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•iTRAQ analysis revealed the carbon metabolism regulation for MW treatment with BACT.•Carbon source composition was optimized to enhance microalgal biomass production.•High IC/OC ...ratio improved the expression of key enzymes in photosynthetic pathways.•The enhancement of lipid production attributed to an upregulation of glycolysis.
Acidogenic fermentation coupled with microalgae cultivation is efficient for mariculture wastewater (MW) treatment and energy recovery, but there is limited information regarding carbon metabolic networks as a response to varied broth composition at the proteome level. In this study, ethanol-type, propionate-type, and butyrate-type fermentation effluent of MW were applied to microalgae cultivation. The carbon source composition of different types of acidogenic fermentation was optimized to enhance microalgal biomass production and nutrients removal. Compared with ethanol-type fermentation effluent, higher efficiency in biomass accumulation and ammonia assimilation of Chlorella pyrenoidosa was observed in propionate-type and butyrate-type. Lipid accumulation in microalgae was enhanced with ethanol-type fermentation effluent, and the maximum lipid content reached 513.3 and 546.7 mg/L at an inorganic carbon/organic carbon (IC/OC) ratio of 3:1 and 2:1, respectively. The increasing ratio of IC/OC improved the expression of key enzymes related to the photosynthetic system, which had a positive effect on carbohydrate production and microalgal growth. The upregulation of magnesium chelatase with bicarbonate supply was revealed by iTRAQ analysis, thereby promoting chlorophyll production in microalgal cells. In response to an increasing proportion of IC, more energy and precursor substances for lipid production were generated with the enhancing expression of glycolysis and pyruvate metabolism.
The method of preparing Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO photocatalyst was the precipitation grinding. This photocatalyst was characterized by UV-Vis, PL, EDS, SEM, and ...XRD. The results indicated the Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO photocatalyst was highly active under the visible light. The photocatalytic degradation efficiency of chlortetracycline hydrochloride was analyzed in mariculture wastewater by various experimental parameters, namely calcination temperature, dosage of Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO, Zn.sup.2+/Fe.sup.3+/Mn.sup.2+ molar ratio, H.sub.2O.sub.2 mass concentration, chlortetracycline hydrochloride initial concentration, and illumination time. The degradation of chlortetracycline hydrochloride in mariculture wastewater was optimized by orthogonal experiments. When the H.sub.2O.sub.2 mass concentration was 0.3 g/L, calcination temperature was 500 °C, Zn.sup.2+/Fe.sup.3+/Mn.sup.2+ molar ratio was 10:1:4, dosage of Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO was 0.7 g/L, illumination time was 4.0 h, chlortetracycline hydrochloride initial concentration was 0.01 g/L, and the degradation rate of chlortetracycline hydrochloride reached 73.04% by Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO photocatalyst. The degradation rate of chlortetracycline hydrochloride was 52.86% by ZnFe.sub.2O.sub.4/ZnO photocatalyst. The results indicated that the Zn.sub.0.75Mn.sub.0.75Fe.sub.1.5O.sub.4/ZnFe.sub.2O.sub.4/ZnO photocatalyst obviously enhanced the degradation rate of chlortetracycline hydrochloride, compared with pure ZnO and ZnFe.sub.2O.sub.4/ZnO photocatalyst.
Antibiotics are widely used in mariculture industry, and this study attempts to determine the extent of water and sediment pollution by antibiotic residues in 13 major mariculture sites in China. ...Through chemical and molecular biology analysis, the results showed that the total concentrations of sulfonamides and tetracyclines were in the range 62.0–373.8ngL−1 and 0.2–259.1ngL−1 respectively in water samples, and in the range 0.19–1.59ngg−1 dry weight and 3.45–74.84ngg−1 dry weight respectively, in sediments samples. The occurrence of antibiotic resistance genes (ARGs) was detected in all sites. Compared with the tetracyclines resistance genes, the absolute copy number and relative abundance of the sulfonamides resistance genes were 4.3 times and 2.3 times higher in water and sediment from the mariculture sites, with the dominant resistance genes being sul2. The abundance of sul3 in the water phase was significantly correlated with the concentrations of sulfamerazine, while the abundance of sul2 in the sediment phase was significantly with sulfadiazine concentrations. The abundance of tetM in the sediment phase was significantly correlated with the concentrations of oxytetracycline. The findings demonstrate the persistence of antibiotic residues and ARGs in major mariculture sites in Southeast China.
Total concentrations of the target antibiotics in water and sediments from mariculture sites in SE China. Display omitted
•11 antibiotics were detected in water and sediments from mariculture sites in China.•Water samples were dominated by sulfadiazine.•Sediment samples were dominated by doxycyclinehyclate.•Antibiotic resistance genes were dominated by sul2 in both water and sediments.•Linear relationships between log Koc and log Kow, and between log Koc and log MW.
