Phosphorus Release Patterns and the Effects of Reproductive Stage and Ecdysis in Daphnia magna

1982 ◽  
Vol 39 (9) ◽  
pp. 1310-1314 ◽  
Author(s):  
Donald Scavia ◽  
Margaret J. McFarland

Rates of continuous phosphorus release by individual Daphnia magna (0.3 – 0.9 mg dry weight) were measured using high performance liquid chromatography components in conjunction with a specially designed incubation flow cell. Within the temporal resolution of the technique (3 min), phosphorus release often appeared pulsed rather than only steady. We found significant variation in release rates among the different stages of an individual's parthenogenetic reproductive cycle. Rates observed for animals carrying more mature embryos were lower than those earlier in the reproductive cycle. Rates of phosphorus release observed at and after ecdysis averaged 6.7 times higher than rates observed at other times.Key words: phosphorus, excretion, reproductive stage, ecdysis, Daphnia magna

1981 ◽  
Vol 38 (8) ◽  
pp. 978-981 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
Michael A. Quigley ◽  
John M. Malczyk

Phosphate release rates by Stylodrilus heringianus, tubificids, and Chironomus spp. were quantified in laboratory experiments by incubating the animals in wet sand under two temperature regimes (5 and 20 °C) and under two nutritional states (full and empty guts). Inorganic phosphorus release rates (± SE) for animals incubated 24 h ranged from 0.12 ± 0.02 (n = 5) nmol phosphorus (P)∙(mg ash-free dry weight)−1∙h−1 for S. heringianus beginning with cleared guts at 5 °C to 0.81 ± 0.09 (n = 5) nmol P∙(mg ash-free dry weight)−1∙h−1 for chironomids beginning with full guts at 20 °C. Calculations based on total invertebrate bio-mass and mean basal release rate suggest that benthic invertebrate excretion could account for most P released from aerobic Lake Michigan sediments.Key words: phosphorus, benthic invertebrates, macroinvertebrates, excretion, nutrients, sediments, nutrient release


1983 ◽  
Vol 40 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
David R. Slavens ◽  
Gwenyth A. Laird

Metabolic mineralization of ammonium by tubificid worms and chironomid larvae appears to be an important mechanism contributing to nitrogen regeneration from aerobic lake sediments. Mean weight [ash free dry weight (AFDW)] – specific ammonium release rates ranged from 3 to 15 nmol NH4 (mg AFDW)]−1∙h−1 for chironomid and tubificid species collected at different times and temperatures from nearshore Lake Michigan sediments. Although mean rates of nitrogen release were similar for the two groups of benthic invertebrates, the patterns of release were different. Tubificids released nitrogen (ammonium plus primary amines) continuously, whereas chironomids released it in spurts several times per hour. Mean ammonium-release rates were generally constant with time after the animals were removed from food for both species. This implies that ammonium regeneration for these benthic animals is primarily an endogenous process. Conversely, primary amine nitrogen release often decreased with time after food removal and may reflect either egestion of partially digested materials from the animals' guts or a decrease in the metabolic pool size of free amino acids. Based on previous measurements of phosphorus release, mean molar NH4:PO4 ratios in excreted materials were calculated to be 15:1 for chironomids and 35:1 for tubificids.Key words: nitrogen release, benthic invertebrates, chironomids, tubificids, ammonium excretion, amino acid release


2017 ◽  
Vol 12 (3) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Katarzyna Sułkowska-Ziaja ◽  
Anna Maślanka ◽  
Agnieszka Szewczyk ◽  
Bożena Muszyńska

The content of two groups of compounds with biological activity (non-hallucinogenic indole compounds and free phenolic acids) were analyzed in extracts of fruiting bodies of four species of Phellinus: P. igniarius, P. pini, P. pomaceus and P. robustus. The presence of indole compounds in methanolic extracts was analyzed by high-performance liquid chromatography and thin-layer chromatography coupled with densitometric detection. Three metabolites (serotonin, tryptamine, and L-tryptophan) were identified. The contents of individual indole compounds ranged from 1.70 (tryptamine in P. robustus) to 8.32 mg x 100 g1 dry weight (L-tryptophan in P. robustus). Four free phenolic acids were detected in methanolic extracts by the HPLC method. The total content ranged from 9.9 mg x 100 g1 DW (P. igniarius) to 32.5 mg x 100 g1 DW (P. robustus).


