Johansen CL, Coolen L, Hunik JH
Unilever Research Laboratorium, P.O. Box 114, 3130 AC Vlaardingen, The Netherlands.
Biotechnol Prog. 1998 Mar;14(2):233-40. doi: 10.1021/bp980014x.
The relationship between fungal morphology and heterologous protein production was examined for an Aspergillus awamori strain during a series of fermentations with a batch phase followed by a fed-batch phase. Agitation rate and inoculation concentration were used as controlled variables to generate different fungal morphologies in 20-dm3 stirred tank reactors. Morphology was quantitatively characterized using Image Analysis. The different agitation rates and inoculum concentrations had large effects on the development in hyphal length and number of tips during the fermentations. A reduced inoculum concentration resulted in a more branched mycelium. The different agitation rates affected the morphology after 30 h of fermentation significantly but did not affect the start time of fragmentation. A 3-fold increase in hyphal length increased the apparent viscosity by a factor of 7. The observed morphological differences had only a limited effect on product formation, suggesting that the structural features such as hyphal length and number of tips are of less importance for product formation. The primary effect of morphology on product formation is due to viscosity.
在一系列先分批培养阶段后补料分批培养阶段的发酵过程中，研究了泡盛曲霉菌株的真菌形态与异源蛋白生产之间的关系。在20立方分米的搅拌罐反应器中，使用搅拌速率和接种浓度作为控制变量来产生不同的真菌形态。使用图像分析对形态进行定量表征。不同的搅拌速率和接种浓度对发酵过程中菌丝长度和顶端数量的发展有很大影响。接种浓度降低导致菌丝体分支更多。不同的搅拌速率在发酵30小时后对形态有显著影响，但不影响碎片化的起始时间。菌丝长度增加3倍会使表观粘度增加7倍。观察到的形态差异对产物形成的影响有限，这表明诸如菌丝长度和顶端数量等结构特征对产物形成的重要性较低。形态对产物形成的主要影响是由于粘度。
