ABSTRACT: Highly Efficient Degradation of Ethanol, Acetaldehyde, and Ethyl Acetate Removal by Biological Trickling Filter Reactors with Various Fillers
Project description:Wastewater treatment plants use a variety of bioreactor types and configurations to remove organic matter and nutrients. Little is known regarding the effects of different configurations and within-plant immigration on microbial community dynamics. Previously, we found that the structure of ammonia-oxidizing bacterial (AOB) communities in a full-scale dispersed growth activated sludge bioreactor correlated strongly with levels of NO2- entering the reactor from an upstream trickling filter (Wells et al 2009). Here, to further examine this puzzling association, we profile within-plant microbial biogeography (spatial variation) and test the hypothesis that substantial microbial immigration occurs along a transect (raw influent, trickling filter biofilm, trickling filter effluent, and activated sludge) at the same full-scale wastewater treatment plant. AOB amoA gene abundance increased >30-fold between influent and trickling filter effluent concomitant with NO2- production, indicating unexpected growth and activity of AOB within the trickling filter. Nitrosomonas europaea was the dominant AOB phylotype in trickling filter biofilm and effluent, while a distinct ‘Nitrosomonas-like’ lineage dominated in activated sludge. Prior time series indicated that this ‘Nitrosomonas-like’ lineage was dominant when NO2- levels in the trickling filter effluent (i.e., activated sludge influent) were low, while N. europaea became dominant in the activated sludge when NO2- levels were high. This is consistent with the hypothesis that NO2- production may co-occur with biofilm sloughing, releasing N. europaea from the trickling filter into the activated sludge bioreactor. Phylogenetic microarray (PhyloChip) analyses revealed significant spatial variation in taxonomic diversity, including a large excess of methanogens in the trickling filter relative to activated sludge and attenuation of Enterobacteriaceae across the transect, and demonstrated transport of a highly diverse microbial community via the trickling filter effluent to the activated sludge bioreactor. Our results provide compelling evidence that substantial immigration between coupled process units occurs and may exert significant influence over microbial community dynamics within staged bioreactors.
Project description:The success of bottom-up proteomic analysis frequently depends on the efficient removal of contaminants from protein or peptide samples before LC-MS/MS. For a peptide clean-up workflow, the single-pot solid-phase-enhanced peptide sample preparation on carboxylate-modified paramagnetic beads (termed SP2) was evaluated for sodium dodecyl sulfate or polyethylene glycol removal from Arabidopsis thaliana tryptic peptides. The robust and efficient 40-min SP2 protocol, tested for a 10 ng, 250ng and 10µg peptide sample, was proposed and benchmarked thoroughly against the ethyl acetate extraction protocol. The SP2 protocol on carboxylated magnetic beads proved to be the robust approach even for simultaneous removal of massive sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG) contaminations from AT peptide samples in respect of the LC-MS/MS data outperforming ethyl acetate extraction.
Project description:Protein glycosylation is a common protein post-translational modification (PTM) in living organisms and has been shown to associate with multiple diseases, and thus may potentially be a biomarker of such diseases. Efficient protein/glycoprotein extraction is a key step in the preparation of N-glycans derived from glycoproteins prior to LC-MS analysis. Convenient, efficient and unbiased sample preparation protocols are needed. Herein, we evaluated the use of sodium deoxycholate (SDC) acidic labile detergent to release N-glycans of glycoproteins derived from biological samples such as cancer cell lines. Compared to the filter aided sample preparation approach, the sodium deoxycholate (SDC) assisted approach was determined to be more efficient and unbiased. SDC removal was determined to be more efficient when using acidic precipitation rather than ethyl acetate phase transfer. Efficient extraction of proteins/glycoproteins from biological samples was achieved by combining SDC lysis buffer and beads beating cell disruption. This was suggested by a significant overall increase in the intensities of N-glycans released from cancer cell lines. Additionally, the use of SDC approach was also shown to be more reproducible than those methods that do not use SDC.
