TY - JOUR
T1 - Polyhydroxyalkanoates (PHA) production by photoheterotrophic microbial consortia
T2 - Effect of culture conditions over microbial population and biopolymer yield and composition
AU - Guerra-Blanco, P.
AU - Cortes, O.
AU - Poznyak, T.
AU - Chairez, I.
AU - García-Peña, E. I.
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2018/1
Y1 - 2018/1
N2 - Three microbial consortia (C2, C4, C5) grown under photoheterotrophic conditions assimilated acetate and butyrate, as individual and mixed substrates. By controlling the culture conditions, it was possible to manipulate the microbial population composition and thus the yield of polyhydroxyalkanoates (PHA) accumulation. Under limited ammonium conditions, pH control, and a sequential two-step process, C2 and C4 produced PHA. C4 showed the highest production of 44% of the cell dry mass (CDM), close to the theoretical value calculated with a stoichiometric balance. Analysis of the confocal microscopy images confirmed the accumulated biopolymer percentages produced by each consortium, and it was in close correlation with microbial distribution and substrate consumption pattern. 1H, 13C, NMR, and MALDI-TOF spectra identified the primary structure of the obtained biopolymers as copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). This composition allows for better mechanical properties compared to the PHB homopolymer. Microbial characterization showed a similar microbial population with different proportions for C2 and C4. The highest PHA production in C4 was associated with higher abundances of PHA producers, including Clostridium (29%), Pseudomonas (8%) and Rhodopseudomonas (5%). Both microbial consortia showed that a portion of their microbial populations were able to perform syntrophic reactions (Dysgonomonas and Clostridium).
AB - Three microbial consortia (C2, C4, C5) grown under photoheterotrophic conditions assimilated acetate and butyrate, as individual and mixed substrates. By controlling the culture conditions, it was possible to manipulate the microbial population composition and thus the yield of polyhydroxyalkanoates (PHA) accumulation. Under limited ammonium conditions, pH control, and a sequential two-step process, C2 and C4 produced PHA. C4 showed the highest production of 44% of the cell dry mass (CDM), close to the theoretical value calculated with a stoichiometric balance. Analysis of the confocal microscopy images confirmed the accumulated biopolymer percentages produced by each consortium, and it was in close correlation with microbial distribution and substrate consumption pattern. 1H, 13C, NMR, and MALDI-TOF spectra identified the primary structure of the obtained biopolymers as copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). This composition allows for better mechanical properties compared to the PHB homopolymer. Microbial characterization showed a similar microbial population with different proportions for C2 and C4. The highest PHA production in C4 was associated with higher abundances of PHA producers, including Clostridium (29%), Pseudomonas (8%) and Rhodopseudomonas (5%). Both microbial consortia showed that a portion of their microbial populations were able to perform syntrophic reactions (Dysgonomonas and Clostridium).
KW - Mixed microbial consortium
KW - Photoheterotrophic
KW - Poly(3-hydroxybutyrate) (P3HB)
KW - Poly(3-hydroxyvalerate) (P3HV)
KW - Polyhydroxyalkanoates (PHAs)
UR - http://www.scopus.com/inward/record.url?scp=85033375666&partnerID=8YFLogxK
U2 - 10.1016/j.eurpolymj.2017.11.007
DO - 10.1016/j.eurpolymj.2017.11.007
M3 - Artículo
SN - 0014-3057
VL - 98
SP - 94
EP - 104
JO - European Polymer Journal
JF - European Polymer Journal
ER -