Characterization of the squalene-rich Botryococcus braunii Abt02 strain  

作　　者：CAO Min ZHANG Fangfang MAO Yunxiang KONG Fanna WANG Dongmei 

机构地区：[1]College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China [2]Key Laboratory of Marine Genetics and Breeding (OUC), Ministry of Education, Qingdao 266003, China [3]Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China

出　　处：《Journal of Oceanology and Limnology》2019年第2期675-684,共10页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(Nos.31372517,31672641,31401116);the Fundamental Research Funds for the Central Universities(Nos.201762016,201562018);the MOA Modern Agricultural Talents Support Project,the Scientific;Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02);the National Infrastructure of Fishery Germplasm Resources(No.2018DKA30470)

摘　　要：Botryococcus braunii is widely studied due to its high hydrocarbon content. In this study, B . braunii Abt02 was subjected to several analyses, including cytological observation, hydrocarbon composition analysis by gas chromatography mass spectrometry (GC-MS), phylogenetic identification using known races (A, B and L) of B . braunii strains based on their 18S rDNA sequences, and qPCR-based investigation of transcript accumulation levels of hydrocarbon biosynthesis-related enzymes (DXS, MCS, DLS, SQS) during diff erent growth phases (lag phase, log phase, early stationary growth phase, late stationary growth phase) under nitrogen-replete and nitrogen-depleted growth conditions, respectively. Based on cytological observation and on the 18S rDNA phylogenetic analysis, strain Abt02 was assigned to race B. Analysis of the strain’s chemical composition showed that the B . braunii Abt02 contained high levels of hydrocarbons, which accounted for 43.75% of the cell’s dry weight. Of these hydrocarbons, squalene and its derivatives accounted for up to 87.54%. In addition, all four enzymes investigated were expressed at higher levels during the log growth phase under nitrogen depleted conditions than under nitrogen replete conditions.Botryococcus braunii is widely studied due to its high hydrocarbon content. In this study, B.braunii Abt02 was subjected to several analyses, including cytological observation, hydrocarbon composition analysis by gas chromatography mass spectrometry(GC-MS), phylogenetic identification using known races(A, B and L) of B. braunii strains based on their 18 S rDNA sequences, and qPCR-based investigation of transcript accumulation levels of hydrocarbon biosynthesis-related enzymes(DXS, MCS, DLS, SQS)during dif ferent growth phases(lag phase, log phase, early stationary growth phase, late stationary growth phase) under nitrogen-replete and nitrogen-depleted growth conditions, respectively. Based on cytological observation and on the 18 S rDNA phylogenetic analysis, strain Abt02 was assigned to race B. Analysis of the strain’s chemical composition showed that the B. braunii Abt02 contained high levels of hydrocarbons,which accounted for 43.75% of the cell’s dry weight. Of these hydrocarbons, squalene and its derivatives accounted for up to 87.54%. In addition, all four enzymes investigated were expressed at higher levels during the log growth phase under nitrogen depleted conditions than under nitrogen replete conditions.

关 键 词：BOTRYOCOCCUS braunii cytological observation PHYLOGENETIC analysis HYDROCARBON components qPCR 

分 类 号：P[天文地球]