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利用 ＤＮＡ体外重组技术构建了蓝细菌Ｓｙｎｅｃｈｏｃｈｓｔｉｓ ｓｐ ＰＣＣ ６８０３缺失突变株ＯＲＦ４_（４６９０），其染色体ＤＮＡ中与不依赖于光的叶绿素合成途径相关的ＯＲＦ_（４６９）片段被红霉素抗性基因所取代．该突变株细胞内叶绿素的含量完全受培养过程中光的控制．培养获得的叶绿素含量分别为９．４２７μｇ· ｍｇ~（－１）和 ０．６９５ μｇ· ｍｇ~（－１）的两类藻细胞在实验室条件下进行了热模拟降解，分析了热解产物烷烃生物标志物特征，发现两类细胞在类异戊二烯烃的相对含量上差异明显．低叶绿素含量的蓝藻样品热解产物中Ｐｒ／ｎＣ_（１７）和Ｐｈ／ｎＣ１８值为０．１９２和０．２１６，分别是高叶绿素含量蓝藻样品的１／３和１／７。实验结果为叶绿素分子是植烷和姥鲛烷等类异戊二烯烷烃的分子来源提供了直接的证据，并进一步证实了藻细胞中脂类分子是决定其热解产烃量的主要控制因素．实验结果表明，现代分子生物学与有机地球化学的结合可以为某些生物标志化合物的分子来源研究提供新的可行途径。
The ORF4_ (4690) of Synechochstis sp PCC 6803 deletion mutant was constructed by DNA in vitro recombination. The ORF_ (469) fragment of chromosomal DNA related to chlorophyll biosynthesis pathway independent of light was substituted by erythromycin resistance gene . The content of intracellular chlorophyll in this mutant strain was completely controlled by light during culture. Two types of algal cells with chlorophyll contents of 9.427μg · mg -1 and 0.695 μg · mg -1 were cultured under laboratory conditions. The pyrolysis products Alkane biomarker characteristics and found that the two types of cells in the relative content of isoprenoids significant differences. The results showed that the Pr / nC_ (17) and Ph / nC18 values of pyrolysates with low chlorophyll content were 0.192 and 0.216, respectively, which were 1/3 and 1/7 of the samples with high chlorophyll content. The experimental results provide direct evidence that chlorophyll molecules are the source of isoprenoid alkanes such as phytane and pristane and further confirm that lipid molecules in algae cells are the main controlling factors that determine their pyrolysis hydrocarbon production . The experimental results show that the combination of modern molecular biology and organic geochemistry can provide new and feasible approaches for the study of the molecular sources of certain biomarkers.