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1.
Jerome Honnorat Michele Accominotti Christiane Broussolle Andree-Carole Fleuret Jean-Jacques Vallon Jacques Orgiazzi 《Biological trace element research》1992,32(1-3):311-316
Zinc status was assessed in 53 diabetic patients: 18 insulin-dependent diabetic patients (IDDM), 22 noninsulin-dependent diabetic
patients (NIDDM) treated with oral antidiabetic agents, and 13 insulin-treated, noninsulin-dependent diabetic patients (IRDM).
Plasma zinc concentrations were in the usual range for healthy subjects in these three groups (15.3±0.9 μmol/L). Urinary zinc
excretions were elevated in the IDDM group (18.3±4.1 μmol/24 h;p<0.01 vs normal) and in the NIDDM group (17.5±3.5 μmol/24 h;p<0.01 vs normal), but normal in the IRDM group (11.3±2.4 μmol/24 h). In 14 NIDDM patients treated with transient continuous
sc insulin injections, urinary zinc decreased from 16.5±2.2 μmol/24 h before insulin treatment to 11.5±0.3 μmol/24 h after
insulin treatment without any modification in plasma zinc concentrations. 相似文献
2.
Kedzierska K Bober J Ciechanowski K Gołembiewska E Kwiatkowska E Noceń I Dołegowska B Dutkiewicz G Chlubek D 《Biological trace element research》2005,107(1):21-32
The aim of the study was to verify the hypothesis if copper could influence the activity of sodium-transporting systems in
erythrocyte membrane that could be related to essential hypertension. The examined group of patients consisted of 15 men with
hypertension. The control group was 11 healthy male volunteers. The Na+/H+ exchanger (NHE) activity in erythrocytes was determined according to Orlov et al. The activity of transporting systems (ATP-Na+/K+; co-Na+/K+/Cl−; ex-Na+/Li+; free Na+ and K+ outflow [Na+, K+-outflow]) was determined according to Garay's method. The concentration of copper in plasma was assessed using atomic absorption
spectrometry. The activity of ATP-Na+/K+ (μmol/L red blood cells [RBCs]/h) in hypertensive patients was 2231.5±657.6 vs 1750.5±291 in the control (p<0.05), the activity of co-Na+/K+/Cl− (μmol/L RBCs/h) in hypertensives was 171.3±77.9 vs 150.7±53.9 in the control (NS). Na+-outflow (μmol/L RBCs/h) in hypertensives was 118.3±51.6 vs 113.3±24.4 in the control (NS). The K+-outflow (μmol/L RBCs/h) in hypertensives was 1361.7±545.4 vs 1035.6±188.3 in the control (NS). The activity of ex-Na+/Li+ (μmol/L RBCs/h) in hypertensive patients was 266.1±76.1 vs 204.1±71.6 in the control (p<0.05). NHE activity (mmol/L RBCs/h) in hypertensives was 9.7±2.96 vs 7.7±1.33 in the control (p<0.05). In hypertensive patients, negative correlation was found between the activity of Na+/K+/Cl− co-transport and plasma copper concentration (R
s=−0.579, p <0.05) and between the activity of ex-Na+/Li+ and plasma copper concentration (R
s=−0.508, p<0.05). Plasma copper concentration significantly influences the activity of sodium transporting systems in erythrocyte membrane.
Copper supplementation could be expected to provide therapeutic benefits for hypertensive patients. 相似文献
3.
Plant traits of Malcolmia littorea growing at the Botanic Garden of Rome and transplanted from the wild population developing along the Latium coast (Italy) were analyzed. The highest photosynthetic rates [P
N, 22.5 ± 0.5 μmol(CO2) m−2 s−1], associated to the highest chlorophyll content (Chl, 60 ± 5 SPAD units), and respiration rates [R, 11.1 ± 0.2 μmol(CO2) m−2 s−1] were reached in spring, when mean air temperature (T
m) was in the range 17°C to 23°C. P
N, Chl, and R decreased by 86, 38, and 59% in summer when mean maximum air temperature (T
max) was 30.3 ± 2.6°C. Leaf water potential decreased by 34% in summer compared to the spring value, and it was associated to
a relative water content (RWC) of 74 ± 4%, and to a water-use efficiency (WUE) of 2.15 ± 0.81 μmol(CO2) mmol−1(H2O). Moreover, also low air temperatures determined a significant P
N and R decreases (by 52 and 40% compared to the maximum, respectively). Responsiveness of gross photosynthetic rate (P
g) to R was higher than that to P
N as underlined by the slope of the regression line between the two variables. The results underlined a low tolerance to both
high- and low air temperatures of M. littorea. The selected key traits (R, WUE, Chl) by the discriminant analysis might be used to monitor the M. littorea wild population in the long time. The ex situ cultivated plants could be propagated and used to increase the individuals number of the wild population. 相似文献
4.
