초록
<P>The potential of biodiesel-derived glycerol to be valorized into 1,3-propanediol (1,3-PDO) was hindered by the impurities contained therein. This study introduced a straightforward and effective pretreatment process through microfiltration to remove free fatty acids (FFAs) that could inhibit the fermentation which resulted in remarkable high productivity in batch fermentation. This approach appreciably reduces the cost of pretreatment as compared to previously reported acidification, solvent extraction, electrodialysis, activated carbon adsorption and ion-exchange resins. From the fermentation results, a high productivity of 1,3-PDO of 2.16 g L<SUP>-1</SUP> h<SUP>-1</SUP> was attained when 20 g/L pretreated glycerol was used as the carbon source, an improvement of 62.4% compared with fermentation with crude glycerol using locally isolated strain <I>Clostridium butyricum</I> JKT37, and among the highest compared to previous reports. These results suggested that, with a simple microfiltration pretreatment, the utility of the resultant biodiesel-derived glycerol in bioproduction of 1,3-PDO is comparable to that of pure glycerol. The physical and chemical properties of the biodiesel-derived glycerol were characterized in accordance with American Oil Chemists’ Society (AOCS), International Organization for Standardization (ISO), and American Society for Testing and Materials (ASTM) standard methods, before and after the pretreatment. The sample of crude glycerol comprised 75 wt % glycerol, 15% soap, 8% moisture, 0.8% methanol, and less than 5% ash. FFAs generated from crude glycerol were removed completely by microfiltration.</P><BR>[FIG OMISSION]</BR>