CO2 reduction and the production of high-value biomaterials using waste
medium by Rhodobacter sphaeroides
The purple non-sulfur photosynthetic bacteria, Rhodobacter sphaeroides,
are capable of growing under a variety of environmental conditions. R.
sphaeroides wastewater treatment has received considerable attention,
since it can simultaneously realize wastewater purification and biomass
recycling. In addition, poly-β-Hydroxybutyrate (PHB), a biopolymer that
can be used as a biodegradable thermoplastic material for waste
management strategies, and other polyhydroxyalkanoates (PHAs) are
accumulated by many bacteria as energy and carbon reserve material. In
this study, the used culture media of Escherichia coli and Saccharomyces
cerevisiae were reutilized to grow R. sphaeroides to produce PHB and
reduce carbon dioxide. Moreover when using used media, photopigments,
such as bacteriochlorophyll and carotenoid, was also synthesized.
Finally, the co-fermentation of R. sphaeroides and S. cerevisiae showed
the potential of enhancing ethanol production with higher yield than the
single use of S. cerevisiae. Therefore, this approach provides a
low-cost and eco-friendly process that uses waste media to fix carbon
dioxide, and produce high-value biomaterials.