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Effects of sulfur dioxide on growth, photosynthesis and enzyme activities of Chinese guger-tree seedlings.
1994
Sheu B.H.
Carbon isotope composition, macronutrient concentrations, and carboxylating enzymes in relation to the growth of Pinus halepensis mill. when subject to ozone stress
2010
Inclan , Rosa (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Gimeno , Benjamin S. (Ecotoxicology of Air Pollution, Madrid(Espagne).) | Peñuelas , Josep (Universitat Autónoma de Barcelona, Barcelone(Espagne).) | Gerant , Dominique (INRA , Champenoux (France). UMR 1137 Ecologie et Ecophysiologie Forestières) | Querido , Alberto (Ecotoxicology of Air Pollution, Madrid(Espagne).)
We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.
Показать больше [+] Меньше [-]Effects of norfloxacin on nitrate reduction and dynamic denitrifying enzymes activities in groundwater
2021
Chen, Linpeng | Huang, Fuyang | Zhang, Chong | Zhang, Jia | Liu, Fei | Guan, Xiangyu
The impact of antibiotics on denitrification has attracted widespread attention recently. Norfloxacin, as a representative of fluoroquinolone antibiotics, is extensively detected in groundwater. However, whether the release of norfloxacin into the groundwater poses potential risks to denitrification remains unclear. In this study, effect of norfloxacin on denitrification was investigated. The results showed that increasing norfloxacin from 0 to 100 μg/L decreased nitrate removal rate from 0.68 to 0.44 mg/L/h, but enhanced N₂O emission by 177 folds. Additionally, 100 μg/L of norfloxacin decreased nitrite accumulation by 50.6%. Corresponding inhibition of norfloxacin on bacterial growth, carbon source utilization, electron transport system activity and genes expression was revealed. Furthermore, denitrifying enzyme dynamic monitoring results showed that norfloxacin inhibited nitrate reductase activity, and enhanced nitrite reductase activity to some extent in denitrification process, which was consistent with the variations of nitrate and nitrite. Meanwhile, sensitivity analysis demonstrated that nitrate reductase was more easily affected by norfloxacin than nitrite reductase. Overall, this study suggests that multiple regulation of denitrifying enzyme activity contributes to evaluating the comprehensive effects of antibiotics on groundwater denitrification.
Показать больше [+] Меньше [-]Comparison of microbial community structure and function in sediment between natural regenerated and original mangrove forests in a National Nature Mangrove Reserve, South China
2021
Wei, Pingping | Lei, Anping | Zhou, Haichao | Hu, Zhangli | Wong, Yukshan | Tam, Nora F.Y. | Lu, Qun
Mangrove has been destroyed and reforestation is often undertaken, but whether a regenerated forest could restore its ecological function is not clear. This study compares microbial community structure and function in sediment of the 17-years old natural regenerated mangrove forest (Y17) with the original forest (Y74). No significant differences in phospholipid fatty acid (PLFA) profiles and microbial metabolism of most carbon substrates were found between these two forests. However, activities of dehydrogenase, protease, cellulase and phosphatase were lower in Y17 than Y74, and some specific microbial functions were also different. Both forests exhibited significant seasonal differences in enzyme activities and microbial characteristics, but such difference was larger in Y17 than Y74, indicating the regenerated forest was more sensitive to season. Correspondence analysis based on PLFA profiles and enzyme activities revealed the microbial community in Y17 was comparable to Y74, suggesting sediment microbial characteristics in natural regenerated mangroves could be restored.
Показать больше [+] Меньше [-]Structure and function of soil microbial community in artificially planted Sonneratia apetala and S. caseolaris forests at different stand ages in Shenzhen Bay, China
2014
The present study examined the relationships between soil characteristics, microbial community structure and function in the forests artificially planted with exotic Sonneratia apetala at stand ages of 1-, 2-, 7-, 10- and 14-years and Sonneratia caseolaris of 1-, 4-, 7-, 10- and 14-years in Futian National Nature Reserve, Shenzhen Bay, China. The 7-years old forests of both Sonneratia species reached peak growth and had the highest content of nitrogen and phosphorus, enzymatic activities, including dehydrogenase, cellulase, phosphatase, urease and ß-glucosidase, except arylsulphatase which increased continuously with stand ages. The microbial community structure reflected by phospholipid fatty acid (PLFA) profiles also reached the maximum value in the 7-years old forests and soil bacterial PLFAs in both forests were significantly higher than fungal PLFAs. The canonical correlation analysis revealed that differences in microbial structural variables were significantly correlated to the differences in their functional variables, and the highest correlation was found between the soil enzymatic activities and the content of carbon and nitrogen.
Показать больше [+] Меньше [-]Review on plastic wastes in marine environment – Biodegradation and biotechnological solutions
2020
A., Ganesh Kumar | K., Anjana | M., Hinduja | K., Sujitha | G., Dharani
The marine plastic pollution has drastic effect on marine species. The importance in environmental issues increases the demand to develop a significant technology which does not burden the marine environment or marine life forms. To mitigate the foreseen problems of micro and nanoplastic contamination, different biotechnological solutions has to be considered. Microbial communities exposed to plastic contaminated sites can adapt and form dense biofilms on the plastic surface and produce active catalytic enzymes. These enzymes can be able to degrade the synthetic polymers. In view of their high catalytic activity, microbial enzymes can be applicable for the degradation of synthetic polymers. This review highlights the toxicity of micro and nanoplastics on marine organisms, biodegradation of plastics and futuristic research needs to solve the issues of plastic pollution in marine environment.
Показать больше [+] Меньше [-]Antioxidant responses to simulated acid rain and heavy metal deposition in birch seedlings
1997
Koricheva, J. | Roy, S. | Vranjic, J.A. | Haukioja, E. | Hughes, P.R. | Hanninen, O. (Laboratory of Ecological Zoology, Department of Biology, University of Turku, FIN-20014 Turku (Finland))
Effect of cadmium on germination, amylases and rate of respiration of germinating pea seeds
1996
Chugh, L.K. | Sawhney, S.K. (Department of Chemistry and Biochemistry, CCS Haryana Agricultural University, Hisar 125004 (India))
Glutathione status and glutathione reductase activity in spruce needles of healthy and damaged trees at two mountain sites
1993
Schmieden, U. | Schneider, S. | Wild, A. (Institut fur Allgemeine Botanik, Johannes Gutenberg-Universitat, 55099 Mainz (Germany))
Responses of subterranean clover and ryegrass to sulphur dioxide under field conditions
1984
Murray, F. (Dep. Biol. Sci., Univ. Newcastle, NSW 2308 (Australia))