Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Whole genome analysis of Aspergillus sojae SMF 134 supports its merits as a starter for soybean fermentation (#315)

Inhyung Lee 1 , Kang Uk Kim 1 , Kyung Min Kim 1 , Yong-Ho Choi 2 , Byung Serk Hurh 2
  1. Bio & Fermentation Convergence Technology, BK21 PLUS project, Kookmin University, Seoul, SEOUL, South Korea
  2. Sempio Fermentation Researh Center, Sempio Foods Company, Osongeup, Korea

Aspergillus sojae is a koji (starter) mold that has been applied for food fermentation in Asia. Recently, we have isolated the A. sojae SMF 134 strain form meju (Korean soybean fermented brick) which showed high protease and leucine aminopeptidase (LAP) activities. We analyzed the whole genome of A. sojae SMF 134 to evaluate its potential as a starter for soybean fermentation at the genomic level. The strain SMF 134 had total 151 protease genes (including lap genes), which were more than A. oryzae. According to RNA seq analysis, some endopeptidase genes were highly expressed during soybean fermentation, suggesting that SMF 134 degrades soybean proteins to small peptides efficiently. In addition, the two more lap genes were found in addition to the previously known lap1 and these three lap genes were confirmed to be expressed. Three γ-glutamyltranspeptidase (GGT) genes were also identified and a higher GGT activity was observed in A. sojae SMF 134 than in A. oryzae RIB 40. Because LAP and GGT are known to be important for the flavor development in soybean fermentation, these genome characteristics support that A. sojae has great merits as a starter for soybean fermentation.