BioChem - DOS

Influence of rice straw-derived dissolved organic matter on lactic acid fermentation by Rhizopus oryzae

Journal of bioscience and bioengineering

Chen, Xingxuan; Wang, Xiahui; Xue, Yiyun; Zhang, Tian-Ao; Li, Yuhao; Hu, Jiajun; Tsang, Yiu Fai; Zhang, Hongsheng; Gao, Min-Tian

<P>Rice straw can be used as carbon sources for lactic acid fermentation. However, only a small amount of lactic acid is produced even though <I>Rhizopus oryzae</I> can consume glucose in rice straw-derived hydrolysates. This study correlated the inhibitory effect of rice straw with rice straw-derived dissolved organic matter (DOM). Lactic acid fermentations with and without DOM were conducted to investigate the effect of DOM on lactic acid fermentation by <I>R. oryzae</I>. Fermentation using control medium with DOM showed a similar trend to fermentation with rice straw-derived hydrolysates, showing that DOM contained the major inhibitor of rice straw. DOM assay indicated that it mainly consisted of polyphenols and polysaccharides. The addition of polyphenols and polysaccharides derived from rice straw confirmed that lactic acid fermentation was promoted by polysaccharides and significantly inhibited by polyphenols. The removal of polyphenols also improved lactic acid production. However, the loss of polysaccharides during the removal of polyphenols resulted in low glucose consumption. This study is the first to investigate the effects of rice straw-derived DOM on lactic acid fermentation by <I>R. oryzae</I>. The results may provide a theoretical basis for identifying inhibitors and promoters associated with lactic acid fermentation and for establishing suitable pretreatment methods.</P> <P><B>Highlights</B></P> <P> <UL> <LI> DOM from rice straw consisted mainly of polyphenols and polysaccharides. </LI> <LI> Polyphenols had an inhibitory effect on lactic acid fermentation. </LI> <LI> Polysaccharides had a promoting effect on lactic acid fermentation. </LI> <LI> Removal of polyphenols could improve lactic acid fermentation. </LI> <LI> Loss of polysaccharides could decrease glucose consumption. </LI> </UL> </P>

2018

Elsevier

1389-1723

1347-4421

125

6

pp.703-709

10.1016/j.jbiosc.2018.01.004

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART85073997

Lactic acid fermentation; Rhizopus oryzae; Polyphenols; Polysaccharides; Rice straw