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31.
Growth and dark respiration rates were measured in leaves and roots of seedlings of Avicennia marina (Forsk.) Vierh, (grey mangrove), and Aegiceras corniculatum (L.) Blanco (river mangrove). Plants were grown in a soil mixture at ambient temperatures and watered with 0.25 and 100% sea-water. Oxygen uptake was measured in excised root and leaf samples. In both species growth was maximal in 25% sea-water, and root respiration was lowest in 100% sea-water. Differences were found between the two species in the responses of leaf respiration to salinity. In A. corniculatum leaf respiration was raised in both 25 and 100% sea-water, while in A. marina only leaves in 100% sea-water showed higher rates of respiration. These results are consistent with the view that A. marina is the more salt-tolerant of the two species. In A. corniculatum the respiration rates of the hypocotyl were also measured, and were much higher in 100% sea-water than in the other two treatments. The results suggest that at high salinities there is a high metabolic cost in the shoots of both species, and that at such salinities rates of root respiration may be limited by the supply of substrate from the shoots. 相似文献
32.
Hajime Tokuda 《Journal of bioenergetics and biomembranes》1989,21(6):693-704
The marine bacteriumVibrio alginolyticus was found to possess the respiratory Na+ pump that generates an electrochemical potential of Na+, which plays a central role in bioenergetics ofV. alginolyticus, as a direct result of respiration. Mutants defective in the Na+ pump revealed that one of the two kinds of NADH: quinone oxidoreductase requires Na+ for activity and functions as the Na+ pump. The Na+ pump composed of three subunits was purified and reconstituted into liposomes. Generation of membrane potential by the reconstituted proteoliposomes required Na+. The respiratory Na+ pump coupled to the NADH: quinone oxidoreductase was found in wide varieties of Gramnegative marine bacteria belonging to the generaAlcaligenes, Alteromonas, andVibrio, and showed a striking similarity in the mode of electron transfer and enzymic properties. Na+ extrusion seemed to be coupled to a dismutation reaction, which leads to the formation of quinol and quinone from semi-quinone radical. 相似文献
33.
Christiane Wloczyk Achim Kröger Thomas Göbel Gabriele Holdt Ralf Steudel 《Archives of microbiology》1989,152(6):600-605
Wolinella succinogenes grown on formate and elemental sulphur was found to use the polysulphide derivatives 2,2-tetrathiobispropionate (R2S4) or pentathionate (S5O
6
=
) as acceptors for formate oxidation. The specific activities of formate oxidation with these acceptors were similar to those with elemental sulphur. The main reaction products of R2S4 reduction were 2,2-dithiobispropionate (R2S2) and sulphide. Pentathionate was converted to thiosulphate and some elemental sulphur. The electrochemical proton potential
across the cytoplasmic membrane of the bacterium was measured in the steady state of electron transport from formate to R2S4. The electrical proportion () of the
determined through the distribution of labeled tetraphenylphosphonium cation was obtained as 0.17 Volt. The was zero, when a protonophore was present. The pH-difference across the membrane was negligible. Thus the
generated by sulphur respiration is close to that measured earlier with fumarate as the terminal acceptor of electron transport.Abbreviations DMO
5,5-dimethyloxazolidine-2,4-dione
- R2Sn (n=2–5)
2,2-polythiobispropionate
- TTFB
4,5,6,7-tetrachloro-2-trifluoromethylbenzimidazol
- TPP
tetraphenylphosphonium cation 相似文献
34.
Rolf Bergmann 《Antonie van Leeuwenhoek》1989,55(2):143-152
Thiolutin was found to inhibit the utilization of glucose and other growth substrates in Escherichia coli. The inhibition was detected by a sharp drop of the respiration rate after addition of the antibiotic. The actual function affected was allocated to the cytoplasmic membrane of the bacterial cells by the following evidence:
It was concluded that the transport of certain substrates across the membrane was inhibited. 相似文献
| - spheroplasts were affected like intact cells, |
| - individual reactions of either the electron transport chain or the glycolytic pathway were not inhibited, |
| - glucose consumption in the culture stopped and the cells accumulated guanosine tetraphosphate as under starvation conditions, |
| - activation of the cell's apo-glucose dehydrogenase restored respiration via bypassing the glucose phosphotransferase system. |
35.
