화학공학소재연구정보센터
Biotechnology Progress, Vol.22, No.6, 1671-1682, 2006
Development of a culture sub-population induction model: Signaling pathways synergy and taxanes production by Taxus canadensis
Cell cultures of Taxus canadensis were subjected to exogenously applied ethylene ( ET) hormone and methyl jasmonate ( MJ) elicitation in factorial design experiments. Levels of extracellular taxanes, including paclitaxel, were used with principal component analysis for fault detection and real-coded genetic algorithms for parameter optimization to construct a culture sub-population induction model. Culture sub-populations were identified by the model as ( 1) uninduced, ( 2) induced to unilateral function of the ET-signaling pathway, and ( 3) induced to cooperation between jasmonic acid ( JA)- and ET-signaling pathways. Comprehensive model results suggested greater rates of cellular induction ( resulting in exogenous taxane production) by ET gas as opposed to MJ elicitation. However, cellular induction of ET-signaling pathway genes increased the rate of induction of JA-signaling pathway genes by orders of magnitude. In addition, model results showed that induction of genes leading to extracellular production of the simple taxane 10-deacetylbaccatin III was regulated by the unilateral ET-signaling pathway. However, it was suggested that further processing of this simple taxane to complex taxane structures, such as paclitaxel, required further gene induction by the JA-signaling pathway. Thus, production rate constants of exogenous complex taxanes were predicted to be an order of magnitude lower than that for the simple taxane 10-deacetylbaccatin III. The fraction of the cell culture sub- population displaying unilateral ET-signaling pathway gene induction was found inversely proportional to levels of MJ elicitation. When coupled with simple non-growth product models, levels of all extracellular taxanes were effectively predicted using the culture sub-population induction model.