6-Phosphogluconate dehydrogenase (6PG) was purified from rat small intestine with 36% yield and a specific activity of 15 U/mg.
On SDS/PAGE, one band with a mass of 52 kDa was found. On native PAGE three protein and two activity bands were observed.
The pH optimum was 7.35. Using Arrhenius plots, Ea, ΔH, Q10 and Tm for 6PGD were found to be 7.52 kcal/mol, 6.90 kcal/mol, 1.49 and 49.4°C, respectively. The enzyme obeyed “Rapid Equilibrium
Random Bi Bi” kinetic model with Km values of 595 ± 213 μM for 6PG and 53.03±1.99 μM for NADP. 1/Vm versus 1/6PG and 1/NADP plots gave a Vm value of 8.91±1.92 U/mg protein. NADPH is the competitive inhibitor with a Ki of 31.91±1.31 μM. The relatively small Ki for the 6PGD:NADPH complex indicates the importance of NADPH in the regulation of the pentose phosphate pathway through G6PD
and 6PGD. 相似文献
5.
Two approaches to determine the fraction (μ) of mitochondrial respiration sustained during illumination by measuring CO2 gas exchange are compared. In single leaves, the respiration rate in the light (`day respiration' rate Rd) is determined as the ordinate of the intersection point of A–ci curves at various photon flux densities and compared with the CO2 evolution rate in darkness (`night respiration' rate Rn). Alternatively, using leaves with varying values of CO2 compensation concentration (Γ), intracellular resistance (ri) and Rn, an average number for μ can be derived from the linear regression between Γ and the product riċRn. Both methods also result in a number c* for that intercellular CO2 concentration at which net CO2 uptake rate is equal to –Rd. c* is an approximate value of the photocompensation point Γ* (Γ in the absence of mitochondrial respiration), which is related
to the CO2/O2 specificity factor of Rubisco Sc/o. The presuppositions and limitations for application of both approaches are discussed. In leaves of Nicotiana tabacum, at 22 °C, single leaf measurements resulted in mean values of μ = 0.71 and c* = 34 μmol mol−1. At the photosynthetically active photon flux density of 960 μmol quanta m−2 s−1, nearly the same numbers were derived from the linear relationship between Γ and riċRn. c* and Rd determined by single leaf measurements varied between 31 and 41 μmol mol−1 and between 0.37 and 1.22 μmol m−2 s−1, respectively. A highly significant negative correlation between c* and Rd was found. From the regression equation we obtained estimates for Γ* (39 μmol mol−1), Sc/o (96.5 mol mol−1) and the mesophyll CO2 transfer resistance (7.0 mol−1 m2 s).
