Submitted to: Biotechnology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2009
Publication Date: 1/27/2009
Citation: Renye Jr, J.A., Somkuti, G.A. 2009. INSERTION OF A HETEROLOGOUS GENE CONSTRUCT INTO A NON-FUNCTIONAL ORF OF THE STREPTOCOCCUS THERMOPHILUS CHROMOSOME. Biotechnology Letters. 31:759-764. Interpretive Summary: Streptococcus thermophilus is a food-grade bacterium essential for the production of fermented dairy foods including yogurt and cheeses. Its presence in dairy products makes it a good candidate to serve as a host for the expression of novel genes which may increase the functionality and nutritional value of dairy foods. In this study, a new method was developed for introducing new genes into the bacterium that will not interfere with the production of dairy foods. The developed gene research offers the possibility of generating novel strains of S. thermophilus that produce compounds which may improve the nutritional value of the fermented foods, while maintaining their status as “safe” organisms for human consumption.
Technical Abstract: A vector was constructed to allow for the integration of recombinant genes within the chromosome of Streptococcus thermophilus. The vector, pINTRS, contained a temperature sensitive origin of replication and an erythromycin resistance gene for initial selection in S. thermophilus. The region of the vector containing unique cloning sites, for insertion of recombinant genes, was flanked by homologous DNA sequences corresponding to a known pseudogene in S. thermophilus to facilitate chromosomal integration. The gene encoding green fluorescent protein, regulated by a plasmid borne hsp promoter of S. thermophilus, was cloned into pINTRS to demonstrate proper functioning of the vector.