• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.242-247
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• 1991

- Since steroid $\Delta^1$-dehydrogenase synthesis has been known to be inducible, the mechanism of the enzyme induction of Arthrobacter simplex IAM 1660 was investigated. Among various steroids tested for inducers, hydrocortisone was the most effective inducer when hydrocortisone was used as a substrate for steroid $\Delta^1$-dehydrogenase. Steroid $\Delta^1$-dehydrogenase synthesis was effectively induced by progesterone, prednisolone and androstenedione, while the enzyme was less induced by cholesterol and not by phytosterols. The results suggest that the presence of 3-keto group and short side chain of steroids are the favorable factors for the induction of the $\Delta^1$-dehydrogenase synthesis. The enzyme was induced at the highest level when hydrocortisone was added at early log phase to the concentration of 0.01% of the culture and the culture was grown for 15 hours.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1428-1438
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• 2016

In the present work, Arthrobacter sp. 25, a lead-tolerant bacterium, was assayed to remove lead(II) from aqueous solution. The biosorption process was optimized by response surface methodology (RSM) based on the Box-Behnken design. The relationships between dependent and independent variables were quantitatively determined by second-order polynomial equation and 3D response surface plots. The biosorption mechanism was explored by characterization of the biosorbent before and after biosorption using atomic force microscopy (AFM), scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the maximum adsorption capacity of 9.6 mg/g was obtained at the initial lead ion concentration of 108.79 mg/l, pH value of 5.75, and biosorbent dosage of 9.9 g/l (fresh weight), which was close to the theoretically expected value of 9.88 mg/g. Arthrobacter sp. 25 is an ellipsoidal-shaped bacterium covered with extracellular polymeric substances. The biosorption mechanism involved physical adsorption and microprecipitation as well as ion exchange, and functional groups such as phosphoryl, hydroxyl, amino, amide, carbonyl, and phosphate groups played vital roles in adsorption. The results indicate that Arthrobacter sp. 25 may be potentially used as a biosorbent for low-concentration lead(II) removal from wastewater.

• 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.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.142-144
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• 1996

To clone the gene coding for steroid $\Delta^1$-dehydrogenase of Arthrobacter simplex, its genomic library was constructed with a , $\lambda$gt11 expression vector and immunoscreened with antiserum against the enzyme. One positive clone was found to carry a 1.6-kb EcoR I restriction endonuclease fragment of A. simplex DNA. The restriction map of the 1.6-kb EcoR I fragment was determined after cloning of the DNA into pBS vector.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.156-160
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• 2000

In an attempt to develop an unique enzyme (inulinase) for fructan utilization. bacterial strains were isolated [yom soil. Stram 96-11 secreting inulinase o[ high activity was tentatively identificated as Arthrobacter protophmmiae/ranwsus. The optimum culture conditions o[the slnin for the production of the inulinase were as follow: inorganic saIl basal medium contained sources fl % (w/v) inulin, 1 % (w/v) tryptone, and 1 % (w/v) $NH_4Cl$]. $35^{\circ}C$, initial pH 7.5. aeration 1 vvm and agitation 200 rpm.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.29-33
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• 1997

The efficient production of glucose isomerase (G. I0.) produced form Arthrobacter sp. L-3 was studied. The optimum culture time of the enzyme was 40hr. The maximum enzyme activity was found at glucose concentration 1%. G. I. activity did not affect inoculum size. The glucose isomerase activity was strongly influenced by the addition of glucose.

