Whole Genome Sequence and Development of a Transposon Mutagenesis System for Pseudomonas Putida sp.12

Abstract

Nowadays, Heavy metal pollution is one of the most important environmental problems. All metals

occurring in the biosphere originated in the earth’s crust; however, the toxic metal pollution of the biosphere

has intensified rapidly since the onset of the industrial revolution, posing major environmental and

health problems. Several studies have demonstrated the effect of metals on microbial diversity, biomass

and activity. It is believed that metal Microbial activity is responsible for the bioremediation of the third

elements in the periodic table. Selenium is an important trace element that required for in trace amounts for

growth and metabolism but toxic at elevated concentration. The ability of a single mutant Pseudomonas

putida sp.12(mariner transposon) has been used to search for genes involved in the biotransformation of

selenite to red elemental selenium. This study aims to develop a transposon mutagenesis system for the

model P. putida sp.12 to investigate the gene(s) that involved in selenite reduction. The conjugative plasmid

pSAM_R1 containing the mariner transposon was used for transposon mutagenesis. A single mutant reliably

impaired in selenite transformation, found that the mutant clones, contained an inactivation within pmoB,

one of two copies of the gene encoding the largest subunit of particulate selenite-reduction. Physiological

analysis of this “white mutant” indicated that the selenite-reducing activity, which was located primarily in

the cytoplasm of the cells, could be rescued by adding format as an alternative source of electrons