BioChem - DOS

Fermentative production of high titer citric acid from corn stover feedstock after dry dilute acid pretreatment and biodetoxification

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

Zhou, Ping-Ping; Meng, Jiao; Bao, Jie

<P><B>Abstract</B></P> <P>The aim of this work is to study the citric acid fermentation by a robust strain <I>Aspergillus niger</I> SIIM M288 using corn stover feedstock after dry dilute sulfuric acid pretreatment and biodetoxification. Citric acid at 100.04g/L with the yield of 94.11% was obtained, which are comparable to the starch or sucrose based citric acid fermentation. No free wastewater was generated in the overall process from the pretreatment to citric acid fermentation. Abundant divalent metal ions as well as high titer of potassium, phosphate, and nitrogen were found in corn stover hydrolysate. Further addition of extra nutrients showed no impact on increasing citric acid formation except minimum nitrogen source was required. Various fermentation parameters were tested and only minimum regulation was required during the fermentation. This study provided a biorefining process for citric acid fermentation from lignocellulose feedstock with the maximum citric acid titer and yield.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High citric acid accumulation was obtained from corn stover feedstock. </LI> <LI> 100.04g/L of citric acid with yield of 94.11% were obtained from corn stover. </LI> <LI> No extra inorganic salts or inducers are required to corn stover hydrolysate. </LI> <LI> Zero waste water was generated from pretreatment to citric acid fermentation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2017

Elsevier

0960-8524

224

pp.563-572

10.1016/j.biortech.2016.11.046

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART77034355

Citric acid; Lignocellulose; Biodetoxification; Aspergillus niger; Zero nutrients requirement