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D K Chatterjee

Publications and source records attributed to D K Chatterjee.

At least 37 records · Page 2Linked to original sources
PubMed1985

Genes specifying degradation of 3-chlorobenzoic acid in plasmids pAC27 and pJP4.

All of the structural genes for 3-chlorobenzoate degradation are clustered in a 4.2-kilobase (kb) region of plasmid pAC25 (or pAC27) in Pseudomonas putida. An approximate 10-kb DNA segment containing three structural genes for chlorocatechol metabolism present on plasmid pJP4 in Alcaligenes eutrophus shows homology with the above 4.2-kb region of pAC27. In spite of the detectable sequence homology in the structural genes present on both plasmids, the regulation of their expression seems quite different; unlike pAC27, structural rearrangements are prerequisite for efficient expression of the 3-chlorobenzoate genes on plasmid pJP4. Structural features such as stem-loop structures present on plasmid pJP4 are most likely the starting materials for such rearrangements.

Alcaligenes↗
PubMed1984

Microbial biodegradation of 2,4,5-trichlorophenoxyacetic acid and chlorophenols.

We have succeeded in isolating a pure culture of Pseudomonas cepacia, AC1100, from a chemostat enrichment culture experiment that is capable of growing on 2,4,5-trichlorophenoxyacetic acid as its sole source of carbon and energy. AC1100 is not only capable of degrading 2,4,5-T but is also able to completely or partially dehalogenate a wide variety of halophenols. The regulation of the dehalogenating ability of AC1100 has been investigated which demonstrates that the enzyme(s) which allow the conversion of 2,4,5-T to 2,4,5-TCP are constitutive, while the enzymes that allow the degradation of 2,4,5-TCP are inducible by 2,4,5-TCP (or some metabolite of 2,4,5-TCP) but not by 2,4,5-T or other halophenols which can serve as substrates. Moreover, the 2,4,5-TCP degradative pathway is repressed by the presence of an abundant alternative carbon source. The detailed pathway of 2,4,5-T degradation by AC1100 is currently under study. Although field tests have yet to be conducted, laboratory experiments have demonstrated rapid and complete degradation of 2,4,5-T from contaminated soil. Soil previously contaminated with as much as 5,000 micrograms of 2,4,5-T/g of soil could be detoxified by AC1100 treatment, allowing the growth of plants sensitive to less than 10 micrograms 2,4,5-T/g of soil. Moreover soil contaminated with as much as 20,000 micrograms of 2,4,5-T/g of soil showed greater than 90% degradation after six weekly AC1100 treatments. After 2,4,5-T has been substantially degraded in contaminated soil the titer of AC1100 rapidly falls to nearly undetectable levels, which indicates that no serious ecological disturbance is likely to result from the application of AC1100. It appears possible that the treatment of contaminated areas with appropriate microorganisms may allow essentially a total restoration of the original soil condition.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1984

Caerulomycin, an antifungal antibiotic with marked in vitro and in vivo activity against Entamoeba histolytica.

The anti-amoebic action of the bipyridyl antibiotic caerulomycin was assessed in vitro and in vivo using various strains of Entamoeba histolytica from polyxenic, axenic and monoxenic cultures. Minimum inhibition concentrations of caerulomycin (metronidazole) were 7.5 (5), 15.6(1.95) and 60 (2.5) micrograms/ml against polyxenic, axenic and monoxenic cultures of E. histolytica, respectively. The ED50 values ascertained in golden hamsters (extraintestinal amoebiasis) and rats (intestinal amoebiasis) after the oral route were 136 and 199 mg/kg (X4), respectively. Metronidazole proved to be approximately four times more active against tissue forms of E. histolytica than caerulomycin [ED50 of metronidazole: less than 40 mg/kg (X4)]. The antibiotic was slightly superior to metronidazole in its action on lumen forms of E. histolytica [ED50 of metronidazole: 233 mg/kg (X4)]. The antibiotic was in some cases toxic to hamsters and rats within the therapeutic range.

2,2'-Dipyridyl↗
PubMed1984

Restriction mapping of a chlorobenzoate degradative plasmid and molecular cloning of the degradative genes.

The genes for the degradation of 3-chlorobenzoic acid ( 3Cba ) are present in a 110-kb plasmid pAC27 . A circular map is established using the restriction endonucleases EcoRI, HindIII and Bg/II. The map is derived from the results obtained by partial restriction digestion, complete single and double restriction digestion and finally confirmed with hybridization of the digested fragments using different purified fragments as probes. The 3Cba degradative genes are found to be clustered in one region of the map (EcoRI fragment A) as judged by molecular cloning with a broad host range vector pLAFRI . A portion of the 3Cba degradative gene cluster appears to undergo ready recombination with the chromosome, even in a recA host, suggesting the probable transposable nature of such gene cluster.

Chlorobenzoates↗
PubMed1983

Comparative studies on the amoebicidal activity of known 5-nitroimidazole derivatives and CG 10213-Go in golden hamsters, Mesocricetus auratus, infected in the liver or caecum or both with trophozoites of Entamoeba histolytica.

CG 10213-Go, a 5-nitroimidazole derivative synthesized at the CIBA-Geigy Research Centre, Bombay, proved superior to such currently used 5-nitroimidazole derivatives as metronidazole, ornidazole, secnidazole, tinidazole and nimorazole, against experimental amoebic infections of the liver and caecum in a golden hamster model. CG 10213-Go is now undergoing clinical trials.

Amebicides↗
PubMed1983

Detoxification of 2,4,5-trichlorophenoxyacetic acid from contaminated soil by Pseudomonas cepacia.

