Engineering of Shewanella marisflavi BBL25 for biomass-based polyhydroxybutyrate production and evaluation of its performance in electricity production
Polyhydroxybutyrate (PHB) is a biodegradable plastic with physical properties similar to petrochemically derived plastics. Here, Shewanella marisflavi BBL25 was engineered by inserting the pLW487 vector containing polyhydroxyalkanoates synthesis genes from Ralstonia eutropha H16. Under optimal conditions, the engineered S. marisflavi BBL25 produced 1.99 ± 0.05 g/L PHB from galactose. The strain showed high tolerance to various inhibitors and could utilize lignocellulosic biomass for PHB production. When barley straw hydrolysates were used as a carbon source, PHB production was 3.27 ± 0.19 g/L. In addition, PHB production under the microbial fuel cell system was performed to confirm electricity coproduction. The maximum electricity current output density was 1.71 mA/cm2, and dry cell weight (DCW) and PHB production were 11.4 g/L and 6.31 g/L, respectively. Our results demonstrated PHB production using various lignocellulosic biomass and the feasibility of PHB and electricity production, simultaneously, and it is the first example of PHB production in engineered Shewanella.
This research was supported by the C1 Gas Refinery Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT, South Korea ( 2015M3D3A1A01064882 ), and Research Program to solve the social issues of the National Research Foundation of Korea (NRF)s funded by the Ministry of Science and ICT [grant number 2017M3A9E4077234 ]. This study was also performed with the support of the R&D Program for Forest Science Technology [grant number 2020261C10-2022-AC02 ] provided by Korea Forest Service (Korea Forestry Promotion Institute) and by the National Research Foundation of Korea [ NRF-2020R1A2C2102381 and NRF-2019M3E6A1103979 ].