蓝藻的抗药性及其诱导与质粒关系

考察5个种9株水生蓝藻对8 种抗菌素和Hg~(2+)、Ca~(2+)离子的抗性及其诱导与质粒遗传的关系,结果表明,蓝藻种间及株系间对药物的抗性有显著差异。某些藻株对几种抗菌素的抗性可因诱导而显著增强。经三次连续药物诱导培养后抗药性可提高5～20倍。诱导获得的抗药性是可以传递的。对7株蓝藻进行质粒DNA检测,发现其中4 株分别含有1、2或3个质粒。对比分析表明这些株系的抗药性与其内含质粒不存在对应关系,表明蓝藻抗药性遗传不是质粒编码的。讨论了蓝藻抗药性诱导的实质及其用于除污染的意义。

Drug Resistance and Plasmids of Cyanobacteria

The antibiotic and toxic heavy metal resistance of 5 genus (9 strains) Cyanobacteria have been tested. These strains showed different tolerance level to the drugs. Some of the strains showed inducible resistance. Higher level(5-20 times) Sm resistants were induced by subculruring in three graduated step of elevating concentration of Sm, and the induced resistance appeared to be inheritable. Several plasmids were isolated from four strains and their molecular weights were estimated. By analysing the relationship between plasmid and drug resistance, we suggest that Cyanobacteria differ from eubacteria in that drug resistance is encoded elsewhere other than plasmid.