Sorption of Cadmium and its Effect on Growth and the Utilization of Inorganic Carbon and Phosphorus of Two Freshwater Diatoms

1979 ◽  
Vol 36 (5) ◽  
pp. 579-586 ◽  
Author(s):  
H. Lee Conway ◽  
Susan C. Williams
Keyword(s):  
Growth Rate ◽  
Inorganic Carbon ◽  
Cadmium Toxicity ◽  
Cadmium Concentration ◽  
Cadmium Content ◽  
Site Location ◽  
Key Words Cadmium ◽  
Asterionella Formosa ◽  
Freshwater Diatoms ◽  
Fragilaria Crotonensis

Cadmium was rapidly sorbed by Asterionella formosa and Fragilaria crotonensis during the first 5–10 min of exposure (0.05 to ~9 μg Cd∙L−1), followed by a hyperbolic increase in the cellular cadmium content as a function of time. Results obtained from experiments conducted in the light and dark, experiments using live and dead populations, and cellular site location studies imply that the sorption of cadmium by A. formosa is partially an active process, but for F. crotonensis it appears to be passive. Populations of A. formosa exhibited a corresponding decrease in the growth rate as the ambient cadmium concentration was increased from ~2 to ~9 μg∙L−1. In contrast, the growth rate of F. crotonensis was unaffected at levels ranging from ~0.05 to ~9 μg Cd∙L−1. The utilization of inorganic carbon by A. formosa was unaffected at ~4 μg Cd∙L−1, but reduced 45% at ~9 μg Cd∙L−1. The utilization rates of carbon and phosphorus by F. crotonensis were reduced at the lower cadmium concentrations and enhanced at the highest. Key words: cadmium, toxicity, sorption, diatom, Asterionella formosa, Fragilaria crotonensis

A cadmium-tolerant strain of Neocosmospora vasinfecta shows reduced cadmium influx

1991 ◽  
Vol 69 (6) ◽  
pp. 1296-1301 ◽  
Author(s):  
K. Budd
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Response ◽  
Specific Growth ◽  
Cadmium Toxicity ◽  
Recovery Phase ◽  
Growth Responses ◽  
Cadmium Level ◽  
Key Words Cadmium ◽  
Net Uptake

Neocosmospora vasinfecta was grown in a defined liquid medium and its growth responses to CdSO4 were measured. The specific growth rate of mycelium not previously exposed to cadmium was reduced to 50% by 51 μM cadmium. The growth response to concentrations of cadmium above 50 μM was complex, showing declining and then recovery phases. Inoculum taken from a culture grown to the recovery phase in presence of 100 μM cadmium was cadmium tolerant; a cadmium level of 420 μM was required to reduce its specific growth rate by 50%. Tolerance was not lost by growth in the absence of cadmium. The tolerant mycelium showed markedly reduced net uptake of cadmium as compared with the normal (cadmium sensitive) mycelium. This reduction was due to a decrease in the unidirectional influx of cadmium, with little or no change in efflux. Cadmium toxicity in the normal mycelium was strongly antagonized by calcium but only weakly by manganese or zinc. Calcium also inhibited the uptake of cadmium. Key words: cadmium, calcium, Neocosmospora, tolerance, toxicity, transport.

scholarly journals Genetic loci regulating cadmium content in rice grains

Euphytica ◽  
2021 ◽  
Vol 217 (3) ◽  
Author(s):  
Gareth J. Norton ◽  
Anthony Travis ◽  
Panthita Ruang-areerate ◽  
Graeme W. Nicol ◽  
Ayotunde A. Adeosun ◽  
...  
Keyword(s):  
Water Treatment ◽  
Water Regime ◽  
Field Experiments ◽  
Cadmium Concentration ◽  
Chromosome 9 ◽  
Chromosome 7 ◽  
Cadmium Content ◽  
Rice Grains ◽  
Water Treatments ◽  
Grain Cadmium

