Abstract DBI 9750147 Brian Nowak-Thompson This action funds an NSF Postdoctoral Research Fellowship in Biosciences Related to the Environment for 1997. This fellowship provides an opportunity for the Fellow to gain additional scientific training beyond the doctoral degree and to pursue innovative and imaginative into the fundamental mechanisms underlying the interactions between organisms and their environment at the molecular, cellular, organismal, population, community and/or ecosystem level in any area of biology supported by the Directorate for Biological Sciences of the National Science Foundation. Each fellowship supports a research and training plan to be carried out in a sponsoring laboratory. The research and training plan for this fellowship is entitled "Environmental and genetic regulation of penicillin biosynthesis in Aspergillus." Ambient pH is a dominant environmental factor affecting the transcriptional regulation of ipnA, a key penicillin biosynthetic gene within Aspergillus nidulans. Under acid conditions, however, available carbon sources strongly influence ipnA expression through a mechanism independent of creA-mediated carbon catabolite repression. The goals of this study are to identify and characterize carbon regulatory loci affecting ipnA expression, characterize regulatory elements within the ipnA promoter region required for carbon regulation, and examine the relationship of ipnA promoter regions controlling carbon and pH regulation.