Microbially — related redox changes in a subtropical lake I.In situ monitoring of the annual redox cycle

Eckert, Werner; Trüper, Hans G.

doi:10.1007/bf00002685

Cited by 25 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Referring to the assumption that the prevailing redox conditions reflect the intracellular microbial metabolism (see introduction) the observed pe shift could be an indication for an direct effect of the PSB on the platinum electrode potential. A comparison of the experimental results obtained with this study with the field data from Lake Kinneret (Eckert & Triiper 1993) shows that the pe 7 -pH 2 S relationship calculated from meta-and hypolimnetic data is similar to the pe-pH 2 S function in Fig. 5 when hydrogen sulfide was added to metalimnion water from Lake Kinneret.…”

Section: Discussionsupporting

confidence: 54%

“…5 when hydrogen sulfide was added to metalimnion water from Lake Kinneret. Finally, the linear function (equation 18) that was calculated from the co-culture experiment resembles the one found in the metalimnion of Lake Kinneret during the first peak of the Chlorobium bloom in July (Eckert & Triiper 1993). It seems that this pe-pH 2 S relationship is a characteristic for the coexistence of two microbially mediated processes: sulfate reduction and phototrophic sulfide oxidation.…”

Section: Discussionmentioning

confidence: 99%

“…To what extent are microbes involved in the electron exchange reactions, since most of the in situ redox processes are mediated by bacterial activity (Frevert 1984;Kjaergaard 1977;Wimpenny 1969Wimpenny , 1984Wimpenny & Necklen 1971;Eckert 1987;Eckert & Triiper 1993) When relating the pe values obtained for Lake Kinneret to the in situ hydrochemical conditions (Eckert & Triiper 1993), a linear function evolved between meta-and hypolimnetic pe and pH 2 S values (pH 2 S = -log [H 2 S]) during the evolution of the chemocline. During the metalimnetic bloom period of phototrophic sulfur bacteria a variation within the pe -pH 2 S function emerged as depicted by a steeper slope.…”

Section: Introductionmentioning

confidence: 99%

“…The annual redox cycle of Lake Kinneret was investigated recently by means of a multi probe for the in situ measurement of highly resolving vertical profiles of redox, pH, and pH 2 S values, temperature and dissolved oxygen (DO) (Eckert & Triiper 1993). The measured platinum electrode potentials were expressed as pe values following the sensor specific redox concept (Frevert 1979(Frevert , 1984, with:…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Microbially — related redox changes in a subtropical lake 2. Simulation of metalinmetic conditions in a chemostat

Eckert

1993

Biogeochemistry

Self Cite

View full text Add to dashboard Cite

Abstract. The individual influence of sulfate reducing and brown phototrophic sulfur bacteria from Lake Kinneret on the metalimnetic redox conditions was investigated by simulating the hydrochemical and microbiological conditions in a specially designed chemostat. The results show a strong correlation between measured redox values and the prevailing hydrogen sulfide concentration leading to a linear relationship. Changes in this relationship allowed differentiation between the on-going microbial processes, sulfate reduction and sulfide oxidation. The comparison of in vitro and in situ redox values shows that the results of the simulation experiments agree with the data previously measured in the metalimnion of Lake Kinneret.

show abstract

Section: Discussionsupporting

confidence: 54%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microbially — related redox changes in a subtropical lake 2. Simulation of metalinmetic conditions in a chemostat

Eckert

1993

Biogeochemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…In summer, the hypolimnion is anoxic with lower pH (7.3-8.0). More details on the hydrography and chemistry of this lake are given in Eckert and Hambright (1996) and Nishri at al. (1997).…”

mentioning

confidence: 99%

Evaluation of community respiratory mechanisms with oxygen isotopes: A case study in Lake Kinneret

Luz

Barkan

Sagi

et al. 2002

Limnology & Oceanography

125

View full text Add to dashboard Cite

Gross and net O 2 production between May 1996 and February 1999 was determined in bottle incubation experiments with H 2 18 O spike and from the change in O 2 concentration. Carbon fixation rates were obtained from 14 C incubations. In general, production rates determined using the H 2 18 O-spike were about twice the primary production determined by the 14 C method, where the latter was close to net oxygen evolution. These relationships are similar to results for the open ocean. During the spring bloom, when the dinoflagellate Peridinium was abundant, the ratio of gross O 2 production to carbon fixation was about 7.5, and net O 2 production was greater than carbon fixation. The difference between O 2 gross production and carbon fixation results, at least in part, from uptake by Mehler reaction and from recycling of the 14 C tracer by dark respiration and the alternative oxidase (AOX). We used the difference in isotopic discrimination against 18 O, occurring during O 2 consumption by various biological pathways, to place constraints on the relative engagement of these pathways. We estimated the overall discrimination against 18 O in the lake from O 2 isotopic mass balance as 20.5-29‰. The only mechanism that can explain the strong overall fractionation in the lake is AOX, which strongly discriminates against 18 O (ϳ31‰). Our results show, for the first time, that uptake by AOX is widespread and quantitatively important to oxygen consumption in aquatic systems.Oxygen exchange by photosynthesis and respiration is the largest biogeochemical cycle in aquatic systems. In order to understand this cycle, it is necessary to know the gross rates of the major processes involved in oxygen production and uptake. Production of O 2 is known to occur in one process in photosystem II, but O 2 consumption in aquatic organisms is possible by several reactions. These include ordinary respiration through the cytochrome oxidase pathway, respiration by the alternative oxidase pathway, Mehler reaction, and photorespiration. The first two processes take place in light as well as in dark conditions, whereas the latter two occur only under illumination. Although the presence of the above mechanisms has been established in different studies, their quantitative importance in the overall O 2 uptake in aquatic systems is not well known, and it is necessary to assess their role in natural environments. In this respect, ordinary O 2 incubation methods, which are very useful for the assessment of photosynthetic production from light-and dark-incubation experiments (e.g., Williams and Purdie 1991), do not provide the necessary information. The main drawback of these methods is their inability to measure the rate of O 2 AcknowledgmentsWe thank Y. Geiffman and the Mekorot Watershed Unit for provision of wind data and extend special thanks to the Kinneret Limnological Laboratory skipper M. Hatab. We are grateful

show abstract

The Application of Electrochemical Tools for In Situ Measurements in Aquatic Systems

2000

View full text Add to dashboard Cite

Since the 1970's, when the ®rst in situ measurements of oxygen in the oceans were reported, the development of electrochemical sensors for in situ measurements in aquatic systems has signi®cantly intensi®ed. A synthesis of the progress made in limnology and oceanography to measure chemical species in situ is presented. From amperometric and potentiometric sensors that can measure a single analyte to voltammetric sensors that can measure several species during the same scan, a variety of electrodes have been used in situ to better understand the nature of the biogeochemical processes occurring in aquatic systems. The advantages and disadvantages of each technique, the technical improvements over the years, and some recommendations are presented together with representative data reported in the literature over the last two decades.

show abstract

Microbially — related redox changes in a subtropical lake I.In situ monitoring of the annual redox cycle

Cited by 25 publications

References 29 publications

Microbially — related redox changes in a subtropical lake 2. Simulation of metalinmetic conditions in a chemostat

Microbially — related redox changes in a subtropical lake 2. Simulation of metalinmetic conditions in a chemostat

Evaluation of community respiratory mechanisms with oxygen isotopes: A case study in Lake Kinneret

The Application of Electrochemical Tools for In Situ Measurements in Aquatic Systems

Contact Info

Product

Resources

About