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1.
The growth rate of a highly CO 2‐tolerant green alga, Chlorococcum littorale, was investigated in semi‐batch cultures at a temperature of 22°C, a light intensity of 170 μmol‐photon m ?2 s ?1 and CO 2 concentrations ranging from 1 to 50% (v/v) at atmospheric pressure. In the experiments, solutions were bubbled with CO 2 and N 2 gas mixtures to adjust CO 2 concentrations to minimize the influence of O 2. Growth rate, which was defined in terms of a specific growth rate μ, decreased with increasing CO 2 concentration at the conditions studied. The inhibition of growth by CO 2 gas could be attributed to the concentration of inorganic carbon in the culture medium. A growth model is proposed where key assumptions are the formation of bicarbonate ion HCO as substrate for algal growth and equilibrium between CO 2 inhibitor. The proposed growth model based on the Monod equation agreed with the experimental data to within 5% and provides better correlation than the conventional inhibition model, especially in the high CO 2 concentration region. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献
2.
Soybeans were grown at three CO 2 concentrations in outdoor growth chambers and at two concentrations in controlled-environment growth chambers to investigate the interactive effects of CO 2, temperature and leaf-to-air vapour pressure difference (LAVPD) on stomatal conductance. The decline in stomatal conductance with CO 2 was a function of both leaf temperature and LAVPD. In the field measurements, stomatal conductance was more sensitive to LAVPD at low CO 2 at 30 °C but not at 35 °C. There was also a direct increase in conductance with temperature, which was greater at the two elevated carbon dioxide concentrations. Environmental growth chamber results showed that the relative stomatal sensitivity to LAVPD decreased with both leaf temperature and CO 2. Measurements in the environmental growth chamber were also performed at the opposing CO 2, and these experiments indicate that the stomatal sensitivity to LAVPD was determined more by growth CO 2 than by measurement CO 2. Two models that describe stomatal responses to LAVPD were compared with the outdoor data to evaluate whether these models described adequately the interactive effects of CO 2, LAVPD and temperature. 相似文献
3.
Summary The effect of dissolved carbon dioxide concentration in the anaerobic growth of Escherichia coli was investigated. E. coli was grown anaerobically with the dissolved CO 2 concentration controlled over the range from 8x10 -6 M to 3.7x10 -2 M in the liquid phase. The maximum specific growth rate was 0.75h -1 at 1.3x10 -3 M CO 2 and the maximum yield of cells on glucose was 0.32 at 1.75x10 -4 M CO 2. The maximum specific growth rate occurs close to the concentration of CO 2 prevalent in the mammalian gut where E. coli naturally resides.Alberta Research Council contribution, paper 1364 相似文献
4.
Soybean plants were grown continuously at 350 and 700cm 3m ?3 CO 2 at constant temperature. Respiration rates of third trifoliolate leaves were measured at the growth CO 2 concentration for the whole dark period from 5d before through to 5d after full area expansion. The short-term response of respiration rate to the measurement CO 2 concentration was also determined at each age. Respiration rates per unit of dry mass declined with age and were significantly less at a given age or RGR in leaves grown and measured at the elevated CO 2. The difference in respiration rate was largest in mature leaves and resulted from the different measurement CO 2 concentrations. The respiratory costs of the tissue synthesis, estimated from the elemental composition of the tissue, did not differ substantially between CO 2 treatments. The response of respiration rate to carbon dioxide concentration was not strongly affected by the form of nitrogen supplied. Maintenance respiration calculated by subtracting growth respiration from total respiration was negative in rapidly growing leaves for both CO 2 treatments. This indicates that CO 2 efflux in the dark does not accurately reflect the average 24 h rate of energy expenditure on growth and maintenance for soybean leaves. 相似文献
5.
Rising atmospheric carbon dioxide concentration ([CO 2]) significantly influences plant growth, development, and biomass. Increased photosynthesis rate, together with lower stomatal conductance, has been identified as the key factors that stimulate plant growth at elevated [CO 2] (e[CO 2]). However, variations in photosynthesis and stomatal conductance alone cannot fully explain the dynamic changes in plant growth. Stimulation of photosynthesis at e[CO 2] is always associated with post‐photosynthetic secondary metabolic processes that include carbon and nitrogen metabolism, cell cycle functions, and hormonal regulation. Most studies have focused on photosynthesis and stomatal conductance in response to e[CO 2], despite the emerging evidence of e[CO 2]'s role in moderating secondary metabolism in plants. In this review, we briefly discuss the effects of e[CO 2] on photosynthesis and stomatal conductance and then focus on the changes in other cellular mechanisms and growth processes at e[CO 2] in relation to plant growth and development. Finally, knowledge gaps in understanding plant growth responses to e[CO 2] have been identified with the aim of improving crop productivity under a CO 2 rich atmosphere. 相似文献
6.
