Acidiphilium cryptum DX1-1 CO2固定相关基因的克隆及在不同营养方式下的差异表达研究

目的：研究Acidiphilium cryptum DX1-1 CO2固定相关基因的克隆及在不同营养方式下的差异表达。方法：以Acidiphilium cryptum DX1-1（CCTCCM208056）的DNA为模板，基于A．cryptum JF-5同源功能基因序列（JGI，http：／／genome．oml．gov／cgi-bin／JGI_microbial／keggcategories．cgi）设计引物，对菌株DX1-1中的CO2固定相关基因Acry_0824，Acry_082，Acry_1067，Acry_1272，Acry_0022和Acry_0827进行了克隆和序列比对分析；并对它们在不同营养条件下的基因差异表达进行了分析。结果：从菌株DX1—1成功克隆了所选择的CO2固定相关基因，其序列与菌株JF的同源功能基因序列一致性分别达到了99．8％，99．6％，99．6％，99．5％，99．3％和99．8％；Acry_0824，Acry_1272和Acry_0827三个基因在各种混合养条件下表达均上调，说明它们在DX1—1 CO2固定中起较关键的作用。在加入0．1％的葡萄糖混合养条件下，DX1—1细胞明显利用空气中的CO2来生长和累积PHB。结论：限制性葡萄糖可以促进细胞自养生长和累积PHB。

Cloning and Differential Expression of Acidiphilium Cryptum DX1-1 CO2 Fixed -Related Gene

Objective： To investigate the energy substrates impact on the expression of genes related with CO2 fixed in Acidiphilium cryptum DXI-1. Methods： DNA ofAcidiphilium DXI-1 （CCTCC M 208056） was used as template. The annotation of A. cryptum DXI-1 genes and their putative cellular functions were from Comprehensive Microbial Resource （CMR） of A. cryptum JF-5 （JOI, http：//genome.oml.gov/cgi-bin/JGI_microbial /kegg_categories.cgi）. Results： The genes related with CO2 fixed -Acry_0824, Acry_082,Acry_1067,Acry_1272, Aery_0022 and Acry_0827 were cloned successfully. The RT-qPCR result shows that in mixotrophy with addition of limited 0.1% glucose, the expression of Arcy 0824, Arcy 1272, Arey_0827, were significantly upregulated in the mixotrophy comparing to that in heterotrophy and autotrophy. Conclusion： PHB metabolism of DXI-1 is more activated in mixtrophy and utilizing CO2 to accumulate PHB.