2009 ◽  
Vol 3 (2) ◽  
pp. 91-98
Author(s):  
Sattar A. Shlahi ◽  
Zahra N. Hashim Al- Hattab

This research was conducted to study the effect of the chemical mutagen N-methyl-N-nitro-N-nitrosoguanidine on the percentage of callus induction and survival from mature beans embryos harvester cultivar. Seeds were treated with (0.2 or 0.4) millimolar of the mutagen NTG in combination with 0.0, 4 or 8% of ethanol, pH 5 ±2 0. for 24 h. Calli were induced on mature embryos by using MS medium with 0.5 mg/l of Benzyl adenine (BA), 1 mg/l Indole acetic acid (IAA) and 100 mg/l from each of Casein hydrolysate, Glycine, Asparagine, Tyrosine, and Myo-Inositol. Results showed that the hypocotyl surpassed the radical and the plume significantly in terms of survival reached 56.3%. Mutagen treatments showed asignificant effect on calli survival. Treatment with 8% Ethanol was lethal for all explants. While treatment with 0.4 mM NTG without Ethanol gaved the highest survival rate. The interaction between the treatments and the explants showed that the lowest survival percentage was which 8.8% that was for shoots treated with 0.2 mM of 4% Ethanol. Calli induced on hypocotyls treated with 0.4 mM NTG without Ethanol gave the highest fresh weight (347.2) mg while the lowest was (60) mg for calli induced on the radical treated with 0.4 mM NTG with 4% Ethanol. Moreover the highest dry weight was 22.5 mg for calli induced from hypocotyls treated with 0.4 millimolar NTG without Ethanol that was higher than the control 17.2 mg.The lowest dry weight obtained from calli induced on the radical treated with 0.4 mM NTG with 4% Ethanol was 3 mg. In conclusion the results showed that 0.4 mM NTG without Ethanol gave the highest survival rate and the highest fresh and dry weight for calli induced on the hypocotyl.


2006 ◽  
Vol 61 (9-10) ◽  
pp. 619-624 ◽  
Author(s):  
Xinkun Wang ◽  
Yinghua Huang ◽  
Andrew J. Mort ◽  
Yuhong Zeng ◽  
Charles G. Tauer ◽  
...  

AbstractNeedles from 17 different Taxus x media cultivars, belonging to 4 groups showing different growth characteristics, were analyzed using high performance liquid chromatography for their content of 10-deacetylbaccatin III, baccatin III, cephalomannine and paclitaxel (Taxol®). The 4 Taxus x media cultivar groups were: 1.) medium to fast growing and upright form; 2.) slow growing and upright form; 3.) fast growing and spreading form; and 4.) slow growing and spreading form. The purpose of this study was to identify yew cultivars of fast growth rate, upright growth and high taxane content in their needles. The highest content of paclitaxel was found in ‘Coleana’ of group 1 (378 μg/g of the extracted dry weight). Three cultivars in group 1, ‘Coleana’, ‘Stovekenii’ and ‘Hicksii’, make good candidates for taxane extraction because of their high paclitaxel and 10-deacetylbaccatin III content, fast biomass accumulation and upright growing form. They are also good starting materials to develop alternative methods for the production of paclitaxel and its analogous compounds through modern biotechnology approaches.


2019 ◽  
Vol 20 (7) ◽  
pp. 1787 ◽  
Author(s):  
Muhammad Asad Ullah ◽  
Duangjai Tungmunnithum ◽  
Laurine Garros ◽  
Samantha Drouet ◽  
Christophe Hano ◽  
...  

Lepidium sativum L. is a rich source of polyphenols that have huge medicinal and pharmaceutical applications. In the current study, an effective abiotic elicitation strategy was designed for enhanced biosynthesis of polyphenols in callus culture of L. sativum. Callus was exposed to UV-C radiations for different time intervals and various concentrations of melatonin. Secondary metabolites were quantified by using high-performance liquid chromatography (HPLC). Results indicated the total secondary metabolite accumulation of nine quantified compounds was almost three fold higher (36.36 mg/g dry weight (DW)) in melatonin (20 μM) treated cultures, whereas, in response to UV-C (60 min), a 2.5 fold increase (32.33 mg/g DW) was recorded compared to control (13.94 mg/g DW). Metabolic profiling revealed the presence of three major phytochemicals, i.e., chlorogenic acid, kaemferol, and quercetin, in callus culture of L. sativum. Furthermore, antioxidant, antidiabetic, and enzymatic activities of callus cultures were significantly enhanced. Maximum antidiabetic activities (α-glucosidase: 57.84%; α-amylase: 62.66%) were recorded in melatonin (20 μM) treated callus cultures. Overall, melatonin proved to be an effect elicitor compared to UV-C and a positive correlation in these biological activities and phytochemical accumulation was observed. The present study provides a better comparison of both elicitors and their role in the initiation of physiological pathways for enhanced metabolites biosynthesis in vitro callus culture of L. sativum.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Min Wei ◽  
Yangling Tuo ◽  
Ye Zhang ◽  
Qi Deng ◽  
Cuiying Shi ◽  
...  