The influence of ethylene and CO 2 on pollen germination and tube growth was investigated employing ventilated culture systems. Ethylene had no effect on pollen germinability or tube growth. Germinating pollen did not produce a detectable amount of ethylene (less than 0.1 nl/g·hr). Supplementing the cultures with CO 2 caused a marked increase in germination and tube growth. The half-maximal response for germination was less than 0.5%. CO 2 levels ranging from 1.08 to 2.22% were found in the internal cavity of lily styles. CO 2 derived from stylar metabolism may, therefore, modulate pollen tube growth thus integrating the events leading to fertilization. 相似文献
7.
Effects of rising atmospheric CO 2 concentrations on gas exchange, growth and productivity were investigated on an important grassland species, Trifolium repens L. cv. Blanca. Pure stands of this species were cultivated over an entire growing season in small acrylic greenhouses with an artificial atmosphere of ±367 or ±620 ppm CO 2, respectively. Effects on growth and development were examined in a functional growth analysis, while consequences for gas exchange were determined by photosynthesis and transpiration measurements on canopy level. The stands were regularly clipped for production assessment. Canopies grown at high CO 2 levels showed an average increase in productivity of almost 75%. Growth analysis indicated development of a larger foliage area as the major cause, particularly in the first days of regrowth after cutting. The growth advantage that began in this stage was maintained or bettered during the following weeks. The difference between gas exchange measurements expressed per unit leaf area and per unit ground area suggested that changes in net photosynthesis and respiration did not contribute to the increase in total yield. Transpiration declined under high CO 2 if expressed on a leaf area basis but total canopy transpiration was at least as large as in ambient CO 2 due to the larger leaf area. Water-use efficiency calculations on the summer data indicated a 35% improvement with a doubling of CO 2 concentration. 相似文献
8.
The average atmospheric concentration of CO 2 will probably double before the end of next century. Many of the consequences for plant growth can and should be determined now. In this review the effects of [CO 2] on a variety of plant processes are summarized: stomatal opening and closing; stomatal density; respiration; root morphogenesis; and flowering. The effects of growth under elevated [CO 2] on crop yield and seed composition are also discussed. Adverse effects on the composition of C 3 cereal grains are clearly indicated. 相似文献
9.
Butyribacterium methylotrophicum, an anaerobic acetogen, obligately required pantothenate for growth on either glucose, CH 3OH?CO 2, H 2?CO 2, or carbon monoxide. Growth on glucose but not single carbon substrates was stimulated by lipoate and biotin. Sulfide but not sulfate served as the sole sulfur source for growth. This study established that B. methylotrophicum was both a true autotroph when grown on H 2?CO 2 and a unicarbonotroph on CO as the sole carbon and energy source. In addition, the vitamin requirements of this species further suggest its distinctiveness from Eubacterium limosum (Butyribacterium rettgeri). 相似文献
10.
By increasing water use efficiency and carbon assimilation, increasing atmospheric CO 2 concentrations could potentially improve plant productivity and growth at high salinities. To assess the effect of elevated CO 2 on the salinity response of a woody halophyte, we grew seedlings of the mangrove Avicennia germinans under a combination of five salinity treatments [from 5 to 65 parts per thousand (ppt)] and three CO 2 concentrations (280, 400 and 800 ppm). We measured survivorship, growth rate, photosynthetic gas exchange, root architecture and foliar nutrient and ion concentrations. The salinity optima for growth shifted higher with increasing concentrations of CO 2, from 0 ppt at 280 ppm to 35 ppt at 800 ppm. At optimal salinity conditions, carbon assimilation rates were significantly higher under elevated CO 2 concentrations. However, at salinities above the salinity optima, salinity had an expected negative effect on mangrove growth and carbon assimilation, which was not alleviated by elevated CO 2, despite a significant improvement in photosynthetic water use efficiency. This is likely due to non‐stomatal limitations to growth at high salinities, as indicated by our measurements of foliar ion concentrations that show a displacement of K + by Na + at elevated salinities that is not affected by CO 2. The observed shift in the optimal salinity for growth with increasing CO 2 concentrations changes the fundamental niche of this species and could have significant effects on future mangrove distribution patterns and interspecific interactions. 相似文献
11.
