To study the regulation of the plg1 and plg2 genes of Penicillium griseoroseum, in order to identify the industrial potential of their products in alternative carbon sources that are cheaper and widely available in Brazil. RT-PCR and Northern blot were used to investigate if plg1 and plg2 expression is under influence of catabolic repression, ambient pH and cAMP. Results demonstrated that the genes were differentially regulated depending on the carbon sources in the culture medium and pH. Sucrose, a noninducing carbon source of the pectinolytic system, was able to promote plg1 transcription but only when yeast extract was added into the culture medium. The plg genes are differentially expressed. The plg1 gene is more attractive for industrial use due to its expression in alternative carbon sources like sucrose and yeast extract. In recent years, industries have been trying to replace the toxic conventional treatments employed in these processes by more eco-friendly enzyme treatment. Alternative carbon sources will be tested with the aim to reduce the costs associated to pectin lyase production in Brazil.