PROCESS OPTIMISATION OF 1,3-PROPANEDIOL PRODUCTION BY Klebsiella pneumoniae STRAIN

The 1,3-propanediol (1,3-PD) is a versatile chemical feedstock with a wide range of applications: cosmetic, food and polymers synthesis. Although 1,3-PD is conventionally chemically synthesised, it has drawbacks such as requiring high pressure and temperature. Therefore, a more economical biological approach to produce 1,3-PD is crucial. This study attempted to investigate the effects of common fermentation parameters temperature, pH, glycerol concentration and inoculum size on the production of 1,3-PD by Klebsiella pneumoniae via one-factor-at-a-time (OFAT) method. The optimised conditions: temperature, 34 degrees C; pH, 7.5; glycerol concentration, 30 g litre(-1) and inoculum size, 20% (v/v) showed 1.78-fold increase in 1,3-PD production, i.e. from the initial 4.89 g litre(-1) to 8.70 g litre(-1) in shake flask experiment after 48 hr. The 1,3-PD productivity by K. pneumoniae was higher (0.18 g litre(-1) hr(-1)) from the unoptimised conditions (0.07 g litre(-1) hr(-1)).The other parameter studied - varying nitrogen sources in the fermentation medium - revealed that their addition unexpectedly did not show any improvement in 1,3-PD production unlike those reported in the literature. It can be concluded that both glycerol concentration and incubation temperature were the most significant factors in producing higher 1,3-PD yield.