Potential Use of the Herbicide Quizalofop_p_ethyl for Eicosapentaenoic Acid Overproduction by the Diatom Nitzschia laevis
除草剂精喹禾灵用于硅藻过量产生二十碳五烯酸

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.