除草剂精喹禾灵用于硅藻过量产生二十碳五烯酸

Potential Use of the Herbicide Quizalofop_p_ethyl for Eicosapentaenoic Acid Overproduction by the Diatom Nitzschia laevis

摘要:

硅藻itzschia laevis是EPA很好的替代来源。除了对硅藻进行高密度培养外，EPA的产量还能利用除草剂来提高。本文研究了除草剂精喹禾灵对硅藻的生长和产EPA的影响。DMSO作为除草剂的溶剂，会对硅藻的生长造成抑制，DMSO在培养基中的添加量最好不要超过0.2%。除草剂能对硅藻的细胞形态造成损害，随着除草剂浓度的增加，硅藻的产量减低了，但脂质和EPA的含量提高了。当除草剂浓度为0.1mmol/L时，EPA的含量从3.00%增加到3.58%，提高了19.3%，EPA占总脂肪酸的含量也由25.15%提高到了32.88%。实验表明，除草剂精喹禾灵能促进硅藻EPA的积累，因而在筛选过量产生EPA微藻方面有重要用途。

Abstract:

The diatom Nitzschia laevis is a good alternative source of eicosapentaenoic acid (EPA). Besides strategies for high cell density culture, EPA productivity may be further improved by herbicides. The effect of the herbicide quizalofop-p-ethyl on the growth and EPA production was studied in this paper. As the solvent of the herbicide, DMSO was proved to inhibit the growth and EPA production of N. laevis. The concentration of DMSO in the medium should not exceed 0.2%. Quizalofop-p-ethyl could cause morphology damage to the N. laevis cells. With the increasing concentration of quizalofop-p-ethyl from 0mmol/L to 0.4mmol/L, the dry cell weight production decreased, while at the same time, the lipid content of the dry cell mass increased. When treated with 0.1mmol/L quizalofop-p-ethyl, the EPA content increased from 3.00% to 3.58% (of dry cell weight, DW), and the proportion of EPA (20:5) in total fatty acids (TFA) increased from 25.15% to 32.88%. These results indicated that the herbicide quizalofop-p-ethyl could stimulate the accumulation of EPA; therefore it might be useful for selecting algae colonies that overproduce EPA.