The purpose of this work is to establish a new method using high-performance liquid chromatography-diode array detection (HPLC-DAD) with chemometrics analysis to determine the content of catechin, isoquercetin, astragalin, phloridzin, trilobatin, and phloretin for one flavanol and five flavonoids, filter out the key compounds, and evaluate the quality of 26 batches of tender leaves and flower spikes of Lithocarpus polystachyus Rehd. (LP) from ten areas in China. The result showed that the HPLC-DAD method had excellent performance for accurate quantification analysis. S3 (tender leaf from Lushan, Sichuan) had the highest contents for six measured chemicals with trilobatin content of up to 27.82% in dry weight. S22 (flower spike from Liangping, Chongqing) had the highest content of phloridzin (up to 7.28%). All samples were divided into three types based on spatial distribution using principal component analysis. The result showed that the tender leaves and flower spikes from the same areas had many similar properties, and there were significant differences between the samples from different regions. Furthermore, phloridzin and trilobatin were identified as chemical markers for quality evaluation of two parts with different tender leaves and flower spikes of LP from geographical areas by orthogonal partial least squares discrimination analysis. These results will be helpful to establish an effective and comprehensive evaluation system of the development and utilization of LP resources.


2013 ◽  
Vol 79 (10) ◽  
pp. 3225-3233 ◽  
Author(s):  
Hongchao Wang ◽  
Haiqin Chen ◽  
Guangfei Hao ◽  
Bo Yang ◽  
Yun Feng ◽  
...  

ABSTRACTMortierella alpinais a filamentous fungus commonly found in soil that is able to produce lipids in the form of triacylglycerols that account for up to 50% of its dry weight. Analysis of theM. alpinagenome suggests that there is a phenylalanine-hydroxylating system for the catabolism of phenylalanine, which has never been found in fungi before. We characterized the phenylalanine-hydroxylating system inM. alpinato explore its role in phenylalanine metabolism and its relationship to lipid biosynthesis. Significant changes were found in the profile of fatty acids inM. alpinagrown on medium containing an inhibitor of the phenylalanine-hydroxylating system compared toM. alpinagrown on medium without inhibitor. Genes encoding enzymes involved in the phenylalanine-hydroxylating system (phenylalanine hydroxylase [PAH], pterin-4α-carbinolamine dehydratase, and dihydropteridine reductase) were expressed heterologously inEscherichia coli, and the resulting proteins were purified to homogeneity. Their enzymatic activity was investigated by high-performance liquid chromatography (HPLC) or visible (Vis)-UV spectroscopy. Two functional PAH enzymes were observed, encoded by distinct gene copies. A novel role for tetrahydrobiopterin in fungi as a cofactor for PAH, which is similar to its function in higher life forms, is suggested. This study establishes a novel scheme for the fungal degradation of an aromatic substance (phenylalanine) and suggests that the phenylalanine-hydroxylating system is functionally significant in lipid metabolism.


2000 ◽  
Vol 66 (1) ◽  
pp. 176-179 ◽  
Author(s):  
Hee-Mock Oh ◽  
Seog June Lee ◽  
Min-Ho Jang ◽  
Byung-Dae Yoon

ABSTRACT The production of microcystins (MC) from Microcystis aeruginosa UTEX 2388 was investigated in a P-limited continuous culture. MC (MC-LR, MC-RR, and MC-YR) from lyophilized M. aeruginosa were extracted with 5% acetic acid, purified by a Sep-Pak C18 cartridge, and then analyzed by high-performance liquid chromatography with a UV detector and Nucleosil C18 reverse-phase column. The specific growth rate (μ) ofM. aeruginosa was within the range of 0.1 to 0.8/day and was a function of the cellular P content under a P limitation. The N/P atomic ratio of steady-state cells in a P-limited medium varied from 24 to 15 with an increasing μ. The MC-LR and MC-RR contents on a dry weight basis were highest at μ of 0.1/day at 339 and 774 μg g−1, respectively, while MC-YR was not detected. The MC content of M. aeruginosa was higher at a lower μ, whereas the MC-producing rate was linearly proportional to μ. The C fixation rate at an ambient irradiance (160 microeinsteins m−2s−1) increased with μ. The ratios of the MC-producing rate to the C fixation rate were higher at a lower μ. Accordingly, the growth of M. aeruginosa was reduced under a P limitation due to a low C fixation rate, whereas the MC content was higher. Consequently, increases in the MC content per dry weight along with the production of the more toxic form, MC-LR, were observed under more P-limited conditions.


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