Lanfaloni L, Trinei M, Russo M, Gualerzi C O
Institute of Cell Biology, University of Perugia, Italy.
FEMS Microbiol Lett. 1991 Sep 15;67(1):85-90. doi: 10.1016/0378-1097(91)90449-k.
The production of Spirulina platensis cells resistant to 8-azaguanine or beta-(2-thienyl)-DL-alanine following mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and UV-irradiation is described. The conditions for the mutagenesis were determined by monitoring cell viability and the appearance of the two types of mutants as a function of the stage of growth of the tricomes and the length and the conditions of the treatment. The optimal conditions for UV and MNNG mutagenesis were found to be 1-3 min irradiation and 30 min incubation with 50 micrograms MNNG/ml of tricomes derived from cultures entering stationary phase sonicated for 10 s and 5 s respectively. Under these conditions beta-(2-thienyl)-DL-alanine-resistant mutants appeared at a frequency greater than or equal to 10(-4) and greater than or equal to 10(-5) following UV- and MNNG-mutagenesis, respectively. Mutants resistant to 8-azaguanine were found at a frequency approx. 10(-5) only after MNNG mutagenesis. A few chlorate-resistant mutants were also obtained following UV treatment.
描述了在用N-甲基-N'-硝基-N-亚硝基胍（MNNG）诱变和紫外线照射后，钝顶螺旋藻细胞对8-氮杂鸟嘌呤或β-（2-噻吩基）-DL-丙氨酸产生抗性的情况。通过监测细胞活力以及两种类型突变体的出现情况，作为藻丝生长阶段、处理时间长度和处理条件的函数，确定了诱变条件。发现紫外线和MNNG诱变的最佳条件分别为：用来自进入稳定期的培养物的藻丝（分别超声处理10秒和5秒），用50微克MNNG/毫升藻丝进行30分钟孵育，紫外线照射1-3分钟。在这些条件下，紫外线诱变和MNNG诱变后，β-（2-噻吩基）-DL-丙氨酸抗性突变体出现的频率分别大于或等于10^(-4)和大于或等于10^(-5)。仅在MNNG诱变后，发现8-氮杂鸟嘌呤抗性突变体的频率约为10^(-5)。紫外线处理后也获得了一些抗氯酸盐突变体。
