Figure7-2.5: Illustrates the whole schema of recombinant protein/enzyme production in E. coli

(Acknowledgement: http://www.southampton.ac.uk/cruk/protein/index.page )

Table 7-2.5 List of industrially important enzymes produced in recombinant microorganisms:

7-2.6 Genetic engineering in Methylophilus methylotrophus:

Methylophilus methylotrophus, the obligate methylotrophs are able to efficiently convert methanol to single-cell protein, a process of major importance to a variety of industries.

The glutamate dehydrogenase gene of E. coli has been cloned into broad host range plasmid and can complement glutamate synthase mutants of Methylophilus methylotrophus. Assimilation of ammonia via glutamate dehydrogenase is more energy efficient than via glutamate synthase. Thus the recombinant microorganism can convert more growth-substrate, methanol into cellular carbon.

Trans-conjugants were selected for the antibiotic resistance encoded by the vector, and the GDH enzyme activity measured to confirm the presence of the GDH gene.

The strain constructed by these manipulations was able to convert methanol to single-cell protein more efficiently than the original parent strain.