초록
<P><B>Abstract</B></P><P>Residual (raw) glycerol originated from biodiesel synthesis is becoming of great environmental and economical concern due to its ever-growing surplus. In the present study, several bacterial strains were isolated and characterized for their ability to convert this raw glycerol into 1,3-propanediol (1,3-PD) and ethanol. The best producers of both 1,3-PD and ethanol were identified by 16S rDNA sequences to be <I>Klebsiella pneumoniae</I> and <I>Pantoea agglomerans</I> strains. Batch bioreactor cultivations under anaerobic and aerobic conditions were carried out in order to access the kinetics of glycerol consumption and product formation. Results showed that one isolated, <I>K. pneumoniae</I> BLh-1, was able to simultaneously produce up to 9.4 g/L of 1,3-PD with yields of 0.41 mol product mol<SUP>−1</SUP> glycerol, and 6.1 g/L of ethanol with yields of 0.14 mol product mol<SUP>−1</SUP> glycerol under anaerobic conditions, showing great potential for bioprocesses.</P> <P><B>Highlights</B></P><P>► Residual (raw) glycerol originated from biodiesel synthesis is of great environmental and economical concern. ► Raw glycerol can be used as a substrate for microbial fermentation. ► Bacteria strains were isolated that can efficiently convert this raw glycerol into 1,3-propanediol (1,3-PD) and ethanol.</P>