Growth in relation to CO 2-depletion and CO 2-enrichment was investigated for the freshwater diatoms Asterionella formosa and Fragilaria crotonensis in batch cultures. Algal concentration and pH were measured during growth cycles, and inorganic carbon quantities determined by potentiometric Gran titrations and from pH-alkalinity relationships. After the primary growth with CO 2-depletion and pH increase, successive CO 2-enrichments induced further such cycles and produced a final three- to fivefold increase in algal biomass over that of unenriched controls. The extent of CO 2-depletion, and pH rise, was greater in later cycles, indicative of some cellular adaptation. Values of pH reached 9·7 for Asterionella and 9·9 for Fragilaria. The lowest residual quantities of free CO 2 were 0·1 and 0·03 μmol 1 -1 for Asterionella and Fragilaria respectively, which were less than 0·05% of the corresponding residual quantities of total CO 2. The primary limitation of CO 2-uptake and growth was probably related to the concentration of free CO 2, given the relative excess of other major nutrients (N, P, Si) in he media used. Limited of CO 2-uptake could be restored without CO 2 additions if the CO 2 present was redistributed between its several forms (increasing free CO 2) by the addition of strong acid, although growth was still restricted. Limitation of CO 2-uptake, either by CO 2-depletion or the addition of an inhibitor of photo-synthesis (DCMU), increased the sinking rate of Asterionella cells from 0·3 to 1 m day -1. The possible ecological implications of CO 2-pH-growth and CO 2-pH-buoyancy relationships are discussed, which may contribute to the frequent paucity of diatoms during summer in manv productive lakes. 相似文献
12.
Soybean ( Glycine max L. Merrill cv `Bragg') plants were grown in pots at six elevated atmospheric CO 2 concentrations and two watering regimes in open top field chambers to characterize leaf xylem potential, stomatal resistance and conductance, transpiration, and carbohydrate contents of the leaves in response to CO 2 enrichment and water stress conditions. Groups of plants at each CO 2 concentration were subjected to water stress by withholding irrigation for 4 days during the pod-filling stage. Under well watered conditions, the stomatal conductance of the plants decreased with increasing CO2 concentration. Therefore, although leaf area per plant was greater in the high CO2 treatments, the rate of water loss per plant decreased with CO2 enrichment. After 4 days without irrigation, plants in lower CO2 treatments showed greater leaf tissue damage, lower leaf water potential, and higher stomatal resistance than high CO2 plants. Stomatal closure occurred at lower leaf water potentials for the low CO2 grown plants than the high CO2 grown plants. Significantly greater starch concentrations were found in leaves of high CO2 plants, and the reductions in leaf starch and increases in soluble sugars due to water stress were greater for low CO2 plants. The results showed that even though greater growth was observed at high atmospheric CO2 concentrations, lower rates of water use delayed and, thereby, prevented the onset of severe water stress under conditions of low moisture availability. 相似文献
13.
Rising atmospheric carbon dioxide concentration ([CO 2]) has generated considerable interest in the response of agricultural crops to [CO 2]. The objectives of this study were to determine the effects of a wide range of daytime [CO 2] on dark respiration of rice ( Oryza sativa L. cv. IR-30). Rice plants were grown season-long in naturally sunlit plant growth chambers in subambient (160 and 250), ambient (330), or super-ambient (500, 660 and 900 μmol CO 2 mol ?1 air) [CO 2] treatments. Canopy dark respiration, expressed on a ground area basis (R d) increased with increasing [CO 2] treatment from 160 to 500 μmol mol ?1 treatments and was very similar among the superambient treatments. The trends in R d over time and in response to increasing daytime [CO 2] treatment were associated with and similar to trends previously described for photosynthesis. Specific respiration rate (R dw) decreased with time during the growing season and was higher in the subambient than the ambient and superambient [CO 2] treatments. This greater R dw in the subambient [CO 2] treatments was attributed to a higher specific maintenance respiration rate and was associated with higher plant tissue nitrogen concentration. 相似文献
14.
