• Citer

Characterization of a polyhydroxyalkanoate producing strain isolated from the Bidong Island in Terengganu, Malaysia

par Naandam, Yennupaak
Président du jury Dahdouh-Guebas, Farid
Promoteur BHUBALAN, Kesaven
Co-Promoteur Peeters, Eveline;PEIRIS, Harshini H
Publication Non publié, 2022-08-30

Mémoire

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Polyhydroxyalkanoates (PHAs), a biodegradable and plastic-like biopolymer, have been receiving research and industrial attention due to severe plastic pollution, resource depletion, and global waste issues. Despite the fact that oligotrophic conditions in the marine environment support a variety of bacteria that can utilize a variety of carbon sources. However, the marine environment has been poorly explored in terms of prospecting for species that produce PHA. Commercialization of these biopolymers has been hindered due to the huge cost of carbon source. In this study, a strain previously isolated from the Bidong Island in Terengganu, Malaysia was identified as Klebsiella aerogenes using 16S ribosomal ribonucleic acid amplicon sequencing (16S rRNA). PHA accumulation by the strain was screened on different carbon sources; glucose, sucrose, mannitol, xylose, xylose plus valeric acid, galactose, and glycerol. However, we were unable to quantify the amount of PHA produced from these carbon sources due to the low amount of polymer extracted. Physicochemical characterization of the extracted polymer using Nuclear Magnetic Resonance (NMR) confirmed 3-hydroxybutyrate (3HB) monomer was present. The 3D structure of polyhydroxyalkanoate synthase (PhaC) was predicted and the model proved reliable as validated by structural validation tools; Verify 3D, ERRAT, and PROCHECK. In studying the function of the putative PhaC enzyme, we sought to express the phaC gene of the strain in Escherichia coli, due to time restriction, the in-vivo characterization, has yet to be done. Thus, the study highlights the potential of the use of Klebsiella aerogenes in the production of PHB albeit not on a commercial scale.