Cell Catalysis of Citrate to Itaconate by Engineered Halomonas bluephagenesis

• DOI: 10.1021/acssynbio.1c00320
• Publication Date: 2021-10-27T14:34:11Z
• Authors: Jing Zhang; Biao Jin; Kunqiang Hong; You Lv; Zhiwen Wang; Tao Chen
• Keywords: Bioproduction; Itaconic acid; Halomonas; Metabolic Engineering

Itaconic acid (IA), an important five-carbon unsaturated dicarboxylic acid, is one of the top 12 renewable chemicals with urgent need to reduce industrial production costs. Halomonas bluephagenesis, which possesses potential for cost-effective bioproduction and organic acids due its ability grow under open nonsterile conditions high tolerance salts, was genetically engineered used produce IA from citrate by a cell catalytic strategy. Here, two essential genes (cis-aconitate decarboxylase encoding gene cadA aconitase (ACN) acn) were introduced into H. bluephagenesis construct biosynthesis pathway. Further engineering modifications including coexpression molecular chaperones GroESL, increasing copy number rate-limiting enzyme ACN, weakening competing pathway implemented. Under optimized condition system, strain TAZI-08 produced 451.45 mM (58.73 g/L) 500 citrate, 93.24% conversion in 36 h productivity 1.63 g/(L h). An intermittent feeding strategy further increased titer 488.86 (63.60 g/L). The are highest among heterologous hosts reported so far, demonstrating that this suitable chassis hyperproduction IA.