scholarly journals Grazing Intensity Changed The Activities of Nitrogen Assimilation Related Enzymes In Desert Steppe Plants

2021 ◽  
Author(s):  
Aimin Zhu ◽  
Guodong Han ◽  
Haili Liu ◽  
Yuehua Wang
Keyword(s):  
Nitrogen Content ◽  
Root System ◽  
Total Nitrogen ◽  
Nitrogen Assimilation ◽  
Rhizosphere Soil ◽  
Total Nitrogen Content ◽  
Desert Steppe ◽  
Related Factors ◽  
Heavy Grazing ◽  
Grassland Plants

Abstract Background: The study on nitrogen assimilation mechanism of grazing grassland plants is of great significance to reveal the law of nutrient absorption and utilization of grassland vegetation. Methods: This study took Stipa breviflora desert steppe which was grazed for 17 years as the research object, and sampled the root system, leaf and rhizosphere soil of constructive species Stipa breviflora under the treatments of no grazing, light grazing, moderate grazing and heavy grazing during the peak growing season. The activities of enzymes related to nitrogen assimilation in roots and leaves were measured, and the related factors affecting nitrogen content were analyzed. Results: The results showed that heavy grazing significantly increased the total nitrogen content in the root system of Stipa breviflora, but decreased the total nitrogen content in the leaves, and the performance of grazing prohibition was consistent with that of heavy grazing; The activities of Nitrate reductase (NR), glutamine synthetase (GS), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) were stronger under light or moderate grazing. Under grazing prohibition and heavy grazing, the content of proline in roots and leaves of Stipa breviflora increased significantly, especially in leaves; NR, GS, GOT and GPT were significantly correlated with total nitrogen content in roots and leaves of Stipa breviflora. Conclusions: Grazing prohibition and heavy grazing were not conducive to the nitrogen absorption and utilization of Stipa breviflora, which was closely related to the reduction of nitrate and ammonium nitrogen contents in the rhizosphere soil of Stipa breviflora by grazing. Grazing prohibition and heavy grazing affected the nitrogen content of Stipa breviflora by affecting the activities of related enzymes in the process of nitrogen assimilation of roots and leaves.

scholarly journals Grazing intensity changed the activities of nitrogen assimilation related enzymes in desert Steppe Plants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aimin Zhu ◽  
Haili Liu ◽  
Yuehua Wang ◽  
Hailian Sun ◽  
Guodong Han
Keyword(s):  
Nitrogen Assimilation ◽  
Net Primary Productivity ◽  
Assimilation Efficiency ◽  
Nitrate Content ◽  
Limiting Factor ◽  
Desert Steppe ◽  
Grassland Ecosystems ◽  
Heavy Grazing ◽  
Grassland Plants ◽  
Grazing Disturbance

Abstract Background Nitrogen, as a limiting factor for net primary productivity in grassland ecosystems, is an important link in material cycles in grassland ecosystems. However, the nitrogen assimilation efficiency and mechanisms of grassland plants under grazing disturbance are still unclear. This study investigated Stipa breviflora desert steppe which had been grazed for 17 years and sampled the root system and leaf of the constructive species Stipa breviflora during the peak growing season under no grazing, light grazing, moderate grazing and heavy grazing treatments. The activities of enzymes related to nitrogen assimilation in roots and leaves were measured. Results Compared with no grazing, light grazing and moderate grazing significantly increased the activities of nitrate reductase (NR), glutamine synthetase (GS), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) in leaves, and GS, GOT and GPT in roots of Stipa breviflora, while heavy grazing significantly decreased the activities of GS in leaves and NR in roots of Stipa breviflora. NR, GOT and GPT activities in leaves and roots of Stipa breviflora were positively correlated with nitrogen content, soluble protein, free amino acid and nitrate content. Conclusions Grazing disturbance changed the activities of nitrogen assimilation related enzymes of grassland plants, and emphasized that light grazing and moderate grazing were beneficial for nitrogen assimilation by grassland plants. Therefore, establishing appropriate stocking rates is of great significance for material flows in this grassland ecosystem and for the stability and sustainable utilization of grassland resources.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

scholarly journals Exploring the role of macroalgal traits on the feeding behaviour of a generalist herbivore in Malaysian waters

