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关键词： Aspergillus oryzae   Recombinant protein production   Cell wall   alpha-1,3-Glucan   Galactosaminogalactan  

摘要： Filamentous fungi are used as production hosts for various commercially valuable enzymes and chemicals including organic acids and secondary metabolites. We previously revealed that alpha-1,3-glucan and galactosaminogalactan (GAG) contribute to hyphal aggregation in the industrial fungus Aspergillus oryzae, and that production of recombinant protein in shake-flask culture is higher in a mutant lacking both alpha-1,3-glucan and GAG (AG Delta-GAG Delta) than in the parental strain. Here, we compared the productivity of the wild type, AG Delta-GAG Delta, and mutants lacking alpha-1,3-glucan (AG Delta) or GAG (GAG Delta) in batch culture with intermittent addition of glucose in a 5-L lab-scale bioreactor. The hyphae of the wild type and all mutants were dispersed by agitation, although the wild type and AG Delta formed small amounts of aggregates. Although mycelial weight was similar among the strains, the concentration of a secreted recombinant protein (CutL1) was the highest in AG Delta-GAG Delta. Evaluation of fluid properties revealed that the apparent viscosities of mycelial cultures of the wild type and AG Delta-GAG Delta decreased as the agitation speed was increased. The apparent viscosity of the AG Delta-GAG Delta culture tended to be lower than that of the wild-type strain at each agitation speed, and was significantly lower at 600 rpm. Overall, the lack of alpha-1,3-glucan and GAG in the hyphae improved culture rheology, resulting in an increase in recombinant protein production in AG Delta-GAG Delta. This is the first report of flow behavior improvement by a cell-surface component defect in a filamentous fungus. (C) 2021, The Society for Biotechnology, Japan. All rights reserved.

关键词： Intensified biodegradation process   Phenol and p-cresol biodegradation   Countercurrent packed-bed column bioreactor   Pseudomonas putida biofilms   Biomicro-particles   Modeling  

摘要： An intensified biodegradation process in packed-bed column bioreactors (PBCB) with microbial cells attached to packing/micro-particles surface was proposed and simulated via a dynamic 3D model with continuity, momentum, and species (comprising biomicro-particles) balance equations in liquid/gas, accumulation of biomicroparticles in packed-bed, diffusion and enzymatic reaction within biofilm and liquid film. Phenol and phenol/p- cresol biological removal by Pseudomonas putida was chosen to discuss the enhanced biodegradation efficiency. The biodegradation in single/dual-substrate systems is significantly upgraded as biomass loading on micro particles surface increases. Microbial cells addition to the surface of micro-particles is more efficient when the foremost extent of biomass is attached to packing via large biofilms with increased resistance to mass transfer, at low phenol concentrations and liquid velocities. These intensified biodegradation systems aim at maximizing the mass transfer in PBCB for treatment of wastewater having high phenols concentration, without reducing the residence time of liquid or diluting the effluent.

关键词： Biohydrogen   Dark fermentation   Dynamic membrane module bioreacotor   Lignocellulosic biomass   Microbial community  

摘要： This study aimed a high-rate dark fermentative H-2 production from xylose using a dynamic membrane module bioreactor (DMBR) with a 444-mu m pore polyester mesh. 20 g xylose/L was fed continuously to the DMBR different hydraulic retention times (HRTs) from 12 to 3 h at 37 degrees C. The maximum average H-2 yield (HY) and H-2 production rate (HPR) at 3 h HRT were found to be 1.40 +/- 0.07 mol H-2/mol xyloseconsumed and 30.26 +/- 1.19 H-2/L-d, respectively. The short HRT resulted in the maximum suspended biomass concentration (8.92 +/- 0.40 VSS/L) along with significant attached biomass retention (7.88 +/- 0.22 g VSS/L). H-2 was produced by both butyric and acetic acid pathways. Low HY was concurrent with lactic acid production. The bacterial population shifted from non-H-2 producers, such as Lactobacillus and Sporolactobacillus spp., to Clostridium sp., when HY increased. Thus, xylose from lignocellulose is a feasible substrate for dark fermentative H-2 production using DMBR.

