Gowthaman M K, Ghildyal N P, Rao K S, Karanth N G
Fermentation Technology and Bioengineering Discipline, Central Food Technological Research Institute, Mysore, India.
J Chem Technol Biotechnol. 1993;56(3):233-9. doi: 10.1002/jctb.280560303.
Mass transfer plays an important role in solid state fermentation (SSF) systems. Earlier work on SSF in tray bioreactors indicated that steep gaseous concentration gradients developed within the substrate bed, owing to mass transfer resistances, which may adversely affect the bioreactor performance. For all practical purposes these gradients have been eliminated using a packed bed column bioreactor with forced aeration. Gaseous concentrations (oxygen and carbon dioxide) and enzyme activities were measured at various bed heights for various air flow rates during the course of fermentation. The results indicated that concentration gradients were decreased effectively by increasing air flow rate. For example, the actual oxygen and carbon dioxide concentration gradients reduced from 0.07% (v/v) cm-1 and 0.023% (v/v) cm-1 to 0.007% (v/v) cm-1 and 0.0032% (v/v) cm-1 respectively when the air flow rate was increased from 5 dm3 min-1 to 25 dm3 min-1. This resulted in an overall improvement in the performance of the bioreactor in terms of enzyme production.
传质在固态发酵（SSF）系统中起着重要作用。早期在托盘生物反应器中进行的固态发酵研究表明，由于传质阻力，底物床层内会形成陡峭的气体浓度梯度，这可能会对生物反应器性能产生不利影响。实际上，通过使用强制曝气的填充床柱式生物反应器，这些梯度已被消除。在发酵过程中，针对不同的空气流速，在不同的床层高度测量了气体浓度（氧气和二氧化碳）和酶活性。结果表明，通过增加空气流速可有效降低浓度梯度。例如，当空气流速从5 dm³ min⁻¹增加到25 dm³ min⁻¹时，实际的氧气和二氧化碳浓度梯度分别从0.07%（v/v）cm⁻¹和0.023%（v/v）cm⁻¹降至0.007%（v/v）cm⁻¹和0.0032%（v/v）cm⁻¹。这使得生物反应器在酶产量方面的性能得到了整体提升。
