激光辐照对湛江等鞭金藻的复壮作用及机制研究

用Nd∶YAG激光（波长1.06 μm,功率密度6 W/cm2）对长期保存的湛江等鞭金藻藻种进行辐照处理.研究了激光辐照对藻生长和生理生化特性的影响,并从藻细胞的超微结构和自体荧光特性的变化探讨了激光复壮藻种的可能机制.实验结果表明：辐照剂量为30 s~60 s时,有较好的复壮效果,藻种的生长速率、细胞干重、叶绿素、类胡萝卜素及蛋白质等含量均较对照组有不同程度的提高,增幅约25.3％～48.3％.激光复壮后的藻细胞,线粒体数量增多,光合片层进一步发育.辐照剂量增至90 s时,胞内脂质颗粒增加.藻种的自体荧光光谱中,波长682 nm处的荧光强度明显增强.此结果说明,利用激光的“筛子”与诱变作用,可以提高饵料藻种的生物品质.

The Research of Rejuvenation and Mechanism on Isochrysis Zhangjiangensis Induced by Laser

The stock of long term preservation of marine microalga Isochrysis zhangjiangensis was irradiated by Nd∶YAG laser（1.06 μm, 6 W/cm2 ）.Then,the effects of laser on algal growth,physiological and biochemical characteristic was investigated.The possible mechanisms of algal strain rejuvenation induced by laser irradiation was discussed based on the changes of ultrastructure and autofluorescence.The results showed that the optimal dosage to rejuvenate Isochrysis zhangjiangensis was 30 s~60 s.The growth rate,cell biomass,chlorophyll,carotenoids and protein contents had different degrees of increase compared with the control group,and the increase scope was 25.3％～48.3％.TEM observation showed that both lamellar structure of photosynthesis and chloroplast were more developed,and the number of mitochondria was increased in the cells,which had been rejuvenated by laser.In addition,many oil droplets could be observed in the cells when the irradiation dosage reached 90 s.LSCM analysis showed that the fluorescence intensity at 682 nm of algal autofluorescence spectroscopy was increased significantly after irradiation with low dose.The results show that the biological quality of algal strain could be improved by laser irradiation which played the role of a sieve and mutagen in breeding process.