Numerical Simulation of Baffled Flask Flow Field and Analysis of Its Effects on Clavulanic Acid Seed and Fermentation Culture Process
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摘要: 提出了一种用于模拟摇瓶内气液两相流动的计算流体力学模型——旋转离心加速度模型法。使用该方法成功模拟摇瓶内的气液两相流动，利用形成的模型分别考察了摇瓶挡板作用、摇床转速、摇瓶装液量等对形成的流场中的传质及剪切环境进行了详细研究，结果表明挡板的存在增加了摇瓶内的气液传氧能力，并且提供更大的剪切环境。转速有利于提升气液传质能力，而特定转速下存在最佳的装液量以提供最优的气液氧传质能力。并且考察了在不同摇瓶培养条件下，对好氧菌——棒状链霉菌种子及发酵培养的影响，通过对比过程菌丝形态特征及产物克拉维酸合成情况，结合流场模拟结果分析了挡板摇瓶对克拉维酸种子及发酵培养获得较不带挡板摇瓶更好结果的流场原因。Abstract: In this work, we proposed a computational fluid dynamics model for simulating gas-liquid two-phase flow in a shake flask, which we named the centrifugal acceleration model method. The model was used to investigate the mass transfer and shearing environment in the 3 L flask flow field, and the results showed that the presence of the baffle increased the gas-liquid oxygen transfer capacity inside the flask and provided a larger shearing environment than the unbaffled flask. The speed of rotate is favorable for the gas-liquid mass transfer ability, and the optimal liquid volume exists for a specific rotation speed that provides the best gas-liquid oxygen mass transfer capacity. Finally, the effects of different flask culture conditions on the seed and fermentation culture of aerobic bacteria streptomyces clavuligerus were investigated. and the morphological characteristics of the hyphae and the synthesis of clavulanic acid were compared. Using the flow field simulation results, the flow field of the baffled shake flask was analyzed for interpreting the better result for clavulanic acid seed and fermentation process in baffled flask. The method formed in this paper can be extended to the fermentation analysis of other products.
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Key words:
- baffled flask /
- clavulanic acid fermentation /
- cfd /
- gas-liquid flow /
- gas-liquid mass transfer
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图 3 摇瓶运动过程中药瓶内发酵液流体微元受力分析
Figure 3. Analysis of the fluid micro-element force in the fermentation liquid of the medicine bottle during shake flask movement
图 5 利用本文提出的旋转离心加速度模型模拟得到的不同时刻形成的气液流动自由表面（80 r/min）
Figure 5. The gas-liquid flow free surface (80 r/min), which is formed at different times, is simulated by the rotational centrifugal acceleration model proposed in this paper
图 6 不同转速下带档板与不带挡板摇瓶中传质参数流场预测值对比（装液量680 mL）
Figure 6. Comparison of flow field prediction values of mass transfer parameters between shaker flask with and without baffle at different speeds (liquid volume 680 mL)
图 7 不同转速下带档板和不带挡板摇瓶形成的气液自由表面对比
Figure 7. Comparison of gas-liquid free surface formed by shaking flask with and without baffle at different rotating speed
图 8 带档板摇瓶中不同装液量下流场参数CFD模拟预测值（摇床转速120 r/min）（a）气液交界面面积；（b）气液比表面积；（c）平均液膜传质系数；（d）体积气液传质系数平均值
Figure 8. CFD simulation prediction value of flow field parameters under different liquid loading in shaking flask with gear plate (rotating speed of shaking table 120 r/min) (a) Gas-liquid interface area; (b) Gas-liquid specific surface area; (c) Average liquid membrane mass transfer coefficient; (d) Volume gas-liquid mass transfer coefficient average
图 9 带档板与不带挡板摇瓶中种子培养过程参数变化对比
Figure 9. Comparison of seed culture parameters in shaking flask with and without baffle
图 10 带档板与不带挡板摇瓶中装液量对克拉维酸的影响
Figure 10. Effect of liquid content in shaking flask with and without baffle on clavulanic acid
