• Journal of Life Science
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• v.25 no.12
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• pp.1458-1469
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• 2015

Many organic solvent-tolerant bacteria have been isolated from all environments such as soil, waste-water, even deep sea after first isolation report of organic solvent-tolerant bacterium. Most organic solvent- tolerant isolates have been determined to be Gram-negative bacteria, because Gram-negative bacteria have inherent tolerance property toward hostile organic solvents more than Gram-positive bacteria. The mechanisms of organic solvent tolerance have been elucidated extensively using mainly organic solvent-tolerant Gram-negative bacteria. The solvent-tolerance mechanisms in Gram-positive bacteria can be found in comparatively recent research. Organic solvents exhibited different toxicity depending on the solvent, and the tolerance levels of organic solvent-tolerant bacteria toward organic solvents were also highly changeable among species and strains. Therefore, organic solvent-tolerant bacteria could coped with solvent toxicity and adapted to solvent stress through the multifactorial and multigenic adaptative strategies. They could be survived even in the hyper concentrations of organic solvents by mechanisms which include: changes in cell morphology and cell behaviour, cell surface modifications, cell membrane adaptations, solvent excretion pumps, chaperones and anti-oxidative response. The aim of this work is to review the representative solvent tolerant bacteria and the adaptative and tolerance strategies toward organic solvents in organic solvent-tolerant bacteria, and their potential industrial and environmental impact.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.1
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• pp.31-36
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• 2003

8개의 수정진동자 위에 서로 다른 종류의 Lipid를 코팅하여서 만든 센서 배열을 가지고 유기용매를 인식할 수 있는 System을 구성한다. 유기용매 인식센서에 대한 수학적 모델을 사용하여 여러 가지 유기용매에 대한 센서의 응답으로부터 센서 표면과 유기용매 간의 물질 전달속도 패턴과 친화력 패턴을 얻어 유기용매 종류를 인식하였다. 패턴인식은 인공신경망을 이용하였으며 인공신경망의 연결 강도 수정은 Levenberg-Marquardt 알고리즘을 사용하였다. 신경망의 출력은 4개로 하였고, 디지털 신호인 0과 1의 조합으로 유기용매 종류를 구분하였다. 이 시스템을 이용하여 9개의 유기용매 Acetone, Benzene, Chloroform, Carbon-tetrachloride, Ethylacetate, Buthylacetate, Cyclohexane, Dichloromethane, 1,1,2,2,Tetrachloroethane, 2,2,4Trimethylpentane을 구분하여 인식할 수 있었다.

• The Microorganisms and Industry
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• v.20 no.1
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• pp.18-22
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• 1994

효소는 반응을 효율적으로 촉진시킬 뿐만 아니라 기질 및 입체특이성을 갖고 있어 광학활성 화합물을 합성하는데 매우 유용한 촉매이다. 효소 반응은 일반적으로 수용액에서 진해오디지만, 유기 용매를 포함하는 용액에서도 가능하다. 대부분의 유기 화학 반응이 유기 용매에서 진행된다는 점을 생각할 때, 유기 용매에서 효소 반응을 이용한 유기합성이 갈수록 중요해지고 있다. 본 글에서는 유기 용매에서 사용가능한 대표적인 효소인 지질 가수분해 효소(lipase)를 이용한 유기합성에 대해서 간략히 기술하고자 한다.

• Journal of Life Science
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• v.27 no.11
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• pp.1381-1392
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• 2017

This review described solvent-tolerant lipases and their potential industrial, biotechnological and environmental impacts. Although organic solvent-tolerant lipase was first reported in organic solvent-tolerant bacterium, many organic solvent-tolerant lipases are in not only solvent-tolerant bacteria but also solvent-intolerant bacterial and fungal strains, such as the well-known Bacillus, Pseudomonas, Streptomyces and Aspergillus strains. As these lipases are not easily inactivated in organic solvents, there is no need to immobilize them in order to prevent an enzyme inactivation by solvents. Therefore, the solvent-tolerant lipases have the potential to be used in many biotechnological and biotransformation processes. With the solvent-tolerant lipases, a large number insoluble substrates become soluble, various chemical reactions that are initially impossible in water systems become practical, synthesis reactions (instead of hydrolysis) are possible, side reactions caused by water are suppressed, and the possibility of chemoselective, regioselective and enantioselective transformations in solvent and non-aqueous systems is increased. Furthermore, the recovery and reuse of enzymes is possible without immobilization, and the stabilities of the lipases improve in solvent and non-aqueous systems. Therefore, lipases with organic-solvent tolerances have attracted much attention in regards to applying them as biocatalysts to biotransformation processes using solvent and non-aqueous systems.

