Engineering Vibrio sp. SP1 for the production of carotenoids directly from brown macroalgae

• Published in: Computational and structural biotechnology journal 2021-01, Vol.19, p.1531-1540
• Main Authors: Park, Sungwoo, Cho, Sung Won, Lee, Yungyu, Choi, Mincheol, Yang, Jina, Lee, Hojun, Seo, Sang Woo
• Format: Article
• Language: English
• Subjects: Alginate; Biorefinery; Carotenoids; Genome sequencing; Macroalgae; Vibrio sp. SP1
• ISSN: 2001-0370; 2001-0370
• DOI: 10.1016/j.csbj.2021.03.007

[Display omitted] •A novel bacterium Vibrio sp. SP1 rapidly consuming alginate was isolated.•Whole genome sequence of this strain was generated.•It was engineered to express heterologous enzymes for carotenoids production.•Direct conversion of brown macroalgae into carotenoids was demonstrated. Macroalgae is regarded as a promising third-generation marine biomass that can be utilized as a sustainable feedstock for bio-industry due to the high sugar level and absence of lignin. Alginate, composed of 1,4-linked D-mannuronate (M) and L-guluronate (G), is one of the major carbohydrates in brown macroalgae. It is difficult to be assimilated by most industrial microorganisms. Therefore, developing engineered microorganisms that can utilize alginate as a feedstock in order to produce natural products from marine biomass is critical. In this study, we isolated, characterized, and sequenced Vibrio sp. SP1 which rapidly grows using alginate as a sole carbon source. We further engineered this strain by introducing genes encoding enzymes under the control of synthetic expression cassettes to produce lycopene and β-carotene which are attractive phytochemicals owing to the antioxidant property. We confirmed that the engineered Vibrio sp. SP1 could successfully produce 2.13 ± 0.37 mg L−1 of lycopene, 2.98 ± 0.43 mg L−1 of β -carotene, respectively, from 10 g L−1 of alginate as a sole carbon source. Furthermore, our engineered strain could directly convert 60 g L−1 of brown macroalgae Sargassum fusiforme into 1.23 ± 0.21 mg L−1 of lycopene without any pretreatment which had been vitally required for the previous productions. As the first demonstrated strain to produce high-value product from Sargassum, Vibrio sp. SP1 is evaluated to be a desirable platform for the brown macroalgae-based biorefinery.