RESEARCH PAPER
The methane fermentation medium as an attractive source of bacteria from genus Clostridium capable of converting glycerol into 1,3-propylene glycol

Microorganisms that efficiently conduct several metabolic processes can be found among the microflora that colonizes

the natural environment. The aim of this study was to select non-pathogenic cultures of bacteria from the genus

Clostridium which capable of converting glycerol into 1,3-propylene glycol from the glycerol-supplemented

methane fermentation medium. Moreover, analyses was performed in which best isolates were tested in terms

of 1,3-propylene glycol production using both pure and waste glycerol. Trials in a microreactor scale were performed

for the best strains identified. Thes trials were aimed at the determination of the effect of pH and temperature

conditions on the effectiveness and duration of 1,3-PD synthesis. Metabolite contents in the culture fluid

were assessed using HPLC. Species were identified by amplification of 16S rRNA coding sequence. A total of 67

isolates were identified, of which a vast majority was capable of synthesizing 1,3-PD. The best results were

obtained for strain C butyricum DS30. Maximum concentration of 1,3-PD for this strain exceeded 38.56 g/l. At

a temperature of 37EC and constant pH of 7.0, the efficiency of this strain fell within the range of 0.66-0.67

mol/mol glycerol in the case of laboratory and bioreactor scales using pure and waste glycerol.