Anaerobic metabolism in the lugworm Arenicola Marina L.: The transition from aerobic to anaerobic metabolism

Schöttler, Udo; Wienhausen, G.; Westermann, J. E. Mills

doi:10.1016/0305-0491(84)90083-x

Cited by 19 publications

(13 citation statements)

References 8 publications

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“…obs. ) and to that of nonsymbiotic animals known to be adapted to long-term anoxic periods (Dales 1958, de Zwaan & Zandee 1972, Gäde 1983, Schöttler et al 1984, Vopel et al 1998. The presence of glycogen in all symbionts of Riftia pachyptila indicates a surplus of carbon arising from autotrophy.…”

Section: Discussionmentioning

confidence: 99%

Glycogen storage in the Riftia pachyptila trophosome: contribution of host and symbionts

Sorgo¹,

Gaill²,

Lechaire³

et al. 2002

Mar. Ecol. Prog. Ser.

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Glycogen storage in host tissue and symbiotic bacteria in the anterior trophosome of the vestimentiferan tubeworm Riftia pachyptila Jones, 1981, was investigated using transmission electron microscope and stereological methods. The relative glycogen content (RGC) of each partner was calculated from the percentage of host and bacterial cytoplasm area taken up by glycogen and from the percentage area that host and symbionts occupy within a trophosome lobule section. Our results show that host and symbionts contribute equally to the total glycogen content of the trophosome; this ratio remains similar for up to 40 h of hypoxia. Furthermore, there is a glycogen gradient in the lobule. In both symbiotic partners, the glycogen content increased from the lobule center toward the periphery, implying different metabolic activities of host cells and bacteria depending on their location within a trophosome lobule.

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Section: Discussionmentioning

confidence: 99%

Glycogen storage in the Riftia pachyptila trophosome: contribution of host and symbionts

Sorgo¹,

Gaill²,

Lechaire³

et al. 2002

Mar. Ecol. Prog. Ser.

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“…This is indicated by a declining energy charge (Sch6ttler et al, 1984b In the body-walI of Arenicola it is 0.86 to 0.89 under normoxic conditions. The EC declines when utilization of ATP exceeds resynthesis.)…”

Section: Anaerobic Metabolismmentioning

confidence: 97%

“…The transition requires a period of several hours and proceeds in a sequence of phases with typical metabolic changes. This has been analysed in detail by Sch6ttler et al (1984b).…”

Section: Anaerobic Metabolismmentioning

confidence: 99%

“…Conversely, pyruvate formation declines to a corresponding extent, which results in decreased alanine accumulation. Concomitantly, utilization of phosphagen and aspartate gradually ceases as the concentrations of these substrates decline to low levels (Sch6ttler et al, 1984b).…”

Section: Anaerobic Metabolismmentioning

confidence: 99%

“…A particularly important feature of the switching phase is the reduction of the metabolic rate (measured by the rate of ATP formation) to one fifth or less of the normal aerobic level (Sch6ttler et al, 1984b) as is shown in Table 1. As a consequence, the energy balance stabilizes as indicated by an {almost) invariable energy charge.…”

Section: Anaerobic Metabolismmentioning

confidence: 99%

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The lugwormArenicola marina: A model of physiological adaptation to life in intertidal sediments

Zebe

Schiedek

1996

Helgolander Meeresunters

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Influence of intracellular pH on reduction of energy metabolism during hypoxia in the lugworm Arenicola marina

Juretschke

Kamp

1990

J. Exp. Zool.

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The influence of intracellular pH (pHi) on the energy metabolism during hypoxia was studied in the lugworm Arenicola marina using in vivo 31P nuclear magnetic resonance (NMR) spectroscopy and biochemical analysis of the metabolic end products during hypoxia. By addition of phenylphosphonic acid (PPA) to the incubation medium to increase the extracellular H + buffering capacity, different degrees of intracellular acidosis during hypoxia could be attained.At low extracellular PPA concentrations pHi dropped within 1 2 h of hypoxia from 7.3 to 6.7. High extracellular PPA concentrations (50 mM) kept pHi stable at 7.2. Glycogenolysis was enhanced during hypoxia at high pHi, as shown by the measured amounts of accumulated end products. ATP production at high pHi was 31 pmol/g h vs. 15 at low pHi. The mobilisation of the phosphagen phosphotaurocyamine (PTC) was, in contrast, decreased at high pHi: the ratio PTC/p-ATP dropped from 4.8 (normoxia) to 2.8 at high vs. 1.3 at low pHi. The reduction of the metabolic rate during hypoxia hence depends on intracellular acidosis: the rate of the Embden-Meyerhof-Parnas pathway at high pHi was 4.5 kmol/g h vs. 1.9 at low pHi.The lugworm Arenicola marina lives in the tidal zone of the sea coast, where during low tide it regularly has to cope with prolonged periods of environmental hypoxia. During hypoxia the energy demand is largely compensated by anaerobic ATP production particularly due to the degradation of aspartate and glycogen to alanine, strombine, acetate, and propionate (Schottler et al., '84; Siegmund et al., '85). The rate of anaerobic energy production, however, is not constant during prolonged periods of hypoxia. It decreases within 24 hours from 40 pmol ATP/h g dry weight to 9 pmol/h g dry weight (Schottler, '86).Such a reduction in ATP production and consumption has been observed in several animals which are able to survive prolonged periods of hypoxia (for review see Gade, '83; Storey, '85a) and it might be an important strategy for saving energy stores and preventing poisoning due to the accumulation of metabolic end products during hypoxia (cf. Hochachka, '86).Our knowledge about the mechanisms regulating the reduction of energy production and consumption are very sparse (cf. Hochachka and Somero, '84; Hochachka and Guppy, '87; Wegener, '88). Due to the general relevance of pH on enzyme activity, a decrease of intracellular pH has been related with the inhibition of the various metabolic pathways during hypoxia (for a review, cf. Roos and Boron, '81; Nuccitelli and Heiple, '82). Studies on the regulatory enzyme of glycolysis, phosphofructokinase (PFK), concerning the flux through the Embden-Meyerhof-Parnas (EMP) pathway evidenced a drastic reduction of the enzyme's activity when pH decreased (Ui, '66; Ebberink, '82). Other findings on molluscs imply that a drop in fructose 2,6-bisphosphate concentration (Storey, '85b) or that a covalent modification of PFK prevents the activation of this enzyme and thereby a Pasteur effect (Storey, '84). Preliminary in v...

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Anaerobic metabolism in the lugworm Arenicola Marina L.: The transition from aerobic to anaerobic metabolism

Cited by 19 publications

References 8 publications

Glycogen storage in the Riftia pachyptila trophosome: contribution of host and symbionts

Glycogen storage in the Riftia pachyptila trophosome: contribution of host and symbionts

The lugwormArenicola marina: A model of physiological adaptation to life in intertidal sediments

Influence of intracellular pH on reduction of energy metabolism during hypoxia in the lugworm Arenicola marina

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