|Skinner, Daniel - Dan|
Submitted to: Journal of Industrial Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2003
Publication Date: 5/15/2003
Citation: Lakrod, K., Chaisrisook, C., Skinner, D.Z. 2003. Expression of pigmentation genes following electroporation of albino monascus purpureus. Journal of Industrial Microbiology. 30:369-374. Interpretive Summary: Monascus purpureus is a fungus used in the production of many food products. The color of the fungus is a significant factor in the acceptability of the food products to the consumer. This study was undertaken to investigate methods of genetically manipulating the fungus, and to develop stock cultures with altered ability to produce the colored pigments, to use in further elucidation of the genetic control of pigment production. Eight cultures were developed that expressed altered levels of pigment production, and two cultures were developed that produced effective levels of antibiotic resistance. These results provide materials and methods for further development of new products with this food fungus.
Technical Abstract: Albino strain KB20M1 of Monascus purpureus was genetically transformed to hygromycin B resistance with cosmid pMOcosX, using biolistic bombardment. The two independent transformants that resulted formed cleistothecia but no ascospores, suggesting the expression of hygromycin resistance interferes with fertilization and/or ascospore formation in this homothallic fungus, possibly representing a means to control mating. The albino strain also was transformed with large genomic DNA from the red, wild-type culture of the fungus, using electroporation. Eight transformants resulted that intermittently, but consistently, expressed color. The growth rates on MEA media of all eight of the transformants was significantly greater than the recipient and donor strains. Spectrophotometric analysis of the pigments extracted from the transformants indicated that some of the pigments had absorbance spectra that were different from the DNA donor strain. These results suggested that transformation with wild-type DNA can repair the defect(s) that resulted in albinism in KB20M1, and in the incorporation of genes that enhanced growth rates under specific culture conditions. Some of the pigments produced by the transformants were different from the wild-type, suggesting alternative metabolic pathways were activated by the incorporation of wild-type DNA, resulting in novel pigment formation.