• KSBB Journal
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• 제17권3호
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• pp.302-306
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• 2002

탈황공정에 많이 이용되는 미생물인 Rhodococcus sp. Strain IGTS8이 hexadecane과 배지 수용액 혼합물에서 생성하는 biosurfactant의 성분분석과 계면물성을 연구하였다. TLC를 이용한 정성적 성분분석 결과 생성되는 biosurfactant는 glucose mycolate와 trehalose monomycolate임을 확인하였고 임계 미셀농도는 pH 6∼6.5와 pH 10∼10.5에서 100 mL의 수용액에 biosurfactant가 0.1∼0.15 g 첨가될 때였으며 유화파괴 속도는 pH가 높을수록 증가하였다.

• KSBB Journal
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• 제17권3호
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• pp.295-301
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• 2002

본 연구에서는 Rhodococcus sp. strain IGTS8을 이용한 미생물 탈황공정에 있어서 비이온 계면활성제인 SPAN의 영향을 조사하였다. 탈황 효율 연구에 있어서 모델 오일로는 DBT가 함유된 hexadecane, 수상으로는 배지 용액을 이용하였다. 연구에 있어서 실험 변수로는 오일/물 혼합물에 있어서 오일의 부피 %, SPAN 20의 농도, 용액의 pH로 하였으며 일반적으로 오일의 부피 비율, 계면활성제의 농도가 증가할 수록 탈황 효율이 감소되었다. 이러한 결과는 오일의 부피비가 증가할수록 계면활성제의 농도가 증가할수록 오일상의 OBT와 균주의 효율적인 접촉이 저해되기 때문으로 고려된다.

• 대한환경공학회지
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• 제28권2호
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• pp.144-149
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• 2006

Hexane을 유일 탄소 에너지원으로 하여 농화배양한 배양액으로부터 hexane 분해능이 우수한 EH741 균주를 순수 분리 동정하였고, 분리균주에 의한 hexane 생분해 특성을 조사하였다. EH741 균주는 Rhodococcus sp.로 동정되었고, 액상 배양계에서 hexane 용해도를 향상시키기 위해 첨가한 계면활성제 Pluronic F68(PF68)은 hexane 생분해 속도에 영향을 미치지 않았다. Hexane을 유일 탄소원으로 첨가한 무기염 배지에서 EH741의 최대 비성장속도(${\mu}_{max}$)값은 $0.04h^{-1}$이었고, 최대 hexane 분해속도($V_{max}$)와 포화상수($K_s$)는 각각 $161{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$ 및 10.5 mM이었다. Rhodococcus sp. EH741은 hexane 처리를 위한 생물학적 공정에 유용하게 활용될 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.605-612
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• 2006

A psychrotrophic bacterium was isolated from oil-contaminated groundwater and identified as Rhodococcus sp. YHLT-2. Growth was observed at the temperature of 4 to $30^{\circ}C$. This strain degraded various petroleum hydrocarbons such as crude oil, diesel oil, and gasoline over the whole range of temperatures tested. The Rhodococcus sp. YHLT-2 was capable of growing even at $4^{\circ}C$, exhibiting 90% of oil biodegradation after 20 days. Degradation of crude oil occurred at low temperature in nature. This strain was also able to grow at 7% NaCl, and utilized not only short chain alkenes $(C_9\;to\;C_{12})$, but also a broad range of long chain alkenes $(C_{19}\;to\;C_{32})$ present in crude oil at $4^{\circ}C$. The Rhodococcus sp. YHLT-2 is expected to be of potential use in the in situ bioremediation of hazardous hydrocarbons under low-temperature and high-salt conditions.

• 한국환경과학회지
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• 제11권9호
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• pp.971-977
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• 2002

The isolated strain, Rhodococcus sp. EL-GT was able to degrade high phenol concentrations up to 10 mM within 24 hours in the medium consisting of 5.3 mM $KH_2PO_4$. 95 mM $Na_2HPO_4$, 18mM $NH_4NO_3$, 1 mM $MgSO_4{\cdot}7H_2O$,\;50{\mu}M CaCl_2$,\;0.5 {\mu}M FeCl_3$, initial pH 8.0, temperature $30^{\circ}C$ in rotary shaker at 200 rpm. This strain was good cell growth and phenol degradation in the alkaline pH range range, and the highest in the pH range of 7 to 9. The microorganism was able to grow at the various chlorinated phenols, benzene, toluene, and bunker-C oil. As Rhodococcus sp. EL-GT was good capable of attachment on the acryl media, it would be used as microorganism to consist of biofilm in wastewater treatment.

