Institute of Hydrobiology, Chinese Academy Of Sciences
Not a member yet
20118 research outputs found
Sort by
Higher carbon sequestration potential and stability for deep soil compared to surface soil regardless of nitrogen addition in a subtropical forest
No full textBackground. Labile carbon input could stimulate soil organic carbon (SOC) mineralization through priming effect, resulting in soil carbon (C) loss. Meanwhile, labile C could also be transformed by microorganisms in soil as the processes of new C sequestration and stabilization. Previous studies showed the magnitude of priming effect could be affected by soil depth and nitrogen (N). However, it remains unknown how the soil depth and N availability affect the amount and stability of the new sequestrated C, which complicates the prediction of C dynamics.
Methods. A 20-day incubation experiment was conducted by adding C-13 labeled glucose and NH4NO3 to study the effects of soil depth and nitrogen addition on the net C sequestration. SOC was fractioned into seven fractions and grouped into three functional C pools to assess the stabilization of the new sequestrated C.
Results. Our results showed that glucose addition caused positive priming in both soil depths, and N addition significantly reduced the priming effect. After 20 days of incubation, deep soil had a higher C sequestration potential (48% glucose-C) than surface soil (43% glucose-C). The C sequestration potential was not affected by N addition in both soil depths. Positive net C sequestration was observed with higher amount of retained glucose-C than that of stimulated mineralized SOC for both soil depths. The distribution of new sequestrated C in the seven fractions was significantly affected by soil depth, but not N addition. Compared to deep soil, the new C in surface soil was more distributed in the non-protected C pool (including water extracted organic C, light fraction and sand fraction) and less distributed in the clay fraction. These results suggested that the new C in deep soil was more stable than that in surface soil. Compared to the native SOC for both soil depths, the new sequestrated C was more distributed in non-protected C pool and less distributed in biochemically protected C pool (non-hydrolyzable silt and clay fractions). The higher carbon sequestration potential and stability in deep soil suggested that deep soil has a greater role on C sequestration in forest ecosystems
Seasonal variation of microcystins and their accumulation in fish in two large shallow lakes of China
No full textBioaccumulation of microcystins (MCs) has been widely observed in aquatic vertebrates and invertebrates, but its seasonal and specific variations remain unclear. In the present study, dissolved MCs in water, algal cell-bound MCs and muscle tissue MCs of nine fish species were investigated monthly in two of the largest shallow lakes in China: Lake Taihu and Lake Chaohu. The fish species were grouped as carnivorous, planktivorous, and omnivorous fish. Seasonal variations in dissolved and algal cell-bound MCs in water and MCs contents of fish hepatopancreas and muscle were investigated in the two lakes from 2009 to 2010. Dissolved MCs in water ranged from 0.35 to 2.56 mu g l(-1) in Lake Taihu and 0.16 to 2.45 mu g l(-1) in Lake Chaohu, and showed seasonally a unimodal distribution. Algal cell-bound MCs also showed a similar seasonal variation in both lakes, but dissolved MCs in water peaked about one month later than algal cell-bound MCs. The MCs content in the Fish muscle was higher MCs from October to December than in the other months. For most of the fish species, it exceeded the tolerable daily intake value established by the WHO. The averaged MCs content in the muscle of carnivorous, planktivorous, omnivorous fish was 48.2, 28.7 and 37.8 mu g kg(-1) in Lake Taihu, respectively, and 27.8, 18.6 and 20.4 mu g kg(-1) in Lake Chaohu. It was significantly higher in carnivorous fish than in planktivorous and omnivorous fish, indicating that carnivorous fish has a higher exposure risk to the local people when consuming the harvested fish. The average ratio of hepatopancreas to muscle MCs contents was 13.0, 25.2, 13.8 for carnivorous, planktivorous, omnivorous fishes in Lake Taihu, respectively, and 18.0, 24.9, 14.8 in Lake Chaohu. These ratio for planktivorous fish almost doubled that for carnivorous and omnivorous fish. High correlation of MC content in carnivorous, omnivorous and planktivorous fish indicates that MCs can be delivered along trophic levels in the food chains
Seasonal variation of microcystins and their accumulation in fish in two large shallow lakes of China
