Bioreactor Scalability: Laboratory-Scale Bioreactor Design Influences Performance, Ecology, and Community Physiology in Expanded Granular Sludge Bed Bioreactors.
Bioreactor Scalability: Laboratory-Scale Bioreactor Design Influences Performance, Ecology, and Community Physiology in Expanded Granular Sludge Bed Bioreactors.
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DOI：
10.3389/fmicb.2017.00664
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发表时间：
2017
影响因子：
5.2
通讯作者：
Collins G
中科院分区：
文献类型：
--
作者：
Connelly S;Shin SG;Dillon RJ;Ijaz UZ;Quince C;Sloan WT;Collins G
研究新的或改进的生物技术的可行性，如废水处理沼气池，不可避免地要从实验室规模的试验开始。然而，很少确定实验室规模的结果是否反映了全面的性能或微生物生态。膨胀颗粒污泥床（EGSB）生物反应器是一种高速率厌氧消化池配置，在本研究中被用作解决这一知识差距的模型。两个实验室规模的EGSB理想化模型——一个是全尺寸设计的一维模型，另一个是全尺寸设计的三维模型——在与全尺寸EGSB几乎相同的条件下进行了三次复制。实验室规模的生物反应器使用从全尺寸生物反应器中获得的生物质作为种子，玉米威士忌蒸馏的废水作为两个规模的基质。在70天的时间里，采用16S rRNA基因测序（V4区）、特定产甲烷活性（SMA）测定以及一系列物理和化学监测方法，对污泥床不同深度的生物反应器性能、微生物生态学和微生物群落生理学进行了监测。SMA分析表明，氢营养途径在全尺寸试验中占主导地位，而在实验室规模试验中发展出更平衡的活动概况。在各尺度上，产甲烷菌属均为优势菌属。总体而言，生物反应器在实验室规模上的性能优于全尺寸。我们观察到，实验室规模的生物反应器设计显著影响了生物反应器污泥床中微生物群落生理学和分类的空间分布，一维生物反应器类型促进了每种生物反应器的分层。在1-D实验室生物反应器中，厚壁菌门丰度的增加与污泥床中的颗粒位置和对醋酸盐和乙醇作为底物的活性增加有关。我们进一步观察到，在1-D实验室规模的生物反应器中，污泥床的分层与物种（OTU）水平上潜在微生物群落的丰富度增加和整体性能的提高有关。
Studies investigating the feasibility of new, or improved, biotechnologies, such as wastewater treatment digesters, inevitably start with laboratory-scale trials. However, it is rarely determined whether laboratory-scale results reflect full-scale performance or microbial ecology. The Expanded Granular Sludge Bed (EGSB) bioreactor, which is a high-rate anaerobic digester configuration, was used as a model to address that knowledge gap in this study. Two laboratory-scale idealizations of the EGSB—a one-dimensional and a three- dimensional scale-down of a full-scale design—were built and operated in triplicate under near-identical conditions to a full-scale EGSB. The laboratory-scale bioreactors were seeded using biomass obtained from the full-scale bioreactor, and, spent water from the distillation of whisky from maize was applied as substrate at both scales. Over 70 days, bioreactor performance, microbial ecology, and microbial community physiology were monitored at various depths in the sludge-beds using 16S rRNA gene sequencing (V4 region), specific methanogenic activity (SMA) assays, and a range of physical and chemical monitoring methods. SMA assays indicated dominance of the hydrogenotrophic pathway at full-scale whilst a more balanced activity profile developed during the laboratory-scale trials. At each scale, Methanobacterium was the dominant methanogenic genus present. Bioreactor performance overall was better at laboratory-scale than full-scale. We observed that bioreactor design at laboratory-scale significantly influenced spatial distribution of microbial community physiology and taxonomy in the bioreactor sludge-bed, with 1-D bioreactor types promoting stratification of each. In the 1-D laboratory bioreactors, increased abundance of Firmicutes was associated with both granule position in the sludge bed and increased activity against acetate and ethanol as substrates. We further observed that stratification in the sludge-bed in 1-D laboratory-scale bioreactors was associated with increased richness in the underlying microbial community at species (OTU) level and improved overall performance.