scholarly journals Systemic suppression of cluster-root formation and net P-uptake rates in Grevillea crithmifolia at elevated P supply: a proteacean with resistance for developing symptoms of ‘P toxicity’

2005 ◽  
Vol 57 (2) ◽  
pp. 413-423 ◽  
Author(s):  
Michael W. Shane ◽  
Hans Lambers
2007 ◽  
Vol 2 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Jasna Hrenovic ◽  
Tomislav Ivankovic

AbstractThe harmful effects of surfactants to the environment are well known. We were interested in investigating their potential toxicity in a pure culture of Acinetobacter junii, a phosphate (P)-accumulating bacterium. Results showed a high acute toxicity of sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HDTMA) against A. junii. The estimated EC50 values of the HDTMA for the inhibition of CFUs in the pure culture of A. junii was 3.27 ± 1.12 × 10−7 mol L−1 and for the inhibition of the P-uptake rates 2.47 ± 0.51 × 10−6 mol L−1. For SDS, estimated EC50 values for the inhibition of CFUs in the pure culture of A. junii was 5.00 ± 2.95 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 3.33 ± 0.96 × 10−4 mol L−1. The obtained EC50 values in the standardised yeast toxicity test using Saccharomyces cerevisiae were 3.03 ± 0.38 × 10−4 and 4.33 ± 0.32 × 10−5 mol L−1 for SDS and HDTMA, respectively. These results emphasized the need to control concentrations of surfactants entering the activated sludge system. The negative effects of these toxicants could greatly decrease populations of P-accumulating bacteria, as well as eukaryotic organisms, inhabiting activated sludge systems, which in turn could result in the decrease of the system efficiency.


1991 ◽  
Vol 48 (10) ◽  
pp. 1951-1959 ◽  
Author(s):  
Alan D. Steinman ◽  
Patrick J. Mulholland ◽  
David B. Kirschtel

Four treatments were imposed on eight laboratory streams in a factorial design to examine the roles of nutrient reduction and herbivory on periphyton communities. Treatments included two flow regimes (once-through flow or 90% recirculated water) and two levels of grazer density (1000 or 0∙m−2, using the snail Elimia clavaeformis). Periphyton biomass was significantly greater in streams without snails than in those with them, but water supply had no overall significant effect on biomass, even though inorganic P and N concentrations were significantly lower in recirculated than in once-through streams. Areal-specific P uptake rates (measured with 33P) were significantly greater on two dates in no-snail streams compared with snail streams, presumably because of the greater biomass levels in the former systems. Differences in biomass-specific P uptake rates were not significantly affected by either grazer density or water supply. Relative abundances of most algal species were unaffected by the water supply treatment, although percent biovolume of two Epithemia species was greater in no-snail, recirculated than in no-snail, once-through streams. Grazing activity dramatically reduced the percent biovolume of species with upright growth forms, resulting in dominance by species with prostrate growth forms.


2009 ◽  
Vol 59 (1) ◽  
pp. 57-64 ◽  
Author(s):  
M. Swinarski ◽  
J. Makinia ◽  
K. Czerwionka ◽  
M. Chrzanowska

Carbon source alternatives for denitrification belong to the highest research area priorities as they allow to optimize N removal within the existing capacities. In particular, some food industry effluents appear to be good candidates for such alternatives due to their high C/N ratios and high content of readily biodegradable organic fraction. The aim of this study was to determine the immediate effects of dosing different types of industrial wastewater on the denitrification capability of process biomass originating from the “Wschod” WWTP in Gdansk (northern Poland). Three types of industrial wastewater (effluents from a distillery, brewery and fish-pickling factory) were tested in two kinds of batch experiments. The results of this study revealed that the investigated industrial wastewater can be a potential external carbon source to improve denitrification efficiency. The observed single nitrate utilization rates (NURs) were ranging from 2.4 to 6.0 g N/(kg VSS·h) and were comparable to the rates associated with the utilization of readily biodegradable COD in the settled wastewater. When the NURs were measured during anoxic P uptake, the P uptake rates did not appear to be adversely affected by the addition of any carbon source.


