(Salehizadeh and van Loosdrecht, 2004). This technique imposes
selective pressure on highly diverse mixed microbial communities
(MMC) to select microorganisms with a certain production capacity
(Ciesielski et al., 2008). To enrich the bacterial community with
these bacteria that effectively produce PHAs, selective pressure is
applied in the form of changing periods of presence and absence of
the external carbon substrate (feast/famine phases) (Serafim et al.,
2008).