Abundance and composition of ammonia-oxidising bacteria and archaea of a degraded lake wetland, Inner Mongolian Plateau, China

Soil Research ◽  
2013 ◽  
Vol 51 (6) ◽  
pp. 554 ◽  
Author(s):  
Linhui Wu ◽  
Lihua Hui ◽  
Xiaoyi Wang ◽  
Jingyu Li ◽  
Jingli Yu ◽  
...  
Keyword(s):  
Population Size ◽  
Community Composition ◽  
Chemical Properties ◽  
Amoa Gene ◽  
Water Withdrawal ◽  
Drying Process ◽  
Pcr Cloning ◽  
Copy Numbers ◽  
Drying Up ◽  
Ammonia Oxidising Bacteria

Wetlands are one of the most highly threatened ecosystems on Earth, and their loss and degradation are regarded as major environmental problems. The degradation rate of lake wetlands of the Huitengxile grassland, Inner Mongolia, has increased over recent years. In this study, soil samples were collected in a degraded lake wetland of the Huitengxile grassland. The abundance and composition of soil ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) were assessed by quantitative real-time PCR, cloning, and sequencing approaches. Four sampling sites were selected according to the order of water withdrawal. The lakeshore sample appeared to have the highest copy numbers of AOB amoA genes, and the lowest AOB population size was found in the lakebed sample. Similar to AOB, the AOA were most abundant in the lakeshore sample, and the population size in the lake centre sample was the lowest. Ex2cept in one lakebed sample, AOB were more abundant than AOA in all other samples, with AOB to AOA ratios ranging from 11 to 13. Phylogenetic analysis of the amoA gene fragments showed that all AOB sequences from different sites were affiliated to class β-Proteobacteria, order Nitrosomonadales, family Nitrosomonadaceae and can be grouped into two clusters. Little difference was found in AOB community composition among different samples, which indicated that AOB community composition was stable during the drying process of the degraded lake. However, the AOA community compositions were very different between samples. All AOA sequences fell into four clusters. Cluster 1 was dominant in the sample from the centre of the lake, and cluster 2 was dominant in the lakeshore sample, indicating a difference in the community composition of AOA in response to the drying up of the lake. No clear relationship was found between the AOA and AOB community populations and soil physio-chemical properties. This study suggested that the AOA community in wetland systems is more sensitive than the AOB community to the drying process of the wetland ecosystem.

Abundance and community composition of ammonia-oxidizing archaea and bacteria in two different zones of Lake Taihu

2012 ◽  
Vol 58 (8) ◽  
pp. 1018-1026 ◽  
Author(s):  
Jin Zeng ◽  
Da-Yong Zhao ◽  
Rui Huang ◽  
Qinglong L. Wu
Keyword(s):  
Community Composition ◽  
Gene Diversity ◽  
Lake Taihu ◽  
Amoa Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Bacterial Amoa Gene ◽  
Ammonia Oxidizing Archaea ◽  
Archaeal Amoa Gene ◽  
Copy Numbers ◽  
Meiliang Bay

The abundance and community composition of ammonia-oxidizing archaea and ammonia-oxidizing bacteria in the surface sediments of 2 different zones (Meiliang Bay and Eastern Lake Taihu) of Lake Taihu were investigated using real-time quantitative polymerase chain reaction and clone libraries. The amoA gene copy numbers in the surface sediment of Meiliang Bay ranged from 4.91 × 105 to 8.65 × 106 copies/g dry sediment for the archaeal amoA gene and from 3.74 × 104 to 3.86 × 105 copies/g dry sediment for the bacterial amoA gene, which were significantly higher than those of Eastern Lake Taihu (P < 0.05). Concentrations of ammonia (NH4+), total nitrogen, organic matter, and pH of the sediments exhibited significantly negative correlations with the abundance of ammonia-oxidizing archaea or ammonia-oxidizing bacteria (P < 0.05 or P < 0.01, respectively). The potential nitrification rates show remarkable correlations with the copy numbers of the archaeal amoA gene. Diversity of the archaeal amoA gene in Eastern Lake Taihu was significantly higher than that of Meiliang Bay, whereas the bacterial amoA gene diversity was comparable for the 2 lake zones. The data obtained in this study would be useful to elucidate the role of ammonia-oxidizing archaea and ammonia-oxidizing bacteria in the nitrogen cycle of freshwater ecosystems.

