Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
J Ind Microbiol Biotechnol. 2011 Sep;38(9):1187-92. doi: 10.1007/s10295-010-0895-2. Epub 2010 Nov 17.
Beauvericin (BEA) is a cyclic hexadepsipeptide mycotoxin with notable phytotoxic and insecticidal activities. Fusarium redolens Dzf2 is a highly BEA-producing fungus isolated from a medicinal plant. The aim of the current study was to develop a simple and valid kinetic model for F. redolens Dzf2 mycelial growth and the optimal fed-batch operation for efficient BEA production. A modified Monod model with substrate (glucose) and product (BEA) inhibition was constructed based on the culture characteristics of F. redolens Dzf2 mycelia in a liquid medium. Model parameters were derived by simulation of the experimental data from batch culture. The model fitted closely with the experimental data over 20-50 g l(-1) glucose concentration range in batch fermentation. The kinetic model together with the stoichiometric relationships for biomass, substrate and product was applied to predict the optimal feeding scheme for fed-batch fermentation, leading to 54% higher BEA yield (299 mg l(-1)) than in the batch culture (194 mg l(-1)). The modified Monod model incorporating substrate and product inhibition was proven adequate for describing the growth kinetics of F. redolens Dzf2 mycelial culture at suitable but not excessive initial glucose levels in batch and fed-batch cultures.
beauvericin (BEA) 是一种具有显著植物毒性和杀虫活性的环状十六元环二肽真菌毒素。红镰孢 Dzf2 是一种从药用植物中分离出来的高 BEA 产生真菌。本研究旨在开发一种简单有效的红镰孢 Dzf2 丝状真菌生长动力学模型，并对其进行最优补料分批操作以实现高效 BEA 生产。基于红镰孢 Dzf2 丝状真菌在液体培养基中的培养特性，构建了一个包含基质（葡萄糖）和产物（BEA）抑制的修正 Monod 模型。通过模拟分批培养的实验数据得出模型参数。该模型在 20-50 g l(-1)葡萄糖浓度范围内与分批发酵的实验数据拟合良好。该动力学模型与生物量、基质和产物的化学计量关系相结合，用于预测补料分批发酵的最佳进料方案，导致 BEA 产量（299 mg l(-1))比分批培养（194 mg l(-1))提高了 54%。该修正的 Monod 模型包含基质和产物抑制，适用于描述在适当但不过度的初始葡萄糖水平下，红镰孢 Dzf2 丝状真菌在分批和补料分批培养中的生长动力学。