关键词： Moving-bed-biofilm submerged membrane   bioreactor (MBBF-SMBR)   Shale gas wastewater (SGW)   Ozonation   Microbial community   Submerged membrane bioreactor (SMBR)  

摘要： Shale gas wastewater (SGW) with complex composition and high salinity needs an economical and efficient method of treatment with the main goal to remove organics. In this study, a coupled system consisting of ozonation and moving-bed-biofilm submerged membrane bioreactor (MBBF-SMBR) was comprehensively evaluated for SGW treatment and compared with a similar train comprising ozonation and submerged membrane bioreactor (SMBR) without addition of carriers attaching biofilm. The average removal rates of MBBF-SMBR were 77.8% for dissolved organic carbon (DOC) and 37.0% for total nitrogen (TN), higher than those observed in SMBR, namely, 73.9% for DOC and 18.6% for TN. The final total membrane resistance in SMBR was 40.1% higher than that in MBBF-SMBR. Some genera that specifically contribute to organic removal were identified. Enhanced gene allocation for membrane transport and nitrogen metabolism was found in MBBF-SMBR biofilm, implying that this system has significant industrial application potential for organics removal from SGW.

关键词： Microplastics   Membrane bioreactor   Polypropylene   Microbial community   Wastewater treatment  

摘要： The effective interception of membrane leads to the accumulation of microplastics (MPs) in membrane bioreactor (MBR) process for long-term operation. However, the influence of MPs accumulation on the performance of MBR hasn't been well understood. In this study, the accumulation of polypropylene microplastics (PP-MPs) in two MBRs run for 3 yr with or without discharging sludge was simulated by operating the lab-scale MBRs for 84 days. The variations of pollutant removal, membrane fouling, composition of soluble microbial product (SMP) and extracellular polymeric substance (EPS), and microbial community of MBRs were systematically investigated. The results show that the removal efficiency of COD and NH4+-N was not depressed by PP-MPs accumulation. However, the presence of PP-MPs in the range of 0.14-0.30 g/L could inhibit the growth of microorganisms, enhance the secretion of SMP and EPS, and reduce the microbial richness and diversity. In the contrary, the high concentration of PP-MPs (2.34-5.00 g/L) exhibited the opposite effects and mitigated membrane fouling, suggesting the important role of MPs concentration. It was also found that the exposure to high concentration of PPMPs enhanced relative abundance of Clostridia, and inhibited the growth of Proteobacteria. The findings of this study provide a foresight to understand the effects of MPs accumulation on the performance of MBRs.

关键词： Carbon neutral   Nutrient recycling   Microalgae   Energy neutral   Wastewater  

摘要： Conventional sewage treatment applying activated sludge processes is energy-intensive and requires great financial input, hampering widespread implementation. The introduction of anaerobic membrane bioreactors (AnMBR) followed by an algal reactor growing species of commercial interest, may present an alternative, contributing to the envisaged resource recovery at sewage treatment plants. AnMBRs can be applied for organic matter removal with energy self-sufficiency, provided that effective membrane fouling management is applied. Haematococcus pluvialis, an algal species with commercial value, can be selected for ammonium and phosphate removal. Theoretical analysis showed that good pollutant removal, positive financial output, as well as a significant reduction in the amount of hazardous activated sludge can be achieved by applying the proposed process, showing interesting advantages over current sewage treatment processes. Microbial contamination to H. pluvialis is a challenge, and technologies for preventing the contamination during continuous sewage treatment need to be applied.

关键词： Loofah bioreactor   Denitrification   Mn(II) removal   TC removal   Community diversity   Metagenome  

摘要： The remediation of multiple pollutants in water, for instance, nitrate, heavy metals, and antibiotics is urgent and necessary for the global water resources protection. Herein, a modified loofah bioreactor was designed for simultaneous denitrification, manganese (Mn) oxidation, and tetracycline (TC) removal. The maximum removal efficiencies of NO3--N (91.97%), Mn(II) (71.25%), and TC (57.39%) were achieved at a hydraulic retention time (HRT) of 9 h, Mn(II) concentration of 20 mg L-1, and TC concentration of 1 mg L-1. SEM and XRD were carried out to characterize the bioprecipitation in the operation of bioreactor. TC addition affected the gaseous denitrification products, dissolved organic matter, as well as reduced the OTU in the bioreactor. The Zoogloea were regarded as the dominant species in the microbial community and played an essential role in the operation of bioreactor. Metagenomic analysis proved the great potential for denitrification, manganese oxidation, and antibiotic removal of loofah bioreactor.

