Microbial production and characterization of poly-3-hydroxybutyrate by Neptunomonas antarctica

• Published in: PeerJ (San Francisco, CA) Vol. 4; p. e2291
• Main Authors: Liu, Xiao-Jie, Zhang, Jie, Hong, Peng-Hui, Li, Zheng-Jun
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 02.08.2016; PeerJ, Inc; PeerJ Inc
• Subjects: Bacteria; Biodegradability; Biopolymers; Biotechnology; Chromatography; Fructose; Glycerol; Halophilic; Marine bacteria; Metabolism; Microbiology; Microorganisms; Molecular weight; Neptunomonas antarctica; NMR; Nuclear magnetic resonance; Poly-3-hydroxybutyrate; Polyhydroxybutyric acid; Polymers; Seawater; Sediments; Vibrio; Neptunomonas antarctica; Halophilic; Poly-3-hydroxybutyrate; Marine bacteria; Seawater
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/PEERJ.2291

Considering the industrial interest of biodegradable polymer poly-3-hydroxybutyrate (PHB), the marine bacteria Neptunomonas antarctica was studied for its ability to accumulate PHB. The extracted polymer was confirmed to be PHB by nuclear magnetic resonance analysis. In shake flask cultures using natural seawater as medium components, PHB was produced up to 2.12 g/L with a yield of 0.18 g PHB/g fructose. In the presence of artificial seawater, the PHB titer and yield reached 2.13 g/L and 0.13 g PHB/g fructose, respectively. The accumulated polymer gradually decreased when fructose was exhausted, indicating that intracellular PHB was degraded by N. antarctica. The weight-average and number-average molecular weights of PHB produced within natural seawater were 2.4 × 10(5) g/mol and 1.7 × 10(5) g/mol, respectively. Our results highlight the potential of N. antarctica for PHB production with seawater as a nutrient source.