Biosynthesis of high molecular weight hyaluronic acid by Streptococcus zooepidemicus using oxygen vector and optimum impeller tip speed

• Published in: Journal of bioscience and bioengineering Vol. 114; no. 3; pp. 286 - 291
• Main Authors: Lai, Zee-Wei, Rahim, Raha Abdul, Ariff, Arbakariya B., Mohamad, Rosfarizan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2012; Elsevier
• Subjects: Alkanes - metabolism; Biological and medical sciences; Bioreactors; biosynthesis; Biotechnology; cell growth; Fermentation; Fundamental and applied biological sciences. Psychology; Gases - metabolism; Helical ribbon impeller; hexadecane; Hyaluronic acid; Hyaluronic Acid - biosynthesis; Hyaluronic Acid - chemistry; Hyaluronic Acid - metabolism; KLa; Molecular Weight; n-Dodecane; n-Hexadecane; oxygen; Oxygen - metabolism; Oxygen vector; Streptococcus; Streptococcus equi - metabolism; Streptococcus equi subsp. zooepidemicus; n-Hexadecane; Oxygen vector; KLa; Helical ribbon impeller; Hyaluronic acid; n-Dodecane; a; Oxygen; Biosynthesis; K; Streptococcaceae; Streptococcus equi subsp. zooepidemicus; Bacteria; Micrococcales; Molecular mass; Vector
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/j.jbiosc.2012.04.011

The potential use of n-dodecane and n-hexadecane as oxygen vectors for enhancing hyaluronic acid (HA) biosynthesis by Streptococcus zooepidemicus ATCC 39920 was investigated using a 2-L stirred-tank bioreactor equipped with helical ribbon or Rushton turbine impellers. The volumetric fraction of the oxygen vector influenced the gas–liquid volumetric oxygen transfer coefficient (KLa) positively. Batch HA fermentation with 1% (v/v) n-dodecane or 0.5% (v/v) n-hexadecane addition was carried out at different impeller tip speeds. Even though cell growth was lower in the fermentation with oxygen vector addition, the HA productivity and molecular weight were higher when compared to the fermentation without oxygen vector at low impeller tip speed. The highest HA concentration (4.25 gHA/l) and molecular weight (1.54 × 107 Da) were obtained when 0.5% (v/v) n-hexadecane and 0.785 m/s impeller tip speed of helical ribbon were used.