Influence of hyaluronidase addition on the production of hyaluronic acid by batch culture of Streptococcus zooepidemicus

Enhancement of hyaluronic acid (HA) production by Streptococcus zooepidemicus through increasing oxygen transfer rate via degradation of HA by hyaluronidase was investigated. Dissolved oxygen (DO) level became a limiting factor for HA production during 8-16 h, and thus hyaluronidase (0.05, 0.10, 0.15, 0.20, 0.25 g/l) was added at 8 h to degrade HA. Oxygen transfer rate coefficient and DO level during 8-16 h increased with increased hyaluronidase concentration. Compared to 5.0 +/- 0.1 g/l of the control without hyaluronidase addition, HA production was increased from 5.0 +/- 0.1 g/l to 6.0 +/- 0.1 g/l when hyaluronidase concentration was 0.15 g/l. Further increase of hyaluronidase concentration had no effect on HA production. The molecular weight of HA decreased with the increased hyaluronidase concentration and decreased to 21 kDa when hyaluronidase concentration was 0.25 g/l from 1300 kDa of the control. The prepared low molecular weight HA (LMW-HA) could function as potential anti-angiogenic substances, antiviral and anti-tumor agents to possibly be used as functional food ingredients. (C) 2008 Published by Elsevier Ltd.