123
also one of the most prevalent following fermentation of complex feedstocks. If
used as a carbon source alone, it results in higher polyhydroxybutyrate content and
in some cases pure polyhydroxybutyrate. Butyrate alone was found to produce only
polyhydroxybutyrate, while the presence of propionate results in a higher polyhydroxyvalerate content (Saharan et al. 2014). In an experiment conducted by
Bengtsson et al., the impact of acetate, propionate, butyrate, and valerate on
glycogen- accumulating organisms for polyhydroxyalkanoates production was
investigated under the same conditions. They found that acetate resulted in the highest hydroxybutyrate/hydroxyvalerate ratio at 89:11, followed closely by a pure
butyrate substrate at a ratio of 83:7 hydroxybutyrate/hydroxyvalerate, along with
new monomers. A pure valerate carbon source produced the highest hydroxyvalerate content at a ratio of 12:78 hydroxybutyrate/hydroxyvalerate, followed by propionate at a ratio of 12:63 hydroxybutyrate/hydroxyvalerate (Bengtsson et al. 2010).
Yu et al. explored the impact of various concentrations of butyrate and valerate
using Cupriavidus metallidurans (previously known as Alcaligenes eutrophus) on
their ability to accumulate various types of monomers. The research revealed that
100% butyrate substrate resulted in polyhydroxybutyrate monomers only, while
100% valerate substrate resulted in 46:54 hydroxybutyrate/hydroxyvalerate (Yu
et al. 1998). Polyhydroxyalkanoates experiments conducted by Takabatake et al.
confirmed the relationship between acetate and propionate substrates and their
impact on the hydroxybutyrate/hydroxyvalerate ratio, observing a 97:3 hydroxybutyrate/hydroxyvalerate monomer ratio with acetate feed and 16:84 hydroxybutyrate/
hydroxyvalerate ratio with propionate as substrate (Takabatake et al. 2000). Mixed
cultures fed with mixed carbon sources result in more diverse monomer production.
Lemos et al. produced a polyhydroxyalkanoates polymer with hydroxybutyrate/
hydroxyvalerate/H2MV at 6:58:24 ratio using microbial mixed culture with a mixture of acetate and propionate (Lemos et al. 2006). Jiang et al. conducted experiments on microbial mixed cultures with acetate, propionate, and an acetate-propionate
mixture. While there was little change to the dominating microorganism as the substrate changed, they discovered a relationship between the concentrations of acetate
and propionate and the ratio of hydroxybutyrate/hydroxyvalerate monomers produced (Jiang et al. 2011a). Yu et al. used malt waste on Cupriavidus metallidurans,
Azohydromonas lata, and an activated sludge. While the pure cultures resulted in
polyhydroxybutyrate monomers only, the activated sludge produced 92:8 hydroxybutyrate/hydroxyvalerate (Yu et al. 1998).
Pure culture studies highlight the influence of substrate on both polyhydroxyalkanoates production and polyhydroxyalkanoates monomer composition.
Cupriavidus necator is a widely utilized organism for polyhydroxyalkanoates production as it has displayed the interesting ability to not only produce polyhydroxyalkanoates under heterotrophic growth but also to produce polyhydroxyalkanoates
under autotrophic metabolism with hydrogen. Cupriavidus necator can utilize CO 2 ,
CO, or acetic acids based on the growth mode. Various experiments have demonstrated that substrate change does not affect the ability of Cupriavidus necator to
produce polyhydroxyalkanoates, obtaining high cell dry weight of polyhydroxyalkanoates under autotrophic or heterotrophic modes in the region of 72–75% (Volova
5 Integration of Polyhydroxyalkanoates Production with Industrial Wastewater…
also one of the most prevalent following fermentation of complex feedstocks. If
used as a carbon source alone, it results in higher polyhydroxybutyrate content and
in some cases pure polyhydroxybutyrate. Butyrate alone was found to produce only
polyhydroxybutyrate, while the presence of propionate results in a higher polyhydroxyvalerate content (Saharan et al. 2014). In an experiment conducted by
Bengtsson et al., the impact of acetate, propionate, butyrate, and valerate on
glycogen- accumulating organisms for polyhydroxyalkanoates production was
investigated under the same conditions. They found that acetate resulted in the highest hydroxybutyrate/hydroxyvalerate ratio at 89:11, followed closely by a pure
butyrate substrate at a ratio of 83:7 hydroxybutyrate/hydroxyvalerate, along with
new monomers. A pure valerate carbon source produced the highest hydroxyvalerate content at a ratio of 12:78 hydroxybutyrate/hydroxyvalerate, followed by propionate at a ratio of 12:63 hydroxybutyrate/hydroxyvalerate (Bengtsson et al. 2010).
Yu et al. explored the impact of various concentrations of butyrate and valerate
using Cupriavidus metallidurans (previously known as Alcaligenes eutrophus) on
their ability to accumulate various types of monomers. The research revealed that
100% butyrate substrate resulted in polyhydroxybutyrate monomers only, while
100% valerate substrate resulted in 46:54 hydroxybutyrate/hydroxyvalerate (Yu
et al. 1998). Polyhydroxyalkanoates experiments conducted by Takabatake et al.
confirmed the relationship between acetate and propionate substrates and their
impact on the hydroxybutyrate/hydroxyvalerate ratio, observing a 97:3 hydroxybutyrate/hydroxyvalerate monomer ratio with acetate feed and 16:84 hydroxybutyrate/
hydroxyvalerate ratio with propionate as substrate (Takabatake et al. 2000). Mixed
cultures fed with mixed carbon sources result in more diverse monomer production.
Lemos et al. produced a polyhydroxyalkanoates polymer with hydroxybutyrate/
hydroxyvalerate/H2MV at 6:58:24 ratio using microbial mixed culture with a mixture of acetate and propionate (Lemos et al. 2006). Jiang et al. conducted experiments on microbial mixed cultures with acetate, propionate, and an acetate-propionate
mixture. While there was little change to the dominating microorganism as the substrate changed, they discovered a relationship between the concentrations of acetate
and propionate and the ratio of hydroxybutyrate/hydroxyvalerate monomers produced (Jiang et al. 2011a). Yu et al. used malt waste on Cupriavidus metallidurans,
Azohydromonas lata, and an activated sludge. While the pure cultures resulted in
polyhydroxybutyrate monomers only, the activated sludge produced 92:8 hydroxybutyrate/hydroxyvalerate (Yu et al. 1998).
Pure culture studies highlight the influence of substrate on both polyhydroxyalkanoates production and polyhydroxyalkanoates monomer composition.
Cupriavidus necator is a widely utilized organism for polyhydroxyalkanoates production as it has displayed the interesting ability to not only produce polyhydroxyalkanoates under heterotrophic growth but also to produce polyhydroxyalkanoates
under autotrophic metabolism with hydrogen. Cupriavidus necator can utilize CO 2 ,
CO, or acetic acids based on the growth mode. Various experiments have demonstrated that substrate change does not affect the ability of Cupriavidus necator to
produce polyhydroxyalkanoates, obtaining high cell dry weight of polyhydroxyalkanoates under autotrophic or heterotrophic modes in the region of 72–75% (Volova
5 Integration of Polyhydroxyalkanoates Production with Industrial Wastewater…