[Utilization and growth response of Chrysosporum ovalisporum to different phosphorus compounds]. / 卵孢金孢藻对不同磷化合物的利用及生长响应.

To explore the ability of bloom-forming cyanobacterium Chrysosporum ovalisporum to utilize different kinds of phosphorus compounds in the water column, we examined the growth response of C. ovalisporum in the laboratory by taking dipotassium hydrogen phosphate as the control and set different treatments of phosphorus substrates. The results showed that C. ovalisporum could utilize sodium tripolyphosphate and terasodium pyrophosphate decahydrate, with better utilization of sodium tripolyphosphate. After 15 days, it had the highest biomass and chlorophyll a concentrations under the treatment of sodium tripolyphosphate, with a value of (426.96±47.42) mg·L-1 and (1852.34±116.60) µg·L-1, respectively. Compared with the control, there was no significant difference in biomass of C. ovalisporum under both the (2-aminoethyl)-phosphonic acid and disodium ß-glycerol phosphate pentahydrate treatments. The change characteristics of dissolved inorganic phosphate were related to the alkaline phosphatase activity, indicating that C. ovalisporum was able to utilize these two organophosphorus compounds via enzyme hydrolysis. The concentration of dissolved inorganic phosphate reached 0 mg·L-1 during the whole experiment when the C. ovalisporum were fed with glyphosate. Biomass, specific growth rate, chlorophyll a concentration and photosynthetic activity of algal cells were significantly lower than those of the control, indicating that C. ova-lisporum could not uptake phosphorus compounds in the glyphosate substrate and thus their growth being inhibited. Our results present new insights to understand the diffusion mechanism of C. ovalisporum into different aquatic ecosystems and had theoretical reference value for the prevention and control of new cyanobacterial blooms.

[Characteristics of Phytoplankton Community and Its Relationship with Environmental Factors in Different Regions of Yilong Lake, Yunnan Province, China].

Yilong Lake, a shallow, plateau lake, is the ninth largest water body in the Yunnan Province, China. In order to figure out the characteristics of phytoplankton communities in different regions of this lake, the phytoplankton and environmental factors in the west region, east region, and in a submerged macrophytes restoration demonstration region were monthly investigated and analyzed from August 2013 to July 2014. The results showed that the habitats in different regions were spatially heterogeneous. Total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH4+-N), five-day biochemical oxygen demand (BOD5), transparency (SD), turbidity (Turb.), and electrical conductivity (EC) had no significant differences between the demonstration region and the west region, but these two regions showed significant differences in comparison with the east region (P<0.05). The largest phytoplankton density was Cyanophyta and the dominant species in the three regions were different. Mersmopedia tenuissima had the highest dominance in the west region; Cylindrospermopsis raciborskii and Pseudanabaena limntica were the most dominant taxa in the east region; while Merismopedia tenuissima and Anabaenopsis sp. were dominant in the O. uminata restoration demonstration region. PCoA compared the ß diversity of phytoplankton communities in the three different regions based on the entire year investigations. It was found that the community structures of the west region and O. uminata restoration demonstration region were similar (P>0.05), but they were significantly different from the community from the east region (P<0.01). Redundant analysis (RDA) showed that TN, TP, BOD5, and SD were the main environmental factors affecting the distribution of phytoplankton community in Yilong Lake. In addition, NH4+-N, EC, permanganate index, and pH also have a certain effect on the phytoplankton community.

Two symmetrical unsaturated acids isolated from Viscum album.

In the present study, two new acetylene conjugate compounds, dibutyl (2Z, 6Z)-octa-2, 6-dien-4-yne dioate (1), and dibutyl (2E, 6E)- octa-2, 6-dien-4-yne dioate (2), were isolated from the dry stem leaves of Viscum album, along with nine known compounds (3 - 11). Their structures were confirmed on the basis of spectroscopic data. Compounds 1 and 8 showed antioxidant activity against xanthine oxidase (XOD) and 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydroxyl (DPPH), with the IC50 of 1.22 and 1.33 µmol·L-1, and the SC50 of 4.34 and 8.22 µmol·L-1, respectively.

[Succession Characteristics of Phytoplankton Functional Groups and Their Relationships with Environmental Factors in Dianshan Lake, Shanghai].