Predominance of ammonia-oxidizing archaea andnirK-gene-bearing denitrifiers among ammonia-oxidizing and denitrifying populations in sediments of a large urban eutrophic lake (Lake Donghu)

2013 ◽  
Vol 59 (7) ◽  
pp. 456-464 ◽  
Author(s):  
Jie Hou ◽  
Xiuyun Cao ◽  
Chunlei Song ◽  
Yiyong Zhou
Keyword(s):  
Amoa Gene ◽  
Eutrophic Lake ◽  
Gene Copy ◽  
Nirs Gene ◽  
Bacterial Amoa Gene ◽  
Archaeal Amoa Gene ◽  
Copy Numbers ◽  
Significant Difference ◽  
Nirk Gene ◽  
Gene Copy Numbers

The coupled nitrification–denitrification process plays a pivotal role in cycling and removal of nitrogen in aquatic ecosystems. In the present study, the communities of ammonia oxidizers and denitrifiers in the sediments of 2 basins (Guozhenghu Basin and Tuanhu Basin) of a large urban eutrophic lake (Lake Donghu) were determined using the ammonia monooxygenase subunit A (amoA) gene and the nitrite reductase gene. At all sites of this study, the archaeal amoA gene predominated over the bacterial amoA gene, whereas the functional gene for denitrification nirK gene far outnumbered the nirS gene. Spatially, compared with the Tuanhu Basin, the Guozhenghu Basin showed a significantly greater abundance of the archaeal amoA gene but less abundance of the nirK and nirS genes, while there was no significant difference of bacterial amoA gene copy numbers between the 2 basins. Unlike the archaeal amoA gene, the nirK gene showed a significant difference in community structure between the 2 basins. Archaeal amoA diversity was limited to the water–sediment cluster of Crenarchaeota, in sharp contrast with nirK for which 22 distinct operational taxonomic units were found. Accumulation of organic substances were found to be positively related to nirK and nirS gene copy numbers but negatively related to archaeal amoA gene copy numbers, whereas the abundance of the bacterial amoA gene was related to ammonia concentration.

scholarly journals The prediction model of moisture content’s stabilization during tobacco strip drying process

2018 ◽  
Author(s):  
Mingjian Zhang ◽  
Feng Huang ◽  
Qing Chen ◽  
Le Wang ◽  
Haisheng Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Probability Distributions ◽  
Chemical Properties ◽  
Mean Value ◽  
Drying Process ◽  
Variance Model ◽  
Initial Stage ◽  
The Mean ◽  
Agriculture Products ◽  
Physical And Chemical

A mathematical model was established to predict the mean value and variance of tobacco strip during drying processing, based that the physical and chemical properties of tobacco strip as agriculture products show probability distributions. The results show that the model can predict the mean value of moisture content at different times, and there is a certain deviation in predicting the variance of moisture content at initial stage of drying process. However, the prediction value of the variance of tobacco strip is much more accurate while the moisture content is between 8% and 10%, which is the interval of quality requirements.Keywords: tobacco strip; drying; mean value;variance model.  

Effects of Preparation of Cement Raw Meal with Carbide Slag on the Environment and Equipments

2014 ◽  
Vol 787 ◽  
pp. 123-127 ◽  
Author(s):  
Ya Li Wang ◽  
Su Ping Cui ◽  
Hui Wang ◽  
Shi Jie Dong ◽  
Yan Yao
Keyword(s):  
Heavy Metal Ions ◽  
Raw Materials ◽  
Chemical Properties ◽  
Exhaust Gas ◽  
Physical And Chemical Properties ◽  
Drying Process ◽  
Calcination Process ◽  
Carbide Slag ◽  
Physical And Chemical ◽  
And Chemical Properties

Based on the physical and chemical properties of carbide slag, the contents of heavy metals in effluent came from carbide slag drying process were studied, and then the composition of exhaust gas emitted from the carbide slag drying process and calcinations process of raw materials prepared with carbide slag was detected, in order to know whether there are harmful or corrosive gases released and the effect of the emissions on the environment and related equipments. The results indicate that the exhaust gases emitted from the calcination process of raw meal prepared with carbide slag is mainly composed of CO2 and water vapor, and is free from harmful gases. However, a lot of water in carbide slag during the pre-heat and decomposition process under high temperature would accelerate the corrosion of equipments. Simultaneously, a small number of heavy metal ions contained in the carbide slag can cause environmental pollution and sulfides would be adverse to the cement calcination process resulting in the crust blockage of kiln.

