Synthesis of multicomponent polyhydroxyalkanoates from fatty acid sources in Cupriavidus necator H16 and its recombinant strain C. necator H16/pMPJAS03

Abstract

This thesis focused on developing fermentation strategies for the production of multicomponent PHAs, mainly of the type scl-mcl copolymers with a decreased melting temperature and crystallinity. The thesis consists of 7 chapters. Chapters 1 and 2 are the introduction and literature review, respectively. Chapter 3 to 6 correspond to four specific objectives, described as follows: Chapter 3: To evaluate the viability of multicomponent PHA biosynthesis from avocado oil in C. necator H16, as an alternative substrate for PHA production. Chapter 4: To investigate the effect of co-expressing heterologous fadE and phaJ genes in C. necator H16 under the control of the arabinose promoter (araC-PBAD) system and evaluating its impact on scl/mcl PHA production from vegetable oils as carbon source. . Chapter 5: To cultivate in a well-controlled exponential fed-batch followed by constant feeding the recombinant strain C. necator H16/pMPJAS03 in an attempt to increase the incorporation of mcl subunits, derived from canola oil or canola oil/decanoic acid (DA). Chapter 6: To investigate the full capability of the wild-type synthase in the recombinant strain C. necator H16/pMPJAS03 to polymerize scl-mcl PHAs from different carbon chain-lengths fatty acids in the presence of acrylic acid. And finally, Chapter 7 gives conclusions and recommends future work