表 1 不同转速下带档板与不带档板摇瓶中平均剪切应变率（SSR）大小对比
Table 1. Comparison of average shear strain rate (SSR) in shaker with and without shaker at different rotational speeds
Roatation speed/(r·min−1) Average SSR/s−1 Relative difference/% Baffled Unbaffled 40 2.75 2.70 2 80 22.48 16.63 35 120 40.00 30.93 29 160 60.18 51.09 18 
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[1] XIA J, WANG G, LIN J, et al. Advances and practices of bioprocess scale-up[J]. Advances in Biochemical Engineering-Biotechnology, 2016, 152: 137-151. [2] 何伟. 克拉维酸发酵过程工艺优化[D]. 华东理工大学, 2013. [3] 丁健, 槐强强. 基于自动化和计算流体力学技术的发酵工厂设计课程教学探索[J]. 教育教学论坛, 2016, 0(17): 136-137. doi: 10.3969/j.issn.1674-9324.2016.17.066 [4] 董淑浩, 朱萍, 徐晓滢, 等. 高粘发酵体系不同搅拌桨的CFD模拟及发酵验证[J]. 生物工程学报, 2015, 31(7): 1099-1107. [5] MAYER A F, DECKWER W D. Simultaneous production and decomposition of clavulanic acid during Streptomyces clavuligerus cultivations.[J]. Applied Microbiology and Biotechnology, 1996, 45(1/2): 41-46. [6] 何伟, 冯涛, 王永红, 等. 有机氮源氨基酸组成对克拉维酸发酵的影响[J]. 华东理工大学(自然科学版), 2013, 6(39): 669-674. [7] KHALEELI N L R. The origin of the carbons of clavulanic acid[J]. Journal of the Chemical Society, Chemical Communications, 1999: 1025-1026. [8] THIRKETTLE JE B J E J. The origin of the β-lactam carbons of clavulanic acid[J]. Journal of the Chemical Society, Chemical Communications, 1997: 1025-1026. [9] TOWNSEND C A. The role of molecular oxygen in clavulanic acid biosynthesis: evidence for bacterial oxidative deamination[J]. Journal of the Chemical Society, Chemical Communications, 1988: 1234-1236. [10] 朱校适, 冯涛, 王永红, 等. 克拉维酸发酵过程变温控制的研究[J]. 中国抗生素杂志, 2008, 33(8): 467-470. [11] 蒋顺进, 杨亚勇, 王惠青. 克拉维酸发酵工艺的优化研究[J]. 中国抗生素杂志, 2004(6): 335-337. doi: 10.3969/j.issn.1001-8689.2004.06.005 [12] SCHMIDT F R. Optimization and scale up of industrial fermentation processes[J]. Applied Microbiology and Biotechnology., 2005, 68(4): 425-435. doi: 10.1007/s00253-005-0003-0 [13] 王艳萍, 郭金体, 张阳, 等. 无机盐MgCl2和微量金属离子Zn2+对克拉维酸产量的影响[J]. 天津科技大学学报, 2008(1): 13-16. doi: 10.3969/j.issn.1672-6510.2008.01.004 [14] 朱薇玲. 克拉维酸产生菌的优化培养[J]. 生物技术, 2003(1): 27-28. doi: 10.3969/j.issn.1004-311X.2003.01.019 [15] 李丹丹, 黄喜桂, 林文良, 等. 棒状链霉菌甘油耐受量与克拉维酸合成的关系[J]. 中国抗生素杂志., 1999(1): 14-15. [16] HIGBIE R L. The Rate of Absorption of a Pure Gas into a Still Liquid during Short Periods of Exposure[J]. American Institute of Chemical Engineers, 1935(35): 365-389. [17] DANCKWERTS P V. Significance of liquid-film coefficients in gas absorption[J]. Industrial & Engineering Chemistry, 1951(43): 1460-1467. [18] AZIZAN A, BÜCHS J. Three-dimensional (3D) evaluation of liquid distribution in shake flask using an optical fluorescence technique[J]. Journal of Biological Engineering, 2017, 11(1): 28. doi: 10.1186/s13036-017-0070-7 [19] ZHANG H, WILLIAMS-DALSON W, KESHAVARZ-MOORE E, et al. Computational-fluid-dynamics (CFD) analysis of mixing and gas-liquid mass transfer in shake flasks[J]. Biotechnology and Applied Biochemistry, 2005, 41(Part 1): 1-8. [20] LI C, XIA J, CHU J, et al. CFD analysis of the turbulent flow in baffled shake flasks[J]. Biochemical Engineering Journal, 2013, 70: 140-150. doi: 10.1016/j.bej.2012.10.012 [21] HORVATH I R, CHATTERJEE S G. A surface renewal model for unsteady-state mass transfer using the generalized Danckwerts age distribution function[J]. Royal Society Open Science, 2018, 5(5): 172423. doi: 10.1098/rsos.172423 -
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