Oxygen transfer and culture characteristics of self‐immobilized Solanum aviculare aggregates
Oxygen transfer and culture characteristics of self‐immobilized Solanum aviculare aggregates
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DOI：
10.1002/bit.260470506
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发表时间：
1995-09
影响因子：
3.8
通讯作者：
Ita Ananta;M. A. Subroto;P. Doran
中科院分区：
文献类型：
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作者：
Ita Ananta;M. A. Subroto;P. Doran
使用直径为3.0至12.5 mm的聚集体测量自固定化茄细胞的氧转移特性。在没有外部边界层的情况下，表观比氧吸收率在5.9 × 10−11至8.5 × 10−7 kg kg−1 s−1干重之间变化，但并不随颗粒尺寸的增加而连续下降。氧在失活聚集体中的有效扩散系数随粒径的增加而增加，在5.0 × 10−11 ~ 1.0 × 10−9 m2 s−1之间变化，或在相同温度下在水中分子扩散系数的2%~ 40%之间变化。在较大聚集体中检测到的气体空间被限制在中央核心，并且不分布在整个组织中以促进氧气转移。使用可观察到的Thiele模量和零级反应的有效性因子之间的关系估计不存在扩散限制的氧消耗速率。计算结果表明，严重的氧限制在聚集体，但不一致的观察，相对较大的S。扁蓄聚集体含有高比例的活细胞，并且能够活性生长和甾体生物碱合成。这项工作表明，氧的输送是促进活的植物细胞聚集体的机制，这取决于代谢活动，并在失活的细胞不起作用。John Wiley & Sons Inc.
Oxygen transfer characteristics of self‐immobilized Solanum aviculare cells were measured using aggregates 3.0 to 12.5 mm in diameter. Apparent specific oxygen uptake rates in the absence of external boundary layers varied from 5.9 × 10−11 to 8.5 × 10−7 kg kg−1 s−1 dry weight, but did not decline continuously with increasing particle size. The effective diffusivity of oxygen in deactivated aggregates increased with particle diameter, varying from 5.0 × 10−11 to 1.0 × 10−9 m2 s−1 or between 2% and 40% of the molecular diffusivity in water at the same temperature. Gas spaces detected in the larger aggregates were confined to the central core and were not distributed throughout the tissue to facilitate oxygen transfer. Oxygen consumption rates in the absence of diffusional limitations were estimated using the relationship between the observable Thiele modulus and effectiveness factor for zero‐order reaction. The calculated results indicated severe oxygen limitations in the aggregates, but were inconsistent with the observation that relatively large S. aviculare aggregates contained a high fraction of viable cells and were capable ofactive growth and steroidal alkaloid synthesis. This work suggests that oxygen delivery is facilitated in living plant cell aggregates by mechanisms which depend on metabolic activity and which do not function in deactivated cells. © 1995 John Wiley & Sons Inc.