No full textBioaccumulation of microcystins (MCs) has been widely observed in aquatic vertebrates and invertebrates, but its seasonal and specific variations remain unclear. In the present study, dissolved MCs in water, algal cell-bound MCs and muscle tissue MCs of nine fish species were investigated monthly in two of the largest shallow lakes in China: Lake Taihu and Lake Chaohu. The fish species were grouped as carnivorous, planktivorous, and omnivorous fish. Seasonal variations in dissolved and algal cell-bound MCs in water and MCs contents of fish hepatopancreas and muscle were investigated in the two lakes from 2009 to 2010. Dissolved MCs in water ranged from 0.35 to 2.56 mu g l(-1) in Lake Taihu and 0.16 to 2.45 mu g l(-1) in Lake Chaohu, and showed seasonally a unimodal distribution. Algal cell-bound MCs also showed a similar seasonal variation in both lakes, but dissolved MCs in water peaked about one month later than algal cell-bound MCs. The MCs content in the Fish muscle was higher MCs from October to December than in the other months. For most of the fish species, it exceeded the tolerable daily intake value established by the WHO. The averaged MCs content in the muscle of carnivorous, planktivorous, omnivorous fish was 48.2, 28.7 and 37.8 mu g kg(-1) in Lake Taihu, respectively, and 27.8, 18.6 and 20.4 mu g kg(-1) in Lake Chaohu. It was significantly higher in carnivorous fish than in planktivorous and omnivorous fish, indicating that carnivorous fish has a higher exposure risk to the local people when consuming the harvested fish. The average ratio of hepatopancreas to muscle MCs contents was 13.0, 25.2, 13.8 for carnivorous, planktivorous, omnivorous fishes in Lake Taihu, respectively, and 18.0, 24.9, 14.8 in Lake Chaohu. These ratio for planktivorous fish almost doubled that for carnivorous and omnivorous fish. High correlation of MC content in carnivorous, omnivorous and planktivorous fish indicates that MCs can be delivered along trophic levels in the food chains
REVIEW PAPER ON TREATMENT OF INDUSTRIAL AND DOMESTIC WASTEWATERS USING UASB REACTORS INTEGRATED INTO CONSTRUCTED WETLANDS FOR SUSTAINABLE REUSE
No full textThe successful use of anaerobic technologies, especially up-flow sludge blanket (UASB) reactors for the treatment of raw domestic sewage and industrial wastewaters in tropical and subtropical countries opened the opportunity to substitute the aerobic processes with anaerobic reactors in removal of organic matter. Proper management of domestic and industrial wastewaters in developing nations is negligible. Even cost effective integrated green technologies like anaerobic reactor with constructed wetland technologies are not applied. Hence the objective of the present review was to assess the pollutant removal efficiency of the up flow anaerobic sludge blanket (UASB) reactor coupled with a constructed wetland (CW) in treating these wastewaters and their capability to produce quality water for sustainable reuse. To achieve the objectives, the review was organized using reputable journals, articles, and review papers. The interpretation of the result of each document was done using tables, bar graphs, Pie chart and lines. The results were reorganized again by calculating average flow rate, hydraulic loading rate, and percentage removal efficiencies. Most research results revealed that use of UASB-CW integrated treatment system is a promising technology in wastewater treatment and able to complying the effluent discharge standards Globally, the following abatement efficiencies ranged from 79.2-93.9%, 89.2-92.9%, 87.2-96.3%, 22.6-96.9%, 33-85.9%, and 97.9-99.99% were achieved for Chemical oxygen demand (COD), Biological oxygen demand (BOD), Total suspended solid (TSS), Total Kjeldhal Nitrogen (TKN), Total phosphorus (TP) and fecal Coliforms (FC), respectively using UASB-CW treatment systems. UASB-CW technologies are effectively integrated treatment systems and can be used for resource scarce developing countries. Since, both treatment technologies are cost-effective, easy operation and maintenance and capable of meeting effluent standards Hence, the indiscriminate disposal of wastewaters and their environmental impacts in Ethiopia can be resolved using these low-cost combined treatment technologies
Establishment of an Agrobacterium mediated transformation protocol for the detection of cytokinin in the heterophyllous plant Hygrophila difformis (Acanthaceae)
