Cloning and Functional Characterization of Gene Promoters from Rhizopus oryzae AS 3.819

In this paper, promoter fragments of four genes, lactate dehydrogenase A(ldh A), pyruvate decarboxylase A(pdc A), glucoamylase A(amy A) and phosphoglycerate kinase 1(pgk1), from genome DNA of Rhizopus oryzae strain AS 3.819, were amplified and screened in Escherichia coli strain JM109 by using promoter probe vector p UKMR containing β-lactamase gene(bla) as its reporter gene. The results suggested that the four promoter fragments all possessed the ability to drive the expression of the β-lactamase gene. The promoters of ldh A and pgk1 genes possessed high promoting strength even though no inducing substrate was present, while the strength of pdc A and amy A promoters could be enhanced when the suitable carbon source was adopted. The strength of ldh A promoter was enhanced as the fragment length increased until it reached 500 bp. This research provides a quick and easy method to isolate and detect gene promoters form Rhizopus oryzae.