Developing a single strain for in vitro salvage synthesis of NAD+ at high temperatures and its potential for bioconversion.

The integrated strain allows preparation of an enzyme cocktail that can solve the problem of NAD+ instability at high temperatures. The strain simplifies preparation of the enzyme cocktail, and thus expands the applicability of the in vitro metabolic engineering method using thermostable enzymes. Further optimization of gene expressions in the integrated strain can be achieved by using various types of ribosome binding sites as well as promoters.