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关键词： Marc-145细胞   生物反应器   微载体   胰蛋白酶   放大技术   猪繁殖与呼吸综合征病毒  

摘要： 为了建立Marc-145细胞微载体培养放大技术,使其用于猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome,PRRS)疫苗的规模化生产,试验在7 L生物反应器内微载体培养Marc-145种子细胞,再用胰蛋白酶消化,然后进行逐级放大培养,并通过细胞最佳消化状态试验、保留胰蛋白酶消化液的影响试验、测试回收微载体试验等方法摸索胰蛋白酶消化放大技术参数。结果表明:Marc-145细胞在初级生物反应器内培养时,微载体使用量为5 g/L,细胞密度达3.18×10^6个/mL,并且在状态饱满时进行消化放大;在14 L生物反应器内培养时,Marc-145细胞均匀分布在微载体上并且代谢旺盛,在细胞密度为2.91×10^6个/mL时进行14 L消化放大;在14 L生物反应器内培养Marc-145细胞时,采用批培养方式,细胞比生长速率最大达0.031/h,在培养96小时时细胞密度达2.37×10^6个/mL。说明试验成功建立了生物反应器微载体培养Marc-145细胞的胰蛋白酶消化放大技术,并实现了逐级放大。

关键词： Biofilm   Biofilm structure   Wastewater treatment   Dynamic membrane bioreactor   Solids retention time  

摘要： Biofilms have permeable structures, which can be used as membranes for solids separation, e.g., dynamic membrane bioreactors (DMBRs) that relied on the biofilm developed on the support material with large apertures for filtration. This study found that the biofilm formed on the support material in DMBRs under different solids retention time (SATs) had diverse structures, which in turn determined the hydraulic resistance and filtration performance. At 5-day SRT, a thin but compact gel-like biofilm layer (porosity = 27.5%) was formed on the support materials, which had a higher hydraulic resistance of approximately 4.9 x 10(11) m(-1). As a result, the transmembrane pressure (TMP) rose dramatically every 20-40 days' operation. A thick but porous biofilm layer (porosity > 60% and hydraulic resistance < 2.5 x 10(9)m(-1)) was formed at longer SRTs of 20 and 40 days and the TMP could keep consistently low ( < 20 Pa) for more than 180 days. Therefore, a longer SRT could facilitate the formation of a porous biofilm layer on the support material, which was of critical importance for achieving long-term and low-pressure filtration. The biofilm porosity was negatively correlated with the protein/polysaccharide ratio of its extracellular polymeric substance (EPS). Extending SRT would reduce the Live/Dead cell ratio of biofilm, thus lowering EPS production while increasing the porosity. Moreover, extending SRT promoted the growth of protozoa (e.g., Euglypha) that inhabited the biofilm, which could maintain the biofilm porous and mitigate the support layer biofouling though feeding and movement.

关键词： Isolation   Identification   beta-Galactosidase   Production   Bioreactor   Scale-up  

摘要： beta-Galactosidase is an industrially important enzyme with many applications in various health, diagnostic and food processing industries. The present work describes the isolation and identification of a new isolate capable of producing beta-galactosidase. The work was further extended to optimize the production medium and investigate the kinetics of cell growth and enzyme production during batch cultivation in shake-flask and 5L-stirred tank bioreactor. The isolated strain was identified as Bacillus licheniformis using 16S rRNA and BLAST analysis. The final optimized production medium contained (g/L): yeast extract, 14.0;lactose, 8.0;NaCl, 16.0;(NH4)H2PO4, 0.1;MgSO4 center dot 7H(2)O, 0.1;K2HPO4, 0.1. The optimized medium afforded maximal beta-galactosidase production of 116.4 U/mL with a specific yield coefficient (Y-P/X) of 27.6 x 10(3) U/g cells. These results corresponds to an increase of about 4.4- and 2.8-folds, respectively, than the initial un-optimized production medium. Further improvement in the production process was achieved by cultivating cells in 5L-stirred tank bioreactor, which increased volumetric enzyme productivity and specific yield coefficient by 8.5- and 6.0-folds than the initial un-optimized production medium, respectively. A new beta-galactosidase producing strain was identified and the volumetric as well as specific productivities were greatly enhanced through medium optimization and bioreactor cultivation.

