Isolation of Citrobacter sp. mutants defective in decolorizing malachite green.
To identify genes involved in the decolorization of malachite green, random mutants generated by transposon insertion in the malachite green-decolorizing bacterium, Citrobacter sp. were isolated. The resulting mutant bank yielded 24 mutants with complete defects in their abilities to decolorize malachite green. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 7 mutants, which appeared to have insertions at different sites of the chromosome. The Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. Based on a sequence database, the putative protein products encoded by the mg genes were identified as follows. mg3, an ABC transporter homolog; mg6, a LysR-type regulatory protein; m11, an oxidoreductase; mg17, a MalG protein in the maltose transport system; and mg21, a sugar kinase. The deduced sequences from two mg genes (mg7 and mg18) showed no significant similarity to any protein with a known function, suggesting that these two mg genes encode unidentified proteins that are responsible for the decolorization of malachite green.
Jang
Moon-Sun
MS
Faculty of Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Korea.
Lee
Young-Mi
YM
Choi
Yong-Lark
YL
Cho
Young-Su
YS
Kim
Cheorl-Ho
CH
Lee
Young-Choon
YC
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002954:Citrobacter / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*; D003001:Cloning, Molecular; D003116:Color; D004251:DNA Transposable Elements; D016254:Mutagenesis, Insertional; D009154:Mutation; D012394:Rosaniline Dyes / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D012394:Rosaniline Dyes; C005095:malachite green