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关键词： Short-term effect   Long-term effect   Critical flux   Flocculation   Magnetic induced bio-effect  

摘要： This study aims to systematically investigate the short-term and long-term effects of magnetic microparticles (MPs) and nanoparticles (NPs) on critical flux in membrane bioreactors (MBRs). Comparison among six MBRs was carried out with different activated sludge samples. Results showed that the short-term adsorption and flocculation contributed only minimally, however, the long-term magnetic induced bio-effect improved the critical flux by conditioning sludge properties. Additional molecular weight distribution of soluble microbial product (SMP) indicated that long-term magnetic induced bio-effect declined the content of macromolecules (> 500 kDa and 300-500 kDa), but promoted the content of small molecules (< 100 kDa), consequently reduced the free energy of SMP gelling foulants, and further promoted the higher critical flux. Moreover, the magnetic MPs presented the better performance than NPs. This study illustrated that sufficient pre-acclimatization of magnetic activated sludge is significantly necessary to improve the critical flux in MBRs.

关键词： Transient transfection   HEK293 cells   polyethylenimine   recombinant protein production   bioreactor   ambr  

摘要： HEK293 transient expression systems are used to quickly generate proteins for research and pre-clinical studies. With the aim of engineering a high-producing host that grows and transfects robustly in bioreactors, we deleted the pro-apoptotic genes Bax and Bak in an HEK293 cell line. The HEK293 Bax Bak double knock-out (HEK293 DKO) cell line exhibited resistance to apoptosis and shear stress. HEK293 DKO cells sourced from 2 L seed train bioreactors were most productive when a pH setpoint of 7.0, a narrow pH deadband of +/- 0.03, and a DO setpoint of 30% were used. HEK293 DKO seed train cells cultivated for up to 60 days in a 35 L bioreactor showed similar productivities to cells cultivated in shake flasks. To optimize HEK293 DKO transfection cultures, we first evaluated different pH and agitation parameters in ambr15 microbioreactors before scaling up to 10 L wavebag bioreactors. In ambr15 microbioreactors with a pH setpoint of 7.0, a wide pH deadband of +/- 0.3, and an agitation of 630 rpm, HEK293 DKO transient cultures yielded antibody titers up to 650 mg/L in 7 days. The optimal ambr15 conditions prompted us to operate the 10 L wavebag transfection without direct pH control to mimic the wide pH deadband ranges. The HEK293 DKO transfection process produces high titers at all scales tested. Combined, our optimized HEK293 DKO 35 L bioreactor seed train and 10 L high titer transient processes support efficient, large-scale recombinant protein production for research studies.

关键词： Cellulases   Cyanobacteria   pET system   Genetic engineering   Heterologous expression  

摘要： BackgroundThe production of glucose from cellulose requires cellulases, which are obtained from decomposing microorganisms such as fungi and bacteria. Among the cellulases, beta-glucosidases convert cellobiose to glucose and have low concentration in commercial cocktails used for the production of second-generation (2G) ethanol. Genetic engineering can be used to produce recombinant beta-glucosidases, and cyanobacteria may be interesting bioreactors. These photosynthetic microorganisms can be cultured using CO2 emitted from the first-generation ethanol (1G) industry as a carbon source. In addition, vinasse, an effluent of 1G ethanol production, can be used as a source of nitrogen for cyanobacteria growth. Thus, photosynthetic bioreactors cannot only produce cellulases at a lower cost, but also reduce the environmental impact caused by residues of 1G ethanol *** the present work, we produced a strain of Synechococcus elongatus capable of expressing high levels of a heterologous beta-glucosidase from a microorganism from the Amazonian soil. For this, the pET system was cloned into cyanobacteria genome. This system uses a dedicated T7 RNA polymerase for the expression of the gene of interest under the control of a nickel-inducible promoter. The results showed that the pET system functions efficiently in S. elongatus, once nickel induced T7 RNA polymerase expression which, in turn, induced expression of the gene of the microbial beta-glucosidase at high levels when compared with non-induced double transgenic strain. beta-glucosidase activity was more than sevenfold higher in the transformed cyanobacteria than in the wild-type *** T7 system promotes high expression levels of the cloned gene in S. elongatus, demonstrating that the arrangement in which an exclusive RNA polymerase is used for transcription of heterologous genes may contribute to high-level gene expression in cyanobacteria. This work was the first to demonstrate the use of

