TNT biotransformation: when chemistry confronts mineralization

Smets, Barth F.; Yin, Hong; Esteve‐Núñez, Abraham

doi:10.1007/s00253-007-1008-7

Cited by 62 publications

(51 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Multiple systems have been reported for several other pesticides and toxins. For example, at least three and often more have been described for organophosphates, carbamates, glyphosate, triazines, 2,4,6-trinitrotoluene, and even other organochlorines like endosulfan and trichloroethylene (3,28,81,154,156,157,164,188; C. J. Hartley, S. J. Dorrian, L. J. Briggs, M. R. Williams, R. J. Russell, and J. G. Oakeshott, international patent application PCT/Au2007/000640). This unusual feature of the lin system may reflect the relative recalcitrance of HCH to degradation, as is also suggested by the length of the lin pathway.…”

Section: Evolutionary Issues and Scope For Improvementmentioning

confidence: 99%

Biochemistry of Microbial Degradation of Hexachlorocyclohexane and Prospects for Bioremediation

Lal

Pandey

Sharma

et al. 2010

Microbiol Mol Biol Rev

352

338

View full text Add to dashboard Cite

SUMMARY Lindane, the γ-isomer of hexachlorocyclohexane (HCH), is a potent insecticide. Purified lindane or unpurified mixtures of this and α-, β-, and δ-isomers of HCH were widely used as commercial insecticides in the last half of the 20th century. Large dumps of unused HCH isomers now constitute a major hazard because of their long residence times in soil and high nontarget toxicities. The major pathway for the aerobic degradation of HCH isomers in soil is the Lin pathway, and variants of this pathway will degrade all four of the HCH isomers although only slowly. Sequence differences in the primary LinA and LinB enzymes in the pathway play a key role in determining their ability to degrade the different isomers. LinA is a dehydrochlorinase, but little is known of its biochemistry. LinB is a hydrolytic dechlorinase that has been heterologously expressed and crystallized, and there is some understanding of the sequence-structure-function relationships underlying its substrate specificity and kinetics, although there are also some significant anomalies. The kinetics of some LinB variants are reported to be slow even for their preferred isomers. It is important to develop a better understanding of the biochemistries of the LinA and LinB variants and to use that knowledge to build better variants, because field trials of some bioremediation strategies based on the Lin pathway have yielded promising results but would not yet achieve economic levels of remediation.

show abstract

Section: Evolutionary Issues and Scope For Improvementmentioning

confidence: 99%

Biochemistry of Microbial Degradation of Hexachlorocyclohexane and Prospects for Bioremediation

Lal

Pandey

Sharma

et al. 2010

Microbiol Mol Biol Rev

352

338

View full text Add to dashboard Cite

show abstract

“…These compounds are susceptible to the reduction of the nitro side groups to yield hydroxylamino groups. This type of activity is also called nitroreductase activity (6,7,8,9,20,28,34) and will be referred to here as type I hydride transferase activity. Other OYE members have been described to additionally catalyze the nucleophilic attack on the aromatic ring of 2,4,6-trinitrotoluene (TNT) by hydride ions to produce Meisenheimer monohydride and dihydride complexes (13,23,24,29,32,37).…”

mentioning

confidence: 99%

Subfunctionality of Hydride Transferases of the Old Yellow Enzyme Family of Flavoproteins of Pseudomonas putida

Dillewijn

Wittich

Caballero

et al. 2008

Appl Environ Microbiol

View full text Add to dashboard Cite

To investigate potential complementary activities of multiple enzymes belonging to the same family within a single microorganism, we chose a set of Old Yellow Enzyme (OYE) homologs of Pseudomonas putida. The physiological function of these enzymes is not well established; however, an activity associated with OYE family members from different microorganisms is their ability to reduce nitroaromatic compounds. Using an in silico approach, we identified six OYE homologs in P. putida KT2440. Each gene was subcloned into an expression vector, and each corresponding gene product was purified to homogeneity prior to in vitro analysis for its catalytic activity against 2,4,6-trinitrotoluene (TNT). One of the enzymes, called XenD, lacked in vitro activity, whereas the other five enzymes demonstrated type I hydride transferase activity and reduced the nitro groups of TNT to hydroxylaminodinitrotoluene derivatives. XenB has the additional ability to reduce the aromatic ring of TNT to produce Meisenheimer complexes, defined as type II hydride transferase activity. The condensations of the primary products of type I and type II hydride transferases react with each other to yield diarylamines and nitrite; the latter can be further reduced to ammonium and serves as a nitrogen source for microorganisms in vivo.

show abstract

“…The reported products for systems that were not N limited were very similar to those for abiotic processes (e.g. aminotoluene) (Cruz-Uribe and Rorrer 2005, Gonzalez-Perez et al 2007, Newcombe and Crawford 2005, Nyanhongo et al 2006, Popesku et al 2006, Smets et al 2007. The amount of mineralization (usually reported as a percentage of the starting material rather than a rate) is usually low (less than 2%).…”

Section: Discussionmentioning

confidence: 64%

Union Support Recovery in High-Dimensional Multivariate Regression

Obozinski

Wainwright

Jordan

2008

View full text Add to dashboard Cite

Standard Form 298 (Rev. 8-98)Prescribed by ANSI Std. Z39.18Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Once released in the environment, either through detonation, casing breakage, or by slow leaks from unexploded ordnance (UXO), nitrogenous energetic compounds (NEC, such as TNT, HMX, RDX) may sorb onto particulates, partition to dissolved organic matter, or remain dissolved in aqueous media. Our hypothesis was that NEC would be transient in coastal ecosystems. This was based primarily on the understanding that microbial growth in these systems is typically nitrogen-limited and there are few examples of nitrogen based organic compounds that are not rapidly metabolized in these environments. During 14 sampling events in coastal waterways from 2002 to 2007, we measured TNT mineralization rates in surface sediment and water samples that were often the same as, or within one order of magnitude of, the rate of total heterotrophic bacterial metabolism. These rates were often similar to those of other organic compounds that are transient in natural ecosystems due to their use in bacterial metabolism, such as petroleum hydrocarbons and amino acids. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S ACRONYM(S) 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S REPORT NUMBER(S)

show abstract

TNT biotransformation: when chemistry confronts mineralization

Cited by 62 publications

References 100 publications

Biochemistry of Microbial Degradation of Hexachlorocyclohexane and Prospects for Bioremediation

Biochemistry of Microbial Degradation of Hexachlorocyclohexane and Prospects for Bioremediation

Subfunctionality of Hydride Transferases of the Old Yellow Enzyme Family of Flavoproteins of Pseudomonas putida

Union Support Recovery in High-Dimensional Multivariate Regression

Contact Info

Product

Resources

About