Extreme environments are a unique source of microorganisms encoding metabolic capacities that remain largely unexplored. In this work, we isolated two Antarctic bacterial strains able to produce poly(3-hydroxyalkanoates) (PHAs), which were classified after 16S rRNA analysis as Pseudomonas sp. MPC5 and MPC6. The MPC6 strain presented nearly the same specific growth rate whether subjected to a temperature of 4 °C 0.18 (1/h) or 30 °C 0.2 (1/h) on glycerol. Both Pseudomonas strains produced high levels of PHAs and exopolysaccharides from glycerol at 4 °C and 30 °C in batch cultures, an attribute that has not been previously described for bacteria of this genus. The MPC5 strain produced the distinctive medium-chain-length-PHA whereas Pseudomonas sp. MPC6 synthesized a novel polyoxoester composed of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate-co-3-hydroxydecanoate-co-3-hydroxydodecanoate). Batch bioreactor production of PHAs in MPC6 resulted in a titer of 2.6 (g/L) and 1.3 (g/L), accumulating 47.3% and 34.5% of the cell dry mass as PHA, at 30 and 4 °C, respectively. This study paves the way for using Antarctic Pseudomonas strains for biosynthesizing novel PHAs from low-cost substrates such as glycerol and the possibility to carry out the bioconversion process for biopolymer synthesis without the need for temperature control.
|Number of pages||15|
|Journal||Journal of Industrial Microbiology and Biotechnology|
|State||Published - 1 Aug 2019|
Bibliographical noteFunding Information:
Funding This study was funded by CONICYT (Fondecyt Inicio Grant number 11150174) to I.P–C, and from the Chilean Antarctic Institute (INACH) through the Grant (RT_51-16) to A.E.M.
Nicolas Pacheco acknowledges the scholarship provided by Doctorado en Biotecnologia (UNAB). We thank the technical assistant of the Centro de Instrumentaci?n of the Pontificia Universidad Cat?lica de Chile through CONICYT-FONDEQUIP EQM120021. Andr?s Marcoleta acknowledges to Macarena Varas for its aid in sample collection during the 53rd Chilean Antarctic Scientific Expedition, and to Johanna Rojas Salgado and Jos? Ignacio Costa for their assistance in the isolation of the strains and its initial microbiological characterization.
Acknowledgements Nicolas Pacheco acknowledges the scholarship provided by Doctorado en Biotecnologia (UNAB). We thank the technical assistant of the Centro de Instrumentación of the Pontifi-cia Universidad Católica de Chile through CONICYT-FONDEQUIP EQM120021. Andrés Marcoleta acknowledges to Macarena Varas for its aid in sample collection during the 53rd Chilean Antarctic Scientific Expedition, and to Johanna Rojas Salgado and José Ignacio Costa for their assistance in the isolation of the strains and its initial microbiological characterization.
© 2019, Society for Industrial Microbiology and Biotechnology.
- Antarctic Pseudomonas
- Low temperature