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自絮凝颗粒酵母表观生长动力学 被引量:2
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作者 尹冬丽 刘晨光 +2 位作者 李凡 葛旭萌 白凤武 《化工学报》 EI CAS CSCD 北大核心 2011年第11期3149-3155,共7页
首先利用激光聚焦反射颗粒测量系统在线监测了自絮凝颗粒酵母粒径分布,通过提高发酵罐搅拌速率减小了颗粒粒径,消除了内扩散影响,获得了本征动力学模型。进而基于颗粒内部薄壳物料衡算理论,建立了表观动力学模型,并通过不同底物浓度和... 首先利用激光聚焦反射颗粒测量系统在线监测了自絮凝颗粒酵母粒径分布,通过提高发酵罐搅拌速率减小了颗粒粒径,消除了内扩散影响,获得了本征动力学模型。进而基于颗粒内部薄壳物料衡算理论,建立了表观动力学模型,并通过不同底物浓度和自絮凝酵母颗粒粒径分布条件下发酵实验数据拟合,获得了模型的参数。在此基础上,分析了内扩散效应导致颗粒内部可能出现死区的影响,绘制了发酵培养基初始糖和自絮凝颗粒酵母粒径影响的操作图,分析了这一发酵体系的性能。结果表明对于工业生产中普遍采用的多级串联连续乙醇发酵系统,主发酵罐和后发酵罐由于残糖水平差别较大,使颗粒内部因底物枯竭而导致内扩散效应的可能性显著不同:主发酵罐适宜于较大粒径自絮凝颗粒酵母体系,以利于固定化,提高发酵罐中细胞密度和生产强度;而后发酵罐适宜于较小粒径自絮凝颗粒酵母,以减轻底物内扩散影响,保持所需的发酵活性。因此需要综合考虑工程操作和动力学行为,对自絮凝颗粒酵母粒径分布进行优化控制。 展开更多
关键词 自絮凝颗粒酵母 本征与表观动力学 内扩散效应
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絮凝颗粒酵母悬浮液流变特性比较分析 被引量:2
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作者 俞路 白凤武 《化学工程》 CAS CSCD 北大核心 2010年第6期71-74,共4页
絮凝酵母细胞流变特性是影响发酵过程重要的基础数据之一。利用旋转黏度计测定自絮凝颗粒酵母悬浮液和其亲本游离酵母悬浮液的流变特性,分别建立流变本构方程并进行模型比较分析。低质量浓度絮凝酵母悬浮液近似为牛顿性流体,随着菌体质... 絮凝酵母细胞流变特性是影响发酵过程重要的基础数据之一。利用旋转黏度计测定自絮凝颗粒酵母悬浮液和其亲本游离酵母悬浮液的流变特性,分别建立流变本构方程并进行模型比较分析。低质量浓度絮凝酵母悬浮液近似为牛顿性流体,随着菌体质量浓度的增加流动行为指数降低,悬浮液为非牛顿性流体。絮凝酵母悬浮液表观黏度随剪切速率增加而降低,表明剪切使絮凝酵母颗粒聚合力降低从而产生剪切稀化现象。利用柠檬酸对絮凝酵母解絮凝从而改变颗粒聚集分布状态,进一步测定流变行为。结果证明,不同絮凝酵母颗粒聚集状态的分布是决定絮凝酵母流变行为的主要因素。 展开更多
关键词 流变特性 自絮凝颗粒酵母 非牛顿型流体 颗粒聚集状态
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自絮凝酵母颗粒的在线检测与定量表征 被引量:8
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作者 葛旭萌 俞路 +2 位作者 赵心清 白凤武 安利佳 《化工学报》 EI CAS CSCD 北大核心 2005年第2期306-311,共6页
On-line monitoring of self-flocculating yeast cell p articles (SFYCPs) that were characterized by their weak strength, irregular morp hology, special size distribution, and so on, was realized by using the Focused Bea... On-line monitoring of self-flocculating yeast cell p articles (SFYCPs) that were characterized by their weak strength, irregular morp hology, special size distribution, and so on, was realized by using the Focused Beam Reflectance Measurement (FBRM) technique.The experimental results showed go od correlation between the total counts of the FBRM chord length and the biomass concentration of SFYCPs, which could be used to measure the biomass concentrati on for the SFYCP system quantitatively.Furthermore, the mode of FBRM chord lengt h distribution was linearly correlated to both the mean (R2=0.986) and th e 95th percentile (R2=0.988)of the length-weighted chord length distribu tion, which could be used to evaluate SFYCP size distribution effectively.The CO 2 bubbles produced during cell growth/fermentation were observed and proved to create disturbance on on-line measurement of the SFYCP system.This disturbance could be excluded by estimating SFYCP size distribution based on the mode of FB RM chord length distribution. 展开更多
关键词 自絮凝酵母颗粒 FBRM 在线检测 定量表征
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絮凝酵母SPSC01酒精连续发酵并联产酵母工艺过程 被引量:7
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作者 王江龙 孜力汗 白凤武 《化工学报》 EI CAS CSCD 北大核心 2004年第6期1024-1027,共4页
A bioreactor system with a total working volume of 4 8 L,composed of four airlift suspended bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was esta... A bioreactor system with a total working volume of 4 8 L,composed of four airlift suspended bed bioreactors, one of which was designated for seed cultivation and the others in series for ethanol fermentation, was established and continuously operated for 40 days A self flocculating fusant from Saccharomyces cerevisiae and Schizosaccharomyces pombe (SPSC 01) was used and ethanol and yeast were co produced from corn dry milling, two stage enzymatic hydrolysis (raw material residues were separated after saccharification).The results showed that average levels of 98 g·L -1 for ethanol, 4 g·L -1 for residual reduced sugar and 6—9 g·L -1 for residual total sugar were achieved when the medium containing total sugar of 220 g·L -1 was fed at a dilution rate of 0 05 h -1 .Pure yeast, equivalent to 5% (mass) of ethanol and containing protein as high as 48 6%(mass), was co produced Ethanol production is expected to be more economically competitive as this high quality yeast potentially can be further processed as value added by products. 展开更多
关键词 自絮凝颗粒酵母 酒精发酵并联产酵母 悬浮床生物反应器
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