초록
<P><B>Abstract</B></P> <P>The microbial conversion of biodiesel derived crude glycerol to 1,3-propanediol (1,3-PDO) has attained high industrial value due to the broad range of applications as a monomer (1,3-PDO) in textile, cosmetic and polymer industries. This fine chemical through biological production addressed several limitations of the chemical process like high temperatures, pressure and expensive catalysts. In this study 1,3-propanediol production was achieved from a non-pathogenic lactic acid bacterial strain <I>Lactobacillus brevis</I> N1E9.3.3 in suspended and immobilized form under batch, sequential batch and continuous modes of fermentation. The microorganism was immobilized in polyurethane foam cubes. The effects of initial glycerol concentration on suspended and immobilized cells were investigated in stirred tank reactor. The maximum 1,3-PDO titers of 51.5g<SUB>1,3-PDO</SUB>/l and 42.59g<SUB>1,3-PDO</SUB>/l with a yield of 0.64g<SUB>1.3-PDO</SUB>/g<SUB>Glycerol</SUB> and 0.53g<SUB>1.3-PDO</SUB>/g<SUB>Glycerol</SUB> using suspended and immobilized cells respectively was observed in batch fermentation with an initial glycerol concentration of 80g/l. In repeated batch (self-cycling) fermentation 78.3g/l 1,3-PDO with 0.65g<SUB>1.3-PDO</SUB>/g<SUB>Glycerol</SUB> yield and 0.65g/l/h productivity was observed at the end of 5th cycle. A constant yield between 0.3–0.65g<SUB>1.3-PDO</SUB>/g<SUB>Glycerol</SUB> was observed with cell recycling using suspended and immobilized cells. The highest productivity of 1.735g<SUB>1,3-PDO</SUB>/l/h was observed in chemostat with immobilized cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 1,3-PDO titers of 51.51g/l in batch mode and 78.33g/l in repeated batch mode was observed. </LI> <LI> A higher yield of 0.64g<SUB>1,3-PDO</SUB>/g<SUB>Glycerol</SUB> was established with a non pathogenic strain in batch and repeated batch fermentation. </LI> <LI> Strain was observed to be efficient in suspended or immobilized form. </LI> </UL> </P>