Fan-Hua Nan

The occurrence and distribution of pharmaceutical compounds in the effluents of a major sewage treatment plant in Northern Taiwan and the receiving coastal waters.

The pharmaceutical residues in waste water from the largest sewage treatment plant (STP) in Northern Taiwan and in seawater around the effluent discharged area were determined. An environmental risk assessment for the marine environment was conducted based on the environment risk quotient (ERQ). The concentrations of the analyzed compounds in STP influent and effluent were generally higher than those found in coastal seawater. Relatively higher values were found at the estuarine mouth and the discharged area, suggesting that the STP effluent is a point source. The removal efficiency and half life of the analyzed compounds were 6.3-46.8% and 3-18 days, respectively. The ERQ value theoretical calculation was generally greater than 1. However, when the measured concentrations replaced the predicated concentrations, the ERQ values were considerably lower than 1. Therefore, our results call for a re-evaluation of the risks posed by pharmaceuticals to coastal marine ecosystems in Northern Taiwan.

Relationships between persistent organic pollutants and carbonaceous materials in aquatic sediments of Taiwan

Recent studies have shown that many persistent organic pollutants (POPs, e.g., polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and various pesticides), are strongly associated with carbonaceous materials (including organic carbon (OC) and black carbon (BC)). We hypothesize that carbonaceous materials can be used as a first-order pollution index, to indicate areas where POP pollution may require further investigation. We tested our hypothesis and found that strong, positive correlations between BC and OC contents versus the concentrations of PCBs (and PAHs) existed in estuarine sediments of the Danshui River in 2005 and 2008. Thus, our preliminary results demonstrate that POC and BC are potential indicators of the POP pollution potential in fluvial sediments of the Danshui River in Taiwan. This innovative approach can provide a simple, relatively inexpensive and expedient means to monitor concentrations of POPs in polluted aquatic sediments of Taiwan, and/or those having a legacy of POP inputs.

Polycyclic aromatic hydrocarbons in surface sediments of the East China Sea and their relationship with carbonaceous materials.

This study measured concentrations of polycyclic aromatic hydrocarbons (PAHs) in surface sediments in the East China Sea (ECS) to investigate possible sources and fate of PAHs. Total concentration of PAHs in the sediments of the ECS ranged from 22 to 244 ng g(-1), with the highest levels in the coastal area and outer shelf. The observed PAH results showed elevated levels in both inner and outer shelf areas, a finding that is different from predictions by an ocean circulation model, suggesting that terrestrial sources are important for PAH contaminations in the ECS, while sediment resuspension, tidal changes and lateral transport may be important in affecting the distribution of PAHs in the outer shelf. The distribution of PAHs in the surface sediments of the ECS is similar to the distribution of carbonaceous materials (e.g., particulate organic carbon and black carbon), suggesting that carbonaceous materials may strongly affect the distribution of PAHs.

Detection and removal of mercury and lead ions by using gold nanoparticle-based gel membrane

This paper describes the use of two types of bovine serum albumin (BSA)-capped 14.2 nm diameter gold nanoparticles (Au NPs) for the separate detection of mercury (Hg2+) and lead (Pb2+) ions in highly saline media. The BSA-capped Au NPs were stable in solutions containing up to 500 mM NaCl. Introduction of BSA to a solution of rhodamine 6G (R6G) and 3-mercaptopropionic acid (MPA)-modified Au NPs (R6G/MPA–Au NPs) provided a R6G/MPA–Au NP@BSA probe for the sensing of Hg2+ ions. We also used BSA-capped Au NPs to detect Pb2+ ions through a mechanism based on Pb2+ ions accelerating the leaching rate of Au NPs in the presence of thiosulfate (S2O32−) and 2-mercaptoethanol (2-ME). The resulting deposition of Hg2+ ions onto the Au NPs induced the release of R6G from the surfaces of the Au NPs, causing increased fluorescence from the R6G/MPA–Au NP@BSA solution. The Pb2+ ions accelerated the dissolution of the 2-ME/S2O32−–Au NPs@BSA into solution, leading to dramatic decreases in the absorption. These two Au NP-based probes were highly sensitive (LOD ≈ nM) and selective (over 100-fold against other metal ions) toward Hg2+ or Pb2+ ions. We validated the practicality of these two probes through analyses of seawater and urine samples. We also developed a simple gel-based membrane for removal and sensing of Hg2+ or Pb2+ in aqueous solutions. The agarose gel was used to trap BSA-Au NPs, leading to the preparation of a nanocomposite film of Au NPs@BSA-decorated agarose gel membrane (Au NPs@BSA/AGM) for removing Hg2+ or Pb2+ in solution. In addition, R6G/MPA–Au NP@BSA-trapped agarose gel membrane (R6G/MPA–Au NP@BSA/AGM) and 2-ME/S2O32−–Au NPs@BSA/AGM allowed for the rapid and simple detection of Hg2+ and Pb2+, respectively.

