurements of the rate of lncolporatlon of trltlated thymldlne Into d e o x y r~b o n u c l e~c acld (DNA) T h e dllutlon of Isotope In DNA w a s used to estlmate the s u m of the pools of thymldlne In the sedlment and of other cellular precursors of t h y m~d~n eIn DNA Growth rates of bacterla In the surface zone of seagrass bed sedlrnents v a r~e d from 3 7 X 10' cell d l v~s~o n s h -' g -' dry weight of sediment on a hot autumn day to 3 3 X 10" cell d l v l s~o n s h -' g ' In w~n t e r By c o m b~n~n g growth rate measurements uslng the ~s o t o p e d~l u t~o n procedure with biomass measurements ~t IS now p o s s~b l e to obtaln redsondbly r e l~a b l e estimates of b a c t e r~a l product~vity In sedlments Seagrass beds are highly productive plant communltles, in which much of the primary production 1s not u t~l i z e d directly by animals, but enters h~g h e r trophlc levels through microorganisms, especially bacteria ( P h i l l~p s and McRoy, 1980) To quantify this process we need to know not only the blomass of the bacterial population, but also its growth rate Methods are available for measuring biomass in these sedim e n t~, w h~c h show that bacteria in seagrass beds of Moreton Bay Queensland constitute dbout 20 O/o of the sedlment organic matter excluding that which seagrass roots contribute ( M o r l a~t y ,1980) The measurement of growth rates of the whole population has not been possible by classical microb~ological techniques By measuring the rate of synthesis of d e o x y r~b o n u c l e~c acid (DNA), we hoped to be able to estimate the growth rate of bactena In the sedlment Bacteria In sedlments take up [ m e t h~l -~H ] thymidine (thymine-2-deoxyribose Tdr) and use lt for DNA synthesis (Tobln a n d Anthony, 1978) Fuhrman a n d Azam (1980) have used the rate of incorporation of Tdr into DNA in seawater to e s t~m a t e growth rate of planktonic bacterm They assumed that by adding a large excess of ~s o t o p e , the contribution of Tdr from other pools or pathways would be negligible In fact this may not be the case as Rosenbaum-Oliver and Zamenhof (1972) found that exogenous Tdr contributed only a portlon of the Tdr in DNA, varylng from 35 % to 63 % In a normal strain of Escherichia coli, depending on the culture conditions. The highest value of 63 % of exogenous Tdr was obtalned with l mg Tdr m l -' of culture medium. If natural populations of bacteria behave similarly, then to estlmate the rate of DNA synthesis, a n d thus obtain the rate of bacterial division, it is necessary to measure the dilution of a d d e d Tdr by pools in the cells a n d in the sediment. Thymidine-5'-triphosphate (dTTP), the final precursor in DNA synthesis, is synthesised only partly from exogenous Tdr and partly via other pathways within the cell (Rosenbaum-Oliver and Zamenhof, 1972). An isotope dilution experiment can be used to d e t e r m~n e the effect of added 'cold' precursor on the amount of labelled precursor incorporated into ...

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Section: Methodsmentioning

confidence: 91%

“…As Tobin and Anthony (1978) showed, DNA is the buted only 63 % of thymine bases to DNA when suponly source of label after purification by the above plied at a concentration of 1 mg m1 ' in the presence of procedure.…”

Section: Discussionmentioning

confidence: 98%

DNA Synthesis as a Measure of Bacterial Productivity in Seagrass Sediments

Moriarty¹,

Pollard²

1981

Mar. Ecol. Prog. Ser.

178

113

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“…DNA synthesis does not respond immediately to changes in the microenvironment, thus using [3H]thymidine incorporation into DNA to assess bacterial activity and growth may circumvent the disturbance artifact problem (Findlay et al 1985;Moriarty et al 19853). Tobin and Anthony (1978) showed that thymidine was incorporated into DNA in lake sediments, but they did not determine the degree of participation of [ 3H] thymidine in DNA synthesis. Thus their measurements cannot be properly evaluated.…”

mentioning

confidence: 99%

“…There are no comparable data for shallow, eutrophic lakes, but production rates of about 0.1 pg C g-l h-l for Lake Erie can be approximated from data given by Tobin and Anthony (1978). Bacterial production on 24 June for a 1 -cm layer of sediment was -6 mg C m-2 h-l, roughly 10% of the bacterial production integrated through the total 4 m of the water column (57 mg C m-2 h-* : Bell unpubl.…”

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confidence: 99%

Thymidine incorporation and microbial respiration in the surface sediment of a hypereutrophic lake1

Bell

Ahlgren

1987

Limnology & Oceanography

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“…Microbial deoxyribonucleic acid (DNA) synthesis was estimated by 3H-thymidine incorporation into DNA (Tobin and Anthony, 1978). 3H-thymidine (0.04 m1 of 5 pCi ml-' solution) was added to 1 c m h f sediment (triplicates with a formalin-killed control) from each microcosm.…”

Section: Microbial and Macroconsumer Activity Measurementsmentioning

confidence: 99%

Microbial Metabolism and Incorporation by the Polychaete Capitella capitata of Aerobically and Anaerobically Decomposed Detritus

Hanson¹,

Tenore²

1981

Mar. Ecol. Prog. Ser.

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Detritus derived from Spartind rlllerniflord (cordgrass), Grdcilaric, foliilera (red seaweed), and periphyton (mixed algae) was decomposed aerobically and anaerobically for various lengths of time and then fed to the polychaete Cdpilelld capilald in flow-through microcosms. Rates of detrital mineralization [CO, production), microbial respiration (0, consumption) and biomass (adenosine triphosphate and total adenylates, A,), and net incorporation by C. cdpitata varied with detrital source and length of pre-aging. Oxygen consumpt~on per unit microbial biomass (ymoles 1cgA;' d-') increased linearly with age of the detritus: periphytic algal detritus had the highest daily increase of 4 %, followed by G. foliiferd and S. dlterniflora detritus at 1 % and 0.3 % respectively. Metabolic respiratory quotient ( C 4 / O 2 ) , which varied from < 1 to about 5 0 . 1, was a function of detrital source and age; ~t indicated that anaerobic bacteria were important decomposers of detritus. Net incorpordtion rates by C. capitata, microbial biomass, and 0, consumption rates did not dlffer among G. foliifera detritus aged under oxic and anoxic conditions. Rates of CO, production, however, were up to 6 times higher for G. foliifera detritus aged anaerobically. The results suggest that a n a e r o b~c metabolism, which causes a high CO, production, could represent a sign~ficant loss of carbon from benthic food webs.

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Tritiated thymidine incorporation as a measure of microbial activity in lake sediments

Cited by 47 publications

References 7 publications

DNA Synthesis as a Measure of Bacterial Productivity in Seagrass Sediments

DNA Synthesis as a Measure of Bacterial Productivity in Seagrass Sediments

Thymidine incorporation and microbial respiration in the surface sediment of a hypereutrophic lake1

Microbial Metabolism and Incorporation by the Polychaete Capitella capitata of Aerobically and Anaerobically Decomposed Detritus

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