TY - JOUR
T1 - Beyond Intracellular Accumulation of Polyhydroxyalkanoates
T2 - Chiral Hydroxyalkanoic Acids and Polymer Secretion
AU - Yañez, Luz
AU - Conejeros, Raúl
AU - Vergara-Fernández, Alberto
AU - Scott, Felipe
N1 - Funding Information:
FS gratefully acknowledges financial support from CONICYT – Chile (National Commission for Scientific and Technological Research), grants Fondecyt Iniciación 11170081 and Proyectos REDES ETAPA INICIAL, Convocatoria 2017, REDI170254. LY, AV-F, and FS acknowledge financial support from grant Apoyo a la Formación de Redes Internacionales entre Centros de Investigación REDES190137, CONICYT-PCI.
Publisher Copyright:
© Copyright © 2020 Yañez, Conejeros, Vergara-Fernández and Scott.
PY - 2020/4/3
Y1 - 2020/4/3
N2 - Polyhydroxyalkanoates (PHAs) are ubiquitous prokaryotic storage compounds of carbon and energy, acting as sinks for reducing power during periods of surplus of carbon source relative to other nutrients. With close to 150 different hydroxyalkanoate monomers identified, the structure and properties of these polyesters can be adjusted to serve applications ranging from food packaging to biomedical uses. Despite its versatility and the intensive research in the area over the last three decades, the market share of PHAs is still low. While considerable rich literature has accumulated concerning biochemical, physiological, and genetic aspects of PHAs intracellular accumulation, the costs of substrates and processing costs, including the extraction of the polymer accumulated in intracellular granules, still hampers a more widespread use of this family of polymers. This review presents a comprehensive survey and critical analysis of the process engineering and metabolic engineering strategies reported in literature aimed at the production of chiral (R)-hydroxycarboxylic acids (RHAs), either from the accumulated polymer or by bypassing the accumulation of PHAs using metabolically engineered bacteria, and the strategies developed to recover the accumulated polymer without using conventional downstream separations processes. Each of these topics, that have received less attention compared to PHAs accumulation, could potentially improve the economy of PHAs production and use. (R)-hydroxycarboxylic acids can be used as chiral precursors, thanks to its easily modifiable functional groups, and can be either produced de-novo or be obtained from recycled PHA products. On the other hand, efficient mechanisms of PHAs release from bacterial cells, including controlled cell lysis and PHA excretion, could reduce downstream costs and simplify the polymer recovery process.
AB - Polyhydroxyalkanoates (PHAs) are ubiquitous prokaryotic storage compounds of carbon and energy, acting as sinks for reducing power during periods of surplus of carbon source relative to other nutrients. With close to 150 different hydroxyalkanoate monomers identified, the structure and properties of these polyesters can be adjusted to serve applications ranging from food packaging to biomedical uses. Despite its versatility and the intensive research in the area over the last three decades, the market share of PHAs is still low. While considerable rich literature has accumulated concerning biochemical, physiological, and genetic aspects of PHAs intracellular accumulation, the costs of substrates and processing costs, including the extraction of the polymer accumulated in intracellular granules, still hampers a more widespread use of this family of polymers. This review presents a comprehensive survey and critical analysis of the process engineering and metabolic engineering strategies reported in literature aimed at the production of chiral (R)-hydroxycarboxylic acids (RHAs), either from the accumulated polymer or by bypassing the accumulation of PHAs using metabolically engineered bacteria, and the strategies developed to recover the accumulated polymer without using conventional downstream separations processes. Each of these topics, that have received less attention compared to PHAs accumulation, could potentially improve the economy of PHAs production and use. (R)-hydroxycarboxylic acids can be used as chiral precursors, thanks to its easily modifiable functional groups, and can be either produced de-novo or be obtained from recycled PHA products. On the other hand, efficient mechanisms of PHAs release from bacterial cells, including controlled cell lysis and PHA excretion, could reduce downstream costs and simplify the polymer recovery process.
KW - 3-hydroxyalkanaoic acids
KW - biosynthesis
KW - chiral compounds
KW - metabolic engineering
KW - polyhydroxyalkanoates
KW - 3-hydroxyalkanaoic acids
KW - biosynthesis
KW - chiral compounds
KW - metabolic engineering
KW - polyhydroxyalkanoates
UR - http://www.scopus.com/inward/record.url?scp=85083522557&partnerID=8YFLogxK
U2 - 10.3389/fbioe.2020.00248
DO - 10.3389/fbioe.2020.00248
M3 - Review article
AN - SCOPUS:85083522557
SN - 2296-4185
VL - 8
JO - Frontiers in Bioengineering and Biotechnology
JF - Frontiers in Bioengineering and Biotechnology
M1 - 248
ER -