Effect of ambient ammonia on ammonia-N excretion and ATPase activity of Penaeus chinensis

Abstract Ammonia-N excretion, total ATPase and Na+, K+-ATPase activities of Penaeus chinensis (10.38 ± 0.30 g) which were individually exposed to 0.037, 5.043, 10.106 and 20.093 mg/l ammonia-N (un-ionized plus ionized ammonia as nitrogen) were determined every 4 h up to 24 h. Ammonia-N excretion of shrimp exposed to control (0.037 mg/l ammonia-N) increased with time elapsed. Ammonia-N excretion of shrimp increased with ambient ammonia-N in the range of 0.037 to 5.043 mg/l, but decreased in the range of 5.043-20.093 mg/l. Ammonia-N excretion was inhibited as shrimp were exposed to higher than 10.106 mg/l ammonia-N after 4 h. Shrimp exposed to 20.093 mg/l ammonia-N had higher ammonia-N uptake than those exposed to 10.106 mg/l ammonia-N. The shrimp exposed to 5.043 mg/l ammonia-N had higher total ATPase and Na+, K+-ATPase activities in the gill than controls after 4, 8, 16 and 24 h. However, total ATPase and Na+, K+-ATPase activities of shrimp exposed to 10.106 and 20.093 mg/l ammonia-N were significantly lower than those exposed to 5.043 and 0.037 mg/l ammonia-N after 8 h.

Changes of Oxygen Consumption and Ammonia-n Excretion by Penaeus Chinensis Osbeck at Different Temperature and Salinity Levels

ABSTRACT Both oxygen consumption (O2 mg/g/h) and ammonia-N excretion (mg/g/h) by juveniles of Penaeus chinensis Osbeck (0.315 ± 0.062 g) were higher at 25°C than at 15°C at salinities of 15, 20, 25, and 30 ppt. At both temperatures (15° and 25°C) measured at 15, 20, 25, and 30 ppt, oxygen consumption was highest at 30 ppt and lowest at 20 ppt. Ammonia-N excretion decreased with increasing salinity from 15-30 ppt at 15° and 25°C. The change in the ratio of oxygen consumed to nitrogen excreted by atom according to the increase of salinity indicated a shift in nutrient utilization from protein-dominated to lipid-dominated metabolism that was more marked at 15°C than at 25°C.

Immunochemical and molecular characterization of a novel cell line derived from the brain of Trachinotus blochii (Teleostei, Perciformes): A fish cell line with oligodendrocyte progenitor cell and tanycyte characteristics.

Ependymal radial glial cells, also called tanycytes, are the predominant glial fibrillary acidic protein (GFAP)- and vimentin (VIM)-expressing cells in fish ependyma. Radial glial cells have been proposed to be neural stem cells but their molecular expression is not well understood. Previous studies revealed that fish neural progenitor and neural stem cells have A2B5, a marker for oligodendrocyte progenitor cells (OPCs). In this study, an A2B5(+) cell line, SPB, was isolated from the brain of the teleost Trachinotus blochii and characterized. SPB cells usually grew as polygonal epithelial cells, but at high density, long processes were commonly observed. Using immunocytochemistry, SPB cells were shown to exhibit oligodendrocyte markers such as galactocerebroside and Olig2, and radial glial cell markers such as brain lipid-binding protein, GFAP, Sox2, and VIM. SPB cells were also observed to have DARPP-32, a marker for tanycytes in mammals, and primary cilia. RT-PCR additionally revealed expression of bone morphogenetic protein 4, connexin35, Noggin2, and proteolipid protein in SPB cells. Results of this study suggest that SPB cells are OPCs that can display tanycyte characteristics. Fish tanycytes can be neural stem cells suggesting that SPB cells are neural stem cells. SPB is the first fish cell line showing primary cilia and markers for both OPCs and tanycytes.