2013 ◽  
Vol 64 (10) ◽  
pp. 965 ◽  
Author(s):  
Qinghua Ma ◽  
Hongliang Tang ◽  
Zed Rengel ◽  
Jianbo Shen

Localised supply of phosphorus (P) plus ammonium improves root proliferation and nutrient uptake by plants grown on calcareous soils, but how nitrogen (N) forms (ammonium and urea) and placements affect maize (Zea mays L.) root distribution and nutrient uptake is not fully understood. A soil column study was conducted with four N and P combinations including P plus urea (UP), mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and P plus ammonium sulfate (ASP), and two fertiliser application methods (banding in the 10–25 cm layer or mixing throughout the 45-cm soil profile). Shoot N and P content increased by 11–31% and 14–37% in the treatments with banding P plus ammonium (MAP, DAP or ASP) compared with banding UP and the mixing treatments. Shoot N and P uptake rates per root dry weight or root length were higher with banding P plus ammonium than their respective mixing treatments. Banding P plus ammonium increased root-length density in the fertiliser-banded layer compared with banding UP and the mixing treatments. The results show that modifying root spatial distribution by banding P plus ammonium leads to an increase in N and P uptake rates, and consequently enhances nutrient accumulation by maize.


2008 ◽  
Vol 3 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Jasna Hrenovic ◽  
Tomislav Ivankovic ◽  
Lavoslav Sekovanic ◽  
Mirela Rozic

AbstractThe antibacterial effect of cationic surfactants against the pure culture of phosphate (P)-accumulating bacterium Acinetobacter junii was investigated. The estimated EC50 values of the N-dodecylpyridinium chloride (DPC) for growth inhibition was 1.4±0.5 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 7.3±2.6 × 10−5 mol L−1. The estimated EC50 values of the N-cetylpyridinium chloride (CPC) for growth inhibition was 4.9±1.3 × 10−7 mol L−1 and for the inhibition of the P-uptake rates 7.7±2.9 × 10−6 mol L−1. This suggests the importance of controlling the amounts of cationic surfactants in influent of the wastewater treatment systems in order to avoid the possible failure of the biological P removal from wastewaters.


2007 ◽  
Vol 4 (3) ◽  
pp. 2027-2068 ◽  
Author(s):  
S. Duhamel ◽  
T. Moutin ◽  
F. Van Wambeke ◽  
B. Van Mooy ◽  
P. Rimmelin ◽  
...  

Abstract. Predicting heterotrophic bacteria and phytoplankton growth rates (μ) is of great scientific interest. Many methods have been developed in order to assess bacterial or phytoplankton μ. One widely used method is to estimate μ from data obtained on biomass or cell abundance and rates of biomass or cell production. According to Kirchman (2002), the most appropriate approach for estimating μ is simply to divide the production rate by the biomass or cell abundance estimate. Most of the methods using this approach are expressed using carbon (C) data. Nevertheless it is also possible to estimate μ using phosphate (P) data. We showed that particulate phosphate (PartP) can be used to estimate biomass and that the phosphate uptake rate to PartP ratio can be employed to assess μ. Contrary to other methods using C, this estimator does not need conversion factors and provides an evaluation of μ for both autotrophic and heterotrophic organisms. We report values of P-based μ in three size fractions (0.2–0.6; 0.6–2 and >2 μm) along a Southeast Pacific transect, over a wide range of P-replete trophic status. P-based μ values were higher in the 0.6–2 μm fraction than in the >2 μm fraction, suggesting that picoplankton-sized cells grew faster than the larger cells, whatever the trophic regime encountered. Picoplankton-sized cells grew significantly faster in the deep chlorophyll maximum layer than in the upper part of the photic zone in the oligotrophic gyre area, suggesting that picoplankton might outcompete >2 μm cells in this particular high-nutrient, low-light environment. P-based μ attributed to free-living bacteria (0.2–0.6 μm) and picoplankton (0.6–2 μm) size-fractions were relatively low (0.11±0.07 d−1 and 0.14±0.04 d−1, respectively) in the Southeast Pacific gyre, suggesting that the microbial community turns over very slowly.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Mario E. Biondini ◽  
Jack E. Norland ◽  
Carolyn E. Grygiel

