Enhanced treatment of synthetic wastewater by bioaugmentation with a constructed consortium.

Bioaugmentation by adding well-functioning mixed microorganism consortia represents a potentially useful approach to improve contaminant removal in wastewater treatment plants (WWTPs). However, unfavorable environmental conditions (i.e., low temperatures) can severely inhibit microbial activity, drawing our attention to constructing cold-tolerant microorganism preparations and investigating their availability in practical applications. Here we screened four in situ functional isolates from the activated sludge of secondary sedimentation tanks in WWTPs to construct a psychrophilic microbial consortium, which was used to perform bioaugmentation for enhanced removal of nitrogen and phosphorus under low temperatures. The consortium was established by cocultivation of four isolates, characterized by 16 S rRNA as the COD-degrading bacterium Aeromonas sp. Z3, aerobic denitrifying bacterium Acinetobacter sp. HF9, nitrifying bacterium Klebsiella sp. X8, and polyphosphate-accumulating bacterium Pseudomonas sp. PC5 respectively. The microorganism preparation was composed of Z3, HF9, X8, and PC5 under the ratio of 1: 1: 3: 1, which can exert optimal pollutant removal under the conditions of 12 °C, 6.0-9.0 pH, 120-200 r‧min-1, and a dosage of 5% (V/V). A 30-day continuous operation of the bioaugmented and control sequencing batch reactors (SBRs) was investigated, and the bioaugmented SBR showed a shorter start-up stage and a more stable operating situation. Compared to the control SBR, the COD, NH4+-N, TN, and TP removal efficiency of the bioaugmented SBR increased by an average of 7.95%, 9.05%, 9.54%, and 7.45% respectively. The analysis of the microbial community revealed that the introduced isolates were dominant in the activated sludge and that functional taxa such as Proteobacteria, Bacteroidota, and Actinobacteria were further enriched after a period of bioaugmentation. The study provides some basis and guidance for the practical application of how to strengthen the stable operation of WWTPs under low temperatures.

Harnessing Paenarthrobacter ureafaciens YL1 and Pseudomonas koreensis YL2 Interactions to Improve Degradation of Sulfamethoxazole.

Sulfamethoxazole (SMX) is a widespread and persistent pollutant in the environment. Although the screening and analysis of SMX-degrading bacteria have been documented, the interaction mechanisms of functional microorganisms are still poorly understood. This study constructed a consortium with strain YL1 and YL2 supplied with SMX as the sole carbon and energy source. The coexisting mechanism and the removal of SMX of the consortium were investigated. The total oxidizable carbon (TOC) removal rate of the combined bacterial system was 38.94% compared to 29.45% for the single bacterial system at the same biomass. The mixed bacterial consortium was able to resist SMX at concentrations up to 400 mg/L and maintained a stable microbial structure at different culture conditions. The optimum conditions found for SMX degradation were 30 °C, pH 7.0, a shaking speed of 160 r·min-1, and an initial SMX concentration of 200 mg·L-1. The degradation of SMX was accelerated by the addition of YL2 for its ability to metabolize the key intermediate, 4-aminophenol. The removal rate of 4-aminophenol by strain YL2 reached 19.54% after 5 days. Genome analysis revealed that adding riboflavin and enhancing the reducing capacity might contribute to the degradation of SMX. These results indicated that it is important for the bioremediation of antibiotic-contaminated aquatic systems to understand the metabolism of bacterial communities.

Synthesis and Application of AS1411-Functionalized Gold Nanoparticles for Targeted Therapy of Gastric Cancer.

Gastric cancer therapy is still a big challenge, and nanomedicines bring much more hope. It is essential to develop multifunctional nanoparticles, especially those with high targeted capacity and antitumor effects, to improve gastric cancer therapy. In this study, we constructed AS1411 aptamer-based gold nanoparticles with appropriate size facilitating endocytosis and actively targeted drug delivery for gastric cancer cells via the specific AS1411-nucleolin interaction. The AS1411-based nanoparticles showed obviously increased targeted capacity towards AGS cells compared to random ssDNA-based nanoparticles. Meanwhile, compared to L929 cells, the AS1411-based nanoparticles showed selective drug uptake and delivery for AGS cells. Importantly, the AS1411-based nanoparticles exhibited significantly stronger antitumor effects on AGS cells under laser irradiation compared to chemotherapy alone. Our nanoparticles combined targeted drug delivery and efficient antitumor effects within one single nanoplatform, which are promising to be applied as targeted nanomedicines against gastric cancer.

Laser-triggered collaborative chemophotothermal effect of gold nanoparticles for targeted colon cancer therapy.

Nanotechnology has shown advantages for cancer treatment. Multimodal nanoparticles (NPs) combining chemotherapy and photothermal therapy are promising and elicit synergetic benefit. However, there were still less multifunctional nanomaterials with good targeting and anti-tumor property applied as the colon cancer therapeutic strategy. In this study, we designed the gold NPs modified with AS1411 and DNA riched of GC intercalation (hairpin DNA) with doxorubicin (DOX) for targeted chemotherapy and NIR laser-triggered chemo-photothermal effect (PTT). We took advantage of PTT effect to realize DOX release from hairpin DNA. We also demonstrated AS1411 based NPs exhibited remarkable targeted binding towards SW480 colon cancer cells in vitro and enhanced uptake inside the cells. Strikingly, AS1411 based NPs exhibited the most efficient cytotoxicity and markedly enhanced inhibition effect on cells proliferation to SW480 cells under laser exposure when compared to the NPs merely with PTT or chemotherapy. Our study appears to provide an alternative nanoplatform with good targeted and chemo-photothermal therapy against colon cancer.

Rapid probe and isolation of bioactive compounds from Dioscorea panthaica using human serum albumin functionalized magnetic nano-particles (HSA-MNPs)-based ligand fishing coupled with electrospray ionization mass spectrometry.

The chemical diversity of secondary metabolites in medicinal plant makes it a huge challenge to isolate the bioactive compounds from herbal extracts, so quick recognition of the bioactive ones is of vital importance for improving the efficiency of isolation. In this study, a ligand fishing experiment based on human serum albumin functionalized magnetic nano-particles (HSA-MNPs) was performed to probe the bioactive components in a traditional Chinese medicinal plant, Dioscorea panthaica. The minor compounds fished out by HSA-MNPs were identified by electrospray ionization mass spectrometry (ESI-MS), and then separated from the extract of the whole plant by one or two steps of column chromatography under the guidance of ESI-MS. Four biologically active compounds, progenin II, progenin III, dioscin and gracillin, were isolated much faster than in the normal lengthy phytochemical procedure. The present study demonstrates that biological macromolecule (protein, enzyme, receptor, et al.) functionalized MNPs may serve as baits to recognize bioactive small molecules in complex herbal extracts. It is expected that a macromolecule functionalized MNPs-based ligand fishing experiment coupled with ESI-MS may accelerate the process of identification and isolation of bioactive components from medicinal plants, and thus benefit the speed of drug discovery.