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Background: Aquatic plants play a crucial role in nature-based wastewater treatment and provide a promising substrate for renewable energy production using anaerobic digestion (AD) technology. This study aimed to examine the contaminant removal from AD effluent by water lettuce (WL) and produce biogas from WL biomass co-digested with pig dung (PD) in a farm-scale biogas digester. Methods: The first experiment used styrofoam boxes containing husbandry AD effluent. WLs were initially arranged in 50%, 25%, 12.5%, and 0% surface coverage. Each treatment was conducted in five replicates under natural conditions. In the second experiment, WL biomass was co-digested with PD into an existing anaerobic digester to examine biogas production on a farm scale. Results: Over 30 days, the treatment efficiency of TSS, BOD5, COD, TKN, and TP in the effluent was 93.75-97.66%, 76.63-82.56%, 76.78-82.89%, 61.75-63.75%, and 89.00-89.57%, respectively. Higher WL coverage increased the pollutant elimination potential. The WL biomass doubled after 12 days for all treatments. In the farm-scale biogas production, the biogas yield varied between 190.6 and 292.9 L kg VSadded-1. The methane content reached over 54%. Conclusions: WL removed AD effluent nutrients effectively through a phytoremediation system and generated significant biomass for renewable energy production in a farm-scale model.
Assuntos
Araceae , Poluentes Ambientais , Animais , Suínos , Biocombustíveis , Biomassa , FazendasRESUMO
Fibroblast growth factor 2 (FGF-2) is a multi-functional protein involving in wound healing. However, FGF-2 is easily degradable in vivo, which limited its use for wound treatment. In this study, we investigated a drug-delivery model for FGF-2 via incorporation with biodegradable carboxylmethyl chitosan (CMCS). CMCS nanoparticles (NPs) could be synthesized by ionic gelation using CaCl2 as a crosslinking reagent with the CMCS:CaCl2 ratio of 1:0.8. Synthesized CMCS NPs had a diameter of 32.68±6.83nm, and were non-toxic at concentrations up to 2.5mg/ml. Incorporated CMCS:FGF-2 NPs had a diameter of 34.83±5.89nm and incorporation efficiency was 95%. CMCS:FGF-2 NPs released 36.36% and 58.47% of FGF-2 after 48h incubation in two different pH of 7.4 and 5.8, respectively. The incorporation and release processes did not have a significant effect on FGF-2 activity. Simultaneously, CMCS:FGF-2 NPs could protect FGF-2 from the degradation of trypsin in vitro. Our results laid the groundwork for the manufacturing of protein incorporated CMCS NPs for bio-applications.
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BACKGROUND: Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) is a glycoprotein that has been approved by the FDA for the treatment of neutropenia and leukemia in combination with chemotherapies. Recombinant hGM-CSF is produced industrially using the baker's yeast, Saccharomyces cerevisiae, by large-scale fermentation. The methylotrophic yeast, Pichia pastoris, has emerged as an alternative host cell system due to its shorter and less immunogenic glycosylation pattern together with higher cell density growth and higher secreted protein yield than S. cerevisiae. In this study, we compared the pipeline from gene to recombinant protein in these two yeasts. RESULTS: Codon optimization in silico for both yeast species showed no difference in frequent codon usage. However, rhGM-CSF expressed from S. cerevisiae BY4742 showed a significant discrepancy in molecular weight from those of P. pastoris X33. Analysis showed purified rhGM-CSF species with molecular weights ranging from 30 to more than 60 kDa. Fed-batch fermentation over 72 h showed that rhGM-CSF was more highly secreted from P. pastoris than S. cerevisiae (285 and 64 mg total secreted protein/L, respectively). Ion exchange chromatography gave higher purity and recovery than hydrophobic interaction chromatography. Purified rhGM-CSF from P. pastoris was 327 times more potent than rhGM-CSF from S. cerevisiae in terms of proliferative stimulating capacity on the hGM-CSF-dependent cell line, TF-1. CONCLUSION: Our data support a view that the methylotrophic yeast P. pastoris is an effective recombinant host for heterologous rhGM-CSF production.
