三株小球藻抗旱性能评价

Evaluation of Drought Resistance of Three Chlorella Strains

【目的】研究沙漠小球藻(desert Chlorella)应对干旱胁迫的生理响应,分离培养抗旱能力强的小球藻,为沙漠微藻资源的开发和生产奠定基础。【方法】以2株分离自新疆塔克拉玛干沙漠和古尔班通古特沙漠中的小球藻和1株购买自中国科学院淡水藻种库普通淡水小球藻(Chlorella vulgaris)为材料,使用Bold’s Basal Medium(BBM)作为培养基,通过聚乙二醇(PEG6000)模拟不同程度干旱胁迫,测定3株小球藻在干旱胁迫下的生长速度和生理生化指标,并通过主成分分析、隶属函数、抗旱性综合度量值等方法评价3株小球藻抗旱能力。【结果】干旱胁迫能使小球藻细胞密度(OD_(680))和生物量(干重)下降,叶绿素a、叶绿素b含量降低,丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性上升,但是可溶性糖、蛋白质、脯氨酸(Pro)含量和过氧化氢酶(CAT)活性则因胁迫程度和时间的变化而不同,主成分分析显示糖、Pro、SOD、CAT、叶绿素b在小球藻抗干旱过程中发挥重要作用;根据抗旱系数分析,重度干旱时沙漠小球藻可溶性糖、蛋白质、Pro、SOD、CAT比普通时作用更强。【结论】综合评价显示3株小球藻的抗旱性强弱依次为:沙漠小球藻TLD 6B>沙漠小球藻GTD 8A1>普通小球藻FACHB-2338,且沙漠小球藻在生长速度、糖含量、蛋白质含量方面相比普通小球藻更具有优势。

【Objective】In order to study the physiological response of desert Chlorella to drought stress,we isolated and cultured Chlorella with strong drought resistance,laying a foundation for the development and production of desert microalgae resources.【Method】Two strains of Chlorella vulgaris isolated from Taklimakan Desert and Gurbantunggut Desert in Xinjiang and one strain of C.vulgaris purchased from Chinese Academy of Sciences Freshwater Algae Seed Bank were used as materials,and Bold's Basal Medium(BBM)as the culture medium.The growth rate and physiological and biochemical indicators of three strains of C.vulgaris under drought stress were measured by polyethylene glycol(PEG6000)to simulate different degrees of drought stress,and the drought resistance capacity of three strains of C.vulgaris was evaluated by principal component analysis,membership function,comprehensive drought resistance measurement value and other methods.【Result】Under drought stress,the cell density(OD_(680))and biomass(dry weight)decreased,chlorophyll a and chlorophyll b content decreased,while the malondialdehyde(MDA)content and superoxide dismutase(SOD)activity increased.However,soluble sugar,protein,proline(Pro)content,and catalase(CAT)activity varied with the degree and time of stress.The principal component analysis table showed that the sugars,Pro,SOD,CAT,and chlorophyll b played important roles in the drought resistance process of C.vulgaris.According to the analysis of drought resistance coefficient,the soluble sugars,proteins,Pro,SOD,and CAT of desert Chlorella had stronger effects than ordinary ones during severe drought.【Conclusion】The comprehensive evaluation shows that the drought resistance of the three strains of Chlorella is in the following order:Desert Chlorella TLD 6B>Desert Chlorella GTD 8A1>Common Chlorella FACHB-2338,and desert Chlorella has advantages in growth rate,sugar content,and protein content compared to common Chlorella.