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
Vogt AM Elsässer A Pott-Beckert A Ackermann C Vetter SY Yildiz M Schoels W Fell DA Katus HA Kübler W 《Molecular and cellular biochemistry》2005,278(1-2):223-232
For both, cardioplegia (CP) and ischemic preconditioning (IP), increased ischemic tolerance with reduction in infarct size
is well documented. These cardioprotective effects are related to a limitation of high energy phosphate (HEP) depletion. As
CP and IP have to be assumed to act by different mechanisms, their effects on myocardial HEP metabolism cannot be assumed
to be identical. Therefore, a systematic analysis of myocardial HEP metabolism for both procedures and their combination was
performed, addressing the question whether there are different effects on myocardial HEP metabolism by IP and CP. In this
study, metabolic control analysis was used to analyze the regulation of HEP metabolism. In open chest pigs subjected to 45
min LAD occlusion (index ischemia), CP and IP preserved myocardial ATP (control (C) 0.14 ± 0.05 μmol/g wwt; CP: 0.95 ± 0.14,
IP: 0.61 ± 0.12; p<0.05 C vs. CP and IP) and reduced myocardial necrosis (infarct size IA/RA: C: 90.0 ± 3.0%; CP: 0.0 ± 0.0% but patchy necroses;
IP: 5.05 ± 2.1%; p<0.05 C vs. CP and IP). The effects on HEP metabolism, however, were different: CP acted predominantly by slowing down the
breakdown of phosphocreatine (PCr) during early phases of ischemia (C: ΔPCr 0–2 min: 5.24 ± 0.32 μmol/g wwt; CP: ΔPCr 0–2
min: 3.38 ± 0.23 μmol/g wwt, p<0.05 vs. C), leaving ATP breakdown during later stages unaffected (C: ΔATP 5–45 min: 1.77 ± 0.11 μmol/g wwt CP: ΔATP 5–45
min: 1.59 ± 0.28 μmol/g wwt, n.s. vs. C). In contrast to CP, in IP PCr breakdown was even increased (IP: ΔPCr 0–2 min: 7.06
± 0.34 μmol/g wwt, p<0.05 vs. C), but ATP depletion greatly attenuated (IP: ΔATP 5–45 min: 0.48 ± 0.10 μmol/g wwt, p<0.05 vs. C and CP). Combining IP and CP yielded an additive effect with slowing down the breakdown of both PCr (IP+CP: ΔPCr
0–2 min: 5.09± 0.35 μmol/g wwt, p<0.05 vs. C and IP) and ATP (IP+CP: ΔATP 5–45 min: 0.56 ± 0.48 μmol/g wwt, p<0.05 vs. C and CP), resulting in a higher ATP content at the end of index ischemia (1.86 ± 0.46 μmol/g wwt, p<0.05 vs. C, CP and IP). Compared to IP, combining IP+CP achieved also a further reduction in infarct size (IA/RA: 0.0 ± 0.0%,
p<0.05 vs IP) and—compared to CP—a disappearance of the patchy necroses. {The concept of major differences in myocardial HEP
metabolism during CP and IP is further supported at a molecular level by metabolic control analysis. CP but not IP slowed
down the CK reaction velocity at high PCr levels. In contrast to CP exerting a continuous decline in vATPase for any given ATP level, in IP myocardium ATPase reaction velocity was even increased at higher ATP contents, whereas
a marked decrease in ATPase reaction velocity was found if ATP levels decreased. The equilibrium of the CK-reaction remained
unchanged following CP, whereas IP induced a changing CK equilibrium, which was the more shifted towards PCr the more myocardial
HEP content decreased. The data demonstrate different effects of CP and IP on myocardial HEP metabolism, i.e. PCr and ATP
breakdown as well as the apparent equilibrium of the creatine kinase (CK)-reaction. For these reasons the combination of the
two protective interventions has an additive effect. (Mol Cell Biochem 278: 222–232, 2005) 相似文献
7.
Ann Van Campenhout Christel Van Campenhout Albert Lagrou Begoña Manuel-y-Keenoy 《Biometals》2008,21(2):159-170
Background: Administration of intravenous iron preparations in haemodialysis patients may lead to the appearance of non-transferrin
bound iron which can catalyse oxidative damage. We investigated this hypothesis by monitoring the oxidative stress of haemodialysis
patients and the impact of iron and diabetes mellitus herein. Materials and methods: Baseline values of serum iron and related proteins, transferrin glycation, non-transferrin bound iron, antioxidant capacity
and lipid peroxidation (malondialdehyde) of 11 haemodialysis patients (six non-diabetic and five type 2 diabetes) were compared
to those of non-haemodialysis control subjects (non-diabetic and type 2 diabetes). Changes in these parameters were monitored
during haemodialysis before and after iron administration. Results: Baseline values of malondialdehyde correlated with ferritin concentration (r = 0.664, P = 0.036) and were elevated to the same extent in non-diabetic and diabetic haemodialysis patients (median of 1.09 compared
to 0.60 μmol/l in control persons, P < 0.02). After iron infusion, transferrin saturation increased more markedly in non-diabetic subjects from 28% to 185% vs.
from 33% to 101% in diabetic patients (P = 0.008). This increase was accompanied by the appearance of non-transferrin bound iron (5.91 ± 1.33 μmol/l), a loss in plasma
iron-binding antioxidant capacity and a further increase in malondialdehyde which was more pronounced in diabetic patients
(from 0.93 ± 0.30 μmol/l to 2.21 ± 0.69 μmol/l vs. from 1.21 ± 0.42 μmol/l to 1.86 ± 0.56 μmol/l in the non-diabetic subjects,
P = 0.046). Conclusions: In haemodialysis patients, higher lipid peroxidation is determined by higher body iron stores. The increase induced by iron
infusion is accompanied by a loss in iron-binding antioxidant capacity and is more pronounced in diabetes mellitus. 相似文献
8.
