Integrated bioconversion of syngas into bioethanol and biopolymers

A two-stage biological gas to liquid transfer process to convert carbon dioxide into bioplastic

“…Despite the increase in biomass, due to the high nitrogen content from the acetogen media, R. eutropha had a higher q PHB and a PHB content compared to what was reported by Lagoa-Coate et al (Lagoa-Costa et al, 2017). It appeared that the medium A2 successfully induced PHB production with a high PHB content by simply adjusting the pH to 7.5 (Table 2).…”

“…The high-pressure reactor used in our study for CO 2 fermentation delivered the gas to the stirring tank only when pressure dropped as a result of microbial consumption. This system prevented loss of gas, which is advantageous compared to previous approaches where large gas volumes flow through the stirring tank (Lagoa-Costa et al, 2017). The process could be coupled with photovoltaics to electrochemically produce H 2 for CO 2 fermentation resulting in a sustainable photovoltaic/Bio-GLT approach for the production of bioplastic.…”

“…The development of a medium that supports both metabolic modes (gas fermentation and PHB production) would markedly enhance costeffectiveness and ease of handling, and hence provide important improvements compared to the approach proposed previously by Lagoa-Costa et al 2017(LagoaCosta et al, 2017. We were indeed able to establish and optimize such a medium that can first be used for A. woodii, and then be kept for R. eutropha after simply filtering out A. woodii and adjusting the pH of the medium.…”

“…The use of Bio-GTL to produce PHB from CO 2 was only reported once by a recent paper (Lagoa-Costa et al, 2017). In that study, in the first stage, the anaerobic syngas fermentation was carried out by Clostridium autoethanogenum to produce ethanol and acetic acid, followed by a second aerobic stage that consequentially converts the produced acetic acid into PHB with a mixed microbial culture.…”

“…First, the microbial conversion of gaseous substrates (e.g., CO 2 and H 2 ) into an intermediate product (e.g., acetic acid). In the second step this intermediate is biologically converted to bioproducts of higher value (Hu et al, 2016;Lagoa-Costa et al, 2017). One of the most interesting end products of Bio-GTL is polyhydroxybutyrate (PHB), a biodegradable biopolymer (Kulpreecha et al, 2009) that can be used in many applications, including packaging, biomedicine, and agriculture (Rehm, 2006).…”