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Selection of passerine birds as bio-sentinel of persistent organic pollutants in terrestrial environment
No full textA broad suite of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethane (DDT) and its metabolites, were analyzed in pectoral muscle of eight terrestrial passerine bird species from an extensive e-waste recycling site in South China. Concentrations of PCBs, PBDEs, and DDTs in bird samples ranged from 1260-279,000, 121-14,200, and 31-7910 ng/g lipid weight, respectively. Insectivorous birds had significantly higher levels of PCBs, PBDEs, and DDTs than those in granivorous birds. Concentrations of POPs in resident insectivorous birds were significantly greater than those in migrant insectivorous birds. PCBs were the predominant pollutants in all bird species from the e-waste site, followed by PBDEs and DDTs, indicating that PCBs were mainly derived from e-wastes. The granivorous birds had higher proportions of hepta-CBs in total PCBs and higher proportions of octa-to deca-BDEs in total PBDEs compared with the insectivorous birds. The various dietary sources, migration behavior, and possible biotransformation were suspected as reasons of the distinct profiles of POPs in different bird species. The delta N-15 values were significantly and positively correlated with concentrations of POPs in resident insectivorous birds, but not in other passerine bird species, suggesting the influence of trophic levels on bioaccumulation of POPs in resident insectivorous birds. The resident insectivorous birds seem to be promising bio-sentinel of POPs in terrestrial environment around the e-waste sites. (C) 2018 Elsevier B.V. All rights reserved
Taxonomy, Morphology and Phylogeny of a New Oligotrich Ciliate-Omegastrombidium hongkongense n. sp (Protozoa: Ciliophora) from Clear Water Bay, Hong Kong
No full textOne new marine oligotrich ciliate, Omegastrombidium hongkongense n. sp., was isolated from a bloom of Noctiluca scuntillans near Port Shelter, Hong Kong. The morphology and infraciliature of this new species were studied on both living and protargol-stained specimens. Its phylogenetic position was discussed based on the sequence of the small subunit rRNA gene. O. hongkongense is different from its congeners with special characters. The cells are usually heart-shaped, and the cell size usually is (20-35) x (20-30) mu m in vivo. Its deep buccal cavity extends obliquely to about 1/2 of cell length. It shows prominent apical protrusion. The adoral zone of membranelles is divided into 17-19 collar membranelles and four buccal membranelles. It has one ball-like macronucleus. The girdle kinety forms a closed loop which obliquely surrounds the body. The ventral kinety and thigmotactic membranelles are not observed. The SSU rRNA sequence of O. hongkongense was close to those of Strombidium paracalkinsi and Varistrombidium kelum with approximately 99% similarity. In the phylogenetic trees, O. hongkongense can be grouped with O. elegans and V. kielum species with very low support (16% ML)
Green Extraction of Natural Antioxidants from the Sterculia nobilis Fruit Waste and Analysis of Phenolic Profile
No full textThe waste of Sterculia nobilis fruit was massively produced during food processing, which contains lots of natural antioxidants. In this study, antioxidants in the Sterculia nobilis fruit waste were extracted using the green microwave-assisted extraction (MAE) technique. The effects of five independent variables (ethanol concentration, solvent/material ratio, extraction time, temperature, and microwave power) on extraction efficiency were explored, and three major factors (ethanol concentration, extraction time, and temperature) showing great influences were chosen to study their interactions by response surface methodology. The optimal conditions were as follows: 40.96% ethanol concentration, 30 mL/g solvent/material ratio, 37.37 min extraction time at 66.76 degrees C, and 700 W microwave power. The Trolox equivalent antioxidant capacity value obtained in optimal conditions was in agreement with the predicted value. Besides, MAE improved the extraction efficiency compared with maceration and Soxhlet extraction methods. Additionally, the phenolic profile in the extract was analyzed by UPLC-MS/MS, and eight kinds of phenolic compounds were identified and quantified, including epicatechin, protocatechuic acid, ferulic acid, gallic acid, p-coumaric acid, caffeic acid, quercetin, and p-hydroxycinnamic acid. This study could contribute to the value-added utilization of the waste from Sterculia nobilis fruit, and the extract could be developed as food additive or functional food
Dartintinnus alderae n. g., n. sp., a Brackish Water Tintinnid (Ciliophora, Spirotrichea) with Dual-ended Lorica Collapsibility
