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71.
V. Molitor M. Trnka W. Erber I. Steffan M. -E. Rivière B. Arrio H. Springer-Lederer G. A. Peschek 《Archives of microbiology》1990,154(2):112-119
During adaptation of photoautotrophically growing fresh water cyanobacterium Anacystis nidulans to high salinity the cells showed a pronounced increase of proton-sodium antiporter activity, and of cytochrome c oxidase in isolated and purified plasma membrane. At the same time the concentrations of plasma membrane-bound EDTA-resistant copper and iron (determined by inductively coupled plasma atomic emission spectrometry) rose proportionately, accompanied by an increase in whole cell respiration. In plasma membranes from salt adapted cells lipid/protein ratios were markedly higher than in control cells, levels of esterified saturated and long-chain fatty acids being significantly higher than the respective levels of unsaturated and short-chain fatty acids which explains the higher lipid-phase transition temperatures derived from Arrhenius plots. Immunoblotting of the membrane proteins with antisera raised against the cytochrome c oxidases from Paracoccus denitrificans and A. nidulans gave two cross-reacting bands with apparent molecular weights around 50000 and 30000 (subunits I and II, respectively) which were more pronounced in plasma membranes from salt adapted cells when compared to control cells. The protein pattern of plasma membranes from salt adapted cells also showed the appearance of bands at apparent molecular weights of 44000–48000 and 54000–56000 which might stem from the proton/sodium-antiporter in this membrane.Abbreviations CM
cytoplasmic or plasma membrane
- ICM
intracytoplasmic or thylakoid membrane
- cyt
cytochrome
- DCCD
N,N-dicyclohexylcarbodiimide
- Hepes
N-2-hydroxyethylpiperazine-N-2-ethanesulfonate
- ICP-AES
inductively coupled plasma atomic emission spectrometry
- SDS-PAGE
sodium dodecylsulfate polyacrylamide gel electrophoresis
- EPR
electron paramagnetic resonance spectrometry 相似文献
72.
Wolfgang Ludwig Michael Weizenegger Silvia Dorm Jan Andreesen Karl Heinz Schleifer 《FEMS microbiology letters》1990,71(1-2):139-143
A 1330 base-pair fragment of a 16S rRNA gene has been amplified, cloned and sequenced. Comparison to other 16S rRNA sequences of eubacteria showed that P. niger represents a deep branch within the subdivision "Gram-positive with Gram-negative cell walls". It is not related to peptostreptococci, representatives of this genus studied so far are more closely related to clostridia. 相似文献
73.
Jan T. Keltjens Ben W. te Brömmelstroet ServéW.M. Kengen Chris van der Drift Godfried D. Vogels 《FEMS microbiology letters》1990,87(3-4):327-332
Abstract In the process of methanogenesis, 5,6,7,8-tetrahydromethanopterin (H4 MPT) is the carrier of the C1 unit at the formyl through methyl state of reduction. By the transfer of a formyl group from formylmethanofuran, 5-formyl- and 10-formyl-H4 MPT are formed in hydrogenotrophic and methylotrophic organisms, respectively. Cyclohydrolysis of the 5- and 10-formyl derivatives then yields 5,10-methenyl-H4 MPT, which is reduced in two subsequent coenzyme F420 -dependent reactions to 5-methyl-H4 MPT. Following the transfer of the methyl group to coenzyme M, the substrate of the terminal step in methanogenesis, methylcoenzyme M, is produced. In this paper properties of the enzymes catalyzing the individual H4 MPT-dependent reactions are discussed. 相似文献
74.