• KSBB Journal
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• v.23 no.4
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• pp.340-344
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• 2008

Coprinus cinereus peroxidase (CiP) was often used as a catalyst for oxidative polymerization of a variety of phenol derivatives to produce a new class of polyphenols. Economical point of view, to know the mechanism of enzyme deactivation is significantly important because cost of enzyme is critically high. Hydrogen peroxide being used as oxidizing agent induced deactivation of peroxidase by destruction of heme structure. In the presence of hydrogen peroxide the stability of peroxidase was unexpectedly improved by adding organic solvent. Especially 2-propanol significantly improved enzyme stability among tested solvents. Radical scavenging by organic solvents may play a major role in protecting peroxidase from the oxidation of oxidizing radicals.

• Journal of Life Science
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• v.29 no.12
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• pp.1401-1407
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• 2019

To elucidate whether or not solvent-tolerant bacteria use anti-oxidative defense systems to defend themselves against toxic solvents, oxidative enzyme activity and total anti-oxidative capacity (T-AOC) were investigated in two tolerant strains of Pseudomonas sp. under toluene stress. The superoxide dismutase (SOD) activities of solvent tolerant BCNU 106 exhibited relatively increased levels at a toluene concentration of 100 mg/l, where those of solvent tolerant BCNU 171 increased at 200 mg/l. A greater than three-fold increase in catalase (CAT) levels was observed at concentrations of 200 and 300 mg/l in BCNU 106, and a two-fold increase was monitored at the same concentrations in BCNU 171. High glutathione S-transferase (GST) levels were also observed in the solvent tolerant bacteria. Higher levels of T-AOC was expressed in the solvent tolerant strains than in the ordinary non-tolerant KACC 10266. The highest plateau of SOD in BCNU 171 was observed at 1 hr of toluene exposure. CAT levels plateaued at 1 hr and 14 hr in BCNU 106 and reached the highest plateau at 3 hr in BCNU 171. The highest peak of T-AOC occurred at 9 hr in BCNU 106, and two high peaks occurred in BCNU 171, at 1 hr and at 9 hr of toluene exposure. The solvent-tolerant bacteria showed active antioxidant responses and could survive under harsh environments, including the presence of solvents, through means of antioxidant defense systems.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.490-494
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• 1985

The effect of organic solvents on the stability and catalytic activity of the microbial lipase from Rhizopus arrhizus for interesterification of fats and oils has been examined. The reaction system used was nonaqueous solvent system (two phase system). The solvents examined were 5 hydrocarbons (n-hexane, n-heptane, n-octane, isooctane, and cyclohexane) and 3 ethers (diethylether, diisopropylether, di-n-butylether). The results revealed that diisopropylether and isooctane are superior to the other solvents examined for interesterification of fats and oils in two phase systems.

• Journal of the Korean Chemical Society
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• v.53 no.3
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• pp.325-334
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• 2009

Many bacteria that are capable to tolerate and degrade organic solvents have been isolated from seawater. However, their roles in the biodegradation of organic solvents in the marine environment have remained unknown. Aeromonas hydrophila IB$B_{ct4}$, isolated from Constanta seawater, was able to tolerate and degrade different organic solvents. Toluene, styrene, xylene isomers, ethylbenzene, with the logarithm of the partition coefficient in octanol-water mixture (log $P_{ow}$) between 2.64 and 3.17, were more toxic for bacterial cells, compared with propylbenzene, n-hexane, n-heptane, with log $P_{ow}$ between 3.69 and 4.39. There were revealed cellular and molecular modifications induced by organic solvents to Aeromonas hydrophila IB$B_{ct4}$. The study of cellular and molecular modifications induced by different organic solvents showed a complex response of bacterial cells to the presence of organic solvents in the culture media.

• Membrane Journal
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• v.32 no.1
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• pp.50-56
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• 2022

In this work, the solvent permeation and separation performance of organic solvent nanofiltration (OSN) membranes were evaluated. Particularly, the PuraMem (PM) series developed for nonpolar solvents were analyzed and tested in dead-end filtration system. PM membranes exhibited higher permeance for nonpolar solvents compared to polar solvents, and their rejection data did not follow conventional trends with respect to solute size. The data showed that simple solution-diffusion model is not suitable to describe the OSN membrane behavior, and a better solvent-solute-membrane interaction parameter must be developed.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.128-132
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• 2016

Volatile organic solvents are used to extract the bioactive materials from raw materials for environmentally-friendly farming materials (EFFM), but the solvent should not remain in EFFM for the safety reasons. Thus qualitative and quantitative analysis method for the solvents using Headspace-GC were evaluated. Water content depleted the detection ratio of hydrophilic solvents and disturbing the hydrophilic interaction with solvents by DMSO might be helped to increase the detection ratio (up to 715%). Surfactant concentration affected to the detection ratio (68.5-179.1%) while surfactant type was not deeply involved the solvent detection. On the other hand, matrix-matched calibration method was accepted the minimum requirements for the quantitative analysis of the solvents in EFFM.