课程文献中心 更多>>

关键词： Gut microbiota   Bioreactors   Metabolites   Antibiotics   Chemostat  

摘要： The study of complex microbial communities has become a major research focus as mounting evidence suggests the pivotal role microbial communities play in host health and disease. Microbial communities of the gastrointestinal tract, known as the gut microbiota, have been implicated in aiding the host with vitamin biosynthesis, regulation of host energy metabolism, immune system development, and resistance to pathogen invasion. Conversely, disruptions of the gut microbiota have been linked to host morbidity, including the development of inflammatory diseases, metabolic disorders, increased cardiovascular risk, and increased risk of infectious diseases. However, studying the gut microbiota in humans and animals is challenging, as many microorganisms are fastidious with unique nutritional or environmental requirements that are often not met using conventional culture techniques. Bioreactors provide a unique solution to overcome some of the limitations of conventional culture techniques. Bioreactors have been used to propagate and establish complex microbial communities in vitro by recapitulating the physiological conditions found in the GI tract. These systems further our understanding of microbial physiology and facilitate our understanding of the impact of medications and xenobiotics on microbial communities. Here, we review the versatility and breadth of bioreactor systems that are currently available and how they are being used to study faecal and defined microbial communities. Bioreactors provide a unique opportunity to study complex microbial interactions and perturbations in vitro in a controlled environment without confounding biotic and abiotic variables.

关键词： 乳品废水   厌氧膜生物反应器   CODCr  

摘要： 采用厌氧膜生物反应器(AnMBR)对乳品废水进行处理,装置连续运行100d,研究了不同进水COD_(Cr)浓度(3 000、5 000、7 000、9 000 mg/L)对出水水质及反应器内污泥特性的影响,并与常规厌氧生物反应器的处理效果进行对比。结果表明,温度为35℃,HRT为48h时,COD_(Cr)去除率和氨化率随着进水COD_(Cr)浓度的降低而升高,最高可达89%和38%以上。TN去除率随着进水COD_(Cr)浓度的增加先增高后降低,在7 000 mg/L条件下,去除率为55%。装置在运行过程中,MLVSS/MLSS平均值约为0. 7,SVI值在60～80 m L/g的范围内,污泥具有良好的活性与沉降性。AnMBR与常规厌氧生物反应器相比,在处理高浓度乳品废水时运行更加稳定,耐冲击负荷能力更强,出水水质更好。

关键词： 波浪式生物反应器   分段式变增益PID   仿真实验   四区段变增益PID   pH调节  

摘要： 目的:设计一种快速高效的波浪式生物反应器pH控制方法,缩短pH调节时间,并降低调节过程的系统超调。方法:根据pH调节特性,设计一种分段式变增益PID(proportion-integration-differentiation)控制算法,并通过仿真实验与传统PID控制进行对比,验证算法的有效性。结合波浪式生物反应器细胞培养的实际情况对该算法进行改进,得到四区段变增益PID控制算法,通过实际实验验证改进算法的有效性。结果:仿真实验表明分段式变增益PID控制相较于传统PID控制调节速度快且系统超调小;实际实验表明四区段变增益PID控制能迅速将pH调节到设定范围内,且稳定性好、精确度高。结论:四区段变增益PID控制能够对pH控制起到很好的调节作用,满足波浪式生物反应器细胞培养过程中对pH控制的要求。

关键词： 无血清培养基   细胞驯化   生物反应器  

摘要： 生物医药是21世纪的朝阳产业,动物细胞无血清培养技术在生物医药领域中发挥着重要作用。无血清培养技术包括无血清培养基的开发、适应细胞株的驯化以及细胞规模化培养技术等关键技术,以细胞生物反应器高密度培养技术作为基础的细胞无血清悬浮培养技术推动了生物制药的快速发展。

关键词： 分置式厌氧膜生物反应器   粉末活性炭   膜污染  

摘要： 主要研究了不同投加量的粉末活性炭(PAC)对分置式厌氧膜生物反应器COD去除效果及膜污染特性的影响。研究结果表明:与0.67 g/L的PAC投加量相比,PAC投加量为1.33 g/L时该厌氧膜生物反应器对COD的去除率并未明显提升,但后者膜污染速率变慢,总阻力、滤饼层阻力、滤饼层阻力所占比例、混合液黏度、Zeta电位的绝对值、溶解性微生物产物(SMP)以及小粒径污泥所占比例均更小,污泥平均粒径更大。在厌氧池水力停留时间(HRT)为32 h,温度为(35±2)℃的情况下,就膜污染控制而言,投加1.33 g/L的PAC比投加0.67 g/L的PAC更有效。