Dianshan Lake, a subtropical shallow lake, is one of the main drinking water sources of Shanghai City. In order to explore the characteristics of phytoplankton functional groups (PFGs) and their relationships with environmental factors in Dianshan Lake, phytoplankton and water samples collected from January 2015 to December 2016 were characterized. Results suggested that there were 26 PFGs during our study period. The biomasses of 15 PFGs (B, C, D, F, G, H1, J, Lo, M, MP, P, W1, W2, X1, and X2) were dominant and had marked annual succession patterns: D/C Lo/C/MP MP/J/P/W1 P in 2015 and P W2/Lo W2/G/M/H1 P in 2016. To elucidate the relationships of PFGs with the environmental factors, canonical correspondence analysis (CCA) was conducted. Results showed that water level fluctuation (WLF), dissolved oxygen (DO), water temperature (WT), total phosphorus (TP), electrical conductivity (EC), transparency (SD), and total nitrogen (TN) were the main impact factors associated with the composition variations of PFGs in Dianshan Lake. From this study, it is proposed that the effects of nitrogen, phosphorus, and WLF on the PFGs in Dianshan Lake should be paid more attention.

[Effects of Nutrient Addition on the Growth and Competition of Bloom Forming Cyanobacterium Chrysosporum ovalisporum: An In-situ Experiment].

An in-situ mesocosm experiment was conducted to study the growth dynamic of Chrysosporum ovalisporum and the other phytoplankton organisms under accelerated eutrophication conditions by using 39 buckets (100 L) in Lake Dishui, Shanghai. The results showed that the growth of both filamentous cyanobacteria (C. ovalisporum) and green algae were promoted with nutrient enrichment. The increase in the algal biomass rate in N plus P addition treatments was significantly higher than in treatments with N or P alone (P<0.05). Although the increasing biomass rate with P addition alone was higher than with N alone, there was no statistically significant difference (P>0.05). The relevant abundance of C. ovalisporum showed a significantly decreasing trend with N addition treatments and N plus P additions treatments (P<0.05), although it was slightly increased with the treatments with P alone (P>0.05). Nutrient addition could significantly improve the growth of small sized algae organisms (Chroococcus spp., Coelastrum spp., Chlorella spp., Tetraedron spp., and Scenedesmus spp.) rather than C. ovalisporum in all treatments (P<0.05). The small sized green algae overcoming C. ovalisporum indicated that small sized algae were more favored by hyper-eutrophicated, high water temperature and relatively undisturbed conditions. This is because small sized algal organisms have higher metabolic and growth rates compared to other sized algae, especially in stationary water regimens and high, light density conditions. We foresee that the small sized algae, Chlorophyte, dominating the small hyper-eutrophic aquatic system may be a potential succession pattern in the high water temperature seasons.

[Distribution and Pollution Assessment of Nutrient and Heavy Metals in Surface Sediments from Lake Gehu in Southern Jiangsu Province, China].

This study investigated the horizontal distribution characteristics of nutrients and heavy metals (Zn, As, Cr, Cu, Ni, Pb, Cd and Hg) in January, 2014, and assessed the potential ecological risk of Lake Gehu. It was found that the average contents of TN and TP were 2,207.94 and 708.62 mg · kg⁻¹ respectively. TN and TP contents of the sediments at the centre were significantly highei than those in the north, while the TN content in the south was also significantly higher than that in the north of Lake Gehu. The average contents of Zn, As, Cr, Cu, Ni, Pb, Cd, Hg were 766.59, 350.66, 307.98, 59.54, 122.67, 168.97, 2.34, 0.41 mg · kg⁻¹, respectively. The content of Cu at the centre was significantly higher than that in the north, and the Zn content at the centre was significantly greater than that in the south of Lake Gehu, however the difference in the content of other heavy metals at these three areas was not significant. Furthermore, the obvious correlation between elements and granularity was only found in the aspect of TP, Cu and Hg. The comprehensive pollution index (PI) indicated that the Lake Gehu was heavily polluted, especially the centre and south areas. The potential ecological risk index (RI) showed that Cd, As and Hg had caused serious pollution in Lake Gehu while the other heavy metals only induced slight or medium pollution. According to the contribution of Cd, As and Hg to RI, it was concluded that the sediments in Lake Gehu were at a serious potential ecological risk.

