Metabolic engineering of Corynebacterium glutamicum for production of 1,5-diaminopentane from hemicellulose



In the present work, the bio-based production of 1,5-diaminopentane (cadaverine), an important building block for bio-polyamides, was extended to hemicellulose a non-food raw material. For this purpose, the metabolism of 1,5-diaminopentane-producing Corynebacterium glutamicum was engineered to the use of the C5 sugar xylose. This was realized by heterologous expression of the xylA and xylB genes from Escherichia coli, mediating the conversion of xylose into xylulose 5-phosphate (an intermediate of the pentose phosphate pathway), in a defined diaminopentane-producing C. glutamicum strain, recently obtained by systems metabolic engineering. The created mutant, C. glutamicum DAP-Xyl1, exhibited efficient production of the diamine from xylose and from mixtures of xylose and glucose. Subsequently, the novel strain was tested on industrially relevant hemicellulose fractions, mainly containing xylose and glucose as carbon source. A two-step process was developed, comprising (i) enzymatic hydrolysis of hemicellulose from dried oat spelts, and (ii) biotechnological 1,5-diaminopentane production from the obtained hydrolysates with the novel C. glutamicum strain. This now opens a future avenue towards bio-based 1,5-diaminopentane and bio-polyamides thereof from non-food raw materials.