• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.218.2-219
• /
• 2003

2-Hydroxymuconic semialdehyde dehydrogenase catalyzes the conversion of 2-hydroxymuconic semialdehyde (HMS) to an enol form of 4-oxalocrotonate which is a step in the catechol-meta cleavage pathway. A tomC gene encoding 2-HMS dehydrogenase of Burkholderia cepacia G4, a soil bacterium that can grow on toluene, cresol, phenol or tricholoro ethylene, is identified in between catechol 2,3-dioxygenase gene and HMS hydrolase gene, its sequence is analysed and the enzyme is characterised. (omitted)

• Journal of Life Science
• /
• v.25 no.5
• /
• pp.515-522
• /
• 2015

Treculia africana Decne, a breadfruit species, is native to many parts of West and Tropical Africa. The breadfruit belongs to the family Moraceae and is one of the four members of the genera Treculia. The crude extract of T. africana has been used in folk medicine as an anti-inflammatory agent for various ailments, such as whooping cough. In this study, we evaluated the anti-oxidative and anti-cancer activities of the methanol extract of T. africana Decne (META) and the molecular mechanisms of its anti-cancer effects in human colon carcinoma HT29 cells. The META exhibited anti-oxidative activity through a DPPH radical scavenging capacity and inhibited cell growth in a dose-dependent manner in HT29 cells. META treatment induced apoptosis of HT29 cells, showing an increase in the percentage of both SubG1 cells and Annexin V-positive cells and the formation of apoptotic bodies in a dose-dependent manner. META-mediated apoptosis was associated with the up-regulation of the death receptor FAS and Bax and a decrease in the Bcl-2 expression. META-treated HT29 cells also showed the release of cytochrome c from the mitochondria into the cytosol, activation of caspase-3, caspase-8, and caspase-9, and proteolytic cleavage of poly ADP-ribose polymerase (PARP). These findings suggest META may exert an anti-cancer effect in HT29 cells by inducing apoptosis through both intrinsic and extrinsic pathways.

• Korean Journal of Microbiology
• /
• v.32 no.1
• /
• pp.40-46
• /
• 1994

The pcb genes of Pseudomonas sp. DJ-12 coded for the catabolism of polychlorinated biphenyl (PCBs) and biphenyl. The products of the pcbCD genes were 2,3-dihydroxy-4'-chlorobiphenyl dioxygenase and meta-cleavage product (MCP) hydrolase, which acted on degradation of 2,3-dihydroxy-4'-chlorobiphenyl to 4-chlorobenzoate. The pcbCD genes were cloned in E. coli XLl-Blue, and then the pcbD gene was further subcloned. As a metabolite transformed from 2,3-dihydroxybiphenyl by the cloned cell of E coli CU103, benzoate was detected by the resting cell assay. The enzyme activities of 2,3-dihydroxybiphenyl dioxygease and MCP hydrolase produced in the cloned cells E. coli CU103 and CU105 were about 17 and 3 times higher than those of Pseudomonas sp. DJ-12, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.6
• /
• pp.804-810
• /
• 1999

There is a possibility that carvone, a monoterpene from spearmint (Mentha spicata), could induce the bph degradative pathway and genes in Alcaligenes eutrophus H850, which is a known Gram-negative PCB degrader with a broad substrate specificity that was thoroughly investigated with Arthrobacter sp. BIB, a Gram-positive PCB degrader. The strains BIB and H850 were unable to utilize and grow on the plant terpene [(R)-(-)-carvone] (50ppm) to be recognized as a sole carbon source. Nevertheless, the carvone did induce 2,3-dihydroxybiphenyl 1,2-dioxygenase (encoded by bphC) in the strain B lB, as observed by a resting cell assay that monitors accumulation of a yellow meta ring fission product from 4,4'-dichlorobiphenyl (DCBp). The monoterpene, however, did not appear to induce the meta cleavage pathway in the strain H850. Instead, an assumption was made that the strain might be using an alternative pathway, probably the ortho-cleavage pathway. A reverse transcription (RT)-PCR system, utilizing primers designed from a conserved region of the bphC gene of Arthrobacter sp. M5, was employed to verify the occurrence of the alternative pathway. A successful amplification (182bp) of mRNA transcribed from the N-terminal region of the bphC gene was accomplished in H850 cells induced by carvone (50ppm) as well as in biphenyl-growth cells. It is, therefore, likely that H850 possesses a specific PCB degradation pathway and hence a different substrate specificity compared with B1B. This study will contribute to an elucidation of the dynamic aspects of PCB bioremediation in terms of roles played by PCB degraders and plant terpenes as natural inducer substrates that are ubiquitous and environmentally compatible.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.2
• /
• pp.267-270
• /
• 2002

Photodissociations of o-, m-, and p-iodotoluene radical cations were investigated by using Fourier-transform ion cyclotron resonance (FT-ICR) spectrometry. Iodotoluene radical cations were prepared in an ICR cell by a photoionization charge-transfer method. The time-resolved one-photon dissociation spectra were obtained at 532 nm and the identities of $C_7H_7^+$ products were determined by examining their bimolecular reactivities toward toluene-$d_8$. The two-photon dissociation spectra were also recorded in the wavelength range 615-670 nm. The laser power dependence, the temporal variation, and the identities of $C_7H_7^+$ were examined at 640 nm. The mechanism of unimolecular dissociation of iodotoluene radical cations is elucidated: the lowest barrier rearrangement channel leads exclusively to the formation of the benzyl cation, whereas the direct C-I cleavage channel yields the tolyl cations that rearrange to both benzyl and tropylium cations with dissimilar branching ratios among o-, m-, and p-isomers. With a two-photon energy of 3.87 eV at 640 nm, the direct C-I cleavage channel results in the product branching ratio, [tropylium cation]/[benzyl cation], in descending order, 0.16 for meta >0.09 for ortho >0.05 for para.