关键词： high-rate digestion   organic solid waste   two stage   biogas  

摘要： Anaerobic digestion (AD) is an attractive and sustainable alternative for stabilizing solid organic waste and producing biogas or biomethane. However, it is carried out by slow-growing bacteria and archaea and it normally demands a hydraulic retention time (HRT) of 20-60 days in the bioreactor. Although high-rate AD methods and technologies have been developed, they are normally applied to liquid wastes such as wastewater. In this work, the theory and latest developments in high-rate digestion of organic solid wastes are reviewed. The process is accomplished by running the AD in a two-stage operation. The first stage involves dissolving the solid materials in water, using robust hydrolytic bacteria. The effluent is then filtered to remove any undigested material, which in some cases contains inhibitory compounds. The filtrate is then fed to bioreactors containing high cell density ADs such as flocculating bacteria (granules) or membrane bioreactors (MBR) to protect the sensitive and very slow-growing methanogen. Different approaches to overcoming problems faced in the first stage of digestion are proposed in this review. These problems include slow digestion of lignocellulosic biomass or failure of digestion due to inhibition problems for feedstocks containing toxic compounds, and rapid acidification for easily degradable substrates. The principle, technology, benefits and drawbacks, and factors affecting the efficacy of each type of high cell-density reactor are presented. (c) 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

关键词： ammonium   clinoptilolite   hydrated ferric oxide (HFO)   phosphate   phosphorus   struvite   wastewater   zeolite  

摘要： Nutrient recovery from municipal wastewater was evaluated using anion exchange media loaded with hydrated ferric oxide (HFO) and copper (Cu2+) (Dow-HFO-Cu resin) to selectively capture phosphate, followed by clinoptilolitc for ammonium removal and recovery. Nutrients were concentrated in the regenerants and recovered as precipitated struvite. Media exchange capacity after multiple ion exchange cycles was determined using permeate from an anaerobic membrane bioreactor (AnMBR) treating synthetic or actual municipal wastewater from a full-scale water reclamation facility. Regeneration through five ion exchange cycles using relatively low concentration regenerant solution (2% NaCl and 0.5% NaOH) resulted in the highest phosphate exchange capacity and phosphate recovery. This regenerant also provided the most consistent ammonium recovery. Column tests treating AnMBR permeate were performed over five ion exchange cycles;Dow-HFO-Cu resin exchange capacities ranged from 1.6 to 2.8 mg PO4-P/g dry media. A maximum of 94% of the removed phosphate was recovered during regeneration. The rate and extent of regeneration was insensitive to regenerant salt concentrations in the range investigated. Precipitation using a mixture of the spent regeneration brines from the Dow-NM-Cu resin and clinoptilolite columns produced low molar ratios of Mg:NH4:PO4, suggesting that the recovered product was not pure struvite. (C) 2019 Water Environment Federation

关键词： Forward osmosis membrane bioreactor   Membrane distillation   Fertilizer draw solute   Reverse solute flux   Salt accumulation  

摘要： The reverse solute flux (RSF) of draw solute ions towards the bioreactor is one of the main issues for concern during the forward osmosis membrane bioreactor (FO-MBR). This RSF can be significantly reduced with fertilizer-based draw solutes with anions of relatively large hydrated diameter. The individual performance of three such fertilizer-based draw solutes, ammonium sulfate (SOA), potassium hydrogen phosphate monobasic (MKP) and mono ammonium phosphate (MAP) was investigated in a forward osmosis membrane bioreactor (FO-MBR) integrated with direct contact membrane distillation (DCMD) process. During FO operation, results demonstrated that use of MAP significantly reduced the RSF (0.113 g/m(2)/hr (gMH)) towards the bioreactor, in contrast with that of SOA (0.568 gMH) and MKP (1.17 gMH). MKP exhibited the shortest filtration run of 12 days because of increased buildup of draw solute inside the bioreactor. On the other hand, SOA showed relatively prolonged filtration runs of 17 days, followed by 15 days for MAP. It was also found that MKP and SOA exhibited inhibitory effects on the mixed liquor characteristics in contrast with MAP in terms of biomass growth, particle size distribution and sludge filterability. Based upon these findings, MAP was found to be the most viable draw solute for the FO-MBR. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Vitellogenin   Fish eggs   Bioreactor   Transgenesis   Firefly luciferase   Medaka  

摘要： In this study, we developed a novel bioreactor system to deliver and accumulate foreign proteins in eggs using medaka fish Oryzias latipes with the aid of a partial sequence of vitellogenin (Vtg). In teleost fish, Vtg, the hepatically generated precursor of egg yolk proteins, is secreted into the bloodstream and then taken up into eggs. We predicted in silico a probable region (Vtg signal) of Vtg that mediates transportation of proteins from the liver into eggs. Then, we established two transgenic lines expressing the fused proteins including the Vtg signal and each reporter gene, enhanced green fluorescent protein (EGFP) or firefly luciferase (LUC)-fused EGFP, in the liver driven by a liver-specific choriogeninH (chgH) promoter. Each reporter signal was detected from the fertilized eggs spawned by the transgenic females, showing successful transportation of the proteins into the eggs with the Vtg signal. This is the first report demonstrating that the Vtg signal has capability to deliver exogenous proteins into eggs. Because Vtg is a highly conserved protein among most of oviparous organisms, our findings hold promise for establishing bioreactor systems viable in a wide range of organisms.