关键词： Recellularization   Decellularization   Perfusion bioreactor   Tissue engineering   Scaffold   Uterus  

摘要： The advances in infertility treatment technologies such as in vitro fertilization (IVF) help many infertile women to be able to get pregnant. However, these infertility treatments cannot be applied to women who are suffering from absolute uterine factor. Fabrication of functional scaffold in tissue engineering approach is believed to play an important role for uterine regeneration and uterus replacement for treating absolute uterine factor infertility. In this research, we developed an internal radial perfusion bioreactor to promote decellularization and recellularization for fabrication of functional engineered uterine tissue. As a result, the DNA contents of the decellularized uterine tissue with high hydrostatic pressure followed by 7 days internal perfusion washing decreased by 90% compared to native tissue. Collagen and proteoglycan contents in the pressurized uterine tissue with the internal perfusion bioreactor, static (control) and shaking treatment with high hydrostatic pressure showed no significant change compared to the native tissue. The newly developed perfusion bioreactor also enabled to recellularize in the decellularized tissue with statistically significant increase of DNA by 614% compared to non-seeded cell groups. Vimentin and 4',6-diamidino-2-phenylindole (DAPI) was homogeneously expressed in the seeded endometrial stromal cells in the recellularized tissue fabricated using the bioreactor. With the developed internal radial perfusion bioreactor, we are the first group to successfully recellularized uterine tissue in all layers including epithelium, endometrium and myometrium. These results showed that the internal perfusion bioreactor has potential to be utilized for fabrication of functional engineered tissue to promote tissue regeneration. (C) 2021, The Society for Biotechnology, Japan. All rights reserved.

关键词： cancer metastasis   experimental methods   extracellular matrix   specialized bioreactors  

摘要： Metastatic cancer spread is responsible for most cancer-related deaths. To colonize a new organ, invading cells adapt to, and remodel, the local extracellular matrix (ECM), a network of proteins and proteoglycans underpinning all tissues, and a critical regulator of homeostasis and disease. However, there is a major lack in tools to study cancer cell behavior within native 3D ECM. Here, an in-house designed bioreactor, where mouse organ ECM scaffolds are perfused and populated with cells that are challenged to colonize it, is presented. Using a specialized bioreactor chamber, it is possible to monitor cell behavior microscopically (e.g., proliferation, migration) within the organ scaffold. Cancer cells in this system recapitulate cell signaling observed in vivo and remodel complex native ECM. Moreover, the bioreactors are compatible with co-culturing cell types of different genetic origin comprising the normal and tumor microenvironment. This degree of experimental flexibility in an organ-specific and 3D context, opens new possibilities to study cell-cell and cell-ECM interplay and to model diseases in a controllable organ-specific system ex vivo.

关键词： Cell culture on paper   Moving bed bioreactor   Continuous virus manufacture   Intensification of vaccine manufacture   MDCK cell growth on paper  

摘要： A moving-bed bioreactor (MBB) could intensify growth of adherent mammalian cells for viral vaccines. A continuously fed sterile paper passing through a thin liquid layer as a flexible cell substrate is a new concept for bioprocess intensification (BPI). Paper could enable cell expansion with reduced footprint and reduced media consumption as the first stage of a 2-stage growth + infection continuous process. This study focused only on cell growth (stage 1). We report a simple 32 mm paper disc method to evaluate growth of adherent Madin Darby canine kidney cells (MDCK CCL-34) adapted to 5% FBS to confluence on unmodified papers to screen substrates. Bibulous paper was found to be the best substrate for proliferation of MDCK. An MBB process was simulated using paper discs to test growth to confluence (stage 1). Growth was characterized using staining, image analysis;confocal microscopy. Cells grew on the surface of bibulous paper to a confluence of >90% in 192 h. Extending this concept by stabilizing MDCK on paper (end of stage 1) by engineering cells to survive freezing or lyoprotection would enable live cells to be shipped as modules to multiple manufacturing sites for infection resulting in rapid, reproducible viral vaccine manufacture.