earticle

영어

Carbonic anhydrase (CA, EC 4.2.1) accelerates to uptake of CO2 from air into intracellular system and phosphoenolpyruvate carboxylase (PEPCase, EC 4.1.1.31) catalyzes the conversion of HCO3 - concentrated by carbonic anhydrase (CA) into four-carbon organic acid oxaloacetate (OAA). PEPcase is also the main anaplerotic enzyme providing OAA and/or malate, replenishing the tricarboxylic acid (TCA) cycle intermediates in all photosynthetic organisms [1]. Our research objective is to develop the platform technology for high-reactivity and high-production of marine CA and PEPCase. To achieve this goal, the experts on marine biology and genetic and protein engineering are collaborated to perform high-production of marine CA and PEPCase via search, screening and fabrication of high-expression recombinant hosts. In our laboratory, three types of CA in two strains of marine microalga (Dunaliella sp., Phaeodactylum tricornutum CCMP632) were identified. In Dunaliella sp., two types of CA, namely alpha and gamma-type CA, were isolated and cloned. Two types of PEPCase were also identified from marine green algae Dunaliella sp. and Dunaliella salina. The molecular cloning of the two PEPCase genes in Dunaliella salina (DsPEPC1, DsPEPC2) and one in Dunaliella sp. (DspPEPC1) were isolated, respectively. The recombinant micro-algae and microbe containing the developed CA and PEPCase variants will be used as important CO2-utilizing bioconversion system for production of useful C4 chemicals. This platform biotechnology for high-reactive design and high-production of marine CA and PEPCase will be essentially employed for development of efficient enzyme-based CO2 fixation/sequestration process.