Effects of training at simulated altitude on performance and muscle metabolic capacity in competitive road cyclists 总被引:1,自引:0,他引:1
Nicolas Terrados Jan Melichna Christer Sylvén Eva Jansson Lennart Kaijser 《European journal of applied physiology and occupational physiology》1988,57(2):203-209
Differences between the effects of training at sea level and at simulated altitude on performance and muscle structural and biochemical properties were investigated in 8 competitive cyclists who trained for 3-4 weeks, 4-5 sessions/week, each session consisting of cycling for 60-90 min continuously and 45-60 min intermittently. Four subjects, the altitude group (AG), trained in a hypobaric chamber (574 torr = 2300 m above sea level), and the other four at sea level (SLG). Before and after training work capacity was tested both at simulated altitude (574 torr) and at sea level, by an incremental cycle ergometer test until exhaustion. Work capacity was expressed as total amount of work performed. Venous blood samples were taken during the tests. Leg muscle biopsies were taken at rest before and after the training period. AG exhibited an increase of 33% in both sea level and altitude performance, while SLG increased 22% at sea level and 14% at altitude. Blood lactate concentration at a given submaximal load at altitude was significantly more reduced by training in AG than SLG. Muscle phosphofructokinase (PFK) activity decreased with training in AG but increased in SLG. All AG subjects showed increases in capillary density. In conclusion, work capacity at altitude was increased more by training at altitude than at sea level. Work capacity at sea level was at least as much improved by altitude as by sea level training. The improved work capacity by training at altitude was paralleled by decreased exercise blood lactate concentration, increased capillarization and decreased glycolytic capacity in leg muscle. 相似文献
75.
Bård Smedsrød Marie Malmgren Jan Ericsson Torvard C. Laurent 《Cell and tissue research》1988,253(1):39-45
Summary Endocytosis via the hyaluronic acid/chondroitin sulphate receptor of rat liver endothelial cells was studied ultrastructurally, by use of a probe consisting of chondroitin sulphate proteoglycan attached to 15-nm gold particles. The probe bound to the surface of the cells exclusively in coated regions of the plasma membrane. Internalization at 37° C took place in less than one minute during which time interval the bound probe was transferred to coated vesicles. Further transfer to lysosomes was delayed in association with an accumulation of probes in a prelysosomal compartment consisting of large vacuoles in which probes lined the inner aspect of the membrane. Transport to lysosomes occurred only after a lag phase of at least 40–60 min at 37° C.Abbreviations
CS
chondroitin sulphate
-
CSPG
chondroitin sulphate proteoglycan
-
CSPG-Au
CSPG-gold complex
-
EM
electronmicroscopical or electron microscopy
-
HA
hyaluronic acid
-
KC
Kuppfer cells
-
LEC
liver endothelial cells
-
PC
parenchymal cells
-
RES
reticuloendothelial system 相似文献
76.
77.
Accompanying the CAM induction of Mesembryanthemum crystallinum L. grown in high salinity there are changes in the enzymes of carbon metabolism. However, there are no changes in the electron transport activities, Chla/b ratios or in the distribution of chlorophyll amongst the various pigment-protein complexes of isolated thylakoids. Hence with CAM induction there are no changes in the photochemical apparatus of M. crystallinum thylakoids. Despite comparable amounts of chlorophylla/b-proteins of photosystem II to those found in typical C3 sun plants, both the C3 and CAM M. crystallinum chloroplasts have relatively more photosystem II, and, concommitantly, less photosystem I complex. This is consistent with greater fluorescence emission at 685 and 695 nm, and lower emission at 735 nm (measured at 77 K) than typically found for C3 plants, whether sun or shade species. Photoinhibition of isolated C3 and CAM thylakoids by white light led to comparable decreases in electron transport capacities and fluorescence emission at 77 K with photosystem II being more affected than PSI. We suggest however, that the presence of more core PSII complexes relative to PSI complexes in this CAM-inducible plant, may provide an additional strategy to mitigate photoinhibition in the short-term. 相似文献
78.
The transfer of excitation energy in intact cells of the thermophilic green photosynthetic bacterium Chloroflexus aurantiacus was studied both at low temperature and under more physiological conditions. Analysis of excitation spectra measured at 4K indicates that the minor fraction of bacteriochlorophyll a present in the chlorosome functions as an intermediate in energy transfer between the main light-harvesting pigment BChl c and the membrane-bound B808-866 antenna complex. This supports the hypothesis that BChl a is associated with the base plate which connects the chlorosome with the membrane. The overall efficiency for energy transfer from the chlorosome to the membrane is only 15% at 4K. High efficiencies of close to 100% are observed above 40°C near the temperature where the cultures are grown. Cooling to 20°C resulted in a sudden drop of the transfer efficiency which appeared to originate in the chlorosome. This decrease may be related to a lipid phase transition. Further cooling mainly affected the efficiency of transfer between the chlorosome and the membrane. This effect can only partially be explained by a decreased Förster overlap between the chlorosomal BChl a and BChl a 808 associated with the membrane-bound antenna system. The temperature dependence of the fluorescence yield of BChl a 866 also appeared to be affected by lipid phase transitions, suggesting that this fluorescence can be used as a native probe of the physical state of the membrane. 相似文献
79.