Project description:Background: Anaerobic Saccharomyces cerevisiae cultures require glycerol formation to re-oxidize NADH formed in biosynthetic processes. Introduction of the Calvin-cycle enzymes phosphoribulokinase (PRK) and ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) has been shown to couple re-oxidation of biosynthetic NADH to ethanol production and improve ethanol yield on sugar in fast-growing batch cultures. Since growth rates in industrial ethanol-production processes are not constant, performance of engineered strains was studied in slow-growing cultures. Results: In slow-growing anaerobic chemostat cultures (D = 0.05 h-1), an engineered PRK-RuBisCO strain produced 80-fold more acetaldehyde and 30-fold more acetate than a reference strain. This observation suggested an imbalance between in vivo activities of PRK-RuBisCO and formation of NADH in biosynthesis. Lowering the copy number of the RuBisCO-encoding cbbm expression cassette from 15 to 2 reduced acetaldehyde and acetate yields by 67% and 29%, respectively. Additional C-terminal fusion of a 19 amino-acid tag to PRK reduced its protein level by 13-fold while acetaldehyde and acetate production decreased by 94% and 61%, respectively, relative to the 15x cbbm strain. These modifications did not affect glycerol production at 0.05 h-1 but caused a 4.6 fold higher glycerol production per amount of biomass in fast-growing (0.29 h-1) anaerobic batch cultures than observed for the 15x cbbm strain. In another strategy, the promoter of ANB1, whose transcript level positively correlated with growth rate, was used to control PRK synthesis in a 2x cbbm strain. At 0.05 h-1, this strategy reduced acetaldehyde and acetate production by 79% and 40%, respectively, relative to the 15x cbbm strain, without affecting glycerol yield. The maximum growth rate of the resulting strain equalled that of the reference strain, while its glycerol yield was 72% lower. Conclusions: Acetaldehyde and acetate formation by slow-growing cultures of engineered S. cerevisiae strains carrying a PRK-RuBisCO bypass of yeast glycolysis was attributed to an in vivo overcapacity of PRK and RuBisCO. Reducing the capacity of PRK and/or RuBisCO was shown to mitigate this undesirable byproduct formation. Use of a growth-rate-dependent promoter for PRK expression highlighted the potential of modulating gene expression in engineered strains to respond to growth-rate dynamics in industrial batch processes.
Project description:MCF12A monolayer cultures were exposed to ethanol or acetaldehyde for eiher 1 week or 4 weeks Total RNA samples were assayed for gene expression and for microRNA expression. MicroRNA expression was accomplished using 2 experiments. The first experiment included untreated control, ethanol treated (4 weeks at 2.5 mM) and acetaldehyde treated (4 weeks at 1 mM). The data are presented in order of control1 for the ethanol and acetaldehyde treated samples followed by the ethanol and acetaldehyde treated samples, and then the control2 for the soft agar selected sample followed by the soft agar selected sample. The microRNA names are included in separate columns.
Project description:Alcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohol's oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. Here, we use the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0-2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4 wk incubation, cells were also tested for anchorage independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immuno-cytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype and mRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage independence in normal breast epithelial cells. MCF12A monolayer cultures were exposed to ethanol or acetaldehyde for either 1 week or 4 weeks. Total RNA samples were assayed for gene expression and for microRNA expression.
Project description:Alcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohol's oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. Here, we use the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0-2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4 wk incubation, cells were also tested for anchorage independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immuno-cytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype and mRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage independence in normal breast epithelial cells. MCF12A monolayer cultures were exposed to ethanol or acetaldehyde for either 1 week or 4 weeks. Total RNA samples were assayed for gene expression and for microRNA expression.
Project description:Alcohol intake is a risk factor for development of osteopenia. Ethanol perturbs gene expression in osteoblasts and osteoclasts and disrupts growth plate morphology. Hepatic metabolism of ethanol to acetate elevates concentrations of acetate in the circulation. We investigated whether acetate could mediate the toxicity of ethanol on gene expression in bone and on chondrocyte differentiation. When ethanol and acetate were compared by gavage for four consecutive days, none of eleven genes involved in bone homeostasis showed expression significantly affected by acetate, but the acetate responses significantly correlated with ethanol responses. Intraperitoneal injection with acetate to transiently elevate serum acetate for four consecutive days significantly increased expression of two markers of osteoclast differentiation, calcitonin receptor (Calcr) and Ocstamp. Early chondrogenic differentiation of ATDC5 cells for 7 days in vitro characterized by aggrecan (Acan) and collagen 2a1 (Col2a1) mRNA expression and proteoglycan production was inhibited by both 50 mM ethanol and 5 mM acetate. Ethanol effects were not blocked by the alcohol dehydrogenase inhibitor 4-methylpyrazole. 50 mM ethanol retarded both ATDC5 cell growth and culture medium acidification. Inhibition of chondrogenic differentiation by 5 mM acetate was associated with elevated phosphorylation of Erk1 and Erk2 and decreased expression of transcription factors Sox9 and Runx2. In acetate-exposed cells, blocking of Erk1 and Erk2 phosphorylation with Trametinib prevented further reduction of Acan and Col2a1 mRNA expression. We conclude that ethanol-derived acetate mediates at least part of the induction of Calcr and Ocstamp expression, and that acetate mimics effects of ethanol on early chondrogenic differentiation.
Project description:Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme to detoxify the ethanol first metabolite acetaldehyde. Approximately 8% world population have inactive ALDH2 and have facial flushing due to high levels of acetaldehyde after alcohol consumption. Alcohol-associated liver disease (ALD) and hepatocellular carcinoma (HCC) in those with inactive ALDH2 have not been characterized. ALD pathogeneses in these individuals are likely very different from those with normal ALDH2, different diagnosis criteria and treatment are required for these two populations. Here we studied ALD in inactive Aldh2 knockin (Aldh2KI) mice with chronic ethanol feeding.
2025-07-16 | GSE288043 | GEO
Project description:Biological methane removal in groundwater trickling filtration