We studied seedling growth responses to ambient and elevated CO 2 (350 and 700 μL L ?1) of three maternal families of yellow birch ( Betula alleghaniensis), raised both individually and in high-density stands. Seedlings in competitive, dense stands exhibited markedly lower average CO 2-induced growth enhancements than individually grown plants (16% vs. 49%). Maternal families differed in their growth responses to elevated CO 2. However, differences among families were contingent upon density; families which exhibited the greatest CO 2-induced growth at low density exhibited the least CO 2-responsiveness at high density. These data are discussed in two separate contexts; the reliability of estimates of the CO 2 fertilization potential of forest species based solely on individually grown plants, and the potential evolutionary consequences of rising CO 2 on regenerating forest tree populations. 相似文献
15.
We evaluated the impacts of elevated CO 2 in a treeline ecosystem in the Swiss Alps in a 9-year free-air CO 2 enrichment (FACE) study. We present new data and synthesize plant and soil results from the entire experimental period. Light-saturated photosynthesis ( A max) of ca. 35-year-old Larix decidua and Pinus uncinata was stimulated by elevated CO 2 throughout the experiment. Slight down-regulation of photosynthesis in Pinus was consistent with starch accumulation in needle tissue. Above-ground growth responses differed between tree species, with a 33 % mean annual stimulation in Larix but no response in Pinus. Species-specific CO 2 responses also occurred for abundant dwarf shrub species in the understorey, where Vaccinium myrtillus showed a sustained shoot growth enhancement (+11 %) that was not apparent for Vaccinium gaultherioides or Empetrum hermaphroditum. Below ground, CO 2 enrichment did not stimulate fine root or mycorrhizal mycelium growth, but increased CO 2 effluxes from the soil (+24 %) indicated that enhanced C assimilation was partially offset by greater respiratory losses. The dissolved organic C (DOC) concentration in soil solutions was consistently higher under elevated CO 2 (+14 %), suggesting accelerated soil organic matter turnover. CO 2 enrichment hardly affected the C–N balance in plants and soil, with unaltered soil total or mineral N concentrations and little impact on plant leaf N concentration or the stable N isotope ratio. Sustained differences in plant species growth responses suggest future shifts in species composition with atmospheric change. Consistently increased C fixation, soil respiration and DOC production over 9 years of CO 2 enrichment provide clear evidence for accelerated C cycling with no apparent consequences on the N cycle in this treeline ecosystem. 相似文献
16.
The main goal of this study was to evaluate short-term interactions between increased CO 2, UVR and inorganic macronutrients (N, P and Si) on summer phytoplankton assemblages in the Ria Formosa coastal lagoon (SW Iberia), subjected to intense anthropogenic pressures and highly vulnerable to climate change. A multifactorial experiment using 20 different nutrient-enriched microcosms exposed to different spectral and CO 2 conditions was designed. Before and after a 24-h in situ incubation, phytoplankton abundance and composition were analysed. Impacts and interactive effects of high CO 2, UVR and nutrients varied among different functional groups. Increased UVR had negative effects on diatoms and cyanobacteria and positive effects on cryptophytes, whereas increased CO 2 inhibited cyanobacteria but increased cryptophyte growth. A positive synergistic interaction between CO 2 and UVR was observed for diatoms; high CO 2 counteracted the negative effects of UVR under ambient nutrient concentrations. Nutrient enrichments suppressed the negative effects of high CO 2 and UVR on cyanobacteria and diatoms, respectively. Beneficial effects of CO 2 were observed for diatoms and cryptophytes under combined additions of nitrate and ammonium, suggesting that growth may be limited by DIC availability when the primary limitation by nitrogen is alleviated. Beneficial effects of high CO 2 and UVR in diatoms were also induced or intensified by ammonium additions. 相似文献
17.
The effect of controlled carbon dioxide environment on in vitro shoot growth and multiplication in Feronia limonia (a tropical fruit plant, Family- Rutaceae) was studied. Carbon dioxide available in the ambient air of the growth room was
insufficient for in vitro growth of the shoots alone. Also, the presence of sucrose only as the C-source in the medium (without CO 2), was found to be inadequate for sustainable growth and multiplication of shoots. The carbon dioxide enrichment promoted
shoot multiplication and overall growth. The promotory effect of CO 2 was independent of the presence of sucrose in the medium. In the presence of both CO 2 and sucrose, an additive effect was observed producing maximum shoot growth. In the absence of sucrose a higher concentration
of CO 2 (10.0)g m −3 was required to achieve photoautotrophic shoot multiplication comparable to ambient air controls. Highest leaf area per shoot
cluster promoting shoot growth and multiplication was recorded under this treatment. Shoots growing on sucrose containing
medium under controlled CO 2 environment of 0.6 g m −3 concentration evoked better response than ambient air controls (shoots growing on sucrose containing medium) in growth room.