China is the largest mariculture producer in the world, but detailed information on the spatiotemporal variations of biogenic elements and sources of sedimentary organic matter (SOM) via mariculture ...is limited. The primary objective of this study was to assess the influence of mariculture on the origin of SOM in relation with biogenic elements and geochemical paramaters due to the importance of SOM as a potential source of nutrients and energy in coastal marine environments. Surface sediments from the Maowei Sea were collected in August (summer) and December (winter), 2016 for grain size, total organic carbon (TOC), total nitrogen (TN), organic phosphorus (OP), biogenic silica (BSi), δ13C and δ15N analyses. Significant correlation (p < 0.01) was observed between TOC and TN in summer and winter respectively, indicating that they have common source in both seasons. The spatiotemporal distributions of TOC, TN, OP and BSi were influenced by the sources and distribution of SOM, grain sizes and hydrodynamic conditions in the Maowei Sea. The overall ranges of δ13C (−26.86‰ to −23.01‰) and δ15N (2.54‰ to 9.82‰) and C/N ratio (5.83 to 18.67) showed that SOM is derived from mixed sources. The δ13C and δ15N-based three-end-member mixing model results revealed that >40% of the deposited SOM originates from terrestrial source during two seasons. The SOM from shellfish mariculture was seasonal, mainly deposited in the intensive mariculture areas, and its proportions were only higher than contributions from marine plankton in summer. Generally, this study indicates that shellfish biodepositions can significantly influence the cycle of carbon and other biogenic elements in the intensive mariculture areas. Nevertheless, the overall dominance of terrestrial and marine SOM suggests that the sources of SOM and factors influencing carbon cycling in the Maowei Sea do not exclusively depend on the intensity of mariculture activities.
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•TOC, TN and BSi relates to SOM sources, sediment texture and hydrodynamics.•SOM is mostly dominated by terrestrial source in the Maowei Sea.•SOM from marine phytoplankton generally exceeds that of shellfish mariculture.•SOM from shellfish biodeposits is significantly impacted by seasons.•More shellfish biodepositions are found in the intensive mariculture regions.
Systems with catalytic cathode in microbial fuel cell can achieve high treatment efficiency enhanced by the cathode. Such bio-electrochemical systems have potential applications in treating ...high-salinity nitrogenous mariculture wastewater. For sustainable development of the mariculture industry, enhancing inorganic nitrogen removal is of vital importance due to the low carbon to nitrogen (C/N) ratio of wastewater and strict discharge standard. Herein, simulated mariculture wastewater (high salinity, low COD/N ratio of 0.5–1.0) was successfully treated in an integrated self-biased bio-electrochemical system, with catalyst (TiO2/Co-WO3/SiC) on the cathode and natural-grown algae in the cathode chamber. Satisfactory nitrogen removal (94.05% NH4+-N and 77.35% inorganic nitrogen) and favorable 76.66% removal of organics (UV254) were both achieved, with visible light illumination. The NH4+-N in the effluent was below 2 mg L−1. The synergy of bacteria, algae and cathode, promoted pollutant removal, and made the system sustainable and efficient in treating mariculture wastewater.
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•Novel cathode with TiO2/Co-WO3/SiC enhanced photo-electrocatalytic nitrogen removal•A system with bacteria-algae-catalytic cathode and bio-anode was constructed.•From mariculture wastewater, the system removed 94.05% NH4+-N at effluent 2 mg L−1.•The system removed 77.35% inorganic nitrogen and 76.66% organic pollutant.•There is synergy of bacteria-algae-catalytic electrode, photo and bio-electricity.
China now accounts for over 2/3 of the world's production of marine-based seafood. Chinese mariculture has contributed to the stability of the global food supply, but millions of tons of excess feed ...and drugs are threatening the sustainability of the waters in which it is conducted. Over 26% of the excess nitrogen in China's waters is likely a result of shrimp production alone, worsening eutrophication and the resulting ‘red tide’ in China. While some Chinese operations require the destruction of carbon-rich wetlands, the sector as a whole can be considered a net CO2 sink at the immediate time of harvest; each year, Chinese mariculture extracts the same quantity of CO2 from the atmosphere as 5000 km2 of forest. Novel technical practices, improved management of the harvested products in the food versus industrial supply chain, optimized sea-use and land-use plans, and the encouragement of participatory decision-making by provincial entities offer some promise to ensure the sustainability of this global public resource – but the national Chinese government will have to step up to address the challenges.
Japan's tiger puffer aquaculture has high level of technology and well-designed regulatory framework. At the present stage, artificial breeding is widely used for ensuring the stable supply of ...juvenile fish. Research institutes also developed new species with higher added value. There are two aquaculture systems: open net pen system and land based aquaculture system. Cage farming has been widely used in the main producing areas, farmed tiger puffer were fed with commercial pellet feed. In terms of institutional management of the tiger puffer aquaculture, standardized farmer certification system was implemented in each region, which had provided the basis for the establishment of regional brand, thus safeguarding the profit, and motivating innovations in scientific research and market expansion. In China, tiger puffer aquaculture is still resource-dependent and labor-intensive. There are several problems need to be solved, such as low level of farming technology and product differentiation. Drawing lessons fro
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