Transcriptional Characteristics Associated with Lichenysin Biosynthesis in Bacillus licheniformis from Chinese Maotai-Flavor Liquor Making

This
work investigated the biosynthetic mechanism of lichenysin,
the newly identified nonvolatile matrix component in Chinese liquors.
Transcriptomes were analyzed in three producers, Bacillus
licheniformis CGMCC 3961, 3962, and 3963, which were
isolated from Maotai-flavor liquor-making process and produced 386.3,
553.5, and 795.2 μg/L lichenysin in a simulative liquor fermentation
process. Lichenysin synthetase genes lchAA–AD in these three producers were expressed much more highly
than those of the nonproducer B. licheniformis ATCC 14580 (>18.4-fold). In addition, ABC transporters were the
most significant responsive metabolic pathway, and the expression
levels of peptide transporter genes dppABCDE all
increased more than 19.2-fold. When B. licheniformis CGMCC 3963 was cultured in synthetic medium, the expression of dppABCDE and lichenysin both increased with the addition
of casein hydrolysate (containing various peptides). This indicated
that peptide would act as a substrate for lichenysin synthesis. This
work sheds new light on the mechanism for lichenysin biosynthesis.