Levandowsky M, Childress W S, Spiegel E A, Hutner S H
J Protozool. 1975 May;22(2):296-306. doi: 10.1111/j.1550-7408.1975.tb05871.x.
Bioconvection in suspensions of Tetrahymena pyriformis and Crypthecodinium cohnii is described and 2 new patterns, the toroid and the cat's-eye, which appear in shallow suspensions of C. cohnii, are reported. Except in very dense cultures, bioconvection does not arise unless the depth of the suspensions or the mean concentration exceed certain critical values, other things being equal. A mathematical model describing the hydrodynamics of suspension of negatively geotactic microorganisms is described which predicts the existence of critical depths and concentrations. The equations presented admit solutions describing the "polka-dot" patterns seen at low organism concentration in suspensions slightly deeper than the critical value. The discussion here is limited to the case of fairly dilute suspensions, but the basic approach can be applied also to richer cultures.
描述了梨形四膜虫和卵形隐甲藻悬浮液中的生物对流现象，并报道了在卵形隐甲藻浅悬浮液中出现的两种新模式，即环形和猫眼形。除了在非常密集的培养物中，在其他条件相同的情况下，除非悬浮液的深度或平均浓度超过某些临界值，否则不会出现生物对流。描述了一个描述负趋地性微生物悬浮液流体动力学的数学模型，该模型预测了临界深度和浓度的存在。所给出的方程允许有描述在略深于临界值的悬浮液中低生物体浓度下出现的“圆点”模式的解。这里的讨论仅限于相当稀的悬浮液情况，但基本方法也可应用于更丰富的培养物。
