• BMB Reports
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• v.41 no.11
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• pp.790-795
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• 2008

An inducible lysine 6-dehydrogenase (Lys 6-DH), which catalyzes the oxidative deamination of the 6-amino group of L-lysine in the presence of $NAD^+$, was purified to homogeneity from Achromobacter denitrificans, yielding a homodimeric protein of 80 kDa. The enzyme was specific for the substrate L-lysine and $NAD^+$ served as a cofactor. The dimeric enzyme associated into a hexamer in the presence of 10 mM L-lysine. The $K_m$ values for L-lysine and $NAD^+$ were 5.0 and 0.09 mM, respectively. The lys 6-dh gene was cloned and overexpressed in E. coli. The open reading frame was 1,107 nucleotides long and encoded a peptide containing 368 amino acids with 39,355 Da. The recombinant enzyme was purified to homogeneity and characterized. Enzyme activities and kinetic properties of the recombinant enzyme were almost the same as those of the endogenous enzyme obtained from A. denitrificans. Crystals of the enzyme were obtained using the hanging drop method.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.189-195
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• 1997

The structural basis of Iysine specificity of Achromobacter protease I (API) was investigated by means of site-directed mutagenesis. The precursor protein in which Glu190, one of the two candidates for determining Iysine specificity, was substituted by glutamine, aspartic acid or leucine was processed autocatalytically to attaln full pretense activity with lysine specificity. The substitution of the other candidate, Asp225, for asparagine or leucine produced no mature active forms of pro-API. The precursor protein of the mutant D225E slowly matured autocatalytically. The lysylendopeptidase activity of the mature D225E was 0.25% of that of native API, and this reduced activity is mainly due to a decrease in the affinity of the enzyme for lysine. These results suggest that Asp225 plays a critical rol in restricted substrate specificity as a lysylendopeptidase. However, D225E exhibited no measurable activity for synthetic ornithine substrate. Since the hydroxyl group of Ser194 in this mutant retained essentially the same reactivity to DFP or PMSF as that in native API, it can be noted that a methylene unit longer side chain of residue 225 is not compensated by a methylene unit shorter side chain at subsite P1 in the bound substrate.

• Ocean and Polar Research
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• v.26 no.1
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• pp.51-58
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• 2004

We isolated and identified culturable Arctic bacteria that had inhabited soils around the Korean Arctic Research Station Dasan located at Ny-Alsund, Svalbard, Norway $(79^{\circ}N,\;12^{\circ}E)$. The collected soils were diluted in distilled water; the diluted soil-water was spread on 3M petri-films at Dasan Station. The petri-films were transported to the laboratory at KORDI, and cultured at $4^{\circ}C$. Colonies grown on the petri-films were subsequently cultured on nutrient agar plates at $4^{\circ}C$ every 7 days. The pure colonies were inoculated into nutrient liquid media, genomic DNA was extracted, and phylogenetic analysis was performed on the basis of 165 rDNA sequences. A total of 227 strains of bacteria were isolated. Among them, 16S rDNA sequences of 185 strains were identical with those of known strains isolated in this study, and 42 strains were finally identified. Phylogenetic analysis using 16S rDNA indicated that the 30 strains belonged to Pseudomonas, 7 strains to Arthrobacter, two strains to Flavobacterium, and the remaining to Achromobacter, Pedobacter, and Psychrobacter. Among the 42 strains, 14 bacteria produced protease: they were 6 strains of Pseudomonax, 4 strains of Arthrobater, an Achromobacter strain, 2 strains of Flavobacterium, and a Pedohacter strain. We expect these Arctic bacteria can be used for screening to develop new industrial enzymes that are active at low temperatures.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.742-753
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• 2012

Copper-containing compounds are introduced into the environment through agricultural chemicals, mining, and metal industries and cause severe detrimental effects on ecosystems. Certain microorganisms exposed to these stressors exhibit molecular mechanisms to maintain intracellular copper homeostasis and avoid toxicity. We have previously reported that the soil bacterial isolate Achromobacter sp. AO22 is multi-heavy metal tolerant and exhibits a mer operon associated with a Tn21 type transposon. The present study reports that AO22 also hosts a unique cop locus encoding copper homeostasis determinants. The putative cop genes were amplified from the strain AO22 using degenerate primers based on reported cop and pco sequences, and a constructed 10,552 base pair contig (GenBank Accession No. GU929214). BLAST analyses of the sequence revealed a unique cop locus of 10 complete open reading frames, designated copSRABGOFCDK, with unusual separation of copCD from copAB. The promoter areas exhibit two putative cop boxes, and copRS appear to be transcribed divergently from other genes. The putative protein CopA may be a copper oxidase involved in export to the periplasm, CopB is likely extracytoplasmic, CopC may be periplasmic, CopD is cytoplasmic/inner membrane, CopF is a P-type ATPase, and CopG, CopO, and CopK are likely copper chaperones. CopA, B, C, and D exhibit several potential copper ligands and CopS and CopR exhibit features of two-component regulatory systems. Sequences flanking indicate the AO22 cop locus may be present within a genomic island. Achromobacter sp. strain AO22 is thus an ideal candidate for understanding copper homeostasis mechanisms and exploiting them for copper biosensor or biosorption systems.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.208-215
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• 2005