This treatment produced the overall best response. The present study highlighted the possibility of photoautotrophic multiplication
which might prove useful for successful hardening and acclimatization in tissue culture plants. 相似文献
18.
During growth of Acetobacterium woodii on fructose, glucose or lactate in a medium containing less than 0.04% bicarbonate, molecular hydrogen was evolved up to 0.1 mol per mol of substrate. Under an H 2-atmosphere growth of A. woodii with organic substrates was completely inhibited whereas under an H 2/CO 2-atmosphere rapid growth occurred. Under these conditions H 2+CO 2 and the organic substrate were utilized simultaneously indicating that A. woodii was able to grow mixotrophically.
Clostridium aceticum differed from A. woodii in that H 2 was only evolved in the stationary phase, that the inhibition by H 2 was observed at pH 8.5 but not at pH 7.5, anf that in the presence of fructose and H 2+CO 2 only fructose was utilized.The hydrogenase activity of fructose-grown cells of C. aceticum amounted to only 12% of that of H 2+CO 2-grown cells. With A. woodii a corresponding decrease of the activity of this enzyme was not observed. 相似文献
19.
Summary Growth parameters of Catharanthus roseus in suspension cultures were examined under various pCO 2 conditions. In CO 2-enriched environments (up to 2 %) for Erlenmeyer flask cultures, enhanced maximum growth rates and conversion yields were observed. Fermenter cultures with a constant pCO 2 of 2 %, gave high conversion yields although no growth-promoting activity was observed. High aeration rates led to decreased rates of growth due to CO 2 stripping. 相似文献
20.
Two strains of Methanosarcina (M. Barkeri strain MS, isolated from sewage sludge, and strain UBS, isolated from lake sediments) were found to have similar cellular properties and to have DNA base compositions of 44 mol percent guanosine plus cytosine. Strain MS was selected for further studies of its one-carbon metabolism. M. barkeri grew autotrophically via H 2 oxidation/CO 2 reduction. The optimum temperature for growth and methanogenesis was 37°C. H 2 oxidation proceeded via an F 420-dependent NADP +-linked hydrogenase. A maximum specific activity of hydrogenase in cell-free extracts, using methyl viologen as electron acceptor, was 6.0 mol min · mg protein at 37°C and the optimum pH (9.0). M. barkeri also fermented methanol andmethylamine as sole energy sources for growth. Cell yields during growth on H 2/CO 2 and on methanol were 6.4 and 7.2 mg cell dry weight per mmol CH 4 formed, respectively. During mixotrophic growth on H 2/CO 2 plus methanol, most methane was derived from methanol rather than from CO 2. Similar activities of hydrogenase were observed in cell-free extracts from H 2/CO 2-grown and methanol-grown cells. Methanol oxidation apparently proceeded via carrierbound intermediates, as no methylotrophy-type of methanol dehydrogenase activity was observed in cell-free extracts. During growth on methanol/CO 2, up to 48% of the cell carbon was derived from methanol indicating that equivalent amounts of cell carbon were derived from CO 2 and from an organic intermediate more reduced than CO 2. Cell-free extracts lacked activity for key cell carbon synthesis enzymes of the Calvin cycle, serine path, or hexulose path.Abbreviations CAPS
cycloaminopropane sulfonic acid
- CH 3-SCoM
methyl coenzyme M
- DCPIP
2,6-dichlorophenolindophenol
- DEAE
diethylaminoethyl
- dimethyl POPOP
1,4-bis-2-(4-mothyl-5-phenyloxazolyl)-benzene
- DNA
deoxyribonucleic acid
- dpm
dismtegrations per min
- DTT
dithiothreitol
- EDTA
ethylenediamine tetraacetic acid
- F 420
factor 420
- G+C
guanosine plus cytosine
- NAD +
nicotinamide adenine dinucleotide
- NADP +
nicotinamide adenine dinucleotide phosphate
- PBBW
phosphate buffered basal Weimer
- PMS
phenazine methosulfate
- PPO
2,5-diphenyloxazole
- rRNA
ribosomal ribonucleic acid
- RuBP
ribulose-1,5-bisphosphate
- Tris
tris-hydroxymethyl-aminomethane
- max
maximum specific growth rate 相似文献
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