BioChem - DOS

Biological caproate production by Clostridium kluyveri from ethanol and acetate as carbon sources

Bioresource technology : biomass, bioenergy, biowastes, conversion technologies, biotransformations, production technologies

Yin, Yanan; Zhang, Yifeng; Karakashev, Dimitar Borisov; Wang, Jianlong; Angelidaki, Irini

<P><B>Abstract</B></P> <P>Caproate is a valuable industrial product and chemical precursor. In this study, batch tests were conducted to investigate the fermentative caproate production through chain elongation from acetate and ethanol. The effect of acetate/ethanol ratio and initial ethanol concentration on caproate production was examined. When substrate concentration was controlled at 100mM total carbon, hydrogen was used as an additional electron donor. The highest caproate concentration of 3.11g/L was obtained at an ethanol/acetate ratio of 7:3. No additional electron donor was needed upon an ethanol/acetate ratio &ge;7:3. Caproate production increased with the increase of carbon source until ethanol concentration over 700mM, which inhibited the fermentation process. The highest caproate concentration of 8.42g/L was achieved from high ethanol strength wastewater with an ethanol/acetate ratio of 10:1 (550mM total carbon). Results obtained in this study can pave the way towards efficient chain elongation from ethanol-rich wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The composition and yield of VFA was influenced by acetate/ethanol ratio. </LI> <LI> Ethanol was used in priority as electron donor than hydrogen. </LI> <LI> High carbon source concentration enhanced caproate production. </LI> <LI> Ethanol concentration over 700mM inhibited biosynthesis process. </LI> <LI> Highest caproate concentration was achieved at acetate/ethanol ratio 1:10. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2017

Elsevier

0960-8524

241

pp.638-644

10.1016/j.biortech.2017.05.184

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART78160779

https://backend.orbit.dtu.dk/ws/files/132846614/1_s2.0_S0960852417308520_main.pdf

Chain elongation; n-Caproate; Clostridium kluyveri; Fermentation; Ethanol/acetate ratio