A novel nicotine catabolic plasmid pMH1 in Pseudomonas sp. strain HF-1

Abstract

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.

Molecular Mechanism of Nicotine Degradation by a Newly Isolated Strain, Ochrobactrum sp. Strain SJY1

“…Horizontal gene transfer plays a central role in bacterial evolution to bring new catabolic pathways (31), and the information gathered over past years from the genetic study of nicotine degradation pathways suggests that many genes involved in nicotine degradation are also obtained in this way through plasmids or genomic islands (7,(32)(33)(34). The VPP pathway was identified in three strains from three different genera, and the GϩC content of the vpp cluster is different from that of the whole genome of strain SJY1, indicating that the genes of the VPP degradation pathway may also have been obtained through horizontal gene transfer.…”

Unraveling the concentration-dependent metabolic response of Pseudomonas sp. HF-1 to nicotine stress by 1H NMR-based metabolomics

“…However, succinate is also a nicotine-degradation intermediate in Pseudomonas sp. HF-1 containing degradative plasmid pMH1 Wang et al 2009a). Outside of the bacterial cells, nicotine can be converted into 3-succinoyl-pyridine (SP).…”

Comprehensive classification of the PIN domain-like superfamily

“…In cyanobacterium Synechococcus elongatus , LabA and its paralog lalA are involved in negative feedback expression regulation of the circadian clock protein KaiC (97,98). Interestingly, LabA homolog (nicB, PSS_0380) in Pseudomonas putida S16 possesses a nicotine-degrading ability, catalyzing the hydroxylation of 6-hydroxy-3-succinoylpyridine (99,100). However, another domain present in the protein, DUF2384, may be responsible for this activity.…”