No full textA tintinnid ciliate isolated from waters of the Thames River (Connecticut, USA) is described through combined in vivo observation, protargol impregnation, and phylogenetic analysis. The novel genus Dartintinnus and its type species, D. alderae are distinct from established tintinnid taxa by a lorica that collapses on both anterior and posterior ends. Dartintinnus is placed in the family Eutintinnidae based on a hyaline, elongated lorica opened at both ends, a ciliary pattern including a ventral kinety, at least one dorsal kinety, and right, left and lateral fields, and a sister relationship with Eutintinnus in gene trees. Main differences between D. alderae and Eutintinnus species include a 5.5-6.5% divergence in the small subunit rRNA gene, the geometry of the lorica (resembling an isosceles tetrahedron when collapsed vs. a cylinder, respectively), the number of macronuclear nodules (two vs. four), and the number of dorsal kineties (one vs. usually two). Considering the features of the new genus, we improve the diagnosis of the family Eutintinnidae, including the presence of a lateral ciliary field that had been overlooked in some Eutintinnus species. This work exemplifies the potential for novel diversity, even in these relatively well-studied protists, and the importance of an integrated approach for the description of tintinnid taxa
Microplastics in oysters &ITSaccostrea cucullata&IT along the Pearl River Estuary, China
No full textAs a transitional zone between riverine and marine environments, an estuary plays an important role for the sources, accumulation and transport of microplastics. Although estuarine environments are hotspots of microplastic pollution, the correlation between microplastic pollution and aquatic organisms is less known. Here we investigated microplastic pollution in wild oysters Saccostrea cucullata from 11 sampling sites along the Pearl River Estuary in South China. The microplastic abundances in oysters ranged from 1.4 to 7.0 items per individual or from 1.5 to 7.2 items per gram tissue wet weight, which were positively related to those in surrounding waters. The oysters near urban areas contained significantly more microplastics than those near rural areas. Fibers accounted for 69.4% of the total microplastics in oysters. Microplastic sizes varied from 20 to 5000 mu m and 83.9% of which were less than 100 mu m. Light color microplastics were significantly more common than dark color ones. Based on the results, oysters are recommended as a biomonitor for the microplastic pollution in estuaries. (C) 2018 Elsevier Ltd. All rights reserved
Synergistic reduction of copper (II) and oxidation of norfloxacin over a novel sewage sludge-derived char-based catalyst: Performance, fate and mechanism
No full textNowadays, clean-up of waters with coexisting heavy metal ions and organic pollutants is of great environmental importance. In this study, a novel sewage sludge-derived char-based catalyst was firstly synthesized, and coupled with hydrogen peroxide for the simultaneous removal of copper (11) and norfloxacin in aqueous solutions. The most relevant findings revealed that zero-valent iron and zero-valent aluminum particles were successfully formed on the catalyst surface when the leaching of the sludge-derived char was reduced by the green tea extract. Nearly 100% of both copper (11) and norfloxacin were simultaneously removed due to a synergistic effect between the reduction of copper (11) and the oxidation of norfloxacin over the catalyst. The gradual addition mode of hydrogen peroxide exhibited a better performance on the simultaneous removal of copper (11) and norfloxacin. The coexisting anions like nitrate and phosphate had significant negative effects on the copper (11) removal, whereas carbonate, fluoride and phosphate had significant negative effects on the norfloxacin removal. Different copper species like zero-valent copper, copper oxide and copper hydroxide were identified in copper (11: reduction process, whereas a total of eight oxidative products were identified in norfloxacin oxidation process. A possible reaction mechanism for the simultaneous removal of copper (II) and norfloxacin by the sewage sludge-derived char-based catalyst/hydrogen peroxide system was proposed. The adsorption of both copper (II) and norfloxacin over the catalyst were firstly occurred, and then the reduction of copper (II) over both zero-valent iron and zero-valent aluminum particles on the catalyst surface as well as the Fenton oxidation of norfloxacin were followed. (C) 2018 Elsevier Ltd. All rights reserved
Beneficial effects of aluminum enrichment on nitrogen-fixing cyanobacteria in the South China Sea
