Fig. 1

Overview of astaxanthin biosynthesis pathway from β-carotene and the strategy (heterologous modules engineering combined with mutagenesis by screening) applied in this study. The targeted protein in module engineering was boxed by red. And the gene targets, that were identified to be associated with astaxanthin biosynthesis in this research, were also presented in black round square in dashed line. ARTP, atmospheric and room temperature plasma