Metabolic hotspots at land–water interfaces are important in supporting biogeochemical processes. Here we confirm the generality
of land–aquatic interfaces as biogeochemical hot spots by extending this concept to marine beach cast materials. In situ atmospheric
pCO2, from a respiration chamber (10 cm in diameter and 20 cm high) inserted into wrack deposits, was determined using a high-precision
(±1 ppm) non-dispersive infrared gas analyzer (EGM-4, PP-systems) at 1 minute recording intervals. The wrack deposits supported
high metabolic activities, with CO2 fluxes averaging (±SE) 6.62 ± 0.88 μmol C m−2 s−1, compared to median value of 0.98 μmol C m−2 s−1 (mean 2.21 ± 1.25 μmol C m−2 s−1) for bare sand adjacent to deposits. Wrack metabolic rates ranged 40-fold across beaches, from a minimum of 0.57 ± 0.22 μmol
C m−2 s−1 to a maximum of 20.8 ± 5.04 μmol C m−2 s−1, both derived from beaches with deposits dominated by Sargassum. Rates tended to increase significantly (F test, P < 0.05) from the shoreline to reach maximum rates at about 10 m from the shoreline, declining sharply further from the shoreline,
and increased with increasing thickness of the deposits (maximum about 10 cm deep), declining for thicker deposits. Wrack
differing in composition had similar metabolic rates, although deposits consisting of a mixture of seagrass and algae tended
to show somewhat higher rates. Our results show a meter square of wrack deposit supports a metabolic rate equivalent to that
supported by 3 m2 of living seagrass or macroalgal habitat. In wrack, the marine environment provides organic material and moisture and the
land environment provides oxygen to render wrack ecosystems an efficient metabolic reactor. Intense wrack metabolism should
also be conducive to organismal growth by supporting the development of a cryptic, but diverse wrack-based food web. 相似文献
9.
Tubek S 《Biological trace element research》2006,114(1-3):127-133
Increased or unchanged urinary zinc excretion has been reported in hypertension. In the present article, this observation
was confirmed in a group of 10 untreated hypertensive patients of both sexes that had no diabetes or obesity. The 24-h zinc
excretion was significantly different between the patients: 7.46±3.01 μmol and healthy controls: 5.19±2.19 μmol (p<0.025). After a 1-mo treatment with 4 mg perindopril per day, a decrease of urinary zinc was observed until it reached levels
not significantly different from those of the healthy controls (5.98±2.13 μmol). The decrease was significantly different
from that of the pretreatment values (p<0.05). 相似文献
10.
M. Torras-Llort R. Ferrer J.F. Soriano-García M. Moretó 《The Journal of membrane biology》1996,152(3):183-193
The properties of l-lysine transport in chicken jejunum have been studied in brush border membrane vesicles isolated from 6-wk-old birds. l-lysine uptake was found to occur within an osmotically active space with significant binding to the membrane. The vesicles
can accumulate l-lysine against a concentration gradient, by a membrane potential-sensitive mechanism. The kinetics of l-lysine transport were described by two saturable processes: first, a high affinity-transport system (K
mA= 2.4 ± 0.7 μmol/L) which recognizes cationic and also neutral amino acids with similar affinity in the presence or absence
of Na+ (l-methionine inhibition constant KiA, NaSCN = 21.0 ± 8.7 μmol/L and KSCN = 55.0 ± 8.4 μmol/L); second, a low-affinity transport mechanism (KmB= 164.0 ± 13.0 μmol/L) which also recognizes neutral amino acids. This latter system shows a higher affinity in the presence
of Na+ (KiB for l-methionine, NaSCN = 1.7 ± 0.3 and KSCN = 3.4 ± 0.9 mmol/L). l-lysine influx was significantly reduced with N-ethylmaleimide (0.5 mmol/L) treatment. Accelerative exchange of extravesicular labeled l-lysine was demonstrated in vesicles preloaded with 1 mmol/L l-lysine, l-arginine or l-methionine. Results support the view that l-lysine is transported in the chicken jejunum by two transport systems, A and B, with properties similar to those described
for systems b
0,+ and y+, respectively.