• 환경생물
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• 제19권1호
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• pp.87-92
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• 2001

For the biological treatment of industrial wastewater containing high concentration of phenol, isolation and characterization of phenol - degrading bacterium were carried out. A bacterial strain P2 capable of degrading phenol was isolated from contaminated soils by enrichment culture technique and identified as the genus Rhodococcus by morphological, cultural, biochemical characteristics, and Biolog system. The optimal medium composition and cultural conditions for the growth and degradation of phenol by Rhodococcus sp. P2 were 0.1% of (NH$_4$)$_2$SO$_4$, 0.2% of KH$_2$PO$_4$, 0.25% of Na$_2$HPO$_4$ㆍ12$H_2O$, 0.2% of MgSO$_4$ㆍ7$H_2O$, and 0.008% of CaC1$_2$ㆍ2$H_2O$ along with initial pH 8.5 at 3$0^{\circ}C$. Rhodococcus sp. P2 could grow with phenol as the sole carbon source up to 1,800 ppm in batch cultures, but did not grow in medium containing above 2,000 ppm of phenol. When 800 ppm phenol was given in the optimal media, Rhodococcus sp. P2 completely degraded it within 24 h. Meanwhile, 1,800 ppm of phenol was degraded within 9 days. Rhodococcus sp. P2 could utilize toluene, n-hexane, xylene and benzene as sole carbon source .

• Journal of Microbiology
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• 제40권1호
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• pp.86-89
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• 2002

Rhodococcus sp. strain T104, which is able to grow on either biphenyl or limonene, was found to utilize phenol as sole carbon and energy sources. Furthermore, T104 was positively identified to possess three separate pathways for the degradation of limonene, phenol, and biphenyl. The fact that biphenyl and limonene induced almost the same amount of catechol 1,2-dioxygenase activity indicates that limonene can induce both upper and lower pathways for biphenyl degradation by T104.

• Journal of Microbiology
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• 제42권2호
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• pp.160-162
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• 2004

Rhodococcus sp. strain T104 is able to utilize both limonene and biphenyl as growth substrates. Fur-thermore, T104 possesses separate pathways for the degradation of limonene and biphenyl. Previously, we found that a gene(s) involved in limonene degradation was also related to indigo-producing ability. To further corroborate this observation, we have cloned and sequenced a 8,842-bp genomic DNA region with four open reading frames, including one for indole oxygenase, which converts indole to indigo (a blue pigment). The reverse transcription PCR data demonstrated that the identified indole oxygenase gene is specifically induced by limonene, thereby implicating this gene in the degradation of limonene by T104.

• 미생물학회지
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• 제49권3호
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• pp.297-300
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• 2013

인삼근계(근권, 근면, 근내부) 내 EPS 생성세균의 밀도를 측정한 결과, 근권토양 내에는 $2.4{\times}10^6$ CFU/g, 근면에는 $9.1{\times}10^6$ CFU/g, 그리고 근내부에는 $2.0{\times}10^4$ CFU/g로 확인되어 다수의 EPS 생성세균이 분포하고 있음이 확인되었다. 인삼 근계로부터 EPS 생성 우수 균주 24균주를 순수분리하고 계통학적 특성을 확인한 결과, 근권(RS)으로부터 분리된 EPS 생성세균은 Arthrobacter 속 6균주, 그리고 Rhizobium 속 1균주로 나타났다. 근면(RP)으로 부터 분리된 EPS 생성세균은 Arthrobacter 속 6균주, Rhodococcus 속 1균주, Pseudomonas 속 1균주로 나타났다. 근내부(IR)에서 분리된 EPS 생성세균은 Rhizobium 속 6균주, Bacillus 속 1균주 그리고 Rhodococcus 속 1균주, Pseudomonas 속 1균주로 나타났다. 근권과 근면에서 분리된 EPS 세균 중 Arthrobacter 속에 속하는 균주는 가장 특징적인 세균으로 밝혀졌으며, Rhizobium 속은 근내부에서 분리된 가장 특징적인 EPS 생성세균으로 나타났다. EPS 생성 우수균주 Rhizobium sp. 1NP2 (KACC 17637)는 10 g/L 그리고 Arthrobacter sp. 5MP1 (KACC 17636)는 4.9 g/L의 다당을 생성하였으며, 당단백질의 구성당 성분을 확인한 결과, galactose, glucose, mannose를 구성하고 있었으며, glucosamine의 아미노당이 나타났다. 특히, glucose는 72.7-84.9%로 주요 구성당임이 확인되었다.

• Journal of Microbiology
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• 제41권4호
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• pp.349-352
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• 2003

Recent studies have shown that some of the PCB (polychlorinated biphenyl)-degraders are able to effectively degrade PCB in the presence of monoterpenes, which act as inducers for the degradation pathway. Rhodococcus sp. T104, an effective PCB degrader, has been shown to induce the degradation pathway by utilizing limonenes, cymenes, carvones, and pinenes as sole carbon sources which can be found in the natural environment. Moreover, the strain T104 proved to possess three separate oxidation pathways of limonene, biphenyl, and phenol. Of these three, the limonene can also induce the biphenyl degradation pathway. In this work, we report the presence of three distinct genes for aromatic oxygenase, which are putatively involved in the degradation of aromatic substrates including biphenyl, limonene, and phenol, through PCR amplification and denaturing gradient gel electrophoresis (DGGE). The genes were differentially expressed and well induced by limonene, cymene, and plant extract A compared to biphenyl and/or glucose. This indicates that substrate specificity must be taken into account when biodegradation of the target compounds are facilitated by the plant natural substrates.