No full textKey message This is the first report of a highly efficient Agrobacterium tumefaciens-mediated transformation protocol for Acanthaceae and its utilization in revealing important roles of cytokinin in regulating heterophylly in Hygrophila difformis. Plants show amazing morphological differences in leaf form in response to changes in the surrounding environment, which is a phenomenon called heterophylly. Previous studies have shown that the aquatic plant Hygrophila difformis (Acanthaceae) is an ideal model for heterophylly study. However, low efficiency and poor reproducibility of genetic transformation restricted H. difformis as a model plant. In this study, we reported successful induction of callus, shoots and the establishment of an efficient stable transformation protocol as mediated by Agrobacterium tumefaciens LBA4404. We found that the highest callus induction efficiency was achieved with 1 mg/L 1-Naphthaleneacetic acid (NAA) and 2 mg/L 6-benzyladenine (6-BA), that efficient shoot induction required 0.1 mg/L NAA and 0.1 mg/L 6-BA and that high transformation efficiency required 100 mu M acetosyringone. Due to the importance of phytohormones in the regulation of heterophylly and the inadequate knowledge about the function of cytokinin (CK) in this process, we analyzed the function of CK in the regulation of heterophylly by exogenous CK application and endogenous CK detection. By using our newly developed transformation system to detect CK signals, contents and distribution in H. difformis, we revealed an important role of CK in environmental mediated heterophylly
Evolution and genetics of bighead and silver carps: Native population conservation versus invasive species control
No full textBighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), collectively called bigheaded carps, are cyprinids native mainly to China and have been introduced to over 70 countries. Paleontological and molecular phylogenetic analyses demonstrate bighead and silver carps originated from the Yangtze-Huanghe River basins and modern populations may have derived from the secondary contact of geographically isolated fish during the last glacial events. Significant genetic differences are found among populations of native rivers (Yangtze, Pearl, and Amur) as well as introduced/invasive environments (Mississippi R., USA and Danube R., Hungary), suggesting genetic backgrounds and ecological selection may play a role in population differentiation. Population divergence of bighead carp or silver carp has occurred within their native rivers, whereas, within the Mississippi River Basin (MRB)-an introduced region, such genetic differentiation is likely taking place at least in silver carp. Interspecific hybridization between silver and bighead carps is rare within their native regions; however, extensive hybridization is observed in the MRB, which could be contributed by a shift to a more homogenous environment that lacks reproductive isolation barriers for the restriction of gene flow between species. The wild populations of native bighead and silver carps have experienced dramatic declines; in contrast, the introduced bigheaded carps overpopulate the MRB and are considered two invasive species, which strongly suggests fishing capacity (overfishing and underfishing) be a decisive factor for fishery resource exploitation and management. This review provides not only a global perspective of evolutionary history and population divergence of bigheaded carps but also a forum that calls for international research collaborations to deal with critical issues related to native population conservation and invasive species control
Infectious pancreatic necrosis virus inhibits infectious hematopoietic necrosis virus at the early stage of infection in a time dependent manner during Co-infection in Chinook salmon embryo cell lines
No full textSalmonids can be co-infected by infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) under natural or experimental conditions. To reveal the influence of IPNV on IHNV in co-infections, CHSE-214 cells were inoculated with IPNV at different time intervals prior to or after IHNV infection. Propagation of IHNV was determined by an immunofluorescence antibody test, real-time quantitative polymerase chain reaction, flow cytometry, and virus titration. The results showed that when cells were inoculated with IPNV prior to IHNV, IHNV multiplication was inhibited. This inhibitory effect became stronger with increasing time intervals (P 0.05) compared with the single IHNV infection group. The findings suggest that IHNV is inhibited at the early stage of infection by IPNV and in a time dependent manner during co-infection. Furthermore, the effect of IPNV on IHNV entry and expression of IHNV entry-related genes clathrin, dynamin-2, adaptor protein 2, and vacuolar protein sorting 35 were also determined. The results showed that IPNV did not affect the amount of IHNV entering the cells. However, the expression levels of clathrin and dynamin-2 were significantly lower in co-infection than those in single IHNV infection, which suggests that IPNV likely inhibits IHNV by affecting IHNV invasion via down-regulating IHNV entry-related genes clathrin and dynamin-2