2020 ◽  
Vol 63 (5) ◽  
pp. 407-417
Author(s):  
Lim Wai Yin ◽  
Lim Phaik Eem ◽  
Affendi Yang Amri ◽  
Song Sze Looi ◽  
Acga Cheng
Keyword(s):  
South China Sea ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
South China ◽  
Nutritional Quality ◽  
Feeding Behaviour ◽  
Total Nitrogen Content ◽  
Generalist Herbivore ◽  
Macroalgal Species ◽  
Straits Of Malacca

AbstractWith the potential adverse effects of climate change, it is essential to enhance the understanding of marine ecosystem dynamics, which can be driven by the co-evolutionary interaction between autotrophs and herbivores. This study looked into the autotroph-herbivore interactions in Malaysian waters, mainly to determine if autotroph nutritional quality significantly influences herbivore consumption rates. We documented the relative consumption rate of a generalist herbivore (Chanos chanos Forsskål) obtained from the Straits of Malacca through multiple feeding trials using 12 macroalgal species collected from different coastal areas of the Straits of Malacca, the Straits of Johor, and the South China Sea. The herbivore fed selectively on the tested macroalgal species, with the most and least consumed species having the lowest and highest total nitrogen content, respectively. Besides total nitrogen content, the least consumed species also had the highest total phenolic content. Interestingly, we observed that the herbivore generally preferred to consume filamentous macroalgae, especially those collected from the South China Sea. Overall, our findings demonstrated that the feeding behaviour of a generalist herbivore could be influenced by the nutritional quality of the autotrophs, which may depend directly or indirectly on other factors such as autotroph morphology and geography.

The Feasibility Research for Detecting the Nitrogen Content in Sewage with NIPGA Method

2014 ◽  
Vol 602-605 ◽  
pp. 2445-2448
Author(s):  
Fu Quan Jia ◽  
Zhu Jun Tian
Keyword(s):  
Nitrogen Content ◽  
Neutron Source ◽  
Total Nitrogen ◽  
Gamma Rays ◽  
Neutron Generator ◽  
Limit Of Detection ◽  
Total Nitrogen Content ◽  
Feasibility Research ◽  
Type Water

NIPGA technology is used in order to detect the total nitrogen content in sewage quickly. D-D neutron generator is used as the neutron source and BGO detector is used to detect gamma rays of nitrogen. The simulated result of MCNP shows the nitrogen’s limit of detection is 0.2 mg/L and the total nitrogen in V-type water can be detected. So this method can be used to detect the total nitrogen content in sewage quickly.

scholarly journals Co-Digestion of Vinasse Waste and Tofu Liquid Waste to Increase Biogas Production

Eksergi ◽  
2015 ◽  
Vol 12 (2) ◽  
pp. 23
Author(s):  
Iqbal Syaichurrozi
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Biogas Production ◽  
Liquid Waste ◽  
Volume Ratio ◽  
Total Nitrogen Content ◽  
Anaerobic Digesters ◽  
Initial Ph

The purpose of this study was to increase biogas production using co-digestion concept. Vinasse Waste (VW) containing high COD and low total Nitrogen content was mixtured with Tofu Liquid Waste (TLW) containing low COD and high total Nitrogen. Substrates were varied with volume ratio of VW:TLW of 100:0, 20:80, 0:100. Total volume of substrates was 250 mL. Anaerobic digesters were operated at room temperatur. After fermentation, biogas total volume of variables of 100:0, 20:80, 0:100 was 88.5; 125.5; 41.5 mL. Initial pH for all variables was 7.0. At the end of fermentation, pH substrates became 3.9; 5.1; 6.8 for variables of 100:0, 20:80, 0:100 respectively.

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