• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.244-251
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• 2015

BACKGROUND: Recent studies have described the importance of bacteria that can degrade polycyclic aromatic hydrocarbons (PAHs). Here we screened bacterial isolates from commercial gasoline for PAH degraders and characterized their ability to degrade PAHs, lipids and proteins as well as their enantioselective epoxide hydrolase activity, salt tolerance, and seawater survival. METHODS AND RESULTS: One hundred two bacteria isolates from commercial gasoline were screened for PAH degraders by adding selected PAHs on to the surface of agar plates by the sublimation method. A clear zone was found only around the colonies of PAH degraders, which accounted for 13 isolates. These were identified as belonging to Bacillus sp., Brevibacterium sp., Micrococcus sp., Corynebacterium sp., Arthrobacter sp., and Gordonia sp. based on 16S rRNA sequences. Six isolates belonging to Corynebacterium sp., 3 of Micrococcus sp., Arthrobacter sp. S49, and Gordonia sp. H37 were lipid degraders. Arthrobacter sp. S49 was the only isolate showing high proteolytic activity. Among the PAH-degrading bacteria, Arthrobacter sp. S49, Brevibacterium sp. S47, Corynebacterium sp. SK20, and Gordonia sp. H37 showed enantioselective epoxide hydrolase activity with biocatalytic resolution of racemic styrene oxide. Among these, highest enantioselective hydrolysis activity was seen in Gordonia sp. H37. An intrinsic resistance to kanamycin was observed in most of the isolates and Corynebacterium sp. SK20 showed resistance to additional antibiotics such as tetracycline, ampicillin, and penicillin. CONCLUSION: Of the 13 PAH-degraders isolated from commercial gasoline, Arthrobacter sp. S49 showed the highest lipid and protein degrading activity along with high active epoxide hydrolase activity, which was the highest in Gordonia sp. H37. Our results suggest that bacteria from commercial gasoline may have the potential to degrade PAHs, lipids, and proteins, and may possess enantioselective epoxide hydrolase activity, high salt tolerance, and growth potential in seawater.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.99-103
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• 1996

A bacterial strain producing a novel endo-inulinase, hydrolysing inulin into oligosaccharides was isolated from soil and identified as Arthrobacter sp. S37 The enzyme production was induced by inulin and jerusalem artichoke extract. The maximum enzyme production was obtained with medium containing 1.5% jerusalem artichoke extract, 1.0% yeast extract, $0.5%\;NaNO_3,\;0.05%\;MgSO_4{\cdot}7H_2O,\;0.05%\;KCl,\;0.0016%\;FeCl_3{\cdot}6H_2O\;and\;0.05%\;KH_2PO_4$. The optimum temperature and pH for the enzyme production were $30^{\circ}C$ and 8.0, respectively. Under the optimum condition, the enzyme activity in the culture broth reached at maximum, 10.8 units/ml after cultivation for 24 hours.

• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.71-74
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• 1999

The crude enzyme prepared from the culture supernantant of Arthrobacter sp. S37 was purified by Phenyl Toyopearl column chromatography. Six endo-inulinases were detected by activity staining on native PAGE and named Inu I to Inu VI. Endo-inulinase were further purified by DEAE cellulose column chromatography and band slicing. Inu II~VI produced mainly inulotriose (F3) and inulotetraose (F4) as well as a small amount of inulobiose (F2) and fructose in contrast to Inu I producing F3, F4 and F5 from inulin. The N-terminal amino acid sequence of native and six CNBr-cleaved fragment of Inu VI were determined. No homology was found in amino acid sequences between Inu VI and other fructan hydrolase including invertase reported.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1875-1879
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• 2007

Strain $CH7^T$, a pale yellow-pigmented bacterium and new isolate from deep subsurface water of the South Coast of Korea, was subjected to a polyphasic taxonomic study. $CH7^T$ grew between 5 and $37^{\circ}C$, pH 5.3-10.5, and tolerated up to 13% NaCl. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain $CH7^T$ was associated with the genus Arthrobacter and phylogenetically closely related to the type strains Arthrobacter tumbae (99.4%) and Arthrobacter parietis (99.1%). However, DNA-DNA hybridization experiments revealed 2.1% and 12% between strain $CH7^T$ and Arthrobacter tumbae and Arthrobacter parietis, respectively. Thus, the phenotypic and phylogenetic differences suggested that $CH7^T$ should be placed in the genus Arthrobacter as a novel species, for which the name Arthrobacter subterraneus sp. novo is proposed. In addition, the type strain for the new species is $CH7^T$ ($=KCTC\;9997^T=DSM\;17585^T$).

• Applied Biological Chemistry
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• v.40 no.1
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• pp.34-38
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• 1997

For the effective production of functional oligosaccharides(DP 3-5) from inulin in chicory extracts, the acid hydrolysis and enzymatic endo-inulinase reaction were compared. Acid hydrolysis was unfavorable ; the content of oligosacharides in total sugar increased to 26.0% for 12 min at $55^{\circ}C$ and 24.6% at 6 min at $65^{\circ}C$ and showed little change for 30 min. The content of high DP(DP 6) decreased from 83.5 to 49.5% and 23.0% for 30 min, repectively. Glucose, fructose and sucrose increased to 24.6% and 50.3%, respectively. Hydrolysis of chicory extracts with purified endo-inulinase from Arthrobacter sp. S37 was carried out at $40^{\circ}C$ and pH 7.5 for 44 hrs. The content of high DP($DP{\geq}6$) in total sugar decreased from 83.5 to 23.0% and that of inulobiose(F2) and DP 3-5 increased to 66.1%. Glucose, fructose and sucrose were not produced. The hydrolysis of chicory extracts without DP 1 and DP 2 with crude or with purified enzyme were also carried out. In contrast to the hydrolysate of crude enzyme, that of purified endo-inulinase did not contain glucose, fructose, sucrose, F2 and 1-kestose(GF2). The content of oligosaccharides in the hydrolysate of the purified endo-inulinase were 79.2%, composed mainly of inulotriose(F3), inulotetraose(F4) and inulopentaose(F5), which shows that the enzymatic hydrolysis using purified endo-inulinase from Arthrobacter sp. S37 is the best method for oligosaccharides production from inulin in chicory extracts.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.109-111
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• 2010

Recent studies have described various microorganisms that can degrade PAH, however, there are currently limited methods available to screen for PAH-degrading microorganisms. To screen for PAH-degrading microorganisms, a sublimation method (Alley, Jeremy F. and Lewis R. Brown. 2000. Appl. Environ. Microbiol. 66, 439-442) was modified to produce a simple screening system. In our results, there were several bacterial species capable of pyrene degradation including genera, Coryenbacterium, Gordonia, Rhodococcus, and Streptomyces, which have been screened from 350 bacterial isolates of commercial gasoline and oil-spilled sediment by the sublimation method. The main advantage of this method is that it (i) safely deposits an even, thin and visible layer of PAH onto the agar surface without the use of solvents and (ii) the quantity of PAH sublimed onto the agar can be easily controlled. Overall, this sublimation method may be an effective and simple technique to screen for PAH-degrading microorganisms.