几种固沙荒漠藻的温度适应性

TEMPERATURE TOLERANCE OF THREE SAND-CONSOLIDATING CYANOBACTERIAL STRAINS

蓝藻结皮在干旱和半干旱区广泛分布,它们在环境状态的维持和改良过程中发挥着重要的作用。在荒漠藻固沙技术的应用过程中,温度不仅影响藻类在培养池中的培养,还影响接种后藻类的生长。因此,摸清优势固沙藻类的温度生长特征及对不同温度的生长适应性,对于接种蓝藻固沙技术的应用具有积极的意义。实验分3部分:研究了室温培养条件下3种荒漠优势蓝藻-具鞘微鞘藻(Microcoleus vaginatus)、爪哇伪枝藻(Scytonema javanicum)、纤细席藻(Phormidium tenue)的生长曲线,在不同温度(2、5、10、15、25、35℃)、开放式载体培养状态下3种蓝藻的生长状况及形态观察,以及爪哇伪枝藻在不同温度(10、15、20、25、30℃)培养条件下的光合活性、光合色素含量和伪枝藻素含量的变化。实验结果表明:(1)在液体培养基中,纤细席藻生长速率最快,高于具鞘微鞘藻和爪哇伪枝藻;(2)开放式载体培养条件下,藻株的生长速率低于液体培养,因此荒漠优势藻类的培养优先选择液体培养,具鞘微鞘藻和爪哇伪枝藻不易被细菌污染,纤细席藻容易受到细菌污染,在培养该藻株时要考虑添加抗生素类药物抑制细菌过度繁殖;(3)爪哇伪枝藻短期培养(18d)宜选择相对较高的培养温度(25—30℃),而长期培养(30d)宜选择相对较低的培养温度(15—20℃)。

Cyanobacterial crusts occur in semiarid and arid regions throughout the world. They play an important role in maintaining and improving the state of the environment. To speed up their recovery in degraded ecosystems, inoculation of soils with mass -cultured cyanobacterial strains has been recommended in recent years. Temperature is one of the most important environmental factors, which affect mass culture and field inoculation of the sand-consolidating cyano-bacterial strains. Studying the temperature tolerance of these cyanobacterial strains is helpful for application of cyano-bacterial inoculation techniques, and then reestablishment of cyanobacterial crusts. Three experiments were conducted to measuring temperature tolerance of three cyanobacterial strains： The growth curves of Microcoleus vaginatus, Scytonema javanicum and Phormidium tenue were examined under room temperature; three strains were cultured in open conditions using carrier cluture method under 2, 5, 10, 15, 25 and 35℃ respectively, and their growth and morphological observation were studied; S. javanicum was cultured under 10, 15, 20, 25 and 30℃ respectively and its biomass, phycobiliprotein content, photosynthetic activity, carotenoids content and scytonemin content were investigated. The results were as follow： （1） P. tenue grew faster than M. vaginatus and S. javanicum in the liquid medium; （2） Liquid medium should be preferred for mass culture of these cyanobaterial strains, because growth rate of these strains in liquid medium was faster than in carrier; P. tenue growing in carriers was easily contaminated with some bacteria and these bacteria should be inhibited by antibiotics; （3） Optimal cultivation temperature for S. javanicum was about 25--30℃ for short-term （18d） culture and about 15--20℃ for long-term （30d） culture.