The germination of Amaranthus paniculatus seeds was inhibited by applying paclobutrazol, a specific inhibitor of gibberellin biosynthesis. This inhibition was markedly counteracted by gibberellin A3 (GA3), suggesting that endogenous gibberellins are required for germination in this species. The inhibitory effect of paclobutrazol was also overcome by ethephon (2-chloroethylphosphonic acid) or the precursor of ethylene biosynthesis, ACC (1-aminocyclopropane-l-carboxylic acid). Thus the physiological effect of gibberellin can be mimicked by ethylene released from ethephon or synthesised from exogenous ACC. It is suggested, that endogenous gibberellins are involved in germination of Amaranthus paniculatus seeds and that action of GA3 can be substituted by ethylene.Abbreviations ACC
1-aminocyclopropane-l-carboxylic acid
- AMO-1618
(2-isopropyl-5methyl-4-trimethylammoniumchloride)-phenyl-l-piperidinium-carboxylate
- ancymidol
-cyclopropyl--(4-methoxyphenyl)-5-pyrimidine methanol
- chloromequat chloride
(2-chloroethyl)trimethylammoniumchloride
- ethephon
2-chloroethylphosphonic acid
- GA
gibberellin A3
- paclobutrazol
(2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-lyl)pentan-3-ol
- Phosphon D
2,4,dichlorobenzyl-tributhylphosphoniumchloride
- tetcyclacis
5,(4-chlorophenyl)-3,4,5,9,10-pentaaza-tetracyclo)5,4,1,0,Z,6,08,11 dodeca-3,9-diene 相似文献
80.
Summary The on-line estimation of biomass concentration and of three variable parameters of the non-linear model of continuous cultivation by an extended Kalman filter is demonstrated. Yeast growth in aerobic conditions on an ethanol substrate is represented by an unstructured non-linear stochastic t-variant dynamic model. The filter algorithm uses easily accessible data concerning the input substrate concentration, its concentration in the fermentor and dilution rate, and estimates the biomass concentration, maximum specific growth rate, saturation constant and substrate yield coefficient. The microorganismCandida utilis, strain Vratimov, was cultivated on the ethanol substrate. The filter results obtained with the real data from one cultivation experiment are presented. The practical possibility of using this method for on-line estimation of biomass concentration, which is difficult to measure, is discussed.Nomenclature
D
dilution rate (h-1)
- DO2
dissolved oxygen concentration (%)
-
E
identity matrix
-
F
Jacobi matrix of the deterministic part of the system equations g
-
g
continuousn-vector non-linear real function
-
h
m-vector non-linear real function
-
K
Kalman filter gain matrix
-
K
S
saturation constant (kgm-3)
- KS
expectation of the saturation constant estimate
-
M
Jacobi matrix of the deterministic part of the measurement equations h
-
P(t0)
co-variance matrix of the initial values of the state
-
P(tk/tk)
c-variance matrix of the error in
(t
k|t
k)
-
P(tk+1/tk)
co-variance matrix of the error in
(t
k+1|t
k
-
Q
co-variance matrix of the state noise
-
R
co-variance matrix of the output noise
-
S
substrate concentration (kgm-3)
-
S
i
input substrate concentration
-
t
time
-
t
k
discrete time instant with indexk=0, 1, 2,...
-
u(t)
input vector
-
v(tk)
measurement (output) noise sequence
-
w(t)
n-vector white Gaussian random process
-
x(t0)
initial state of the system
-
(t0)
expectation of the initial state values
-
x(t)
n-dimensional state vector
-
x(tk)
state vector at the time instantt
k
-
(tk|tk)
expectation of the state estimate at timet
k when measurements are known to the timet
k
-
(tk+1|tk)
expectation of the state prediction
-
X
biomass concentration (kgm-3)
-
expectation of the biomass concentration estimate
-
y(tk)
m-dimensional output vector at the time instantt
k
-
Y
XIS
substrate yield coefficient
-
X|S
expectation of the substrate yield coefficient estimate
-
specific growth rate (h-1)
- M
maximum specific growth rate (h-1)
-
expectation of the maximum specific growth rate estimate
-
state transition matrix 相似文献