Random Transposon Mutagenesis Used to Identify Pigmentation Gene in Chromobacterium violaceum

The pigmentation of the gram-negative bacteria known as Chromobacterium violaceum is characterized by a dark violet color. This study focused on the identification of a gene involved in C. violaceum pigment production. In order to identify one of the genes responsible for pigmentation of this organism, functional genomics methods were implemented using a form of knockout gene; which provides the identification of genes responsible for particular phenotypes. For this case, experimentation on one of the pigmentation genes in C. violaceum, violacein, was performed. Violacein is the product of a long metabolic pathway. Conjugation of Escherichia coli and C. violaceum transferred a pRL27-Tn5 transposon, as a means to generate mutations within C. violaceum. The vector, a transposon-bearing plasmid pRL27-Tn5, also carried kanamycin resistance and an origin of replication called R6Kγ, which marked a section near the cviR gene locus. Genomic DNA was extracted from isolated mutants and fragmented in order to be cloned and sequenced in a host organism. Sequencing and analysis were performed via genetic databases in NCBI BLAST program.