Open AccessTwo‐step salting‐out extraction of 1,3‐propanediol and lactic acid from the fermentation broth of Klebsiella pneumoniae on biodiesel‐derived crude glycerol
Author(s) -
Song Zhiyuan,
Sun Yaqin,
Wei Bochao,
Xiu Zhilong
Publication year - 2013
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201200154
Subject(s) - lactic acid , glycerol , fermentation , biodiesel , chemistry , extraction (chemistry) , biodiesel production , 1,3 propanediol , salting out , food science , raw material , chromatography , biochemistry , bacteria , organic chemistry , biology , catalysis , aqueous solution , genetics
Crude glycerol is a primary by‐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‐produce 1,3‐propanediol (1,3‐PD) and lactic acid through fermentation of Klebsiella pneumoniae . The final concentrations of 1,3‐PD and lactic acid were 62.6 and 33.4 g/L, respectively, and the total mass conversion yield was 55.7%. The two‐step salting‐out extraction method was adopted for the separation of 1,3‐PD and lactic acid from the fermentation broth. In the first step of extraction, the maximal partition coefficient and recovery of 1,3‐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‐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‐produce 1,3‐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.