Received: 14 August 1995/Revised: 2 April 1996 相似文献
11.
Effect of carbon source on compost nitrogen and carbon losses 总被引:32,自引:0,他引:32
The effect of C source on N losses by volatilization during composting was measured using four bulking agents, each at three humidity levels and composted in duplicate under passive and active aeration. The bulking agents were pine shavings alone and corrected with soybean, chopped grass hay alone and corrected with urea, long (unchopped) wheat straw and chopped oat straw. The readily available C of each bulking agent was determined by analyzing for BOD5. In 105 l laboratory vessels, the bulking agents were mixed with liquid swine manure and tap water for a C/N of 20 and three humidity levels of 60%, 65% and 70%. While being aerated actively or passively, the mixtures were composted for 21 days. Their initial and final C and N contents were measured to conduct a mass balance analysis and calculate C and N losses. C and N losses were compared to bulking agent BOD5. N losses were compared to C losses. The humidity level and aeration regime had no effect on C and N losses but the N losses were correlated to C losses and only the C losses could be correlated to the BOD5 of the bulking agent. Thus, the N losses are related not only to the availability of C but also to the extent of composting. A relationship established between N and C losses indicated that 85% of the initial total N of the compost was available for microbial degradation and that 70% of the available C was lost as CO2 during the immobilization process. 相似文献
12.
The effects of temperature (20, 24 and 28 °C) and irradiance (15 and 40 μmol photon m−2 s−1) on the nitrate and ammonium uptake rates of the subtropical red alga, Laurencia brongniartii, were investigated to prepare for tank cultivation. Nitrate uptake followed saturation kinetics and was faster at higher
irradiances and temperatures. In contrast, ammonium uptake was linear over the experimental range and was not affected by
an increase in temperature. A parameter, β, was calculated to compare substrate uptake rates of nitrate along the linear portion
of the uptake curve with that of ammonium. For nitrate, β was lower at low irradiance and higher at high irradiance (β = 0.007
± 0.003 and 0.030 ± 0.002 [μmol N L−1 (μmol N gww−1 d−)−1], respectively). However, β was 0.023 ± 0.002 and 0.034 ± 0.002 [μmol N L−1 (μmol N gww−1 d−1)−1] for ammonium, suggesting a preference for ammonium over nitrate. 相似文献
13.
Helena Ceretti Diana Vullo Anita Zalts Silvana Ramírez 《World journal of microbiology & biotechnology》2010,26(5):847-853
The aim of this study was to evaluate complexing capacity (CC) accompanying microbial growth in a metal supplemented culture
medium. A combined strategy of square wave anodic stripping voltammetry (SWASV) monitored titration and ion-exchange resins
treatment (Chelex 100) has been applied. Culture medium, supplemented with Cd(II) in excess to ligands, was inoculated with
an indigenous bacterial culture; total ligand concentration and stability constants were determined at different bacterial
growth stages. As far as known, determination of CC in such conditions has not been reported (usually ligands in natural or
wastewaters exceed metal concentration). HIDA, (N-(2-hydroxyethyl)iminodiacetic acid), was used as a model ligand to mimic
soluble products derived from the resin treatment and bacterial metabolism. Ligand concentration, Lt (1.3 ± 0.1 μM), and the
conditional stability constant, K′, (log K′ = 5.7 ± 0.2) were in good agreement with expected values (1.0 ± 0.1 μM and log K′ = 6.1). In the supplemented culture medium, total ligand concentration in the micromolar range (60–80 μM) and conditional
stability constants (5.5 < log K′ < 6.5) were determined. Cd(II) complexes detected in the different stages of microbial growth are labile from an electrochemical
point of view. Results were compared to the case of Cd(II) non-supplemented broth. 相似文献
14.