The strain of Pseudomonas cepacia, AC1100, capable of utilizing 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as a sole source of carbon and energy can degrade 2,4,5-T in contaminated soil, removing more than 99% of 2,4,5-T present at 1 mg/g of soil within 1 week. Repeated application of AC1100 even allowed more than 90% removal of 2,4,5-T within 6 weeks from heavily contaminated soil containing as much as 20,000 ppm 2,4,5,-T (20 mg/g of soil). Microbial removal of 2,4,5-T allowed the soil to support growth of plants sensitive to low concentrations of 2,4,5-T. After 2,4,5-T removal, the titer of AC1100 in the soil rapidly fell to undetectable levels within a few weeks.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1983

Genetic homology between independently isolated chlorobenzoate-degradative plasmids.

Two chlorobenzoate-degradative plasmids were studied by the hybridization of the restriction endonuclease-generated fragments of one plasmid after transfer to a nitrocellulose filter with nick-translated radioactive DNA of the other plasmid as a probe. Two strains harboring the 3-chlorobenzoic acid-degradative plasmids were isolated in two different parts of the world at two different times. The plasmids are now found to be closely related to each other by hybridization studies. The chlorobenzoate-degradative plasmid from Pseudomonas sp. strain B13 (termed pB13) has a 6-kilobase deletion but otherwise is homologous with previously described plasmid pAC25.

Base Sequence↗
PubMed1982

Biodegradation of 2,4,5-trichlorophenoxyacetic acid by a pure culture of Pseudomonas cepacia.

A pure culture of Pseudomonas cepacia, designated AC1100, that can utilize 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as its sole source of carbon and energy was isolated. An actively growing culture of AC1100 was able to degrade more than 97% of 2,4,5-T, present at 1 mg/ml, within 6 days as determined by chloride release, gas chromatographic, and spectrophotometric analyses. The ability of AC1100 to oxidize a variety of chlorophenols and related compounds is also reported.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1981

Plasmid-assisted molecular breeding: new technique for enhanced biodegradation of persistent toxic chemicals.

The persistence of synthetic herbicides such as 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and its release in massive amounts as a herbicide (Agent Orange) have created toxicological problems in many countries. In nature, 2,4,5-T is slowly degraded by cooxidation and is not utilized as a sole source of carbon and energy. The technique of plasmid-assisted molecular breeding has led to the development of bacterial strains capable of totally degrading 2,4,5-T by using it as their sole source of carbon at high concentrations (greater than 1 mg/ml). Spectrophotometry and gas chromatography reveal various intermediates during growth of the culture with 2,4,5-T.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1981

Gangrene of the toes with palpable peripheral pulses.

Thirty-five patients with gangrene or pregangrene of the feed associated with palpable peripheral pulses have been treated with the platelet suppressive drugs aspirin and dipyridamole. Sulphinpyrazone was substituted for two patients who could not tolerate aspirin. Complete reversal of the signs and symptoms occurred in more than 50% of the treated patients. Recurrence of pain occurred in the five patients in whom antiplatelet therapy was discontinued. Reversal of symptoms was again achieved by reintroduction of the drugs. An increased incidence of spontaneous platelet aggregation and hypersensitive platelets was observed in those patients who responded to platelet suppressive therapy. These results indicate that platelet suppressive therapy is of therapeutic value in selected patients with peripheral gangrene.

Aged↗
PubMed1981

Plasmid specifying total degradation of 3-chlorobenzoate by a modified ortho pathway.

A plasmid, termed pAC25, specifying biodegradation of 3-chlorobenzoate in a strain of Pseudomonas putida has been characterized. During growth of the plasmid-harboring cells with 3-chlorobenzoate, there was an accumulation of 3-chlorocatechol and beta-chloromuconic acid as intermediates and release of more than 80% of the chlorine in the form of inorganic chloride. The plasmid had a mean molecular mass of 68 x 10(6) daltons and was transmissible to a number of Pseudomonas species such as P. aeruginosa, P. putida strain PpG1, and P. putida strain PRS1. Transfer of pAC25 to various catechol-negative mutants of P. putida strain PRS1 showed that the chromosomally coded pyrocatechase was not complemented by the plasmid-specified pyrocatechase, which appeared to be specific for the chlorinated catechols. In contrast to benzoate, which was metabolized by the ortho pathway through beta-ketoadipate as an intermediate, the plasmid specified ortho cleavage of the chlorocatechols through maleylacetate as an intermediate.

Catechol 1,2-Dioxygenase↗
PubMed1980

Studies on peroxidase-catalysed formation of thyroid hormones on a protein isolated from submaxillary gland.

A protein has been solubilized and purified to homogeneity from the microsomal fraction of goat submaxillary gland. This protein can preferentially be iodinated to form triidothyronine and thyroxine with the help of submaxillary peroxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7) solubilized and purified from the same microsomal fraction. The protein can also be isolated from soluble supernatant and was found to be identical to the microsomal protein as judged by their moelcular properties as well as the formation of triiodothyronine and thyroxine. The protein has the molecular weight of 120 000 and contains two unequal subunits of molecular weight of 80 000 and 44 000. The molecular weight of the peroxidase is 72 000 and consists of a single polypeptide chain. The enzyme has the Rz value of 0.4 and is inhibited by azide and cyanide. Mersalyl, a mercurial, strongly inhibits the enzyme activity while N-ethylmaleimide cannot. The enzyme can catalyze the formation of 62 mumol of I3-/min per mg of protein at its optimun pH of 5.2. The apparent Km for H2O2 and KI is 0.16 . 10(-3) M and 1 . 10(-3) M, respectively.

Animals↗