Abstract:
The aim of the present study is the development of a consolidated bioprocess for the production of lysine
with recombinant Corynebacterium glutamicum DM1729 strains expressing endoglucanase and bglucosidase genes. Here, the endoglucanase genes from Xanthomonas campestris XCC3521 and
XCC2387 and betaglucosidase gene from Saccharophagus degradans Sde1394 were cloned in C. glutamicum DM1729 and expressed either extracellularly or on cell surface. The highest b-glucosidase activity
of 9 ± 0.5 U/OD600 of 1 and endoglucanase activity of 5.5 ± 0.8 U was obtained in C. glutamicum DM
1729 (pVWEx1-TATXCC2387) (pEKEx3-PorC-Sde1394) when cellobiose (20 g/L) alone or in combination
with carboxymethyl cellulose (20 g/L) was used as the carbon sources respectively. The overall efforts
resulted in a lysine titre of 5.9 ± 0.5 mM. The ability of the constructs to utilize carboxymethyl cellulose
and cellobiose for growth and amino acid production proves the concept of utilization of C. glutamicum as
a biocatalyst in the lignocellulosic biorefinery.