In this work, the effect of different inducing factors on trans-resveratrol extracellular production in Monastrell grapevine suspension cultured cells is evaluated. A detailed analysis
provides the optimal concentrations of cyclodextrins, methyljasmonate and UV irradiation dosage, optimal cell density, elicitation
time and sucrose content in the culture media. The results indicate that trans-resveratrol production decreases as the initial cell density increases for a constant elicitor concentration in Monastrell
suspension cultured cells treated with cyclodextrins individually or in combination with methyljasmonate; the decrease observed
in cell cultures elicited with cyclodextrins alone is far more drastic than those observed in the combined treatment. trans-Resveratrol extracellular production observed by the joint use of cyclodextrins and methyljasmonate (1,447.8 ± 60.4 μmol
trans-resveratrol g−1 dry weight) is lower when these chemical compounds are combined with UV light short exposure (669.9 ± 45.2 μmol trans-resveratrol g−1 dry weight). Likewise, trans-resveratrol production is dependent on levels of sucrose in the elicitation medium with the maximal levels observed with
20 g l−1 sucrose and the joint action of cyclodextrins and 100 μM methyljasmonate. The sucrose concentration did not seem to limit
the process although it affects significantly the specific productivity since the lowest sucrose concentration is 10 g l−1, the highest productivity is reached (100.7 ± 5.8 μmol trans-resveratrol g−1 dry weight g−1 sucrose) using cyclodextrins and 25 μM methyljasmonate. 相似文献
15.
The relationship between net photosynthetic (P
N) and leaf respiration (R) rates of Quercus ilex, Phillyrea latifolia, Myrtus communis, Arbutus unedo, and Cistus incanus was monitored in the period February 2006 to February 2007. The species investigated had low R and P
N during winter, increasing from March to May, when mean air temperature reached 19.2 °C. During the favourable period, C. incanus and A. unedo had a higher mean P
N (16.4±2.4 μmol m−2 s−1) than P. latifolia, Q. ilex, and M. communis (10.0±1.3 μmol m−2 s−1). The highest R (1.89±0.30 μmol m−2 s−1, mean of the species), associated to a significant P
N decrease (62 % of the maximum, mean value of the species), was measured in July (mean R/P
N ratio 0.447±0.091). Q10, indicating the respiration sensitivity to short-term temperature increase, was in the range 1.49 to 2.21. Global change
might modify R/P
N determining differences in dry matter accumulation among the species, and Q. ilex and P. latifolia might be the most favoured species by their ability to maintain sufficiently higher P
N and lower R during stress periods. 相似文献
16.
M. V. Karanova A. A. Andreev 《Journal of Evolutionary Biochemistry and Physiology》2010,46(4):335-340
A peculiarity of amino acid profile of the cold-resistant freshwater shrimp Gammarus lacustris in the beginning of autumn is a high level of ornithine, the second after alanine (17.0 ± 1.4 and 22.6 ± 1.4 μmol/ml of homogenate,
respectively). The amount of alanine and ornithine accounts for 39.8% of the total pool of free amino acids and together with
lysine and leucine—55%. Free glucose is the major reducing sugar (6.42 ± 0.78 μmol/ml). 相似文献
17.
The relationships between dark respiration rate (R
D) and net photosynthetic rate (P
N) in Quercus ilex L. shrubs growing at the Botanical Garden in Rome were analysed. Correlation analysis of the data sets collected in the year
2006 confirmed the dependence among the considered leaf traits, in particular, R
D was significantly (p<0.05) correlated with P
N (r = 0.40). R
D and P
N increased from March to May [1.40±0.10 and 10.1±1.8 μmol(CO2) m−2 s−1 mean values of the period, respectively], when air temperature was in the range 14.8–25.2 °C, underlining the highest metabolic
activity in the period of the maximum vegetative activity that favoured biomass accumulation. On the contrary, the highest
R
D [1.60±0.02 μmol(CO2) m−2 s−1], associated to the lowest P
N rates (44 % of the maximum) and carbon use efficiency (CUE) in July underlined the mobilization of stored material during
drought stress by a higher air temperature (32.7 °C). 相似文献
18.