AbstractIt has been estimated that up to 90% of human exposure to cadmium is through food, and that cadmium within rice grains can be a major contributor to that dietary source. In this study genome wide association mapping was conducted on the Bengal and Assam Aus Panel (BAAP) of rice to identify quantitative trait loci and candidate genes for lowering grain cadmium. Field experiments were conducted over two years under two different irrigation systems: continually flooded and alternate wetting and drying (AWD). There was significant effects of water treatment, genotype, and genotype by water treatment interaction. Importantly, AWD increased grain cadmium, on average, by 49.6% and 108.8% in year 1 and 2 respectively. There was between 4.6 and 28 fold variation in cadmium concentration. A total of 58 QTLs were detected but no loci are clearly specific to one water regime despite approximately 20% of variation attributable to genotype by water regime interaction. A number of QTLs were consistent across most water treatments and years. These included QTLs on chromosome 7 (7.23–7.61, 8.93–9.04, and 29.12–29.14 Mbp), chromosome 5 (8.66–8.72 Mbp), and chromosome 9 (11.46–11.64 Mbp). Further analysis of the loci on chromosome 7 (8.93–9.04 Mbp), identified the candidate gene OsNRAMP1, where cultivars with a deletion upstream of the gene had higher concentrations of cadmium compared to the cultivars that did not have the deletion. The distribution of alleles within the BAAP suggest this QTL is easily detected in this population because it is composed of aus cultivars. Local genome cluster analysis suggest high Cd alleles are uncommon, but should be avoided in breeding.

scholarly journals Inorganic carbon uptake in a freshwater diatom, Asterionella formosa (Bacillariophyceae): from ecology to genomics

Phycologia ◽  
2021 ◽  
pp. 1-12
Author(s):  
Stephen C. Maberly ◽  
Brigitte Gontero ◽  
Carine Puppo ◽  
Adrien Villain ◽  
Ilenia Severi ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Carbon Uptake ◽  
Asterionella Formosa ◽  
Inorganic Carbon Uptake ◽  
Freshwater Diatom

scholarly journals Variability of leaf Cadmium content in tetraploid and hexaploid wheat

Genetika ◽  
2009 ◽  
Vol 41 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Marija Kraljevic-Balalic ◽  
Novica Mladenov ◽  
Igor Balalic ◽  
Miroslav Zoric
Keyword(s):  
Cadmium Concentration ◽  
Tetraploid Wheat ◽  
Anthropogenic Sources ◽  
Cadmium Content ◽  
Atomic Absorption Spectrometer ◽  
Wheat Cultivars ◽  
Mean Values ◽  
The Mean ◽  
Heading Stage ◽  
Absorption Spectrometer

Cadmium (Cd) is a toxic trace metal pollutant for humans, animals, and plants. It is a heavy metal present in soils from natural and anthropogenic sources. Much of the Cd taken up by plants is retained in the root, but a portion is translocated to the aerial portions of the plant and into the seed. The objective of this research was to determine the variability and diversity of Cd content in the leaves of 30 wheat cultivars with different ploidy level, during two years. Analyses of Cd content (ppm) in the leaves at heading stage were performed with an atomic absorption spectrometer (AAS). Significant differences between the mean values of the genotypes in Cd content were found. Tetraploid wheat genotypes had higher Cd content than hexaploid genotypes. Cd content was predominantly influenced by the year of growing (73%). The influence of genotype on Cd content amounted 16% and the interaction genotype ? year 11%. The cluster of the genotypes consists of four groups. In the groups three and four were some of the genotypes (Kalyan Sona, Partizanka and NS Rana 5) with lowest Cd content in the leaves. They could be chosen as parents in the hybridization for lower cadmium concentration.

scholarly journals Sources of Carbon to Deep-Sea Corals

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 533-543 ◽  
Author(s):  
Sheila Griffin ◽  
Ellen R M Druffel
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Deep Sea ◽  
Inorganic Carbon ◽  
Sea Water ◽  
Dissolved Inorganic Carbon ◽  
Growth Rings ◽  
Time Histories ◽  
Visible Growth ◽  
Deep Sea Corals

Radiocarbon measurements in deep-sea corals from the Little Bahama Bank were used to determine the source of carbon to the skeletal matrices. Specimens of Lophelia, Gerardia, Paragorgia johnsoni and Corallium noibe were sectioned according to visible growth rings and/or stem diameter. We determined that the source of carbon to the corals accreting organic matter was primarily from surface-derived sources. Those corals that accrete a calcerous skeleton were found to obtain their carbon solely from dissolved inorganic carbon (DIC) in sea water from the depth at which the corals grew. These results, in conjunction with growth-rate studies using short-lived radioisotopes, support the use of deep-sea corals to reconstruct time histories of transient and non-transient tracers at depth in the oceans.

