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Wen L.-L.,Zhejiang University | Lai C.-Y.,Zhejiang University | Yang Q.,Hangzhou Institute of Environmental Protection Science | Chen J.-X.,Zhejiang University | And 3 more authors.
Enzyme and Microbial Technology | Year: 2016

We designed a primer set to target selenate reductase (SerA) for detecting selenate reducing bacteria (SeRB). Our serA gene-based PCR primer set has high specificity in that it and positively amplified some SeRB, but not denitrifying bacteria (DB). Phylogenetic analysis of serA clone sequences of environmental samples from selenate-reducing membrane biofilm reactor (MBfR) biofilms showed that these sequences were closely grouped and had high similarity to selenate reductase gene sequences from SeRB Thauera selenatis and DB Dechloromonas; however, they were distant to other genes from dimethylsulfoxide (DMSO) enzyme family. Constructing a standard curve targeting the serA gene, we found that the good linearity for the qPCR assay when applied it to quantify SeRB in MBfR biofilms, and the gene copies of SeRB correlated well to the selenate removal percentages. Our results demonstrated the feasibility of using the serA gene-based PCR primer set to detect and quantify SeRB in environmental samples. © 2016 Elsevier Inc.

Dong C.-Y.,Zhejiang GongShang University | Yu Z.-M.,Hangzhou Institute of Environmental Protection Science | Wu Z.-X.,Chunan Environmental Monitoring Station | Wu C.-J.,Zhejiang GongShang University
Huanjing Kexue/Environmental Science | Year: 2013

Lake Qiandao is a typical subtropical man-made reservoir in China. The investigation on the seasonal and vertical dynamics of water temperature, dissolved oxygen (DO), pH value, turbidity, photosynthetic available radiation (PAR) and chlorophyll a was conducted in 2011 in order to find out the physical characteristics of Lake Qiandao. The average surface water temperature ranged from 10.4 to 32.7°C. A monomictic thermal stratification was observed in Lake Qiandao, initiating in April and lasting until December. The results showed that thermal stratification had influences on vertical distribution of DO, pH value, turbidity, PAR and chlorophyll a. Very strong stratification of DO was found, inducing lower oxygen concentration in the thermocline layer and temporal hypoxia in the bottom water. The maximum turbidity was found in the thermocline layer and the precipitation affected the surface turbidity value. Moreover, the chlorophyll a concentration was higher in the surface water and lower in the bottom water as found in this study, implying that water quality was affected by stratification. Besides, the maximum photosynthesis rate and algal growth rate were found at the depth 5-10 m below the water surface. Therefore, the results can provide theoretical support for the sampling and analysis of algal blooms in Lake Qiandao.

Wen L.-L.,Zhejiang University | Yang Q.,Hangzhou Institute of Environmental Protection Science | Zhang Z.-X.,Zhejiang University | Yi Y.-Y.,Zhejiang University | And 3 more authors.
Science of the Total Environment | Year: 2016

This work evaluated the interaction of perchlorate and trichloroethene (TCE), two common co-contaminants in groundwater, during bioreduction in serum bottles containing synthetic mineral salts media and microbial consortia. TCE at concentrations up to 0.3 mM did not significantly affect perchlorate reduction; however, perchlorate concentrations higher than 0.1 mM made the reduction of TCE significantly slower. Perchlorate primarily inhibited the reduction of vinyl chloride (VC, a daughter product of TCE) to ethene. Mechanistic analysis showed that the inhibition was mainly because perchlorate reduction is thermodynamically more favorable than reduction of TCE and its daughter products and not because of toxicity due to accumulation of dissolved oxygen produced during perchlorate reduction. As the initial perchlorate concentration increased from 0 to 600 mg/L in a set of serum bottles, the relative abundance of Rhodocyclaceae (a putatively perchlorate-reducing genus) increased from 6.3 to 80.6%, while the relative abundance of Dehalococcoides, the only known genus that is able to reduce TCE all the way to ethene, significantly decreased. Similarly, the relative abundance of Proteobacteria (a phylum to which most known perchlorate-reducing bacteria belong) increased from 22% to almost 80%. © 2016 Elsevier B.V.

Sheng H.,Nanjing Forestry University | Sheng H.,Hangzhou Institute of Environmental Protection Science | Wu Z.,Chunan Environmental Monitoring Station | Liu M.,Hangzhou Institute of Environmental Protection Science | And 4 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2015

Based on the monthly water quality monitoring data and hydro-meteorological data from 2003 to 2012, this study analyzed water quality and nutritional status in Xin'anjiang reservoir and investigated the relationship between water quality change and hydro-meteorological factors. The results showed that the interannual variability of total phosphorus, total nitrogen, BOD and pH value were significant in the past 10 years in Xin'anjiang Reservoir. Chlorophyll a concentration increased in recent 10 years. Comprehensive nutrition state index showed that the reservoir trophic status was improved gradually from oligotrophic to mesotrophic. Nutrient and chlorophyll a was higher in riverine zone than transitional and lacustrine zone and in flooding season than dry season, which indicated that reservoir nutrients came mainly from non-point source pollution. The mean annual air temperature and water temperature decreased, while rainfall, out flow and in flow increased. The correlation analysis showed that hydro-meteorological factors had significant impacts on water quality index. ©, 2014, Science Press. All right reserved.

Sheng H.-Y.,Nanjing Forestry University | Sheng H.-Y.,Hangzhou Institute of Environmental Protection Science | Yu Z.-M.,Hangzhou Institute of Environmental Protection Science | Liu M.-L.,Hangzhou Institute of Environmental Protection Science | And 3 more authors.
Chinese Journal of Ecology | Year: 2014

Qiandao Lake is one of China's ten major reservoirs and the most important strategic source of drinking water in the Yangtze River Delta region. An investigation was conducted on the water quality and the community structure of phytoplankton at 8 sampling sites in Qiandao Lake of Southeast China in January 2010. The photosynthetic activity of phytoplankton was measured by Phyto-PAM (Pulse Amplitude Modulation) and Water-PAM. The water quality indicators were in accordance with the requirements of the water environmental function zones except TN. There was a stratification of water temperature, physical and chemical indicators in winter. The thermocline depth was between 25 -40 m. Diatoms, cyanobacteria, green algae, cryptophyta, dinoflagellates, and golden algae were observed in winter. Dominant phytoplankton groups were Diatoms (Melosira and Cyclotella). They accounted for 60% of the total density. Chlorophyll a concentration varied from 1. 4 to 5. 7 μg·L-1. The results suggested that the photosynthetic activity of phytoplankton was active in winter. Diatoms had the maximum photosynthetic activity, secondly cyanobacteria, and finally green algae. There were significant horizontal and vertical spatial differences in photosynthetic activity. The light saturation intensity of phytoplankton in Qiandao Lake ranged between 700-1000 μmol·s-1·m-2. The results also suggested that the high photosynthetic activity of diatoms relate to the outbreak of diatom bloom in Qiandao Lake in spring.

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