Benchapattarapong N, Anderson W A, Bai F, Moo-Young M
Department of Chemical Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Bioprocess Biosyst Eng. 2005 Jul;27(4):239-47. doi: 10.1007/s00449-005-0399-z. Epub 2005 Mar 3.
A physico-chemical, two phase simulated pseudoplastic fermentation (SPF) broth was investigated in which Solka Floc cellulose fibre was used to simulate the filamentous biomass, and a mixture of 0.1% (w/v) carboxymethyl cellulose (CMC) and 0.15 M aqueous sodium chloride was used to simulate the liquid fraction of the fermentation broth. An investigation of the rheological behaviour and hydrodynamic properties of the SPF broth was carried out, and compared to both a fungal Tolypocladium inflatum fermentation broth and a CMC solution in a 50 L stirred tank bioreactor equipped with conventional Rushton turbines. The experimental data confirmed the ability of the two phase SPF broth to mimic both the T. inflatum broth bulk rheology as well as the mixing and mass transfer behaviour. In contrast, using a homogeneous CMC solution with a similar bulk rheology to simulate the fermentation resulted in a significant underestimation of the mass transfer and mixing times. The presence of the solid phase and its microstructure in the SPF broth appear to play a significant role in gas holdup and bubble size, thus leading to the different behaviours. The SPF broth seems to be a more accurate simulation fluid that can be used to predict the bioreactor mixing and mass transfer performance in filamentous fermentations, in comparison with CMC solutions used in some previous studies.
研究了一种物理化学两相模拟假塑性发酵（SPF）肉汤，其中使用索尔卡弗洛克纤维素纤维模拟丝状生物质，并用0.1%（w/v）羧甲基纤维素（CMC）和0.15 M氯化钠水溶液的混合物模拟发酵肉汤的液体部分。对SPF肉汤的流变行为和流体动力学性质进行了研究，并在配备传统 Rushton 涡轮的50 L搅拌罐生物反应器中与丝状真菌顶头孢霉发酵肉汤和CMC溶液进行了比较。实验数据证实了两相SPF肉汤模拟顶头孢霉肉汤整体流变学以及混合和传质行为的能力。相比之下，使用具有相似整体流变学的均匀CMC溶液模拟发酵会导致传质和混合时间的显著低估。SPF肉汤中固相的存在及其微观结构似乎在气体滞留率和气泡大小方面起着重要作用，从而导致不同的行为。与之前一些研究中使用的CMC溶液相比，SPF肉汤似乎是一种更准确的模拟流体，可用于预测丝状发酵中生物反应器的混合和传质性能。
