ANALYSIS OF THE LYTIC MECHANISM OF FILLAMENTOUS CYANOBACTERIA BY THE LITIC BACTERIA

从微囊藻的菌落中分离到212株异养菌。收藏于日本京都的丰井池。对这些菌株进行了胞外蛋白水解酶的产生率测定。虽然在微囊藻水华(6月)和水华降解期(10月)之前，胞外蛋白酶活性细菌占异养菌的50%左右，但在微囊藻水华期间(7月、8月和9月)，它们所占的比例较低，不到20%。这些结果表明，微囊藻产生的某些蛋白水解酶抑制剂可能是由微囊藻产生的。夏季的活跃生长可能会抑制生活在微囊藻菌落中的胞外蛋白酶活性细菌的生长。此外，根据抗藻活性，从7月在鹿儿湖采集的芽孢杆菌中分离到了舒法菌素。

A total of 212 heterotrophic bacterial strains were isolated from the colonies of the cyanobacteria Miocrocystis spp. collected at the Benkei Pond, Kyoto, Japan. These bacterial strains were assessed the productivity of extrace11ular protease. Although extrace11ular protease-active bacteria occupied around 50% of heterotrophic bacteria before the occurrence of the bloom of Microcytis (June) and the degradation period of the bloom (October), the proportion of them were lower, Iess then 20%, during the bloom of Microcystis (July, August and September). These results suggest the possibility that some protease inhibitors produced by Microcystis spp. actively growing in summer may inhibit the growth of extrace11ular protease-active bacteria living in the Microcystis colonies. Furthermore, sulfactin was isolated from the Bacillus SP., which was collected in the lake Kasumigaura at July, according to the antialgal activity.