초록
<P><B>Background</B></P><P>1,3-propanediol (1,3-PDO) is the most widely studied value-added product that can be produced by feeding glycerol to bacteria, including <I>Lactobacillus</I> sp. However, previous research reported that <I>L</I>. <I>reuteri</I> only produced small amounts and had low productivity of 1,3-PDO. It is urgent to develop procedures that improve the production and productivity of 1,3-PDO.</P><P><B>Results</B></P><P>We identified a novel <I>L</I>. <I>reuteri</I> CH53 isolate that efficiently converted glycerol into 1,3-PDO, and performed batch co-fermentation with glycerol and glucose to evaluate its production of 1,3-PDO and other products. We optimized the fermentation conditions and nitrogen sources to increase the productivity. Fed-batch fermentation using corn steep liquor (CSL) as a replacement for beef extract led to 1,3-PDO production (68.32 ± 0.84 g/L) and productivity (1.27 ± 0.02 g/L/h) at optimized conditions (unaerated and 100 rpm). When CSL was used as an alternative nitrogen source, the activity of the vitamin B12-dependent glycerol dehydratase (<I>dhaB</I>) and 1,3-propanediol oxidoreductase (<I>dhaT</I>) increased. Also, the productivity and yield of 1,3-PDO increased as well. These results showed the highest productivity in <I>Lactobacillus</I> species. In addition, hurdle to 1,3-PDO production in this strain were identified via analysis of the half-maximal inhibitory concentration for growth (IC50) of numerous substrates and metabolites.</P><P><B>Conclusions</B></P><P>We used CSL as a low-cost nitrogen source to replace beef extract for 1,3-PDO production in <I>L. reuteri</I> CH53. These cells efficiently utilized crude glycerol and CSL to produce 1,3-PDO. This strain has great promise for the production of 1,3-PDO because it is generally recognized as safe (GRAS) and non-pathogenic. Also, this strain has high productivity and high conversion yield.</P>