No full textFew studies focus on the effects of aluminum (Al) on marine nitrogen-fixing cyanobacteria, which play important roles in the ocean nitrogen cycling. To examine the effects of Al on the nitrogen-fixing cyanobacteria, bioassay experiments in the oligotrophic South China Sea (SCS) and culture of Crocosphaera watsonii in the laboratory were conducted. Field data showed that 200 nM Al stimulated the growth and the nitrogenase gene expression of Trichodesmium and unicellular diazotrophic cyanobacterium group A, and the nitrogen fixation rates of the whole community. Laboratory experiments demonstrated that Al stimulated the growth and nitrogen fixation of C. watsonii under phosphorus limited conditions. Both field and laboratory results indicated that Al could stimulate the growth of diazotrophs and nitrogen fixation in oligotrophic oceans such as the SCS, which is likely related to the utilization of phosphorus, implying that Al plays an important role in the ocean nitrogen and carbon cycles by influencing nitrogen fixation
Proteomic and metabolomic analysis of marine medaka (Oryzias melastigma) after acute ammonia exposure
No full textAmmonia is both a highly toxic environmental pollutant and the major nitrogenous waste produced by ammoniotelic teleosts. Although the acute toxic effects of ammonia have been widely studied in fish, the biochemical mechanisms of its toxicity have not been understood comprehensively. In this study, we performed comparative proteomic and metabolomic analysis between ammonia-challenged (1.2 and 2.6 mmol L-1 NH4Cl for 96 h) and control groups of marine medaka (Oryzias melastigma) to identify changes of the metabolite and protein profiles in response to ammonia stress. The metabolic responses included changes of multiple amino acids, carbohydrates (glucose and glycogen), energy metabolism products (ATP and creatinine), and other metabolites (choline and phosphocholine) after ammonia exposure, indicating that ammonia mainly caused disturbance in energy metabolism and amino acids metabolism. The two-dimensional electrophoresis-based proteomic study identified 23 altered proteins, which were involved in nervous system, locomotor system, cytoskeleton assembly, immune stress, oxidative stress, and signal transduction of apoptosis. These results suggested that ammonia not only induced oxidative stress, immune stress, cell injury and apoptosis but also affected the motor ability and central nervous system in marine medaka. It is the first time that metabolomic and proteomic approaches were integrated to elucidate ammonia toxicity in marine fishes. This study is of great value in better understanding the mechanisms of ammonia toxicity in marine fishes and in practical aspects of aquaculture
Arctic Micromonas uses protein pools and non-photochemical quenching to cope with temperature restrictions on Photosystem II protein turnover (vol 131, pg 203, 2017)
No full textIn Table 2 of the original publication, all instances of k(rec) in the Parameter and Equation columns should read k(recinact)
A molluscan TNF receptor-associated factor 2 (TRAF2) was involved in host defense against immune challenges
No full textTumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) is a member of the TRAF superfamily that acted as a key signal transduction protein and has been implicated in inflammatory and apoptosis processes in mammals. However, identification of TRAF2s in invertebrates is very limited and its function, in particular that under immune challenges, is still unknown. In this report, a molluscan TRAF2 gene (referred to as AwTRAF2) was cloned and characterized from the freshwater bivalve, Anodonta woodiana. The open reading frame (ORF) of AwTRAF2 was 1683 bp in length, which encoded a putative 560 amino acid-protein. The deduced AwTRAF2 sequence shared similar structural characteristics and close evolutionary relationship with mollusk TRAF2s. The tissue-specific expression analysis revealed that AwTRAF2 mRNA was broadly expressed in all tested tissues, with high expression in gill and hepatopancreas. In addition, in vivo injection experiments directly showed that AwTRAF2 mRNA levels in hepatopancreas were significantly up-regulated in response to bacterial pathogen (Vibrio alginolyticus and Staphylococcus aureus) and PAMPs (Lipopolysaccharides and Peptidoglycan) challenges. Moreover, fluorescence microscopy observations revealed that AwTRAF2 was mainly located in cytoplasm of HEK293T cells and its overexpression significantly increased the transcriptional activities of the NF-kappa B-Luc reporter gene in HEK293T cells. Taken together, this study provided the experimental evidence of the presence of a functional TRAF2 in freshwater bivalves, which revealed its involvement in host response to immune challenges in A. woodiana. (C) 2017 Elsevier Ltd. All rights reserved