Morphological and molecular characterization of a new freshwater microsporidium, Jirovecia sinensis sp. n. (Microsporidia) infecting the coelomocytes of Branchiura sowerbyi (Oligochaeta: Naididae) in China
No full textWe report a new microsporidium Jirovecia sinensis sp. n. from a freshwater oligochaete, Branchiura sowerbyi collected in Hongze city, Jiangsu province, East China. Numerous whitish hypertrophied coelomocytes of 0.33-0.59 mm in diameter indicated infection. Transmission electron microscopy observations revealed that all developmental stages were diplokaryotic. The earliest life stages observed were meronts that were in direct contact with host cytoplasm, accumulated peripherally in the hypertrophied coelomocytes and connected with host cytoplasm through many pinocytotic canals. Mature spores are rod-shaped with a blunt end, measuring 17.0 +/- 0.1 (14.9-18.5) mu m long and 2.0 +/- 0.2 (1.7-2.2) mu m wide. The most conspicuous character of the novel microsporidian parasite is the tail-like posterior prolongations, with a length of 29.6-40.8 mu m. Mature spores have a manubrium with a diameter of 447-485 nm which consist of six density-discontinuous concentric circles. Spores possess a collar-shaped anchoring disk and a bipartite polarplast with an anterior lamellar region and a posterior tubular section. SSU rDNA-based phylogenetic analysis indicated with high support values that the new species clustered with two Bacillidium species (B. vesiculoformis and Bacillidium sp.) infecting the freshwater oligochaetes and Janacekia debaisieuxi infecting the insect Simulium maculatum. Based on the ultrastructural features and molecular characteristics, a new species in the genus Jirovecia, Jirovecia sinensis sp. n., is designated
Ca2+ plays an antiviral role by increasing p53 expression to achieve protection against spring viraemia of carp virus infection
No full textCalcium (Ca) is a messenger that regulates a multitude of physiological processes, but its functions in antiviral progress remain undefined. In this study, we found that Ca-2(+) enhances fish survival to defend against spring viraemia of carp virus (SVCV) infection by reversing the instability of p53 mediated by the viral protein. First, Ca-2(+) significantly protected cells and fish against SVCV infection by inducing early apoptosis. Additionally, p53 expression, which was inhibited by SVCV N protein, was upregulated by Ca-2(+) treatment. Then, the mechanism underlying the reduction of K63-linked p53 ubiquitination by SVCV N protein via the K358 site was completely prevented by Ca-2(+). These findings reveal the role of Ca-2(+) in lower vertebrates in the antiviral response, which is connected to and corresponds with viral immune evasion, providing a solution to fish diseases caused by pathogens
A novel ternary magnetic Fe3O4/g-C3N4/Carbon layer composite for ef ficient removal of Cr (VI): A combined approach using both batch experiments and theoretical calculation
No full textHeavy metal pollution has posed a potential hazard to the ecological environment and human health. Herein, a novel ternary magnetic adsorbent (Fe3O4/g-C3N4/Carbon layer, Carbon layer: hydrothermal products from sucrose) was synthesized through a simple hydrothermal carbonization (HTC) method for removal of hexavalent chromium (Cr (VI)) removal. The Carbon layer (CL) formed during the HTC of carbon precursors (sucrose) acted as a reducing agent. Also, it has abundant oxygen-containing groups on its surface. The Fe3O4/g-C3N4/CL had a high removal capacity for Cr (VI) (50.09 mg/g), and excellent regeneration and magnetic separation performance. Importantly, the Fe3O4/g-C3N4/CL could not only improve the adsorption ability for Cr (VI), but also strengthen the immobilization of Cr (III). Based on the comprehensive experiments and characterization, combined with DFT calculations, we proposed that, the first time, the removal of Cr (VI) was controlled by three consecutive processes: (1) ion exchange of Cr (VI) by hydroxyl groups, (2) reduction of Cr (VI) to Cr (III) by electron-donor (oxygen-containing) groups (EDGs), and (3) complexation of Cr (III) by amine groups. This study provides a new avenue for the removal of toxic oxygen anions and reveals an original removal mechanism of Fe3O4/g-C3N4/CLx (x = hydrothermal products from carbon precursors (glucose, ascorbic acid, cellulose)). (C) 2020 Elsevier B.V. All rights reserved