Isolation and Identification of a Novel Strain of the Genus Ochrobactrum with Phenol-Degrading Activity

EL-SAYED, WAEL S.; IBRAHIM, MOHAMED K.; ABU-SHADY, MOHAMED; EL-BEIH, FAWKIA; Ohmura, Naoya; Saiki, Hiroshi; ANDO, AKIKAZU

doi:10.1263/jbb.96.310

Cited by 21 publications

(26 citation statements)

References 8 publications

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“…3). Many Ochrobactrum strains were studied for the potential capacity to degrade chemical pollutants and for heavy metal detoxification under a wide range of environmental conditions (24)(25)(26). Another Ochrobactrum strain, DN2, could metabolize nicotine; however, the degradation pathway of strain DN2 is still unknown (9).…”

Section: Discussionmentioning

confidence: 99%

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

Tang

Zhu

et al. 2015

Appl Environ Microbiol

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A newly isolated strain, SJY1, identified as Ochrobactrum sp., utilizes nicotine as a sole source of carbon, nitrogen, and energy. Strain SJY1 could efficiently degrade nicotine via a variant of the pyridine and pyrrolidine pathways (the VPP pathway), which highlights bacterial metabolic diversity in relation to nicotine degradation. A 97-kbp DNA fragment containing six nicotine degradation-related genes was obtained by gap closing from the genome sequence of strain SJY1. Three genes, designated vppB, vppD, and vppE, in the VPP pathway were cloned and heterologously expressed, and the related proteins were characterized. The vppB gene encodes a flavin-containing amine oxidase converting 6-hydroxynicotine to 6-hydroxy-N-methylmyosmine. Although VppB specifically catalyzes the dehydrogenation of 6-hydroxynicotine rather than nicotine, it shares higher amino acid sequence identity with nicotine oxidase (38%) from the pyrrolidine pathway than with its isoenzyme (6-hydroxy-L-nicotine oxidase, 24%) from the pyridine pathway. The vppD gene encodes an NADH-dependent flavin-containing monooxygenase, which catalyzes the hydroxylation of 6-hydroxy-3-succinoylpyridine to 2,5-dihydroxypyridine. VppD shows 62% amino acid sequence identity with the hydroxylase (HspB) from Pseudomonas putida strain S16, whereas the specific activity of VppD is ϳ10-fold higher than that of HspB. VppE is responsible for the transformation of 2,5-dihydroxypyridine. Sequence alignment and phylogenetic analysis suggested that the VPP pathway, which evolved independently from nicotinic acid degradation, might have a closer relationship with the pyrrolidine pathway. The proteins and functional pathway identified here provide a sound basis for future studies aimed at a better understanding of molecular principles of nicotine degradation. N icotine, which easily passes biological membranes, is significantly harmful to humans and is considered a potentially addictive drug (1, 2). Large quantities of tobacco waste with high concentrations of nicotine are generated annually by cigarette and cigar manufacturing (3). Due to its water solubility, nicotine can easily spread in the environment, emerging as a threat to public health (3). As a result, the U.S. Environmental Protection Agency classified nicotine as a "toxic release inventory" chemical in 1994 (4). Microbes play significant roles in removing nicotine from the environment, and in the meantime, they serve as the catalysts for biotransformation. Nicotine could potentially be used for the production of value-added chemicals. 6-Hydroxy-3-succinoylpyridine (HSP), an important precursor for the synthesis of compounds with biological activities, was efficiently produced by an engineered nicotine-degrading strain (5). Therefore, the study of the mechanism of nicotine degradation provides useful information for both bioremediation and biocatalysis.Many microorganisms that use various nicotine degradation pathways have been isolated from the environment, including Arthrobacter (6), Pseudomonas (7, 8), Ochroba...

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Section: Discussionmentioning

confidence: 99%

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

Tang

Zhu

et al. 2015

Appl Environ Microbiol

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“…It has been found that the Ochrobactrum species metabolize phenol through catechol, followed by the ortho-or meta-cleavage pathway. 16,26) Degradation of 2,4,6-TBP by the Ochrobactrum species has not previously been reported, and this prompted us to examine more Ochrobactrum species for this ability. We tested the type strains O. anthropi NBRC15819, O. tritici NBRC102585, O. grignonense NBRC102586, and O. lupini NBRC102587.…”

Section: Discussionmentioning

confidence: 99%

“…16) Hence Ochrobactrum anthropi NBRC15819, O. tritici NBRC102585, O. grignonense NBRC102586, and O. lupini NBRC102587, all of which have close phylogenic relationship, to Ochrobactrum sp. strain TB01, were characterized with respect to degradation of 2,4,6-TBP and phenol.…”

