title: Biodegradation of malachite green by strain Pseudomonas sp. K9 and cloning of the tmr2 gene associated with an ISPpu12.
abstract: A bacterial strain K9 capable of degrading malachite green was isolated from the sludge of the wastewater treatment system of a chemical plant. It was identified preliminarily as Pseudomonas sp. Strain K9 was also able to degrade other triphenylmethane dyes, such as Crystal Violet and Basic Fuchsin. The gene tmr2, encoding the triphenylmethane reductase, was cloned from strain K9, and functionally expressed in E. coli. A 5946-bp DNA fragment including the tmr2 gene was cloned from the genomic DNA of strain K9 by chromosome walking. Its sequence analysis showed that tmr2 was associated with a typical mobile element ISPpu12 consisting of tnpA (encoding a transposase), lspA (encoding a lipoprotein signal peptidase) and orf1 (encoding a putative MerR family regulator), orf2 (encoding a CDF family heavy metal/H(+) antiporter). This association was also found in another malachite green-degrading strain Pseudomonas sp. MDB-1, which indicated that the tmr2 gene might be a horizontally transferable gene.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, People's Republic of China.
authors.lastname: Huan-Mei
authors.forename: Li
authors.initials: L
authors.lastname: Lian-Tai
authors.forename: Yan
authors.initials: Y
authors.lastname: Cai-Fang
authors.forename: Sun
authors.initials: S
authors.lastname: Jin-Jin
authors.lastname: Yuan-Gao
authors.forename: Qing
authors.initials: Q
authors.lastname: Hong
authors.forename: Li
authors.initials: L
authors.lastname: Shun-Peng