BioChem - DOS

Engineering β-oxidation in Yarrowia lipolytica for methyl ketone production

Metabolic engineering

Hanko, Erik K.R.; Denby, Charles M.; Sà nchez i Nogué , Violeta; Lin, Weiyin; Ramirez, Kelsey J.; Singer, Christine A.; Beckham, Gregg T.; Keasling, Jay D.

<P><B>Abstract</B></P> <P>Medium- and long-chain methyl ketones are fatty acid-derived compounds that can be used as biofuel blending agents, flavors and fragrances. However, their large-scale production from sustainable feedstocks is currently limited due to the lack of robust microbial biocatalysts. The oleaginous yeast <I>Yarrowia lipolytica</I> is a promising biorefinery platform strain for the production of methyl ketones from renewable lignocellulosic biomass due to its natively high flux towards fatty acid biosynthesis. In this study, we report the metabolic engineering of <I>Y. lipolytica</I> to produce long- and very long-chain methyl ketones. Truncation of peroxisomal &beta;-oxidation by chromosomal deletion of <I>pot1</I> resulted in the biosynthesis of saturated, mono-, and diunsaturated methyl ketones in the C<SUB>13</SUB>-C<SUB>23</SUB> range. Additional overexpression and peroxisomal targeting of a heterologous bacterial methyl ketone biosynthesis pathway yielded an initial titer of 151.5 mg/L of saturated methyl ketones. Dissolved oxygen concentrations in the cultures were found to substantially impact cell morphology and methyl ketone biosynthesis. Bioreactor cultivation under optimized conditions resulted in a titer of 314.8 mg/L of total methyl ketones, representing more than a 6000-fold increase over the parental strain. This work highlights the potential of <I>Y. lipolytica</I> to serve as chassis organism for the biosynthesis of acyl-thioester derived long- and very long-chain methyl ketones.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Production of long- and very long-chain methyl ketones in the C<SUB>13</SUB>-C<SUB>23</SUB> range. </LI> <LI> Peroxisomal targeting of a bacterial methyl ketone biosynthesis pathway. </LI> <LI> Level of dissolved oxygen substantially impacts the biosynthesis of methyl ketones. </LI> <LI> Best strain produced 314.8 mg/L of methyl ketones in bioreactor cultivations. </LI> </UL> </P>

2018

Elsevier

publisher-specific-oa

1096-7176

1096-7184

48

pp.52-62

10.1016/j.ymben.2018.05.018

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART86687728

http://manuscript.elsevier.com/S1096717617304639/pdf/S1096717617304639.pdf

Methyl ketones; Yarrowia lipolytica; Metabolic engineering; Beta-oxidation; Peroxisome; Fatty acid metabolism