Process development for scale-up production of a therapeutic L-asparaginase by Streptomyces brollosae NEAE-115 from shake flasks to bioreactor

Sci Rep. 2019 Sep 19;9(1):13571. doi: 10.1038/s41598-019-49709-6.

Abstract

L-asparaginase is a promising enzyme that has a wide range of significant applications including cancer therapy and starchy food industries. The statistical design of Plackett-Burman and face centered central composite design were employed to optimize L-asparaginase production by Streptomyces brollosae NEAE-115. As a result, a medium of the following formula is the optimum for producing L-asparaginase in the culture filtrate of Streptomyces brollosae NEAE-115: Dextrose 2 g, starch 20 g, L-asparagine 10 g, KNO3 1 g, K2HPO4 1 g, MgSO4.7H2O 0.5 g, NaCl 0.1 g, pH 7, fermentation period 7 days, temperature 30 °C, inoculum size 4%, v/v, agitation speed 150 rpm and inoculum age 48 h. The kinetics of cell growth, carbohydrates consumption and L- asparaginase production were studied in 7-L stirred tank bioreactor under different cultivation conditions. A significant increase in both cell growth and carbohydrate consumption was observed as the stirring speed increased from 200 to 600 rpm under uncontrolled pH. The highest L- asparaginase activity of 108.46 U/mL was obtained after 96 h at 400 rpm. On the other hand, the specific enzyme production (Yp/x) under uncontrolled pH reached its maximal value of about 20.3 U/mg cells. Further improvement of enzyme production was attained by controlling pH at 7 using the selected stirring speed of 400 rpm. Enzyme production of 162.11 U/mL obtained from the controlled pH cultures exceeded this value gained from uncontrolled pH (108.46 U/mL) by about 50%.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asparagine / genetics
  • Asparagine / metabolism*
  • Batch Cell Culture Techniques / instrumentation*
  • Bioreactors / microbiology
  • Carbohydrate Metabolism
  • Culture Media / chemistry
  • Hydrogen-Ion Concentration
  • Protein Engineering
  • Streptomyces / genetics
  • Streptomyces / growth & development*
  • Streptomyces / metabolism
  • Temperature

Substances

  • Culture Media
  • Asparagine

Supplementary concepts

  • Streptomyces brollosae