荒漠微藻XLD-9的分离、初步鉴定及其特性分析

Study on Isolation,Identification and Characterization of Desert Microalgae XLD-9 in Yuli County of Southern Xinjiang

【目的】从新疆的典型干旱荒漠生境中分离出具有一定生物学特性的微藻品系,进行鉴定及分析特性。【方法】扫描电镜和光学显微镜确定细胞形态,并用18S r DNA分子标记方法对此品系进行初步鉴定。XLD-9品系培养在BBM液体培养基上并在此培养条件下确定最佳p H条件,重金属(Cd2+、Ag+、Hg2+)和抗生素(素氯霉素、四环素、链霉素)抗性最佳浓度和生长最高耐受浓度。在BBM固体培养基上培养确定Na Cl抗性最佳浓度和生长耐受浓度。【结果】据18S r DNA分析结果将XLD-9鉴定为Marvania geminata;其细胞近球形,个体较小;属嗜碱性微藻,p H 12.0的培养基中能正常生长。对重金属有一定的抗性,Cd2+的抗性达0.333 Mm。对氯霉素和四环素有很好的抗性,分别为41.7与60μg/m L,但对链霉素敏感。对盐的抗性已到400 m M,超过了模式生物的莱茵衣藻CC-124突变株抗性范围(350 m M)。【结论】从沙漠土壤中分离得到的微藻品系XLD-9,表现出对抗生素、Na Cl显著的抗性,并能在p H 12.0的环境内生长,在抗盐基因的筛选及盐化土壤的治理方面有一定利用价值。

[ Objective ] The main propose of this study is to isolate microalgae species which has certain biological feature in the typical drought desert environment in Xinjiang and clarify their evolutionary status and biological characteristics. [ Method] OM and EM were used to observe the cell morphology and 18S rDNA se- quencing method applied to identify its evolutionary status;XLD -9 was cultured in BBM liquid culture and different amounts of heavy metals （Cd2＋, Ag＋, Hg2＋） added based on the growth condition; Antibiotics （Chloramphenicol, Tetracycline, Streptomycin） were employed to measure its tolerant ability in that adversity, and also the optimum pH in liquid medium was determined; Solid medium was applied to measure the NaC1 resistance. [ Result] XLD -9 was identified as Marvania geminata ,and its cells were spherical ,and the sizes were small and could grow in the alkaline environment （ pH 12.0） ; Certain resistance to heavy metal was found in this test （0. 333 Mm for Cd2 ＋ ）. They expressed remarkable adaptation potential to antibiotics, with the resistant rate of Chloramphenicol and Tetracycline up to 41.7 they displayed salt resistance to the NaC1, with the maximum salt CC- 124（350 mM）. [ Conclusion] The desert microalgae XLD environments such as salty and high pH and it also demonstrated contained different antibiotics. These characteristics told us the salty soil area and screening of new species by adding antibiotics μg/mL and 60 μg/mL respectively ; and also level 400 mM, which was higher than mutant -9 showed resistant ability to some extreme remarkable growth rate in the medium which potentials of XLD -9 at the remediation of to their culture.