关键词： PAH   Benzo(a)pyrene   Benzo(a)anthracene   Bioreactors   Microalgae   Alginate   Water bioremediation  

摘要： Polycyclic aromatic hydrocarbons (PAHs), especially those having four or more rings, are abundant and toxic environmental contaminants that are highly persistent and difficult to remove from contaminated ecosystems. Bioreactors with microalgae have been used to remove some low-molecular-weight PAHs. Immobilization is a good choice for the recovery of biomass from reactors once its function of removing contaminants is fulfilled. Alginate is a natural material that is transparent, is permeable and acts as a protective barrier against other microorganisms and harmful particulates suspended in water. Therefore, in this study, we designed and evaluated four mini-bioreactors packed with alginate beads that contain two microalgal species, Selenastrum capricornutum and Scenedesmus acutus which are capable of removing the high-molecular-weight PAHs benzo(a)anthracene and benzo(a)pyrene. One of the bioreactors was a batch reactor with a continuous magnetic stirring tank, and the other bioreactors were enclosed tubular bioreactors operating in semi-continuous mode with two cycles. The influence of parameters such as the reactor shape, stirring speed, flow, number of alginate beads, number of cells and cell species ratio, as well as the time of contact and the use of two operation cycles were studied. The amounts of the remaining PAHs after exposure tests with microalgae were determined. It was found that the shape and the mode of operation of the bioreactor markedly influenced the efficiency of removal. The removal capacity of these mini-bioreactors and the advantages and the disadvantages of using these mini-bioreactors were analyzed. (C) 2017 Elsevier B.V. All rights reserved.

关键词： 生物反应器   转速   温度   pH   DO  

摘要： 动物细胞培养技术的迅速发展推进了生物制药领域生产的发展,动物细胞大规模培养技术备受关注。生物反应器是动物细胞大规模培养中不可代替的主要设备,动物细胞生物反应器是模拟生物的体内环境,为了得到动物细胞高密度增殖的效果,并且也要保证动物细胞高效分泌的目的,需要对其培养的运行参数进行控制,可以控制的运行参数有:转速、温度、pH、DO等,本文主要对动物生物反应器培养常用参数进行综述。

关键词： 复合式膜生物反应器   启动挂膜   生活污水  

摘要： 采用2阶段挂膜方式进行复合式膜生物反应器启动试验,1阶段为生物填料挂膜;2阶段为活性污泥驯化。结果表明,在进水COD为80～200mg/L,氨氮质量浓度为16～30mg/L的条件下,18d左右完成挂膜,30d的COD和氨氮去除率分别稳定在80%和90%以上,出水水质达到GB18918-2002一级A标准。试验过程中还发现,启动时间取决于第1阶段,且挂膜期间氨氮的去除率的提高明显快于COD去除率的提高,表明该启动方式更有利于强化系统的脱氮效果。系统内生物量在挂膜19d后达到893mg/L,当第21d向系统内添加1200mg/L活性污泥后,附着生物量略有减少,最终稳定在700mg/L左右,活性污泥含量有少量增加,最终维持在1500mg/L左右。

关键词： 氧含量   烟气脱硝脱汞   膜污染   微生物  

摘要： 基于嗜热生物法构建膜生物反应器实现烟气中NO和Hg^0高效处理,研究氧含量对嗜热膜生物反应器烟气脱硝脱汞性能及微生物群落结构的影响。结果表明:氧含量为2%、6%和10%时,NO去除率均稳定在80%,氧含量为17%时氧促进NO降解,NO去除率达91.0%;Hg^0去除率随氧含量的增加而升高,氧含量为17%时,Hg^0去除率可达92.0%。氧含量的增加促进氨氮的降解,且有利于硝化反应的进行。缺氧和厌氧环境有利于减少膜污染,FT-IR结果表明氧含量影响EPS中官能团含量和成分。16S rDNA结果表明氧含量10%中好氧反硝化菌占比重最高。Zobellella、Paracoccus、Bacillus、Alcaligenes、Arthrobacter、Acinetobacter、Pseudomonas均为好氧反硝化菌。