In the first half of 2016, the algalbiotechnology team, led by professor Zhou Zhigang from theCollege of Fisheries and Life Science, has made a series of new researchprogress in the synthesis and control of microalgal oil.
Myrmecia incisa is one of the species containingthe highest content of arachidonic acid (ArA) in the natural world, and thecritical first step in its synthesis, i.e., the introduction of the firstunsaturated double bond into stearic acid, is catalyzed by Δ9 fatty acid desaturase (FAD). Through screening the high-throughputdatabase of the transcriptome, the research team has obtained the cDNA full-length sequence of the Δ9FAD gene of Myrmecia incisa, electro-transferred it into destructedbrewer's yeast, and authenticated the gene’s function of coding Δ9 FAD through mass spectrometry.
On the other hand, the ArA in Myrmecia incisa islargely preserved in cells in the form of triacylglycerol (TAG). Thus, the teamstudied GPAT and PDAT, the two critical enzymes in the two synthesis approaches of TAG, i.e.,the Kennedy approach and the phospholipid-catalyzedapproach. With regard to GPAT, the team used UPLC-ESI-Q-TOF-MS to conduct lipidomics analysis, and found that, in the case of themutation of the polymorphic site Arg195His, the phospholipid content in the destructed yeast also increasedcorrespondingly, possibly because of the enhanced enzyme activity caused by thechanges of MiGPAT proteinconformation; with regard to PDAT, the team adopted fluorogenic quantitativePCR, and found that the transcriptional quantity of MiPDAT was regulated by the nitrogen element, and that its change trend wasthe same with that of the content of TAG cultured under the same conditions.After realizing the fused expression of MiPDAT and GFP, it employed the binary expression system for transfer intotobacco leaves, used laser scanning confocal microscope for observation, andfound that MiPDAT was located on the plasma membrane, possibly still on thechloroplast.
Based on the above mentioned achievements, theresearch team published three SCI papers in the first half of 2016,respectively on Scientific Reports (IF: 5.578), Front. Plant Sci. (IF: IF: 3.948) and Int. J. Mol. Sci. (IF: 3.257). Meanwhile, it was also invited to participate in the composition of Handbook of Biofuels Production (Second Edition), an authoritative treatise on biodiesel alreadypublished by Elsevier. These tasks have been jointly accomplished by postgraduates Liu Xiaoyuand Zhang Li, postdoctor Ouyang Longling and associate research fellow SunZheng under the guidance of professor Zhou Zhigang.