We investigated plant richness-biomass relationships in tall grass (Field 1, 12 years) and mixed grass (Field 2, 5 years) restoration experiments located in the northern Great Plains grasslands (USA). They were organized as randomized factorial experiments with fertilization rates (N or P) and number of species as factors. Results were as follows: (1) above ground biomass (AGB) increased and year-to-year variability declined with plant species and functional form richness. (2) AGB was higher when the species had various combinations: (a) high relative growth rates, root density, root surface area, N or P uptake rates, and N use efficiency; (b) low root-to-shoot ratio and root plasticity. (3) Biomass stability was positively related to high root surface area in Field 1 and N use efficiency and P uptake rates in Field 2. (4) Invasion of nonseeded species declined with plant species and functional form richness.


2022 ◽  
Author(s):  
Jun Wasaki ◽  
Tadashi Okamura ◽  
Taiki Yamauchi ◽  
Hayato Maruyama ◽  
Shinji Uchida ◽  
...  

Abstract Aims The family Proteaceae is one of the dominant families in nutrient-impoverished habitats in the Southern hemisphere, and less common in the Northern hemisphere. Helicia cochinchinensis Lour. is the only Proteaceae species in Japan. This study aimed to unveil the ecophysiological properties of H. cochinchinensis grown on Miyajima Island, Hiroshima, Japan.Methods Phosphorus (P) status and dynamics of soils in H. cochinchinensis habitats were measured. Plant P and nitrogen (N) concentrations of leaves were measured after digestion. Roots and rhizosheath soil were collected to assess root morphology and root exudates.Results Available P (Olsen-P) in soils in habitats of H. cochinchinensis was 0.46–3.7 mg P kg-1 soil. Citrate was the major carboxylate in root exudates and its concentration increased during cluster-root formation. Acid phosphatase activity was greater at the surface of cluster roots that on the surface of other roots and bulk soil, especially for mature cluster roots. Sparingly soluble organic P concentrations decreased in the rhizosheath soil of mature cluster roots. The P concentrations of H. cochinchinensis leaves were relatively low; 0.34–0.69 mg P g-1 DW and 0.15–0.29 mg P g-1 DW in mature and senesced leaves, respectively. The P demand of H. cochinchinensis was less than that of nearby trees, showing greater P-remobilization efficiency.Conclusions Phosphorus mobilization from unavailable P by cluster roots supported P uptake by H. cochinchinensis, and P remobilization from senescing leaves contributed to sustain growth under P-deficient conditions.


2014 ◽  
Vol 955-959 ◽  
pp. 1944-1950
Author(s):  
Dong Chen Weng ◽  
Yong Zhen Peng ◽  
Xiao Xia Wang ◽  
Zhi Jia Miao ◽  
Gui Song Xue

Poly-phosphate accumulating organisms (PAOs) could use nitrite as electron acceptor but poorly function compared to oxygen in phosphorus removal. The authors try to figure out the different effects on anoxic and aerobic P-uptake by environmental factors (pH, temperature and nitrite concentration) and identify the real inhibitor in anoxic metabolisms. 26 sets of batch tests were designed, using highly concentrated PAO cultures. The results show pH influence on P-uptake activity are similar in anoxic and aerobic tests, but temperature has strong effects on aerobic P-uptake activity compared to anoxic. pH values were are correlated linearly with nitrite reduction and P-uptake rates instead of FNA. Also, weak correlation between FNA and two reaction rates shows pH rather than FNA is likely the main inhibitor. P-uptake rates are correlated linearly with nitrite reduction and PHA consumption rates. It’s possible that intracellar concentration isn’t affected by FNA diffusion and don’t affect intracellar P-uptake process.


2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.


Sign in / Sign up

Export Citation Format

Share Document