Diversity of ammonia-oxidising bacteria and archaea in seven different estuarine sediments from Poyang Lake

2016 ◽  
Vol 67 (12) ◽  
pp. 1897 ◽  
Author(s):  
Ping Sheng ◽  
Yizun Yu ◽  
Xiaojuan Tian ◽  
Dongsheng Wang ◽  
Zhihong Zhang ◽  
...  
Keyword(s):  
Poyang Lake ◽  
Gene Diversity ◽  
Nitrogen Concentration ◽  
Amoa Gene ◽  
Estuarine Sediments ◽  
Operational Taxonomic Units ◽  
Uncultured Bacteria ◽  
Culture Independent ◽  
Ammonia Oxidising Archaea ◽  
Ammonia Oxidising Bacteria

In the present study, we used a culture-independent method based on library construction and sequencing to analyse the genetic diversity of the ammonia monooxygenase genes (amoA) of ammonia-oxidising archaea and bacteria in seven different estuarine sediments of Poyang Lake. The total of 67 and 38 operational taxonomic units (OTUs) (similarity <95%) of archaeal (AOA) and bacterial (AOB) amoA genes were retrieved respectively. AOA had higher diversity of amoA genes than did AOB. Phylogenetic analysis showed that AOA amoA sequences were closely related to amoA sequences from Crenarchaeota, Thaumarchaeota and some other uncultured archaea. Fragments from AOB were most associated with sequences from betaproteobacteria and some other uncultured bacteria. On the basis of Kendall’s correlation coefficient, there was a significant positive correlation between AOA amoA gene diversity and temperature, and the AOB diversity was positively correlated with total nitrogen and nitrate nitrogen concentration, and negatively correlated with pH in the sediments, suggesting that AOA and AOB were probably sensitive to several environmental factors. Our work could enhance our understanding of the roles of ammonia-oxidising microorganisms in these seven estuarine sediments from Poyang Lake.

scholarly journals Air drying of macauba fruits: maintaining oil quality for biodiesel production

2019 ◽  
Vol 42 ◽  
pp. e43451 ◽  
Author(s):  
Gutierres Nelson Silva ◽  
José Antônio Saraiva Grossi ◽  
Marcela Silva Carvalho ◽  
Kacilda Naomi Kuki ◽  
Samuel de Melo Goulart ◽  
...  
Keyword(s):  
Oil Quality ◽  
Chemical Properties ◽  
Biodiesel Production ◽  
Drying Process ◽  
Drying Time ◽  
Dried Fruits ◽  
Efficient Storage ◽  
Fruit Samples ◽  
Low Levels

Macauba fruits are oil-rich drupes with high moisture content at harvest. This feature can affect the chemical properties of the oil and increase the costs of biodiesel production. Therefore, it is necessary to adopt postharvest strategies to ensure oil quality. The aim of this work was to evaluate the effect of drying macauba fruit on the quality of the pulp oil. Husked and dehusked fruits were dried at 60°C and then stored. At 0, 15, 45, 100, and 180 days after storage, fruit samples were retrieved, and the oil from the pulp was evaluated for physicochemical parameters. The removal of the husk from the fruits considerably reduced the drying time compared to that of the husked fruits. Drying prevented deterioration of the fruit even after 180 days of storage, regardless of the presence of the husk. The drying process allowed for efficient storage of the macauba fruit while maintaining low levels of oil acidity. Furthermore, the oxidative stability of the pulp oil from the dehusked dried fruits lasted longer than that from the husked dried fruits. Therefore, drying is a viable alternative for the postharvest of macauba fruits to maintain the quality of the oil for biodiesel production.

scholarly journals Protective Effect of Fermented Soybean Dried Extracts against TPA-Induced Oxidative Stress in Hairless Mice Skin

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sandra R. Georgetti ◽  
Rúbia Casagrande ◽  
Fabiana T. M. C. Vicentini ◽  
Marcela M. Baracat ◽  
Waldiceu A. Verri ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Chemical Properties ◽  
Gas Temperature ◽  
Drying Process ◽  
Hairless Mice ◽  
Total Polyphenol ◽  
Biochemical Alterations ◽  
Soybean Extract ◽  
A Minor

This study evaluated the chemical properties (polyphenol and genistein contents) of soybean extracts obtained by biotransformation and dried by spray dryer at different conditions and theirin vivoability to inhibit 12-O-tetradecanoylphorbol-13-acetate- (TPA-) induced biochemical alterations in the skin of hairless mice. By comparing the obtained data with that of the well-known active soybean extract Isoflavin beta, we evaluated the influence of the fermentation and drying process in the extracts efficacy. The results demonstrated that inlet gas temperature and adjuvant concentration for the extract drying process have significantly affected the total polyphenol contents and, to a minor degree, the genistein contents. However, the effect of topical stimulus with TPA, an oxidative stress inducer, which caused significant depletion of reduced glutathione (GSH) and catalase, with increased levels of H2O2and lipid peroxidation (MDA) in the skin of hairless mice, was significantly prevented by the soybean extracts treatment. These results indicate that the spray drying processing resulted in a product capable of limiting the oxidative stress with possible therapeutic applicability as an antioxidant in pharmaceutical forms.

