Abstract: Methods and constructs for the introduction of multiple genes into plants using a single transformation event are described. Constructs contain a single 5′ promoter operably linked to DNA encoding a modified intein splicing unit. The splicing unit is expressed as a polyprotein and consists of a first protein fused to an intein fused to a second protein. The splicing unit has been engineered to promote excision of all non-essential components in the polyprotein but prevent the ligation reactions normally associated with protein splicing. Additional genetic elements encoding inteins and additional proteins can be fused in frame to the 5′-terminus of the coding region for the second protein to form a construct for expression of more than two proteins. A single 3′ termination sequence, such as a polyadenylation sequence when the construct is to be expressed in eucaryotic cells, follows the last coding sequence.

Abstract: A method has been developed for control of molecular weight and molecular weight dispersity during production of polyhydroxyalkanoates in genetically engineered organism by control of the level and time of expression of one or more PHA synthases in the organisms. The method was demonstrated by constructing a synthetic operon for PHA production in E. coli in which the level of PHA synthase activity could be tightly controlled by placement of the synthase behind an inducible promoter. Modulation of the total level of PHA synthase activity in the host cell by varying the concentration of the inducer, isopropyl .beta.-D-thiogalactoside (IPTG), was found to effect the molecular weight of the polymer produced in the cell. Specifically, high concentrations of synthase activity were found to yield polymers of low molecular weight while low concentrations of synthase activity yielded polymers of higher molecular weight.

Abstract: Enhanced efficiency of production of aromatic compounds via the common pathway, as shown in FIG. 1, of a host cell is realized by increasing the expression of enzyme species acting on substrate intermediates in identified rate-limiting reaction steps in the pathway. Prokaryotic cell transformants are described comprising exogenous DNA sequences encoding for the enzymes species, 3-dehydroquinate synthase, shikimate kinase, 5-enolpyruvoyl-shikimate-3-phosphate synthase and chorismate synthase. These transformants can be further transformed with exogenous DNA sequences encoding the enzyme species transketolase and DAHP synthase. In one embodiment of the present invention, one or more of the DNA sequences encoding the enzyme species are incorporated into the genome of the transformant.