• The Korean Journal of Food And Nutrition
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• v.4 no.2
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• pp.155-160
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• 1991

Authrobacter sp. L-3이 생성하는 glucose isomerase를 DEAE-cellulose column chromatography법으로 2단계 NaCl농도 구배로 용출함으로서 순수분리하였다. 이것이 SDS-acrylamide gel electrophoresis상에서 단일띠를 보임으로서 매우 잘 분리되었음을 알 수 있었다. Glucose isomerase의 Km값과 Vmax값이 각각 0.175M, 0.29로 얻어졌다. 한편, SDS-acrylamide gel electrophoresis와 Sephadex-G10050에 의한 gel filtration으로부터 분자량이 각각 42,000과 180,000으로 얻어져, 이 효소는 분자량이 42,500인 4개의 subunit로 구성되었음을 알 수 있었다.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.207-212
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• 1992

To develope the new strains of microorganisms having the degradative ability for various aromatic hydrocarbons. spheroplast cell fusions were performed with Arthrobacter spp. degrading phthalate ester and Pseudomonas putida degrading alkylbenzen sulfonate(ABS) and the characteristics of the fusants were investigated. The spheroplasts of P. putia KUD15 and Arthrobacter sp. were formed effectively by lysozyme-EDTA treatment and by Ampicillin-lysozyme-EDTA treatment. respectively. The Spheroplast formation frequency and the regeneration frequency of the strains were 98-99% and 5-8%, respectively. For cell fusion. 40% PEG6000 was used as a fusogenic agent and the formation frequencies of fusion product were $1.8{\times}10^{4}-$2.9{\times}10^{4}$ Most of the fusants, which were selected in complemented antibiotics media showed the degradative ability in minimal selective medium added phthalate ester or ABS as sole carbon source. ABS degradation by fusant strain was increased about 20% with compared with the parental strain, while the degradative ability of phthalate ester was simillilar to that of parental strain.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1439-1446
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• 2009

Isocarbophos is a widely used organophosphorus insecticide that has caused environmental pollution in many areas. However, degradation of isocarbophos by pure cultures has not been extensively studied, and the degradation pathway has not been determined. In this paper, a highly effective isocarbophos-degrading strain, scl-2, was isolated from isocarbophos-polluted soil. The strain scl-2 was preliminarily identified as Arthrobacter sp. based on its morphological, physiological, and biochemical properties, as well as 16S rDNA analysis. The strain scl-2 could utilize isocarbophos as its sole source of carbon and phosphorus for growth. One hundred mg/l isocarbophos could be degraded to a non detectable level in 18 h by scl-2 in cell culture, and isofenphos-methyl, profenofos, and phosmet could also be degraded. During the degradation of isocarbophos, the metabolites isopropyl salicylate, salicylate, and gentisate were detected and identified based on MS/MS analysis and their retention times in HPLC. Transformation of gentisate to pyruvate and fumarate via maleylpyruvate and fumarylpyruvate was detected by assaying for the activities of gentisate 1,2-dioxygenase (GDO) and maleylpyruvate isomerase. Therefore, we have identified the degradation pathway of isocarbophos in Arthrobacter sp. scl-2 for the first time. This study highlights an important potential use of the strain scl-2 for the cleanup of environmental contamination by isocarbophos and presents a mechanism of isocarbophos metabolism.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.602-608
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• 2010

An atrazine-degrading bacterium, strain KU001, was obtained from a sugarcane field at the Cane and Sugar Research and Development Center at the Kasetsart University, Kamphaeng Saen Campus, Thailand. Strain KU001 had a rod-to-coccus morphological cycle during growth. Biolog carbon source analysis indicated that the isolated bacterium was Arthrobacter histidinolovorans. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KU001 was 99% identical to the same region in Arthrobacter sp. The atrazine degradation pathway in strain KU001 consisted of the catabolic genes trzN, atzB, and atzC. Strain KU001 was able to use atrazine as a sole nitrogen source for growth, and surprisingly, atrazine degradation was not inhibited in cells grown on ammonium, nitrate, or urea, as compared with cells cultivated on growth-limiting nitrogen sources. During the atrazine degradation process, the supplementation of nitrate completely inhibited atrazine degradation activity in strain KU001, whereas ammonium and urea had no effect on atrazine degradation activity. The addition of strain KU001 to sterile or nonsterile soils resulted in the disappearance of atrazine at a rate that was 4- to 5-fold more than that achieved by the indigenous microbial community. The addition of citrate to soils resulted in enhanced atrazine degradation, where 80% of atrazine disappeared within one day following nutrient supplementation.