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

• Published in: PeerJ
• Main Authors: Xiao-Jie Liu, Jie Zhang, Peng-Hui Hong, Zheng-Jun Li
• Format: Article in Journal/Newspaper
• Language: English
• Published: PeerJ Inc. 2016
• Subjects: Halophilic; Neptunomonas antarctica; Poly-3-hydroxybutyrate; Seawater; Marine bacteria; Medicine; R; Biology (General); QH301-705.5; Antarc*; Antarctica
• Online Access: https://doi.org/10.7717/peerj.2291; https://doaj.org/article/0bee1f5daac84103bd4e3ef186a943f4

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 × 105 g/mol and 1.7 × 105 g/mol, respectively. Our results highlight the potential of N. antarctica for PHB production with seawater as a nutrient source.