关键词： Microalgae   Bio-reactive facade   Damage   Classification  

摘要： Having a noticeable role in CO2 sequestration and O-2 production, microalgae as precious sources of the third-generation biofuel, offer various advantages for energy efficient architecture. Although biofuel production from microalgae biomass has a considerable research background, integrating microalgae culture system with building facade is in its infancy. It is mainly due to the fact that there is only one real building named BIQ house adopting the bioreactor facade technology constructed in Germany, 2013. Hence, there are various challenges associated with this newly emerged technology. This paper aims to detect and estimate the probable causes of damage to microalgae photobioreactor panels integrated with building facade known as SolarLeaf. In order to realize the paper key objective, by comprehensively studying the literature review, surveying and interviewing with the experts, the factors causing damage to bioreactors were recognized and categorized. Based on the results, the main damages are classified as internal and external. Internal causes include bio/chemical and structural factors, while external ones involve climatic and operational/constructional ones. These are the fundamental damage categories of microalgae facade systems that architects and engineers should get familiar with in order to meet and consider the defects developed in the bioreactor panel structure during the design and construction process.

关键词： bioelectrochemical system (BES)   electro-fermentation   glycerol metabolism   in situ electrolysis   redox mediator  

摘要： Microbial electrosynthesis or electro-fermentation in bioelectrochemical systems (BES) have recently received much attention. Here, we demonstrate with the glycerol metabolism by Clostridium pasteurianum that H-2 from in situ water electrolysis, especially in combination with a redox mediator, provides a simple and flexible way for shifting product selectivity and enhancing product yield in the fermentation process. In particular, we report and quantify for the first time strictly different effects of Neutral Red (NR) and the barely studied redox mediator Brilliant Blue (BB) on the growth and product formation of C. pasteurianum grown on glycerol in a newly developed BES. We were able to switch the product formation pattern of C. pasteurianum with a concentration-dependent addition of NR and BB under varied iron availability. Interestingly, NR and BB influenced the glycerol metabolism in a strictly opposite manner concerning the formation of the major products 1,3-propanediol (1,3-PDO) and n-butanol (BuOH). Whereas, NR and iron generally enhance the formation of BuOH, BB favors the formation of 1,3-PDO. In BES the metabolic shifts were enhanced, leading to a further increased yield by as high as 33% for BuOH in NR fermentations and 21% for 1,3-PDO in BB fermentations compared with the respective controls. For the first time, the electron transfer mediated by these mediators and their recycle (recharge) were unambiguously quantified by excluding the overlapping effect of iron. BB has a higher capacity than NR and iron. The extra electron transfer by BB can account for as high as 30-75% of the total NAD(+) regeneration under certain conditions, contributing significantly to the product formation.

关键词： aerobic-MOB-anoxic process   biogas   denitrification   mixed methanotroph culture   WWTP  

摘要： We developed a lab-scale aerobic-methane oxidation bioreactor (MOB)-anoxic system, combining a MOB and the aerobic-anoxic denitrification process, and evaluated its potential for advanced nitrogen treatment in wastewater treatment plants (WWTPs). The MOB used biogas generated from a WWTP and secondary-treated wastewater to support mixed methanotroph cultures, which mediated the simultaneous direct denitrification by methanotrophs and methanol production necessary for denitrifying bacteria in the anoxic chamber for denitrification. Compared to the aerobic-anoxic process, the aerobic-MOB-anoxic system with an influent concentration of 4.8 Lday(-1) showed a marked increase in the reduction efficiency for total nitrogen (41.9% vs. 85.9%) and PO4-3-P (41.1% vs. 69.5%). However, the integrated actions of high nitrogen and phosphorus consumption are required for methanotroph growth, as well as the production and supply of methanol as a carbon source for denitrification and methane monooxygenase-mediated oxidation of NH3 into N2O by methanotrophs. After three months of continuous operation using actual wastewater, the total nitrogen removal rate was 76.3%, equivalent to the rate observed in a tertiary-advanced WWTP, while the total phosphorus removal rate reached 83.7%.