[Community structure of macrozoobenthos and its relationship with environmental factors in Lake Gehu, Jiangsu, China.] / æ±Ÿè‹æ»†æ¹–å¤§åž‹åº•æ –åŠ¨ç‰©ç¾¤è½ç»“æž„åŠå ¶ä¸ŽçŽ¯å¢ƒå› å­çš„å ³ç³».

A survey on macrozoobenthos was conducted seasonally and 14 aquatic physicochemical parameters were monitored monthly to reveal the community characteristics of macrozoobenthos and their relationship with aquatic environmental factors at 20 sampling sites in the Lake Gehu from July 2013 to December 2014. A total of 25 macrozoobenthos species including 3 species (12% of total) of Mollusca, 12 species (48%) of Chironomidae, 4 species (16%) of Oligochaeta, 4 species (16%) of Crustacean were identified. The dominant species were Limnodrilus hoffmeisteri, Branchiuras owerbyi, Tanypus chinensis, and Propsilocerus taihuensis. Density and biomass of Chironomid larvae and Oligochata had significant spatial and seasonal changes. The state of aquatic environment was mainly affected by the nitrogen, phosphorus and water temperature in the Lake Gehu, and TN, NO3--N and DO changed significantly with space and season. The Spearman correlation analysis indicated that TN and NO3--N played a key role in the community structure characteristics of the macrozoobenthos in the Lake Gehu. The environmental variables could well explain the changes of main macrobenthic species.

A molecularly imprinted photonic polymer sensor with high selectivity for tetracyclines analysis in food.

A molecularly imprinted photonic polymer (MIPP) sensor for respective detection of tetracycline, oxytetracycline and chlortetracycline is developed based on the combination of a colloidal crystal templating method and a molecular imprinting technique. Colloidal crystal templates are prepared from monodisperse polystyrene colloids. The molecularly imprinted polymer, which is embodied in the colloidal crystal templates, is synthesized with acrylic acid and acrylamide as monomers, N,N'-methylene bisacrylamide as a cross-linker and tetracyclines (TCs) as imprinting template molecules. After removal of the colloidal crystal template and the molecularly imprinted template, the resulted MIPP consists of a three-dimensional, highly ordered and interconnected macroporous array with a thin hydrogel wall, where nanocavities complementary to analytes in shape and binding sites are distributed. The response of MIPP to TCs stimulants in aqueous solution is detected through a readable Bragg diffraction red-shift, which is due to the lattice change of MIPP structures responding to their rebinding to the target TCs molecules. A linear relationship was found between the Δλ and the concentration of TCs in the range from 0.04 µM to 0.24 µM. With this sensory system, direct and selective detection of TCs has been achieved without using label techniques and expensive instruments. The developed method has been applied successfully to detect tetracycline in milk and honey samples.

[Dynamic of phytoplankton abundance and the relationship with environmental factors in Dianshan Lake, Shanghai].

During January 2004 to December 2006, the abundance of phytoplankton and environmental factors such as the water temperature, wind speed, transparency of water (SD), TN, TP, pH, and permanganate index were monitored monthly in Dianshan Lake. The water quality of Dianshan Lake was in the mid-eutrophication state. The correlation analysis between phytoplankton community and environmental factors were performed. It indicated that the phytoplankton abundance, cyanobacteria abundance in Dianshan Lake were positively correlated with temperature (r = 0.487, r = 0.497), pH (r = 0.415, r = 0.379) and permanganate index (r = 0.460, r = 0.436), and negatively correlated with SD (r = -0.382, r = -0.394). Chlorophyta abundance in Dianshan Lake was positively correlated with PO4(3-) -P (r = 0.466). There was also a significant positive correlation between phytoplankton abundance and cyanobacteria abundance (r = 0.970). According to (CCA) ordination analysis, temperature, DO, SD and PO4(3-) -P were main factors affecting dynamic characteristics of phytoplankton community. The meteorological and hydrological factors were more important than nutrition concentration related to the water bloom in Dianshan Lake.