Distribution of the tfdA Gene in Soil Bacteria That Do Not Degrade 2,4-Dichlorophenoxyacetic Acid (2,4-D)

Two different monoclonal antibodies (MAb) were raised against 2,4-dichlorophenol hydroxylase (DCP-hydroxylase) of Ralstonia eutropha JMP134 (pJP4), the second enzyme in the 2,4-D-degradative pathway of this bacterium. The utility of these antibodies in detecting and characterizing 2,4-D-degrading soil bacteria was investigated. One MAb (F6) reacted with DCP-hydroxylase from 27 out of 36 strains tested, while the other (MAb C3) reacted with only 17 isolates. When used with the colony blot technique, MAb F6 was useful for detecting cross-reacting strains on plates of pure cultures or of mixtures containing nondegraders even when 2,4-D degraders were outnumbered 60 to 1. 2,4-D-degrading strains could also be detected from plates spread with enrichment cultures but not from primary isolation plates spread from soil dilutions, presumably because the ratio of degraders to nondegraders was too low. Colonies of some strains that were very distantly related genetically, but produced functionally similar DCP-hydroxlase enzymes, were detected by MAb F6. This result suggests that MAbs could be useful for detecting functionally similar proteins expressed from tfdB analogs, even in the absence of detectable DNA homology between the genes encoding them.Key words: monoclonal antibody, 2,4-dichlorophenol hydroxylase, 2,4-dichlorophenoxyacetic acid, 2,4-D-degrading bacteria.

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Isolation and Characterization of Halotolerant 2,4- Dichlorophenoxyacetic Acid Degrading Bacteria From Sulfidic, Low Salinity Salt Springs

Fine Focus ◽

10.33043/ff.1.1.39-50 ◽

2014 ◽

Vol 1 (1) ◽

pp. 39-50

Author(s):

Michael G. Willis ◽

David S. Treves

Keyword(s):

Bacterial Communities ◽

Dichlorophenoxyacetic Acid ◽

Growth Strategies ◽

Low Salinity ◽

Isolation And Characterization ◽

Degrading Bacteria ◽

History Of ◽

2,4 Dichlorophenoxyacetic Acid ◽

Tfda Gene

The bacterial communities at two sulfidic, low salinity springs with no history of herbicide contamination were screened for their ability to grow on 2,4-dichlorophenoxyacetic acid (2,4-D). Nineteen isolates, closely matching the genera Bacillus, Halobacillus, Halomonas, Georgenia and Kocuria, showed diverse growth strategies on NaCl-supplemented and NaCl-free 2,4-D medium. The majority of isolates were halotolerant, growing best on nutrient rich broth with 0% or 5% NaCl; none of the isolates thrived in medium with 20% NaCl. The tfdA gene, which codes for an a – ketoglutarate dioxygenase and catalyzes the first step in 2,4-D degradation, was detected in nine of the salt spring isolates. The tfdAa gene, which shows ~60% identity to tfdA, was present in all nineteen isolates. Many of the bacteria described here were not previously associated with 2,4-D degradation suggesting these salt springs may contain microbial communities of interest for bioremediation.

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Diversity of tfdC genes: distribution and polymorphism among 2,4-dichlorophenoxyacetic acid degrading soil bacteria

FEMS Microbiology Ecology ◽

10.1111/j.1574-6941.1999.tb00597.x ◽

1999 ◽

Vol 29 (1) ◽

pp. 45-58 ◽

Cited By ~ 25

Author(s):

Lucia Cavalca ◽

Alain Hartmann ◽

Nadine Rouard ◽

Guy Soulas

Keyword(s):

Soil Bacteria ◽

Dichlorophenoxyacetic Acid ◽

2,4 Dichlorophenoxyacetic Acid

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In Vitro Shoot Regeneration from Callus Derived from Marubakaido Apple Rootstock under Different Aluminium Concentrations

HortScience ◽

10.21273/hortsci.33.3.460e ◽

1998 ◽

Vol 33 (3) ◽

pp. 460e-460 ◽

Cited By ~ 1

Author(s):

Marisa F. de Oliveira ◽

Gerson R. de L. Fortes ◽

João B. da Silva

Keyword(s):

Shoot Regeneration ◽

Dichlorophenoxyacetic Acid ◽

Apple Rootstock ◽

Under Five ◽

Significant Difference ◽

Previously Treated ◽

2,4 Dichlorophenoxyacetic Acid ◽

In Vitro Shoot Regeneration

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.

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Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽

10.21273/hortsci.33.3.483a ◽

1998 ◽

Vol 33 (3) ◽

pp. 483a-483

Author(s):

Roy N. Keys ◽

Dennis T. Ray ◽

David A. Dierig

Keyword(s):

Field Experiments ◽

Reproductive Mode ◽

Dichlorophenoxyacetic Acid ◽

Initial Field ◽

Breeding Lines ◽

Reproductive Modes ◽

Desert Southwest ◽

2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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The role of a metabolic intermediate in the biodegradation of inhibitory substrates

Water Science & Technology ◽

10.2166/wst.1997.0352 ◽

1997 ◽

Vol 36 (10) ◽

pp. 27-36 ◽

Cited By ~ 1

Author(s):

P. Mungkarndee ◽

S. M. Rao Bhamidimarri ◽

A. J. Mawson ◽

R. Chong

Keyword(s):

The Other ◽

Metabolic Product ◽

Dichlorophenoxyacetic Acid ◽

Mutual Inhibition ◽

Metabolic Intermediate ◽

Batch Cultures ◽

Ortho Cresol ◽

2,4 Dichlorophenoxyacetic Acid

Biodegradation of the mixed inhibitory substrates, 2,4-dichlorophenoxyacetic acid (2,4-D) and para-chloro-ortho-cresol (PCOC) was studied in aerobic batch cultures. Each substrate added beyond certain concentrations inhibited the degradation of the other. This mutual inhibition was found to be enhanced by 2,4-dichlorophenol (2,4-DCP) which is an intermediate metabolic product of 2,4-D. When 2,4-DCP accumulated to approximatelY 40 mg/l degradation of all compounds in the mixed 2,4-D and PCOC substrate system was completely inhibited. The degradation of 2,4-D and PCOC individually was also found to be inhibited by elevated concentrations of 2,4-DCP added externally, while PCOC inhibited the utilization of the intermediate.

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