附生细菌在微囊藻(Microcystis)藻华颗粒上的定殖和生长

通过测定微囊藻模拟藻华颗粒和微囊藻水华藻华颗粒表面附生菌数量的变化,分析微囊藻（Microcystis）与附生假单胞菌（Pseudomonas）之间相互作用关系。结果表明,在死亡藻体的模拟藻华颗粒表面附生菌数量迅速增加,而活藻藻华颗粒表面附生菌数量增长缓慢,在培养后期藻体大量死亡,附生细菌的数量不断增加,最后超过死亡藻体的模拟藻华颗粒的附生细菌数量。附生细菌在天然微囊藻藻华上定殖和生长也呈现类似的趋势,由于附生菌同藻华中微囊藻之间存在竞争,附生菌的存在促进藻体团聚,抑制附生细菌的定殖,但是在微囊藻的衰亡期产生的大量营养物质有利于附生细菌的生长,水体中附生细菌的数量不断增加,同时天然藻华上附生细菌的数量也大量增加,有利于其生长和定殖。

Colonization and Growth of Bacteria Attached on Microcystis Bloom

The Microcystis and attached bacteria, which form a special microenvironment during the outbreaks of water bloom, interact with each other closely. The interaction between Pseudomonas, an attaehed bacteria, and Microcystis bloom was analyzed through investigation on the density of Pseudomonas on natural and simulative algal bloom colonies. The results showed that the amount of bacteria colonized on simulative algal bloom with dead algae increased more rapidly than with live algae in earlier incubation period, however, the bacteria colonized on simulative algal bloom with live algae increased significantly, higher than that in the dead algae and no algae group finally. The nutrients released from the algae can accelerate the growth and colonization of bacteria on the colonies. In the case of natural water bloom colonies, the presence of attached bacteria caused the conglomeration and death of algal bloom colonies because of their competition for nutrient matters. Microcystis could inhibit the colonization of attached bacteria in the beginning 24 h in the co-incubation system of algal bloom and attached bacteria, but the number of bacteria in aqueous solution and colonized on algal bloom increased sharply after 24 h when algae began to release nutrients into waters, which implied that the nutrients released from the Microcystis were essential for the attached bacteria to colonize on the water bloom.