Metabolite profiling and bioactivity of rice koji fermented by Aspergillus strains.
In this study, the metabolite profiles of three Aspergillus strains during rice koji fermentation were compared. In the partial least squares discriminant analysis-based gas chromatography-mass spectrometry data sets, the metabolite patterns of A. oryzae (KCCM 60345) were clearly distinguished from A. kawachii (KCCM 60552) and only marginal differences were observed for A. oryzae (KCCM 60551) fermentation. In the 2 days fermentation samples, the overall metabolite levels of A. oryzae (KCCM 60345) were similar to the A. oryzae (KCCM 60551) levels and lower than the A. kawachii (KCCM 60552) levels. In addition, we identified discriminators that were mainly contributing tyrosinase inhibition (kojic acid) and antioxidant activities (pyranonigrin A) in A. oryzae (KCCM 60345) and A. kawachii (KCCM 60552) inoculated rice koji, respectively. In this study, we demonstrated that the optimal inoculant Aspergillus strains and fermentation time for functional rice koji could be determined through a metabolomics approach with bioactivity correlations.
Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Korea.
Ah-Jin
AJ
Kim
Jung-Nam
JN
Choi
Jiyoung
J
Kim
Hyang Yeon
HY
Kim
Sait-Byul
SB
Park
Soo-Hwan
SH
Yeo
Ji-Ho
JH
Choi
Kwang-Hyeon
KH
Liu
Choong Hwan
CH
Lee
D001236:Aspergillus oryzae / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D055442:Metabolome; D012275:Oryza / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology*