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The Study Of Detection Antibacterial Activity Extracted From Hainan Microalgae And The Overexpression Of Lipid Related Genes

Posted on:2014-09-24Degree:MasterType:Thesis
Country:ChinaCandidate:B XiaFull Text:PDF
GTID:2180330467485073Subject:Molecular Plant Pathology
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There have been more than50,000kinds of microalgaes discovered in nature, but few of them used. Recently, extracting high value active substances from microalgaes become one of the hot spot in research field. At this stage, more useing marine macroalgae as research material, comparaed the antibacterial activity of freshwater microalgae was less research, while through screening and separation active substances from microalgaes, the antibacterial include esters, phenols, terpenes, polysaccharides, halides and sulfur compounds. the research of the antibacterial activity extracts anti-plant pathogens rarely too.This research use20freshwater microalgaes which isolated from Hainan as research materials, and what results as follows:1. Active substance was extracted from twenty microalgae by7kinds of solvent. And then, we applied agar disc diffusion test to compare antimicrobial effects among9plant pathogens, and the crude grease extracteds from microalgaes with better antimicrobial effect. As results, extracts of7out of total20microalgae had higher antimicrobial activity against8pathogens. And ether was the best extraction to extracts which had the strongest antimicrobial effect and the broadest spectrum resistance. The crude grease with ether extraction had stronger antimicrobial activity than ordinary ether extraction did, and3-5days lasting were necessary to the best antimicrobial effect of extraction. Besides, the anti-bacterial effects of microalgae extract against bacteria were much stronger it against fungi.2. With Chlamydomonas reinhardtii (Chlamydomonas reinhardtii) for basic research object, we studied the lipid inhibitory effect, cloned the full-length sequence of three genesphosphatidylglycerophosphate synthase(CrPGP3), phosphatidate cytidylyltransferase(CrCDS1) and acyl-ACP thioesterase(CrFAT1) which associated with Chlamydomonas reinhardtii lipid synthesis, and construct overexpression vector of the three genes. We also built the the subcellular localization carrier, as well as the prokaryotic expression vector. The results showed that mRNA expression abundance of the3genes in the overexpression transformants has been greatly improved compared with the control group.3. The inhibition effect of plant pathogens have improved to some extent and increased expression of microalgae lipids which has a certain inhibition of the pathogen. Besides, the crude extracts of microalgae, especially lipids in its composition, had inhibition effect to plant pathogens. This provides a theoretical basis for the future through the transformation of microalgae gene to produce a new type of antibacterial drugs.
Keywords/Search Tags:microalgae, plant pathogen, antimicrobial activities, solventextract, overexpression, CrPGP3、CrCDS1and CrFAT1genes
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