Project description:A short-term microcosm experiment was conducted to evaluate the impact of wastewater discharge on coastal microbial communities. Coastal seawater was exposed to two types of treated wastewater: (i) unfiltered wastewater, containing nutrients, pollutants, and allochthonous microbes, and (ii) filtered wastewater, which retained only nutrients and pollutants while removing microbial components. Metaproteomic samples were collected from the coastal seawater prior to the experiment and from each experimental flask at the late exponential growth phase to assess microbial functional responses to wastewater exposure.
Project description:The transcriptome analysis by the human DNA microarray was applied to evaluate the impacts of whole wastewater effluents from the membrane bioreactors (MBRs) and the activated sludge process (AS), on the biological processes of human hepatoma HepG2 cells. The three conventional bioassays (i.e., cytotoxicity tests and bioluminescence inhibition test) and chemical analysis of the domestic effluent standards were conducted in parallel since they are well-established methods with previous applications to wastewater. A significant variation of effluent quality was sdemonstrated among the tested effluents despite that all effluents met the 40 national effluent standards. The three conventional bioassays supported the result of the transcriptome analysis, indicating the comparable or even higher sensitivity of the new assay. The most superior effluent quality was found in the MBR operated at a relatively long sludge retention time (i.e., 40 days) and small membrane pore size (i.e., 0.03 M-NM-<m). In addition, functional analysis of the differentially expressed genes revealed that the effluents made various impacts on the cellular functions, suggesting the transcriptome analysis by DNA microarray as more comprehensive, rapid and sensitive tool to detect multiple impacts of the whole effluents. Moreover, the potential genetic markers were proposed to quantitatively evaluate the treatability of the wastewater effluents. In this study, we examined the gene expression alteration in human hepatoma cell line, HepG2 exposed to the raw wastewater, effluents from three types of membrane bioreactors (MBRs), and the activated sludge process. Wastewater DNA microarray with 8795 human genes. MQ water was used as control. For duplicate, two dishes were prepared for each sample and individually treated in parallel.
Project description:One of the most widely used drugs in municipal wastewater treatment effluents and soil is carbamazepine, a commonly prescribed antidepressants and antiepileptic drug. Carbamazepine exerts an intrinsic biological activity on the nervous system, thus may induce ecotoxicological effects on non-target organisms. Earthworms, one of the essential indicator species of soil health, accumulate biosolid fertilisers and wastewater contaminants. In this project, earthworms (Dendrobaena veneta) were treated with carbamazepine to explore their uptake dynamics, molecular and life cycle endpoints. By conducting transcriptomic profiling of different tissues in an organism exposed to carbamazepine assists in defining detoxification and neural system responses in the terrestrial invertebrate.
Project description:Bio-augmentation could be a promising strategy to improve processes for treatment and resource recovery from wastewater. In this study, the Gram-positive bacterium Bacillus subtilis was co-cultured with the microbial communities present in wastewater samples with high concentrations of nitrate or ammonium. Glucose supplementation (1%) was used to boost biomass growth in all wastewater samples. In anaerobic conditions, the indigenous microbial community bio-augmented with B. subtilis was able to rapidly remove nitrate from wastewater. In these conditions, B. subtilis overexpressed nitrogen assimilatory and respiratory genes including NasD, NasE, NarG, NarH, and NarI, which arguably accounted for the observed boost in denitrification. Next, we attempted to use the the ammonium- and nitrate-enriched wastewater samples bio-augmented with B. subtilis in the cathodic compartment of bioelectrochemical systems (BES) operated in anaerobic condition. B. subtilis only had low relative abundance in the microbial community, but bio-augmentation promoted the growth of Clostridium butyricum and C. beijerinckii, which became the dominant species. Both bio-augmentation with B. subtilis and electrical current from the cathode in the BES promoted butyrate production during fermentation of glucose. A concentration of 3.4 g/L butyrate was reached with a combination of cathodic current and bio-augmentation in ammonium-enriched wastewater. With nitrate-enriched wastewater, the BES effectively removed nitrate reaching 3.2 mg/L after 48 h. In addition, 3.9 g/L butyrate was produced. We propose that bio-augmentation of wastewater with B. subtilis in combination with bioelectrochemical processes could both boost denitrification in nitrate-containing wastewater and enable commercial production of butyrate from carbohydrate- containing wastewater, e.g. dairy industry discharges. These results suggest that B. subtilis bio-augmentation in our BES promotes simultaneous wastewater treatment and butyrate production.
Project description:Laboratory tests with marine flatfish were conducted to investigate associations among gene expression, higher biological responses and wastewater effluent exposure. Previous studies showed molecular responses such as elevated concentrations of plasma estradiol and vitellogenin in wild male hornyhead turbot (Pleuronichthys verticalis). In the present study, male hornyhead turbot were exposed to environmentally realistic (0.5%) and higher (5%) concentrations of chemically enhanced advanced-primary (PL) and full-secondary treated (HTP) effluents from two southern California wastewater treatment plants (WWTP). Hepatic gene expression was examined using a custom low-density microarray. <br><br>