微拟球藻培养中共生关系的初步研究

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共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鉴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Paracoccussp.JAM-AL07,Planom icrobiumsp.EP-20,Stappia stellulatasp和Idiomarinasp.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。

Study on Symbiotic Association in Nannochloropsis Culture

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 themResult]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.