Chukwudi O. Onwosi Frederick John C. Odibo Charles K. Enebechi Amechi S. Nwankwegu Adrian I. Ikele Okeh C. Okeh 《Soil & Sediment Contamination》2017,26(4):438-456
Herein, we conducted a study toward understanding the impact of composting of the diesel-contaminated soil with some locally available bulking agents (rice husks (RHs), sawdust (SD), and wood chips (WCs)). In order to ascertain the effectiveness of petroleum degradation by the process assayed, we compared the protocols with monitored natural attenuation (MNA). The overall degradation pattern was modeled with non-linear regression by comparing the experimental data with first and second-order kinetic equations. At the end of the six-week study, the amount of total petroleum hydrocarbon removed from contaminated soil was 98.26 ± 1.33% (amendment with SD + RHs + WCs), 96.89 ± 1.20 (RHs amendment), 96.55 ± 1.29% (amendment with SD), 90.01 ± 0.22% (WCs amendment), and 85.02 ± 0.21% (MNA). The degradation of TPH trends followed a second-order kinetic model for all the four compost treatments while the MNA was found to follow a first-order (slower) degradation pattern. In general, the results of the parameter estimate showed that amendment with mixture of the three bulking agents was 1.08 (8%) slower (k2 = (1.289 ± 0.16) × 10?5 (g mg?1 d?1), r2 = 0.991) than SD amendment alone (k2 = (1.392 ± 0.14) × 10?5 (g mg?1 d?1), r2 = 0.995). However, the mixture of the bulking agents was found to be 1.67, 1.41, and 2.4 times faster than amendments with WCs, rice, and MNA, respectively. The phytotoxicity test revealed that all the compost treatments except WCs resulted in germination index of ≥80% after six weeks of bioremediation tests. The outcome of the current investigation confirms the effectiveness of bulking agents (especially when combined) in the supply of nutrients for the bioremediation of diesel-impacted soil. 相似文献
19.
Byung Yeoup Chung Jae-Young Cho Seung Sik Lee Yoshiharu Nishiyama Yuji Matsumoto Kenji liyama 《Journal of Plant Biology》2008,51(2):139-144
Tracheary elements (TEs) were physically separated from the hulls of cacao pods(Theobroma cacao L). Their morphological features were extensively investigated with scanning electron microscopy and chemical characterization.
Spiral TEs were covered with a thin layer of primary wall that had a web-like structure on its outer surface. These TEs had
a spiral circularity diameter of 8.2 ± 0.6 μm and an estimated secondary wall thickness of about 2.1 ± 0.2 μm. Polarized microscopy
analysis revealed that the cellulose microfibrils were aligned parallel to that thickening. Lignin content was 36.1%, with
a 0.13:1.00 molar ratio of syringyl to guaiacyl units and a 1.09:1.00 molar ratio of erythronic acid and threonic acid. Total
yields of the alkaline nitrobenzene oxidation and ozonation products were 324.5 and 148.8 μmol g-1 of extract-free TEs, respectively. Based on these morphological and lignin characteristics, we conclude that fully ripened
cacao hulls exhibit the same features of secondary wall thickening as those seen at an earlier stage. 相似文献
20.
M. Schütz Christof Klughammer Christoph Griesbeck Armin Quentmeier Cornelius G. Friedrich Günter Hauska 《Archives of microbiology》1998,170(5):353-360
Reduction of exogenous ubiquinone and of cytochromes by sulfide in membranes of the chemotrophic bacterium Paracoccus denitrificans GB17 was studied. For sulfide-ubiquinone reductase activity, K
m values of 26 ± 4 and 3.1 ± 0.6 μM were determined from titrations with sulfide and decyl-ubiquinone, respectively. A maximal
rate of up to 0.3 μmol decyl-ubiquinone reduced (mg protein)–1 min–1 was estimated. The reaction was sensitive to quinone-analogous inhibitors, but insensitive to cyanide. Reduction of cytochromes
by sulfide was monitored with an LED-array spectrophotometer. Under oxic conditions, reduction rates and extents of reduction
were lower than those under anoxic conditions. Reoxidation of cytochromes was oxygen-dependent and cyanide-sensitive. The
multiphasic behavior of transient reduction of cytochrome b with limiting amounts of sulfide reflects that sulfide, in addition to acting as an electron donor, is a slowly binding inhibitor
of cytochrome c oxidase. The initial peak of cytochrome b reduction is dependent on electron flow to an oxidant, either oxygen or ferricyanide, and is stimulated by antimycin A. This
oxidant-induced reduction of cytochrome b suggests that electron transport from sulfide in P. denitrificans GB17 employs the cytochrome bc
1 complex via the quinone pool.
Received: 8 April 1998 / Accepted: 29 July 1998 相似文献