초록
<P><B>Abstract</B></P> <P>The booming of biodiesel industry all over the world has led to generate a large amount (10% v/v) of crude glycerol, created an oversupply problem. Herein, we compared the product concentrations of major metabolic products attained from pure and crude glycerol biotransformation process using an adapted mutant strain <I>Klebsiella variicola</I> SW3. Real-time qPCR and glycerol dehydrogenase (GDH) enzyme activity assay revealed that the overexpression of GDH gene resulted in an increased GDH enzyme activity, led to a markedly boosted 2,3-butanediol (2,3-BD) production. Based on these results, the SW3 strain obtained from wild type strain <I>Klebsiella variicola</I> SRP3 displayed a 1.39-fold increased 2,3-BD production of 82.5 g/L from 59.3 g/L, yielding 0.62 g/g using pure glycerol. However, in a batch culture, a final 33.5 g/L of 2,3-BD was accumulated within 96 h from 50 g/L glycerol. Moreover, the strain SW3 withstanding high concentration (200 g/L) of crude glycerol displayed 64.9 and 29.25 g/L 2,3-BD in fed-batch and batch cultures respectively. Therefore, this bioconversion of crude glycerol to 2,3-BD –a value-added green product with potential industrial applications as a liquid fuel or fuel additive would represent a remarkable alternative to add value to the biodiesel production helping biodiesel industries development.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of a mutant strain for high production of 2,3-butanediol (2,3-BD). </LI> <LI> Development of a high concentration (20%) crude glycerol tolerated mutant strain. </LI> <LI> Obtained 63.0 g/g product yield of 2,3-BD. </LI> <LI> Production of co-products at trace concentrations as the glycerol concentration gets higher. </LI> </UL> </P>