The filament possesses oblate cell for nutrition and heterocyst.
藻丝的营养细胞是扁平的，具异形胞。
The activity of the soluble protease of heterocyst was 4-5 times higher than that of the vegetative cell.
异形胞可溶部分的蛋白酶活比营养细胞可溶的蛋白酶活高4—5倍。
The result showed that one mutant was unable to differentiate heterocyst, three formed heterocysts but still could not maintain normal growth, four growed slowly with heterocyst differentiation.