关键词： macromolecular protein delivery   cell vector   tumor targeting   intratumoral drug distribution   breast cancer therapy  

摘要： Macromolecular protein drugs are promising anti-neoplastic agents based on their precise tumor affinity and innocuousness to normal tissues. Although direct delivery of protein drugs remains impractical due to its short half-life in circulation, inefficiency in tumor accumulation, and poor penetrability in intratumoral distribution. Recently, biogenetic cell -based drug vectors have been widely reported for antitumor drug delivery. Macrophage is naturally independent with endogenous proteolysis, elimination of reticuloendothelial system, and immune surveillance. Meanwhile, its innate recruitment behaviors responsive to chronic inflammation signals make it a potential cellular vector for tumor targeting drug delivery. In this study, we develop a trained macrophage bioreactor for tumor homing and an in situ expression of fused antitumor protein. The recombinant tumor necrosis factor related apoptosis-inducing ligand is coded on a plasmid vector with penetrating domain on the C terminus, which improves the intratumoral distribution by facilitating protein dispersion in tumor tissue after in situ secretion. The combination of tumor-infiltrating macrophage bioreactor and multifunctional fused protein drug embodies a new effective tumor homing system for antitumor protein delivery.

关键词： Bioreactor   consortium   FTIR   GC   MS   HPLC   nitroglycerin   optimization   phyto-toxicity  

摘要： Nitroglycerin (NG) degrading bacterial strains were isolated from the soil samples obtained from contaminated regions of Salem and Sivakasi, Tamil Nadu, India. The isolated strains were tested for their ability to degrade of nitroglycerin in mineral salts medium at optimum temperature. Among 75 strains isolated, three strains were revealed more potent on the degradation of nitroglycerin. They were selected based on their efficiency in the breakdown of nitrogen molecules, the tolerant ability of glycerin and antagonistic assay. The selected strains were identified as Bacillus sp. and Pseudomonas sp. The mineral salts medium amended with NG was used to find out the optimum carbon source, pH and temperature for the degradation of NG. The rate NG degradation was found to be higher by using 1% glucose, pH 7.0 and 30 degrees C as the appropriate factors. Treated water from the bioreactor study was characterized using UV-Vis spectrophotometer, FTIR, HPLC and GC/MS analysis, which showed a potential degradation of NG by the bacterial consortium. Phyto-toxicity tests revealed that significant growth of green gram in the pots irrigated with treated water.

关键词： tendinopathy   oxidative stress   cell model  

摘要： Because of limitations in the current understanding of the exact pathogenesis of tendinopathy, and the lack of an optimal experimental model, effective therapy for the disease is currently unavailable. This study aims to prove that repression of oxidative stress modulates the differentiation of tendon -derived cells (TDCs) sustaining excessive tensile strains, and proposes a novel bioreactor capable of applying differential tensile strains to cultured cells simultaneously. TDCs, including tendon -derived stem cells, tenoblasts, tenocytes, and fibroblasts, were isolated from the patellar tendons of Sprague-Dawley rats. Cyclic uniaxial stretching with 4% or 8% strain at 0.5 Hz for 8 h was applied to TDCs. TDCs subjected to 8% strain were treated with epigallocatechin gallate (EGCG), piracetam, or no medication. Genes representing non-tenocyte lineage (Pparg, Sox9, and Runx2) and type I and type III collagen were analyzed by quantitative polymerase chain reaction. The 8% strain group showed increased expression of non-tenocyte lineage genes and type III/type I collagen ratios compared with the control and 4% strain groups, and the increased expression was ameliorated with addition of EGCG and piracetam. The model developed in this work could be applied to future research on the pathophysiology of tendinopathy and development of treatment options for the disease. Repression of oxidative stress diminishes the expression of genes indicating aberrant differentiation in a rat cell model, which indicates potential therapeutic intervention of tendinopathy, the often relentlessly degenerate condition.

