天津科技大学学报2017，Vol.32Issue(1)：18-24,7.DOI:10.13364/j.issn.1672-6510.20150239
强光下一氧化氮对三角褐指藻EPA产量的影响
Effect of Nitric Oxide on EPA Yield in Phaeodactylum tricornutum under High Light Irradiance
摘要
Abstract
Eicosapentaenoic acid(EPA,5,8,11,14,17-cis-eicosapentaenoic acid)is an n-3 C20-polyunsaturated fatty acid that has a variety of functions in the field of medicine.In this research,the effect of exogenous nitric oxide(NO)on EPA yield in Phaeodactylum tricornutum under high light irradiance was studied.The relationship between light intensity and photosynthetic rate of Phaeodactylum tricornutum was determined with oxygen electrode method,and the results indicate that the light saturation point of Phaeodactylum tricornutum is 126.3 μmol/(m2·s).The Phaeodactylum tricornutum was cultivated in F/2 medium.15 days later,the EPA content was determined by gas chromatography.It was found that EPA yield in Phaeodactylum tricornutum under high light irradiance was increased by exogenous NO,which depended on the effect of NO promoting Phaeodactylum tricornutum growth,but NO had no significant effect on EPA content per g dry algae powder.The growth rate of Phaeodactylum tricornutum was detected by cell count technique,and the results showed that there was a light inhibition in the growth of Phaeodactylum tricornutum under 200 μmol/(m2·s)light irradiance,and SNP could relieve the inhibition.Glycolic acid oxidase(GO)inhibitor oxalic acid decreased Phaeodactylum tricornutum growth rate which was promoted by exogenous NO which increased GO activity.It indicated that exogenous NO accelerated Phaeo-dactylum tricornutum growth rate by increasing GO activity.After purification,the GO was identified with AMCA switch method,and it was found that both GOX and GLY(two isozyme of GO)were S-nitrosylated by NO.The SNO site positions in GLY and GOX were analyzed by the software of iSNO-AAPair,GPS-SNO and iSNO-PseAAC.The 238th cysteine in GLY,the 237th cysteine and the 332th cysteine in GOX were probably S-nitrosylated by NO.In addition,GOX and GLY gene expression levels detected by Real-Time PCR were increased by exogenous NO.The data demonstrate that NO can increase GO activity both by stimulating gene expression and by post-transcriptional S-nitrosylation.In summary,NO,by enhancing GO activity,can quicken the growth of Phaeodactylum tricornutum under high light condition and then improve the overall EPA yield.关键词
EPA/光照强度/三角褐指藻/S–亚硝基化/一氧化氮/乙醇酸氧化酶Key words
EPA/light irradiance/Phaeodactylum tricornutum/S-nitrosylation/NO/glycolic acid oxidase分类
生物科学引用本文复制引用
许文宗,闫爽,王黎颖,徐仰仓..强光下一氧化氮对三角褐指藻EPA产量的影响[J].天津科技大学学报,2017,32(1):18-24,7.基金项目
教育部留学回国人员科研启动基金资助项目 （）
天津市科技兴海资助项目(KJXH2012-14) （KJXH2012-14）
