BioChem - DOS

Two-step salting-out extraction of 1,3-propanediol and lactic acid from the fermentation broth of Klebsiella pneumoniae on biodiesel-derived crude glycerol

Engineering in life sciences

Song, Zhiyuan; Sun, Yaqin; Wei, Bochao; Xiu, Zhilong

<P>Crude glycerol is a primary by&#8208;product in the biodiesel production process and its large surplus blocks the development of the biodiesel industry. In this study, crude glycerol was used as a substrate to co&#8208;produce 1,3&#8208;propanediol (1,3&#8208;PD) and lactic acid through fermentation of <I>Klebsiella pneumoniae</I>. The final concentrations of 1,3&#8208;PD and lactic acid were 62.6 and 33.4 g/L, respectively, and the total mass conversion yield was 55.7%. The two&#8208;step salting&#8208;out extraction method was adopted for the separation of 1,3&#8208;PD and lactic acid from the fermentation broth. In the first step of extraction, the maximal partition coefficient and recovery of 1,3&#8208;PD reached 9.81 and 92.4% under the optimal conditions of 30% isopropanol and 30% potassium carbonate. Subsequently, 28% ethanol was added into the salt phase to perform the second salting&#8208;out extraction at pH 6.5. The partition coefficient and recovery of lactic acid reached 1.27 and 73.8%, respectively. All cells and most of the proteins (98.5%) were finally removed. The results suggest that crude glycerol can be used as a promising feedstock to co&#8208;produce 1,3&#8208;PD and lactic acid from fermentation broths, and this could not only reduce the production cost but also promote the further development of the biodiesel industry.</P>

2013

1618-0240

1618-2863

13

5

pp.487-495

10.1002/elsc.201200154

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART67138935

1,3&#x2010; Propanediol (1,3&#x2010; PD); Crude glycerol; Fermentation broth; Lactic acid; Two&#x2010; step salting&#x2010; out extraction;