AUTHOR=Ma Donglin , Liu Shuangping , Han Xiao , Nan Mujia , Xu Yuezheng , Qian Bin , Wang Lan , Mao Jian 

TITLE=Complete genome sequence, metabolic model construction, and huangjiu application of Saccharopolyspora rosea A22, a thermophilic, high amylase and glucoamylase actinomycetes

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.995978

DOI=10.3389/fmicb.2022.995978

ISSN=1664-302X

ABSTRACT=<p><italic>Saccharopolyspora</italic> is an important microorganism in the fermentation process of wheat <italic>qu</italic> and <italic>huangjiu</italic>, yet the mechanisms by which it performs specific functions in <italic>huangjiu</italic> remain unclear. A strain with high amylase and glucoamylase activities was isolated from wheat <italic>qu</italic> and identified as <italic>Saccharopolyspora rosea</italic> (<italic>S. rosea</italic>) A22. We initially reported the whole genome sequence of <italic>S. rosea</italic> A22, which comprised a circular chromosome 6,562,638 bp in size with a GC content of 71.71%, and 6,118 protein-coding genes. A functional genomic analysis highlighted regulatory genes involved in adaptive mechanisms to harsh conditions, and <italic>in vitro</italic> experiments revealed that the growth of <italic>S. rosea</italic> A22 could be regulated in response to the stress condition. Based on whole-genome sequencing, the first genome-scale metabolic model of <italic>S. rosea</italic> A22 named <italic>i</italic>SR1310 was constructed to predict the growth ability on different media with 91% accuracy. Finally, <italic>S. rosea</italic> A22 was applied to <italic>huangjiu</italic> fermentation by inoculating raw wheat <italic>qu</italic>, and the results showed that the total higher alcohol content was reduced by 12.64% compared with the control group. This study has elucidated the tolerance mechanisms and enzyme-producing properties of <italic>S. rosea</italic> A22 at the genetic level, providing new insights into its application to <italic>huangjiu</italic>.</p>