微拟球藻培养中共生关系的初步研究

摘要

[目的]为了获得对海洋产油藻的生长具有促进作用的共栖菌株,对实验室条件下微拟球藻与其栖细菌共生关系进行了初步研究.[方法]利用琼脂扩散法,16S rDNA系统发生学分析和互补共培养法,对海洋产油微藻微拟球藻的4株共栖细菌进行分离鏊定并对其与微藻的共生关系进行初步研究.[结果] 16S rDNA系统发生学分析显示FG-2,FG-3,FG-4,FG-5这4株细菌分别与Paracoccus sp.JAM-AL07,Planomicrobium sp.EP-20,Stappia stellulata sp和ldiomarina sp.JAM-GA26的16S rDNA基因序列具有较高的相似性.通过藻菌间相互作用的相关试验表明,来自微拟球藻的胞外有机物能够促进FG-3,FG-4,FG-5的生长；FG-3能够促进微拟球藻的生长.另外,还首次报道了在固体平板上观察到共栖细菌与微拟球藻的共生现象.[结论] FG-3与微拟球藻间存在共生关系,并且FG-3对微拟球藻的生长具有一定的促进作用.%[Objective]Research the relationship between Nannochloropsis and alga-associated bacteria. [ Method]Four bacterial strains identified as FG-1, FG-2, FG-3 and FG-4 were isolated from a laboratory culture of the marine oil microalgae Nannochloropsis sp. OZ-1 for better understanding of the interactions between them[ Result]Phylogenetic analysis of 16S rDNA sequence revealed that strains FG-1,FG-2,FG-3 and FG-4 were close to Paracoccus sp. JAM-AL07, Planomicrobium sp. EP-20,Bacillus sp. YKJ-11,and Stappia stellulata,respectively. In addition to the growth promotion of Nannochloropsis sp. OZ-1 by FG-3,the growth of strains FG-3,FG-4,FG-5 was also significantly enhanced by co-culturing with extracellular organic matter from Nannochloropsis sp. OZ-1. [ Conclusion ] There has a symbiotic relationship between the FG-3 and Nannochloropsis sp. OZ-1, and has positive effect on the growth of Nannachloropsis sp. OZ-1.