• Journal of Microbiology
• /
• v.38 no.2
• /
• pp.53-61
• /
• 2000

Hydroxybenzoic acids are the most important intermediates in the degradative pathways of various aromatic compounds. Microorganisms catabolize aromatic compounds by converting them to hydroxylated intermediates and then cleave the benzene nucleus with ring dioxygenases. Hydroxylation of the benzene nucleus of an aromatic compound is an essential step for the initiation and subsequent disintegration of the benzene ring. The incorporation of two hydroxyl groups is essential for the labilization of the benzene nucleus. Monohydroxybenzoic acids such as 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 4-hydrosybenzoic acid, opr pyrocattechuic acid that are susceptible for subsequent oxygenative cleavage of the benzene ring. These terminal aromatic intermediates are further degraded to cellular components through ortho-and/or meta-cleavage pathways and finally lead to the formation of constituents of the TCA cycle. Many groups of microorganisms have been isolated as degraders of hydroxybenzoic acids with diverse drgradative routes and specific enzymes involved in their metabolic pahtway. Various microorganisms carry out unusual non-oxidative decarboxylation of aromatic acids and convert them to respective phenols which have been documented. Futher, Pseudomonas and Bacillus spp. are the most ubiquitous microorganisms, being the principal components of microflora of most soil and water enviroments.

• Economic and Environmental Geology
• /
• v.30 no.2
• /
• pp.163-174
• /
• 1997

Precambrian metapelites and metapsammites of the Jinan-Osu area (so-called Seologri and Yongamsan Formation) consist of black slate, phyllite, mica schist, quartzite and rarely calc schist. They are intruded by Sunkagsan granite gneiss, Foliated granodiorite, Amphibolite, Sunchang foliated granite and Namwon granite. Mylonite texture, crenulation cleavage and minor shear zone are common. The meta-sedimentary rocks include various rock-fragments xenoliths in size (up to 3 cm) and rock-type. They have various porphyroblastic spots in size (up to 1 cm) and their mineral composition is different. The xenoliths are schists, granite and quartzite, which are rectangular or lens form and recrystallized muscovite, chlorite and quartz. Spots are andalusite and biotite aggregates extensively replaced by chlorite. The metamorphic terrain is divided into three zones of progressive metamorphism on the basis of mineral assemblage. They are chlorite zone, chloite-biotite zone and andalusite-biotite zone ascending order, from west to east approximately. Isograd reactions are phengitic muscovite + chlorite = less phengitic muscovite + biotite + quartz + $H_2O$ and muscovite + chlorite + quartz = andalusite + biotite + $H_2O$ between the chlorite zone and chlorite-biotite zone, and between the chloritebiotite zone and andalusite-biotite zone, respectively. Sample B6 (exposed near the Obong-ri) includes staurolites and greenish biotites, that is different in mineral assemblage and chemical composition from the meta-sedimentary rocks. Sample A12 (exposed near the Shinam-ri) has greenish white spots (up to 1 cm in diameter) mainly composed of Kfeldspar, quartz and sillimanite replaced by muscovite.

• Journal of Microbiology
• /
• v.37 no.2
• /
• pp.73-79
• /
• 1999

Pseudomonas sp. NGK1, isolated by naphthalene enrichment culture technique, is capable of degrading anthracene as a sole source of carbon and energy. The organism degraded anthracene through the intermediate formation of 1,2-dihydroxyanthracene, 2-hydroxy-3-naphthoic acid, salicylate, and catechol. The intermediates were isolated and characterized by TLC, spectrophotometry, and HPLC analysis. The cell free extract of anthracene-grown cells showed activities of anthracene dioxygenase, 2-hydroxy-3-naphthylaldehyde dehydrogenae, 2-hydroxy-3-naphthoate hydroxylase, salicylate hydroxylase and catechol 2,3-dioxygenase. The formed catechol as a metabolite is degraded through meta-cleavage with the formation of ${\alpha}$-hydroxymuconic semi-aldehyde.

• Journal of Microbiology and Biotechnology
• /
• v.7 no.4
• /
• pp.237-241
• /
• 1997

Two isolated strains, Comamonas testosteroni CPW301 and Arthrobacter ureafaciens CPR706, were able to use 4-chlorophenol (4-CP) as a sole carbon and energy source. CPW301 was found to degrade 4-CP via a meta-cleavage pathway in which the chloro-substituent was eliminated even when 4-chlorocatechol was cleaved by the catechol 2, 3-dioxygenase. In contrast, CPR706 removed chloride from 4-CP prior to the ring-fission reaction, producing hydroquinone as a transient intermediate during 4-CP degradation. CPR706 exhibited much higher tolerance for 4-CP than CPW301, which was indicated by the maximum degradable concentration and degradation rate.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.1
• /
• pp.96-100
• /
• 1998

Pseudomonas sp. S-47 degraded 4-chlorobenzoate (4CBA) to 4-chlorocatechol (4CC) that was subsequently ring-cleaved to form 5-chloro-2-hydroxymuconic semialdehyde. These intermediate compounds were identified by GC-mass spectrometry and UV-visible spectrophotometry. 5-chloro-2-hydroxymuconic acid converted from 5-chloro-2- hydroxymuconic semialdehyde (5C-2HMS) was dechlorinated to produce 2-hydroxypenta-2,4-dienoic acid (2HP-2,4DA) by the strain. These results indicate that Pseudomonas sp. S-47 degrades 4CBA to 2HP-2,4DA via a novel pathway including the meta-cleavage of 4CC and dechlorination of 5C-2HMS.