Analysis of Novel Antioxidant Sesquarterpenes (C35 Terpenes) Produced in Recombinant Corynebacterium glutamicum

Abstract

Novel synthetic isoprenoids have been synthesized in engineered microbial hosts by evolving terpene synthase or expressing heterologous terpene synthases. Recently, the native operon, crtN_aN_cM derived from Planococcus sp. PAMC 21323, has isolated for potential industrial applications of C₃₅ carotenoids. For the first time, novel C₃₅ carotenoids (sesquarterpene) were synthesized in Corynebacterium glutamicum expressing the crtN_aN_cM genes. The recombinant strains accumulate various sesquarterpene including 4-apolycopene (red color), 4-aponeurosporene (yellow color), and no pigmentation, depending on the expression of the genetic elements of the crtN_aN_cM genes. Subsequently, the carotenoid extract from the cells harboring pCES-H36-CrtN_aN_cM was analyzed, resulting in significantly higher antioxidant activity than those of other strains harboring pCES-H36-CrtN_cM and pCES-H36-CrtN_aN_c, respectively. This study will promote further engineering of C. glutamicum to increase sesquarterpene productions.

Keywords: Antioxidant activity; C35 carotenoids; Corynebacterium glutamicum; CrtMN.