This study was accomplished in order to collect fundamental data on microbial roles in recycling process of reed rhizosphere. Sunchon bay, which is considered as one of the marsh and mud environments severely affected by human activities such agriculture and fisheries, was selected as a model place. In our initial efforts, two bacterial consortia were obtained by enrichment culture using PAH mixtures containing anthracene, naphthalene, phenanthrene and pyrene as the sources of carbon and energy, and four pure bacteria capable of rapid degradation of PAH were isolated from them. Four strains designated as SCB1, SCB2, SCB6, and SCB7 revealed by morphological, physiological and molecular analyses were identified as Burkholderia anthina, Alcaligenes sp., Achromobacter xylosoxidans., and Pseudomonas putida, respectively with over $99{\%}$ confidence. Notably, Burkholderia anthina SCB1 and Alcaligenes sp. SCB2 were found to utilize anthracene and pyrene more quickly than naphthalene and phenanthrene, whereas Achromobacter xylosoxidans SCB6 and Pseudomonas putida SCB7 exhibited similar growth and degradation patterns except for pyrene. These facts suggest that the rhizosphere microorganisms capable of PAH degradation might be used to clean up the contamination sites with polycyclic aromatic hydrocarbons.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1975.12a
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• pp.182.3-183
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• 1975

본품에 의한 단백질 부해효소의 생산조건, 정제 및 특성을 조사해본 결과는 다음과 같다. 1) 0.5％ nylon oligomer, 0.3％ peptone, 0.1％ yeast extract 및 salt mixture를 함유한 배지에서 24시간 진탕배양 했을 때 가장 높은 생산율을 보여주었다.(중략)

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.96-100
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• 1992

The microbiological degradation of 2-(2-methyl-4-chloro-phenoxy) propionic acid (MCPP) was evaluated using mixed cultures of soil bacteria. The mixed cultures comprised Pseudomonas species, Flavobacterium species, and Achromobacter species. The bacteria used MCPP as the sole source of carbon and energy but only a partial degradation of the parent compound occurred MCPP degradation proceeded via the formation of 2-methyl-4-chlorophenol (2, 4-MCP) which was detected by high pressure liquid chromatography (PHLC) and confirmed by gas chromatography-mass sepctrometry. This intermediate occurred only transiently and no evidence was seen for the presence of other intermediates detectable by the reverse-phase HPLC or UV absorbance.

• KSBB Journal
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• v.14 no.2
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• pp.205-211
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• 1999

We investigated optimal conditions for the microbial transformation of $\gamma$-butyrobetaine into L-carnitine by using Achromobacter cycloclast ATCC 21921. When the cells were cultivated in the medium containing $\gamma$-butyrobetaine as the sole carbon source for both cell growth and L-carnitine production, the maximum L-carnitine production was 2.9 g/L and the conversion yield from $\gamma$-butyrobetaine to L-carnitine was as low as 30.9 mol%. In order to enhance the L-carnitine production and the conversion yield, various carbon sources were added to the $\gamma$-butyronetaine containing basal medium. In the medium supplemented with glycerol, L-carnitine production was as high as 4.6 g/L and the conversion yield was 88.2 mol%, showing a significant improvement in L-carnitine synthesis compared to those in the medium without glycerol. We also examined the additional effect of quaternary ammonium compounds such as betaine and choline, which are similar in structure to $\gamma$-butyrobetaine and L-carnitien. It was observed that in the presence of those quaternary ammonium compounds, both the L-carnitine production rate and the conversion yield increased. In addition, we found that cell growth was inhibited by a $\gamma$-butyrobetaine concentration of more than 3%, while L-carnitine production was efficient at the $\gamma$-butyrobetaine concentration of 2-3%. By cultivating the cells in the optimal medium containing glycerol and choline, we obtained an L-carnitine concentration of 7.2 g/L with the conversion yield of 98.7 mol% in 4 days.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.214-220
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• 2020

Handwashing with soap is an important practice to reduce the transmission of potentially pathogenic microorganisms, but liquid soaps with refillable dispensers are prone to extrinsic bacterial contamination. This study investigated the bacterial contamination of liquid soaps in 58 public restrooms in six buildings. The bacteria were identified by a biochemical test and MALDI-TOF mass spectrophotometry. The antimicrobial susceptibility was determined using the Vitek II system. Of the 58 restrooms examined, 27(46.55%) were using a refill dispenser, of which 25(92.59%) were contaminated with bacteria. The bacteria recovered from the soaps ranged from 1.6×10³ to 2.7×10⁵ CFU/mL. Serratia liquefaciens (12), Achromobacter xylosoxidans (9), S. marcescens (4), Staphylococcus pastueri (1), and Achromobacter spanius (1) were isolated. Except for one A. xylosoxidans, bacteria of the same species isolated in the same building showed a unique resistance pattern. In conclusion, handwashing with contaminated soap may play a role in the transmission of bacteria in public health settings. Therefore, it is necessary to limit the use of refillable liquid soaps in the restrooms of hospitals used by patients with reduced immunity.

• Applied Biological Chemistry
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• v.34 no.4
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• pp.299-306
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• 1991

When $[U-^{14}C]$ 3,3', 4,4'-tetrachloroazobenzene$([U-^{14}C]\;TCAB)$ was added to the $MM_2$ medium as a sole carbon source for the isolated microorganisms and incubated, some radioactive metabolites were detected by autoradiography. No $^{14}CO_2$ was evolved from $[U-^{14}C]\;TCAB$ which was added as a sole carbon source to an organic matter-free soil inoculated by the isolates, wetted with the $MM_2$ salt medium, and incubated at $30^{\circ}C$. One of the metabolites in pure culture of Achromobacter group VD, which was isolated and identified, was tentatively identified as a compound of m/z 250 by means of GC/MS. The possible pathways for its formation are thought to include dechlorination from the TCAB structure, hydroxylation, ortho fission of the two benzene rings, and reduction of the resulting carboxyl group.