García-Ochoa F, Castro EG, Santos VE
Dept. Ingeniería Química, Fac. CC. Químicas, Universidad Complutense, 28040, Madrid, Spain
Enzyme Microb Technol. 2000 Nov 15;27(9):680-690. doi: 10.1016/s0141-0229(00)00272-6.
Oxygen uptake rate and oxygen mass transfer rate have been studied during xanthan gum production process in stirred tank bioreactor. Empirical equations for the oxygen mass transfer coefficient have been obtained taking into account several variables such as air flow rate, stirrer speed and apparent viscosity. Oxygen uptake rate evolution in the course fermentation has been measured, obtaining an equation as a function of biomass concentration, including overall growth and non growth-associated oxygen uptake. A metabolic kinetic model has been employed for xanthan gum production description including oxygen mass transfer and uptake rates. The results point out that this model is able to describe adequately not only oxygen dissolved evolution, but also of the production of xanthan and substrate consumption. Also, the influence of several parameters (k(L)a, air flow rate and dissolved oxygen) in the evolution of the key compounds of the system have been studied. The results of the simulation shown that an increasing of dissolved oxygen concentration favor the xanthan gum production.
在搅拌罐式生物反应器的黄原胶生产过程中，对氧气摄取速率和氧气传质速率进行了研究。考虑到诸如空气流速、搅拌器速度和表观粘度等几个变量，得到了氧气传质系数的经验方程。测量了发酵过程中氧气摄取速率的变化，得到了一个作为生物量浓度函数的方程，包括总体生长和与生长无关的氧气摄取。采用代谢动力学模型来描述黄原胶的生产，包括氧气传质和摄取速率。结果表明，该模型不仅能够充分描述溶解氧的变化，还能描述黄原胶的生产和底物消耗情况。此外，还研究了几个参数（k(L)a、空气流速和溶解氧）对系统关键化合物变化的影响。模拟结果表明，溶解氧浓度的增加有利于黄原胶的生产。
