A novel nicotine catabolic plasmid pMH1 in Pseudomonas sp. strain HF-1.
Attempts were made to acquire a plasmid-loss mutant via various methods (spontaneous mutation, SDS, and mitomycin C), among which the method involving mitomycin C (10 microg/mL) has been proven successful. Concomitant with the loss of the plasmid in Pseudomonas sp. strain HF-1, the cured derivative was identified as having a nicotine-negative (Nic-) phenotype, named mutant strain 6-13 (Nic-). After plasmids were transferred from strain HF-1 (named plasmid pMH1) to the mutant strain 6-13, the mutant strain acquired nicotine-degrading ability, called 6-13 transformant (Nic+). There were no differences in growth or nicotine-degrading efficiency between strain HF-1 (wild-type strain) and strain 6-13 transformant. After pMH1 was transferred to Escherichia coli strain Top10 (Nic-), a distant relative of Pseudomonas, it also gained nicotine-degrading ability, showing the highest nicotine degradation efficiency at pH 7.0, the optimal pH for growth of E. coli. The hsp gene, which encodes 6-hydroxy-3-succinoylpyridine hydroxylase, is involved in nicotine degradation in Pseudomonas putida strain S16 and was present in pMH1 but not in pAO1, the well-known nicotine degradation plasmid in Arthrobacter nicotinovorans. It was demonstrated that plasmid pMH1 is a novel nicotine-degrading plasmid.
College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China.
Meizhen
M
Wang
Guiqin
G
Yang
Hang
H
Min
Zhenmei
Z
Lv
D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009538:Nicotine / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011549:Pseudomonas / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D011725:Pyridines / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013386:Succinates / Q000378:metabolism*; D014169:Transformation, Bacterial
C507268:6-hydroxy-3-succinoyl-pyridine; D004269:DNA, Bacterial; D011725:Pyridines; D013386:Succinates; D009538:Nicotine; D006899:Mixed Function Oxygenases