钝顶螺旋藻低中温适应型新品系的选育及RAPD分析

Breeding and RAPD analysis of a new Spirulina platensis strain with low-medium temperature adaptability

摘要:

【目的】选育低中温适应型螺旋藻新品系，显著拓展螺旋藻工厂化培植的地理范围及时间、提高产量和降低成本。【方法】以用于工厂化培植的钝顶螺旋藻(Spirulina platensis) ZJU0116为出发品系，用组织匀浆和离心分离法制得其单细胞或原生质球，先以0.6%甲基磺酸乙酯(ethyl methanesulfonate, EMS)处理30 min，再用2.4 kGy的⁶⁰Co γ射线辐照，进行低温逆境筛选、5次冷/热(12 ℃/38 ℃)骤变交替处理、藻丝单体分离培养、温度适应面构建和蛋白质含量等检测及生产培植试验。【结果】获得了1株蛋白质含量与ZJU0116的相当、而温度适应面和平均日产量依次提高10.7%和10.9%的低中温适应型突变体，命名为ZJU0116(LMTA)。光学显微形态与随机扩增的多态性DNA (randomly amplified polymorphic DNA, RAPD)分析结果显示，与其亲本ZJU0116相比，ZJU0116(LMTA)藻丝的螺旋数和长度依次减少54.4%和42.1%，螺距增加28.8%；基因组DNA在随机引物S30的扩增产物中多了1条约470 bp的条带。【结论】ZJU0116(LMTA)在工厂化培植中温度适应性好、生产性状稳定，干藻粉产量可增加10%以上，可为当前螺旋藻产业深度融合“双碳”目标、迈向高质量发展新阶段提供必要支撑。

关键词:钝顶螺旋藻;工厂化培植;低中温度适应性;突变体;育种;随机扩增多态性DNA

Abstract:

[Objective] To breed new Spirulina strains with low-medium temperature adaptability for expanding the geographical scope and time, increasing the yield, and reducing the cost of Spirulina cultivation. [Methods] The single cells or spheroplasts of Spirulina platensis ZJU0116 in large-scale cultivation were prepared by tissue homogenization and centrifugation. They were treated with 0.6% ethyl methane sulfonate for 30 min and 2.4 kGy ⁶⁰Co gamma ray, and then screened by low-temperature stress with 5 times of cold (12 ℃)/hot (38 ℃) abrupt alternation. The single filaments were cultured separately for the establishment of temperature adaptation surface, determination of protein content, and test of large-scale cultivation. [Results] We obtained a low-medium temperature adaptive mutant, which was named ZJU0116(LMTA), with the protein content equivalent to that of ZJU0116 and the temperature adaptation surface and average daily yield increased by 10.7% and 10.9%, respectively. ZJU0116(LMTA) had the helix number 54.4% lower, the filament length 42.1% lower, and the pitch 28.8% higher than its parent ZJU0116. Moreover, the randomly amplified polymorphic DNA (RAPD) analysis indicated that the amplification with the random primer S30 for ZJU0116(LMTA) produced an additional band at 470 bp, which revealed significant polymorphisms between ZJU0116(LMTA) and ZJU0116. [Conclusion] ZJU0116(LMTA) has good thermal adaptability and stable production, with a 10% increase in the dry algae powder output in large-scale cultivation. The new strain will promote the development of Spirulina industry towards a new stage of deep integration of the “dual carbon” goal and high-quality upgradation.

Key words:Spirulina platensis;large-scale cultivation;low-medium temperature adaptability;mutant;breeding;randomly amplified polymorphic DNA (RAPD)