Effects of benthic macrofauna bioturbation on the bacterial community composition in lake sediments

2014 ◽  
Vol 60 (8) ◽  
pp. 517-524 ◽  
Author(s):  
Jin Zeng ◽  
Da-Yong Zhao ◽  
Peng Liu ◽  
Zhong-Bo Yu ◽  
Rui Huang ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Lake Taihu ◽  
Bacterial Community Composition ◽  
Chemical Properties ◽  
Eutrophic Lake ◽  
Benthic Macrofauna ◽  
Chironomidae Larvae ◽  
Culture Independent ◽  
Tubificid Worms

Benthic macrofauna are considered to be an important part of the lacustrine ecosystem, and bioturbation may greatly affect the biogeochemical processes and microbial activities in sediments. In the present study, the bacterial community composition in sediments inhabited by 3 different types of benthic macrofauna (Corbicula fluminea, Chironomidae larvae, and tubificid worms) in the shallow and eutrophic Lake Taihu was studied to investigate the different effects of bioturbation on the composition of these communities. Microcosms were constructed, and culture-independent methods, including terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis, were performed to evaluate the bacterial communities. Analysis of similarities (ANOSIM) and multidimensional scaling (MDS) analysis of T-RFLP patterns demonstrated that differences in the bacterial community composition between the control and the macrofauna-inhabited sediments were not as great as expected, although the chemical properties of the sediments changed remarkably. Nevertheless, the dominant bacterial group in each type of macrofauna-inhabited sediment was different. Acidobacteria, Betaproteobacteria, and Deltaproteobacteria were the dominant bacterial groups in sediments inhabited by C. fluminea, tubificid worms, and Chironomidae larvae, respectively. The data obtained in this study are helpful for understanding the effects of bioturbation in a shallow, eutrophic lake.

scholarly journals Long-term dynamics of flora of karst lakes: Changes and current state

2018 ◽  
Vol 26 (2) ◽  
pp. 160-169
Author(s):  
E. A. Belyakov ◽  
E. V. Garin
Keyword(s):  
Native Species ◽  
Chemical Properties ◽  
Floristic Composition ◽  
Water Bodies ◽  
Water Withdrawal ◽  
Zizania Latifolia ◽  
Volga River ◽  
Novgorod Oblast ◽  
Bidens Frondosa

Long-term observations of the rates and pattern of changes in flora and vegetation contribute to understanding of one of the most important contemporary global problems, the eutrophication of water bodies. In this study, using classical floristic methods, we attempt to determine (for a period of almost 80 years) the nature and possible causes of changes in the floristic composition of the lakes of karst origin, Velikoe and Parovoe (Pustinskaya lake-river system, the right bank of Nizhny Novgorod oblast). The paper shows that over a long period of observations a significant transformation of the vegetation cover has occurred in the lakes. The process was accompanied by the disappearance of a number of native species and appearance of others, including adventitious ones (for example, Elodea canadensis Michx., Zizania latifolia (Griseb.) Stapf, Bidens frondosa L. and Epilobium adenocaulon Hausskn.). The weak saturation of the flora with adventive species indicates that the reservoirs are subject to moderate anthropogenic transformation. This is also indicated by the presence of characteristic indicator species, for example, Najas minor All., Glyceria fluitans (L.) R. Br., Hydrocharis morsus-ranae L. and Stratiotes aloides L. in the plant communities. In addition, the studied water bodies are subject to a further increase in the degree of eutrophication. This can be judged by scattered records of Potamogeton trichoides Cham. et Schlecht., the disappearance of a number of species (such as Elatine alsinastrum L. and Callitriche hermaphroditica L.), as well as the presence of a significant number of macrophyte indicators of the eutrophic state of water bodies. We suggest that a gradual increase in the trophicity of the studied water bodies is due to a combination of anthropogenic impact (water withdrawal for economic needs, recreational load), natural and climatic features of the region (alternation of high and low water periods) and the natural succession processes associated with the current fundamental changes in the conditions of the runoff formation in the Volga River basin. As a result of studies conducted by authors in 2014–2015, it has been shown that in general the taxonomic and ecological structures of the flora of both lakes are quite diverse and traditional for the territory and the European part of Russia. Meanwhile, the flora of these two reservoirs insignificantly differs in taxonomic composition, which is due to their individual morphometric characteristics, the physical and chemical properties of the aquatic environment, and the nature of the anthropogenic load. At the same time, the equilibrium balance of coastal and aquatic plants in the flora of Lake Parovoe (in contrast to Lake Velikoe) indicates a degree of successional stability of its floristic complex.

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