Efficient free fatty acid production in engineered Escherichia coli strains using soybean oligosaccharides as feedstock.
To be competitive with current petrochemicals, microbial synthesis of free fatty acids can be made to rely on a variety of renewable resources rather than on food carbon sources, which increase its attraction for governments and companies. Industrial waste soybean meal is an inexpensive feedstock, which contains soluble sugars such as stachyose, raffinose, sucrose, glucose, galactose, and fructose. Free fatty acids were produced in this report by introducing an acyl-ACP carrier protein thioesterase and (3R)-hydroxyacyl-ACP dehydratase into E. coli. Plasmid pRU600 bearing genes involved in raffinose and sucrose metabolism was also transformed into engineered E. coli strains, which allowed more efficient utilization of these two kinds of specific oligosaccharide present in the soybean meal extract. Strain ML103 (pRU600, pXZ18Z) produced ~1.60 and 2.66 g/L of free fatty acids on sucrose and raffinose, respectively. A higher level of 2.92 g/L fatty acids was obtained on sugar mixture. The fatty acid production using hydrolysate obtained from acid or enzyme based hydrolysis was evaluated. Engineered strains just produced ~0.21 g/L of free fatty acids with soybean meal acid hydrolysate. However, a fatty acid production of 2.61 g/L with a high yield of 0.19 g/g total sugar was observed on an enzymatic hydrolysate. The results suggest that complex mixtures of oligosaccharides derived from soybean meal can serve as viable feedstock to produce free fatty acids. Enzymatic hydrolysis acts as a much more efficient treatment than acid hydrolysis to facilitate the transformation of industrial waste from soybean processing to high value added chemicals.
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, People's Republic of China.|Dept. of Bioengineering, Rice University, Houston, TX, 77005.
Dan
D
Wang
Dept. of Bioengineering, Rice University, Houston, TX, 77005.|State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
Hui
H
Wu
Dept. of Biochemistry and Cell Biology, Rice University, Houston, TX, 77005.
Chandresh
C
Thakker
Dept. of Bioengineering, Rice University, Houston, TX, 77005.
Jared
J
Beyersdorf
Dept. of Biochemistry and Cell Biology, Rice University, Houston, TX, 77005.
George N
GN
Bennett
Dept. of Bioengineering, Rice University, Houston, TX, 77005.|Dept. of Chemical and Biomolecular Engineering, Rice University, Houston, TX, 77005.
Ka-Yiu
KY
San
D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000096:biosynthesis*; D005285:Fermentation; D005632:Fructose / Q000737:chemistry; D005690:Galactose / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry*; D030781:Organisms, Genetically Modified; D010957:Plasmids / Q000235:genetics; D011492:Protein Hydrolysates / Q000737:chemistry; D011887:Raffinose / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry; D013869:Thiolester Hydrolases / Q000378:metabolism
D003470:Culture Media; D005230:Fatty Acids, Nonesterified; D009844:Oligosaccharides; D011492:Protein Hydrolysates; D005632:Fructose; D013395:Sucrose; D013869:Thiolester Hydrolases; C018748:oleoyl-(acyl-carrier-protein) hydrolase; D005947:Glucose; D011887:Raffinose; D005690:Galactose
Escherichia coli; enzymatic hydrolysate; free fatty acid; oligosaccharides; soybean meal