Pustaka Ilmiah Universitas Padjadjaran

Abstrak

A Comparative Study on The Transformation of Monascus Purpureus Albino’s Mutant Using Two Different Selection Markers

A comparative study on the transformation of Monascus purpureus albino’s mutant was carried out using two different selection markers, phleomycin resistance gene and the nitrate reductase gene, by polyethyleneglycol-mediated protoplast transformation. The first marker is based on the presence of genes conffering resistance to phleomycin (ble gene). The other marker, the nitrate reductase gene (niaD) from Aspergillus nidulans, utilize the conversion of an auxotroph of nitrate reductase from the albino’s mutant to prototrophy. The efficiency of transformation using ble gene (31-45 transformants/ug plasmid) was higher than the niaD gene (2-16 transformants/g plasmid). Mytotic stability studies demonstrated that all transformants were stabile up to 5 generations. The presence of the ble gene and the niaD gene in the transformants genome were analysed by PCR. These transformation systems are the first essential step in the cloning of the citrinin (a mycotoxin) biosynthetic genes. They provide the tools to prevent citrinin contamination in the other of Monascus metabolites, like azaphilone pigments and monascidin K (an antihypercholesterolemia agent), which used in human food and drugs.