In-situ sulfite treatment enhanced the production of short-chain fatty acids from waste activated sludge in the side-stream anaerobic fermentation.

Sulfite-based technology could enhance methane production from anaerobic sludge digestion. However, its potential for in-situ direct sludge treatment without anaerobic sludge addition in the side-stream remains unclear. This study investigated the feasibility of using in-situ sulfite treating sludge for short-chain fatty acids (SCFAs) production via anaerobic fermentation of waste activated sludge (WAS) as a side-stream treatment. In-situ sulfite direct sludge treatment enhanced SCFAs and acetic acid production by 2.03 and 4.89 times at 500 mg S/L compared to the control. With in-situ sulfite treatment, WAS hydrolysis and acidification were enhanced while methanogenesis was spontaneously hindered. The in-situ sulfite treatment inactivated pathogens and improved the sludge dewatering properties. The relative abundances of SCFAs-production microbial were stimulated, facilitating the sludge bioconversion. The produced SCFAs from in-situ sulfite side-stream treatment could be applied as an "internal carbon source" to enhance biological nutrient removal to improve economic and environmental value from sludge treatment.

Insights into the bacterial species and communities of a full-scale anaerobic/anoxic/oxic wastewater treatment plant by using third-generation sequencing.

For the first time, full-length 16S rRNA sequencing method was applied to disclose the bacterial species and communities of a full-scale wastewater treatment plant using an anaerobic/anoxic/oxic (A/A/O) process in Wuhan, China. The compositions of the bacteria at phylum and class levels in the activated sludge were similar to which revealed by Illumina Miseq sequencing. At genus and species levels, third-generation sequencing showed great merits and accuracy. Typical functional taxa classified to ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), denitrifying bacteria (DB), anaerobic ammonium oxidation bacteria (ANAMMOXB) and polyphosphate-accumulating organisms (PAOs) were presented, which were Nitrosomonas (1.11%), Nitrospira (3.56%), Pseudomonas (3.88%), Planctomycetes (13.80%), Comamonadaceae (1.83%), respectively. Pseudomonas (3.88%) and Nitrospira (3.56%) were the most predominating two genera, mainly containing Pseudomonas extremaustralis (1.69%), Nitrospira defluvii (3.13%), respectively. Bacteria regarding to nitrogen and phosphorus removal at species level were put forward. The predicted functions proved that the A/A/O process was efficient regarding nitrogen and organics removal.

Insights into the mechanism of methylene blue removed by novel and classic biochars.

The adsorption behavior and the underlying mechanism of methylene blue (MB) sorption on biochars prepared from different feedstocks at 500 °C were evaluated. The biochar feedstocks included Magnolia grandiflora Linn. leaves biochar (MBC), pomelo (Citrus grandis) peel biochar (PBC) and badam shell biochar (BBC). The results of characterizing and analyzing the samples showed that different biochars had different effects on the adsorption of MB. It could be found that MBC had the best adsorption effect on MB due to its largest average pore diameter of 5.55 nm determined by Brunauer-Emmett-Teller analysis. Under the optimal conditions, the maximum adsorption capacities of BBC, PBC and MBC were 29.7, 85.15 and 99.3 mg/g, respectively. The results showed that the amount of adsorption was affected by the pH value. The maximum adsorption capacity of MBC was 46.99 mg/g when it was at pH of 3, whereas for the same experimental conditions the maximum adsorption capacity of BBC and PBC was 25.29 mg/g at pH of 11 and 36.08 mg/g at pH of 7, respectively. Therefore, MBC was found to be a most efficient low-cost adsorbentl for dye wastewater treatment compared with BBC and PBC, and it had the best removal effect under acidic conditions.

Tumor associated macrophages deliver iron to tumor cells via Lcn2.

Cancer cells exhibit an increasing iron demand associated with the tumor progression. But the mechanism of iron accumulation in the tumor microenvironment is still unclear. Tumor associated macrophages (TAMs) in the tumor microenvironment may act as extra iron source. However, evidence is still lacking in TAMs as iron donors. In the present study, we found that iron concentration was significantly increased at tumor metastatic stage, which could be attributed to up-regulated expression of lipocalin2 (Lcn2). TAMs in the microenvironment secreted Lcn2. Moreover, TAMs increased intracellular iron concentration in tumor cells via Lcn2 as transporter, which could be restored by Lcn2 antibody neutralization. In conclusion, TAMs increased intracellular iron concentration of the tumor cells via Lcn2 which acted as an iron transporter. Targeting Lcn2 secretion in TAMs to "starve cancer cells" could act as alternative option for tumor therapy.

Deferoxamine-induced increase in the intracellular iron levels in highly aggressive breast cancer cells leads to increased cell migration by enhancing TNF-α-dependent NF-κB signaling and TGF-ß signaling.

Recent studies have suggested that excess iron accumulation may be a risk factor for breast cancer. However the role of iron in breast cancer metastasis has remained unclear. The major goal of our study is to investigate the roles of iron in breast cancer metastasis. We modulated the intracellular iron levels of human breast cancer cells, including the aggressive MDA-MB-231 cells and non-aggressive MCF-7 cells, by using Deferoxamine (DFO) - a most widely used iron chelator. We found that DFO treatment could deplete intracellular iron in MCF-7 cells. In contrast, DFO treatment led to a significant increase in the intracellular iron level in MDA-MB-231 cells. The MDA-MB-231 cells with the increased intracellular iron level exhibited increases in both mesenchymal markers and cell migration. Furthermore, the DFO-treated MDA-MB-231 cells showed increases in both tumor necrosis factor α (TNF-α)-induced nuclear factor kappa B (NF-κB) signaling and transforming growth factor-ß (TGF-ß) signaling, which could contribute to the enhanced cell migration. Collectively, our study has provided the first evidence suggesting that increased intracellular iron levels could lead to enhanced migration of aggressive breast cancer cells by increasing TNF-α-dependent NF-κB signaling and TGF-ß signaling. Our study has also suggested that caution should be taken when DFO is applied for treating breast cancer cells, since DFO could produce differential effects on the intracellular iron levels for aggressive breast cancer cells and non-aggressive breast cancer cells.

Distribution and inhibition effect of Seleno-L-Methionine on 4T1 mouse mammary carcinoma.

To identify the relationship between selenium intake and breast cancer progression, SeMet supplement was applied to 4T1 murine mammary carcinoma for 28 days and the effect of SeMet on tumor growth was assessed. Combined with SXRF mapping, trace metal distribution in tumor tissues in relation to selenium-associated protein expressions and cellular transcription factors, HIF-1α accumulation and its targeted molecule expressions involved in tumor progression, were further investigated using immunohistochemical staining. Our results showed that tumor growth was inhibited significantly and tumor cells apoptosis was promoted after SeMet supplement. High Se intakes in tumor tissues overlaid with high iron distribution were observed by SXRF mapping. SeMet supplement increased SBP1 expression and decreased GPx1 expression, and greatly inhibited VEGF expression and tumor immune suppression cells accumulation in tumor tissues. In conclusion, SeMet-mediated anti-cancer effect was likely to inhibit tumor growth through high expression of SBP1 inhibiting GPx1 activity and HIF-1α, which could be used as chemopreventive strategies in breast cancer.