Impacts of UV radiation on growth and photosynthetic carbon acquisition in Gracilaria lemaneiformis (Rhodophyta) under phosphorus-limited and replete conditions

2009 ◽  
Vol 36 (12) ◽  
pp. 1057 ◽  
Author(s):  
Zhiguang Xu ◽  
Kunshan Gao
Keyword(s):  
Growth Rate ◽  
Carbonic Anhydrase ◽  
Photosynthetic Efficiency ◽  
Inorganic Carbon ◽  
Inorganic Phosphorus ◽  
Gracilaria Lemaneiformis ◽  
Solar Ultraviolet Radiation ◽  
Relative Growth ◽  
Photosynthetic Carbon ◽  
Solar Ultraviolet

Solar ultraviolet radiation (UVR, 280–400 nm) is known to negatively affect macroalgal growth and photosynthesis, while phosphorus availability may affect their sensitivity to UVR. Here, we show that UV-A enhanced the growth rate of the red macroalga, Gracilaria lemaneiformis Bory de Saint-Vincent under inorganic phosphorus (Pi)-replete but reduced it under Pi-limited conditions. Maximal net photosynthetic rates were significantly reduced by both UV-A and UV-B, but the apparent photosynthetic efficiency was enhanced in the presence of UV-A. The UV-induced inhibition was exacerbated under Pi-limited conditions. The activity of total carbonic anhydrase was enhanced and the photosynthetic affinity for exogenous inorganic carbon (Ci) was raised for thalli grown in the presence of UVR under both Pi-replete and Pi-limited conditions. The relative growth rate was closely related to Ci acquisition capability (Vmax/KDIC), which was enhanced by UVR exposure under Pi-replete but not significantly affected under Pi-limited conditions.

Characterization of Cadmium-Resistant Bacteria and Their Application for Cadmium Bioremediation

2009 ◽  
Author(s):  
Surasak Siripornadulsil ◽  
Wilailak Siripornadulsil
Keyword(s):  
Metal Pollution ◽  
Binding Capacity ◽  
Cadmium Concentration ◽  
Resistant Bacteria ◽  
Cadmium Content ◽  
Bacterial Cells ◽  
Edge Structure ◽  
Rice Field Soil ◽  
16S Rdna Sequence Analysis ◽  
Toxic Concentrations

On a global basis, trace-metal pollution is one of the most pervasive environmental problems. It is particularly difficult to prevent or clean up because the metals are toxic in their elemental form and cannot be decomposed. Bioremediation has been shown to be a powerful system for heavy metal pollution clean up and prevention. In this work, we characterized the cadmium (Cd)-resistant bacteria isolated from rice field soil downstream from zinc (Zn) mineralized area which the owners were contaminated at high level of cadmium content in their blood (>10 μgCd/g creatinine). We found that all 24 isolated bacteria tolerated toxic Cd concentrations (2,500 μM). In order to determine whether the Cd toxicity affected the growth of isolated bacteria, we grew the isolated bacterial cells in the absence and presence of toxic concentrations of CdCl2 (500 μM). In the absence of Cd, all isolated bacterial cells grew slightly better than in the presence of toxic concentrations of Cd. In addition, the Cd binding capacity of all isolated bacteria were very high, ranging from 6.38 to 9.38 log[Cd(atom)]/cell when grown in the presence of 500 μM CdCl2. Furthermore, the stability of Cd-bacteria complex of all isolated bacteria was affected by 1mM EDTA. When grown in the presence of 500 μM CdCl2, Cd-resistant isolates S2500-6, -8, -9, -15, -17, -18, -19, and -22 increasingly produced proteins containing cysteine (SH-group) (from 1.3 to 2.2 times) as well as 11 isolates of Cd-resistant bacteria, including S2500-1, -2, -3, -5, -6, -8, -9, -11, -16, -20, and -21, increasingly produced inorganic sulfide (1.5 to 4.7 times). Furthermore, the Sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy studies indicated that Cd-resistant isolated S2500-3 precipitated amounts of cadmium sulfide (CdS), when grown in the presence of 500 μM CdCl2. The results suggested that these Cd-resistant bacteria have potential ability to precipitate a toxic soluble CdCl2 as nontoxic insoluble CdS. Interestingly, Cd-resistant bacteria isolated S2500-3, -8, -9,and -20 increased cadmium tolerance of Thai jasmine rice (Kao Hom Mali 105) when grown in the presence of 200 μM CdCl2. These 4 isolates also decreased cadmium concentration accumulation in Kao Hom Mali 105 plant at 61, 9, 6, and 17%, respectively when grown in the presence of 200 μM CdCl2. They were identified by 16S rDNA sequence analysis and classified as Cupriavidus taiwanensis (isolate S2500-3) and Pseudomonas aeruginosa (isolates S2500-8, -9, and -20).

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