Print Email Facebook Twitter Production of medium-chain-length PHA in octanoate-fed enrichments dominated by Sphaerotilus sp. Title Production of medium-chain-length PHA in octanoate-fed enrichments dominated by Sphaerotilus sp. Author Vermeer, C.M. (TU Delft BT/Environmental Biotechnology) Depaz, Lena (Student TU Delft) van den Berg, Emily (Student TU Delft) Koelmans, Tom (Student TU Delft) Kleerebezem, R. (TU Delft BT/Environmental Biotechnology) Date 2022 Abstract Medium-chain-length polyhydroxyalkanoate (mcl-PHA) production by using microbial enrichments is a promising but largely unexplored approach to obtain elastomeric biomaterials from secondary resources. In this study, several enrichment strategies were tested to select a community with a high mcl-PHA storage capacity when feeding octanoate. On the basis of analysis of the metabolic pathways, the hypothesis was formulated that mcl-PHA production is more favorable under oxygen-limited conditions than short-chain-length PHA (scl-PHA). This hypothesis was confirmed by bioreactor experiments showing that oxygen limitation during the PHA accumulation experiments resulted in a higher fraction of mcl-PHA over scl-PHA (i.e., a PHA content of 76 wt% with an mcl fraction of 0.79 with oxygen limitation, compared to a PHA content of 72 wt% with an mcl-fraction of 0.62 without oxygen limitation). Physicochemical analysis revealed that the extracted PHA could be separated efficiently into a hydroxybutyrate-rich fraction with a higher Mw and a hydroxyhexanoate/hydroxyoctanoate-rich fraction with a lower Mw. The ratio between the two fractions could be adjusted by changing the environmental conditions, such as oxygen availability and pH. Almost all enrichments were dominated by Sphaerotilus sp. This is the first scientific report that links this genus to mcl-PHA production, demonstrating that microbial enrichments can be a powerful tool to explore mcl-PHA biodiversity and to discover novel industrially relevant strains. Subject medium-chain-length polyhydroxyalkanoatesmicrobial enrichment culturesoctanoatepoly(3-hydroxyhexanoate)poly(3-hydroxyoctanoate)Sphaerotilus sp To reference this document use: http://resolver.tudelft.nl/uuid:3a5c9234-8a86-462d-ac86-66c3888d94d1 DOI https://doi.org/10.1002/bit.28306 ISSN 0006-3592 Source Biotechnology and Bioengineering, 120 (3), 687-701 Part of collection Institutional Repository Document type journal article Rights © 2022 C.M. Vermeer, Lena Depaz, Emily van den Berg, Tom Koelmans, R. Kleerebezem Files PDF Biotech_Bioengineering_20 ... ted_by.pdf 2.79 MB Close viewer /islandora/object/uuid:3a5c9234-8a86-462d-ac86-66c3888d94d1/datastream/OBJ/view