Anisotropy and shift of search behavior in Malabar grouper (Epinephelus malabaricus) larvae in response to prey availability

In order to enhance encounters with prey, planktonic predators may display different swimming behavior with respect to food availability and distribution. In this study, we used 3D video techniques to record the swimming behavior of malabar grouper (Epinephelus malabaricus) larvae in both the absence and the presence of prey (Artemia sp. nauplii). Swimming properties were investigated in all of the 3D, the two vertical, and the horizontal projections using scale-dependent (mean speed and Net to Gross Displacement Ratio) and scale-independent (fractal dimension) metrics. When prey was added, larvae swam slower and in a less convoluted way as compared to what was observed in the absence of food. The results obtained with scale-dependant metrics were confirmed by those obtained with scale-independent analyses. Both unveiled the anisotropy of the swimming behavior of grouper larvae that tend to swim toward the vertical axis in order to maximize encounters with prey patches. This study shows that malabar grouper larvae can optimize their search volume by switching their behavior and further draws attention to the need to consider both vertical- and horizontal-projections components while addressing the plankter’s swimming trajectories.

Evaluation of the epinecidin-1 peptide as an active ingredient in cleaning solutions against pathogens

We tested the activity of epinecidin-1, a novel antimicrobial peptide structurally related to pleurocidin, in commercial cleaning solutions stored at 4 and 25 degrees C for 7 and 14 days. The peptides activities against Enterococcus faecalis, Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa, Staphylococcus aureus, Propionibacterium acnes, and Candida albicans were measured in a minimum inhibitory concentration (MIC) determination, minimal bactericidal concentration (MBC) determination, disk diffusion test, and a count of the bacterial numbers. Exposure to epinecidn-1 in a cleaning solution following MIC value comparisons in the disk diffusion test and counts of bacterial numbers after 16, 24, 48, and 72 h suggested that bacterial numbers were much lower than those treated with only commercial cleaning solutions for all bacteria. The efficacy of the antimicrobial activities of inhibiting bacterial numbers by epinecidin-1 in cleaning solutions at a low pH and a low temperature was not affected. Given its simple structure and antimicrobial activity, epinecidin-1 may be a useful component of microbicides designed to prevent pathogen infections and/or remediate abnormal vaginal or skin flora.

Administration of recombinant Reishi immunomodulatory protein (rLZ-8) diet enhances innate immune responses and elicits protection against nervous necrosis virus in grouper Epinephelus coioides.

Nervous necrosis virus (NNV) infection during larvae and juvenile stage in grouper (Epinephelus coioides) has caused severe economic losses in the aquaculture industry in Asia. The aims of this study were to evaluate the influence of recombinant Reishi protein, rLZ-8, on the innate immune responses and the viral resisting ability in fish. Groupers were fed with rLZ-8 supplemented diet (1.25-37.5 mg (rLZ-8)/kg(diet)), and the cytokine gene expression, innate immune responses, and survival rate after NNV challenge were examined. The fish fed with rLZ-8 diet showed 6- to 11-fold upregulated TNF-α and IL-1β gene expression, along with significant increased respiratory burst and phagocytic activity. Moreover, feeding the fish with 37.5 mg/kg rLZ-8 diet elicited significant improvement in post viral challenge survival rate (85.7%). These discoveries indicated that rLZ-8 could be utilized as an ant-pathogen immunostimulant, and provided a new candidate to fight against NNV infection in fish.