Section: Biodegradation Of Other Halogenated Phenolsmentioning

confidence: 99%

Biodegradation of 2,4,6-Tribromophenol byOchrobactrumsp. Strain TB01

Yamada

Takahama

Yamada

2008

Bioscience, Biotechnology, and Biochemistry

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“…Ubiquitous gram-negative Ochrobactrum strains are widely distributed in soils and aqueous environments, where they biodegrade aromatic compounds (11), organophosphorus pesticides (45), and other hydrocarbons (38) and remove heavy metal ions such as chromium and cadmium (24). Having been isolated from clinical specimens, Ochrobactrum anthropi is currently recognized as an emerging opportunistic pathogen, although relatively little is known about its pathogenesis and factors contributing to its virulence (7,30).…”

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confidence: 99%

Novel Denitrifying Bacterium Ochrobactrum anthropi YD50.2 Tolerates High Levels of Reactive Nitrogen Oxides

Doi

Takaya

Takizawa

2009

Appl Environ Microbiol

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Most studies of bacterial denitrification have used nitrate (NO 3؊ ) as the first electron acceptor, whereas relatively less is understood about nitrite (NO 2 ؊ ) denitrification. We isolated novel bacteria that proliferated in the presence of high levels of NO 2 ؊ (72 mM T proliferated even in the presence of higher levels of NO 2 ؊ (100 mM), and both were considerably more resistant to acidic NO 2 ؊ than were the other strains noted above. These results indicated that O. anthropi YD50.2 is a novel denitrifier that has evolved reactive nitrogen oxide tolerance mechanisms.Environmental bacteria maintain the global nitrogen cycle by metabolizing organic and inorganic nitrogen compounds. Denitrification is critical for maintenance of the global nitrogen cycle, through which nitrate (NO 3 Ϫ ) or nitrite (NO 2 Ϫ ) is reduced to gaseous nitrogen forms such as N 2 and nitrous oxide (N 2 O) (19, 47). Decades of investigations into denitrifying bacteria have revealed their ecological impact (9), their molecular mechanisms of denitrification (13,25,47), and the industrial importance of removing nitrogenous contaminants from wastewater (31, 36). Bacterial denitrification is considered to comprise four successive reduction steps, each of which is catalyzed by NO 3 Ϫ reductase (Nar), NO 2 Ϫ reductase (Nir), nitric oxide (NO) reductase (Nor), and N 2 O reductase (Nos). The reaction of each enzyme is linked to the electron transport chain on the cellular membrane and accompanies oxidative phosphorylation, implying that bacterial denitrification is of as much physiological significance as anaerobic respiration (25, 47). Most denitrifying bacteria are facultative anaerobes and respire with oxygen under aerobic conditions. Because denitrification is induced in the absence of oxygen, it is considered an alternative mechanism of energy conservation that has evolved as an adaptation to anaerobic circumstances (13, 47).Nitrite and NO are hazardous to bacteria, since they generate highly reactive nitrogen species (RNS) under physiological conditions and damage cellular DNA, lipid, and proteins (28,37). Denitrifying bacteria are thought to be threatened by RNS since they reduce NO 3 Ϫ to generate NO 2 Ϫ and NO as denitrifying intermediates. Furthermore, denitrifying bacteria often inhabit environments where they are exposed to NO 2 Ϫ and NO and hence high levels of RNS. Recent reports suggest that pathogenic bacteria invading animal tissues are attacked by NO generated by macrophages (12). Such bacteria involve denitrifiers, and some of them, for example, Neisseria meningitidis (1) and Pseudomonas aeruginosa, acquire resistance to NO by producing Nor (44). The utilization (reduction) of NO by Brucella increases the survival of infected mice (2). These examples suggest that production of a denitrifying mechanism affects bacterial survival of threats from both endogenous and extracellular RNS. However, the mechanism of RNS tolerance induced by denitrifying bacteria is not fully understood.Ubiquitous gram-negative Ochrobactrum strains ar...

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Isolation and Identification of a Novel Strain of the Genus Ochrobactrum with Phenol-Degrading Activity

Cited by 21 publications

References 8 publications

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

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

Biodegradation of 2,4,6-Tribromophenol byOchrobactrumsp. Strain TB01

Novel Denitrifying Bacterium Ochrobactrum anthropi YD50.2 Tolerates High Levels of Reactive Nitrogen Oxides

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