Glass-beads (diam. = 250 μm) were buried 10 cm deep in the sediment of a stream. After an exposure of eight weeks, bacterial
densities on the beads varied between 2.7 × 105 and 2.4 × 107/cm2, and the length of the fungal mycelium between 0.2 and 5.3 mm/cm2. Bacterial densities did not show any correlation with the DOC content of the water, but were positively correlated with
respiration on the beads. Fungal mycelium was negatively correlated with water temperature. Acid hydrolysis of stream-exposed
beads released sugars and amino acids, whose combined carbon content exceeded that of the microbial cells by a factor of at
least 4. Gut extracts of Gammarus tigrinus and Tipula caloptera released amino acids and sugars from stream-exposed beads. 相似文献
36.
Functional zooplankton bioassays based on ingestion, reproduction and respiration are described, with methods for a new ingestion bioassay included. All bioassays are compared using three indices, including the variability of controls, the range of experimental responses, and a listing of contaminants causing inhibition/stimulation of response. The ingestion bioassay showed the greatest range of response, and was sensitive to pesticides, PCBs and heavy metals. It was also commonly characterized by a hormesis response. The reproduction bioassay showed the lowest variability, illustrated a reduced range of response, and was sensitive to nutrients and heavy metals. In one study, the respiration bioassay was sensitive only to PCBs. 相似文献
37.
Strain DCB-1 conserves energy for growth from reductive dechlorination coupled to formate oxidation 总被引:26,自引:0,他引:26
Strain DCB-1 is a strict anaerobe capable of the reductive dechlorination of chlorobenzoates. The effect of dechlorination on the yield of pure cultures of DCB-1 was tested. Cultures were incubated with formate or H2 as electron donors and CO2 as a putative carbon source. Relative to control cultures with benzoate, cultures which dechlorinated 3-chlorobenzoate and 3,5-dichlorobenzoate had higher yields measured both as protein and cell density. On the media tested the apparent growth yield was 1.7 to 3.4 g cell protein per mole Cl- removed. Dechlorination also stimulated formate oxidation by growing cultures. Resuspended cells required an electron donor for dechlorination activity, with either formate or elemental iron serving this function. Resuspended cells did not require an electron acceptor for formate consumption, but reductive dechlorination of 3CB to benzoate stoichiometrically stimulated oxidation of formate to CO2. These results indicate that DCB-1 conserves energy for growth by coupling formate, and probably, H2 oxidation to reductive dechlorination.Non-standard abbreviations 3CB
3-chlorobenzoate
- 35DCB
3,5-dichlorobenzoate
- PCF
Propionibacterium sp. culture fluid 相似文献
38.
P.J.L. Derikx H.J.M. Op den Camp A.M. Wagner G. Straatsma L.J.L.D. van Griensven G.D. Vogels 《FEMS microbiology letters》1990,66(1-3):307-311
Abstract The respiratory pathways of Agaricus bisporus and Scytalidium thermophilum were studied. A. bisporus appeared to possess both a cyanide-sensitive and a cyanide-insensitive respiration while in S. thermophilum the cyande-insensitive respiration was absent. Growth experiments showed the ecological advantage for A. bisporus under conditions where cytochrome mediated respiration is inhibited. 相似文献
39.
Douglas G. Sprugel 《Trees - Structure and Function》1990,4(2):88-98
Summary Woody-tissue respiration was measured on five different dates at three to five locations on each of 12 30-year-old Abies amabilis trees. On any given date, temperature-corrected respiration per unit surface area varied 10 to 40-fold between sampling locations. In stems, the two major components of respiration were growth respiration and sapwood maintenance respiration, which were of roughly equal importance during the growing season. There was no evidence of significant cambial maintenance respiration, suggesting that a stand with high bole surface area would not automatically have high respiration. Respiration in branches was much greater than in boles of comparable volume and growth rates, and was significantly correlated with branch height. Branch respiration may include an another significant component in addition to the two seen in bole respiration, possibly associated with carbohydrate mobilization and transport or with CO2 efflux from the transpiration stream. 相似文献
40.