蓝藻Synechococcus sp.PCC7942与其抗氨苄突变株的诱变培养及超微结构观察

Mutagenesis,cultivation and ultrastructural observation of Synechococcus sp.PCC7942 and two Amp-tolerant mutants

利用化学诱变剂,对野生型蓝藻Synechococcussp.PCC7942进行诱变筛选,获得2株抗氨苄的聚球藻突变株.对抗氨苄株1、抗氨苄株2及野生藻PCC7942的生长情况、优化培养条件和超微结构等方面进行了比较分析,结果表明,野生型PCC7942的基础抗性为100 mg.L-1,而抗氨苄株1、抗氨苄株2分别为240和250 mg.L-1.经培养,3种藻的生长都表现出全天光照优于半天光照.在加入氨苄青霉素的BG-11培养基中,抗氨苄株1、2的长势明显好于野生型PCC7942,但都不如它们各自在正常BG-11培养基中的长势.用透射电镜对3种藻不同生理时期的超微结构进行观察,发现在一般情况下3种藻之间以及它们在不同生长时期的外观基本相同,但出现了螺旋结构和出芽生殖的特殊情况.

Two Amp-tolerant mutants of PCC7942 were acquired after ethylmethyl sulphonate （EMS） mutagenesis and ampicillin enrichment. Through comparing among PCC7942 and two mutants on their growing responses, cultivating conditions and ultrastruetures, it was discovered that the basic tolerance of PCC7942 to Amp was 100 mg·L^-1 while the values of mutant 1 and 2 were 240 mg·L^-1 and 250 mg·L^-1. It was also observed that PCC7942 and the two mutants all grew better when receiving all-day illumination than half-day one. In BG-11 containing antibiotic Amp, the growing responses of mutant 1 and 2 were obviously better than wild type PCC7942. In the ultrastruetural level, the structure of the wild-type and two mutants was similar in the different growing phases, but some special phenomenons such as the spiral structure and budding were also discovered.