关键词： tubular membrane   digestion performance   sludge characteristics   long-chain fatty acids   syntrophic relationship  

摘要： The performance and syntrophic metabolism of the Anaerobic Membrane Bio-reactor (AnMBR) treating high-lipid kitchen waste slurry under different sludge cycle frequencies were investigated in this study. When the sludge cycle frequencies were 3.6 cycles/h, 9.0 cycles/h and 14.4 cycles/h, the obtained Organic Loading Rates (OLRs) were 10.3 kg-COD/m(3)d, 12.4 kg-COD/m(3)d and 18.1 kg-COD/m(3)d, while the corresponding biogas productions were 190 L/d, 310 L/d and 520 L/d. Moreover, with an increase of sludge cycle frequency, the Chemical Oxygen Demand (COD) removal efficiency improved from 86.2% to 90.4% and 96.3%. Additionally, the higher sludge cycle frequency did not break up the sludge flocs and further affect the syntrophic degradation of the toxic Long-Chain Fatty Acids (LCFAs). Conversely, the higher sludge cycle frequency enhanced LCFA degradation and decreased LCFA accumulation. Meanwhile, under higher sludge cycle frequencies, the abundance of syntrophic Methanobacterium, Syntrophomonas and Clostridium increased and favored the syntrophic metabolism of LCFAs.

关键词： Sulfides   Hydrocarbons   Phosphorus   Membranes   Energy  

摘要： Concerns regarding ambient temperature operation, dissolved methane recovery, and nutrient removal have limited the implementation of anaerobic membrane bioreactors (AnMBRs) for domestic wastewater treatment. This study addresses these challenges using a pilot-scale gas-sparged AnMBR, with post-treatment recovery of dissolved methane and nutrients. Operating under ambient temperatures for 472 days, the AnMBR achieved an average effluent quality of 58 +/- 27 mg/L COD and 25 +/- 12 mg/L BOD5 at temperatures ranging from 12.7 to 31.5 degrees C. The average total methane yield was 0.14 +/- 0.06 L-CH4/g-COD fed, with 42% of the total methane dissolved in the permeate. Dissolved methane removal using a hollow fiber membrane contactor achieved an average removal efficiency of 70 +/- 5%, producing effluent dissolved methane concentrations of 3.8 +/- 0.94 mg/L. The methane recovered from gaseous and dissolved fractions could generate an estimated 72.8% of the power required for energy neutrality. Nutrient recovery was accomplished using coagulation, flocculation, and sedimentation for removal of sulfide and phosphorus, followed by a clinoptilolite ion-exchange column for removal of ammonia, producing effluent concentrations of 0.7 +/- 1.7 mg-S/L, 0.43 +/- 0.29 mg-P/L and 0.05 +/- 0.05 mg-N/L. The successful integration of AnMBRs in a treatment train that addresses the critical challenges of dissolved methane and nutrients demonstrates the viability of the technology in achieving holistic wastewater treatment.

关键词： 组织工程   人工血管   生物反应器   脉动   音圈电机   体外培养  

摘要： 心脑血管疾病是当今威胁人类生命与健康的最主要疾病之一,对人工血管有着较大需求。其中组织工程血管被认为是制备人工血管的理想方法,而生物反应器在组织工程血管的构建中有着关键作用。针对上述问题,设计了一种用于血管组织工程研究用的新型结构脉动生物反应器。该反应器采用了音圈电机作为脉动发生装置,模拟成人的心室功能,可产生与人体自然压差相近的脉动液流,较好地模拟了体内真实的血液流动环境。此外采用弹性可降解的聚氨酯材料以及涂覆工艺设计并制备了小口径的组织工程血管,并将该反应器用于小口径组织工程血管的体外模拟降解的研究中,以验证生物反应器的有效性。

关键词： 钝顶螺旋藻   培养   预采收   膜光生物反应器  

摘要： 为降低钝顶螺旋藻培养和采收成本,利用膜光生物反应器(MPBR)进行钝顶螺旋藻培养和预采收的条件研究实验。实验结果表明:当生物量达到1.8 g/L时可进行微藻采收;初始藻液质量浓度为1.828 g/L时,MPBR中最大体积浓缩系数为2,最佳稀释率为0.08 d-1,藻产品质量浓度可达3.319 g/L;获得1 g微藻生物量,MPBR中可节约水、氮、磷的量分别为0.301 L、0.248 g、0.053 g。与传统光生物反应器(PBR)相比,MPBR能够降低微藻培养和采收的成本。