• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.163-164
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• 2001

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.196.1-196
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• 2005

• Advances in environmental research
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• 제9권3호
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• pp.215-232
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• 2020

Crude oils are essential source of energy. It is majorly found in geographical locations beneath the earth's surface and crude oil is the main factor for the economic developments in the world. Natural crude oil contains unrefined petroleum composed of hydrocarbons of various molecular weights and it contains other organic materials like aromatic compounds, sulphur compounds, and many other organic compounds. These hydrocarbons are rapidly getting degraded by biosurfactant producing microorganisms. The present study deals with the isolation, purification, and characterization of biosurfactant producing microorganism from oil-contaminated soil. The ability of the microorganism producing biosurfactant was investigated by well diffusion method, drop collapse test, emulsification test, oil displacement activity, and blue agar plate method. The isolate obtained from the oil contaminated soil was identified as Bacillus subtilis. The identification was done by microscopic examinations and further characterization was done by Biochemical tests and 16SrRNA gene sequencing. Purification of the biosurfactant was performed by simple liquid-liquid extraction, and characterization of extracted biosurfactants was done using Fourier transform infrared spectroscopy (FTIR). The degradation of crude oil upon treatment with the partially purified biosurfactant was analyzed by FTIR spectroscopy and Gas-chromatography mass spectroscopy (GC-MS).

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.41-45
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• 1999

A tentative composition and some properties of biosurfactants, type I and type II, from Pseudomonas sp. SW1 are described. Biosurfactant type I and II are soluble in water, dichloromethane, chloroform, and a mixture of chloroform and methanol, respectively. The UV absorption spectrum of biosurfactants showed three characteristic peaks in the range of 212, 250 and 365nm, respectively. As a result of IR spectroscopy, GC/MS analysis and biochemical analysis, biosurfactant type I was a polymeric biosurfactant containing carbohydrate, lipid and protein. The carbohydrate was characterized as rhamnose. The lipid part consists of $C_{14}-C_{23}$ fatty acid when analyzed by GC/MS. The biosurfactant type II was a rhamnolipid consisting of carbohydrate and lipid.

• 접착 및 계면
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• 제14권4호
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• pp.197-211
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• 2013

계면활성제는 상간의 경계면 활성화를 통한 표면장력의 강하능력을 가져 모든 세제(detergents)와 화장품(cosmetics)에 사용되는 필수 주원료이다. 합성세제란 석유화학계의 EO (ethylene oxide), LAB (linear alkylbenzene) 등의 합성계면활성제로 제조한 제품으로 이는 난분해성으로 지구환경, 특히 하천과 강물오염의 주범으로 생태계파괴의 원인이 되고 있다. 이는 또한 분자가 작아 침투력이 강해 피부를 자극하여 아토피피부염을 유발하고 모세관을 통해 기관으로 들어가면 암을 유발할 수도 있다. 최근 합성계면활성제를 대체할 수 있는 양친매성의 생분해성 친환경 및 무자극의 다기능성물질로서 천연 계면활성제 또는 생합성의 생물 계면활성제(biosurfactants)의 개발에 국제적인 관심이 고조되고 있다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.195.4-195
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• 2005

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.95-104
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• 2018

Biosurfactants or microbial surfactants are surface-active biomolecules that are produced by a variety of microorganisms. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of environmental bioremediation as well as the petroleum industry and enhanced oil recovery. However, the major issues in biosurfactant production are high production cost and low yield. Improving the bioindustrial production processes relies on many strategies, such as the use of cheap raw materials, the optimization of medium-culture conditions, and selecting hyperproducing strains. The present work aims to obtain a mutant with higher biosurfactant production through applying mutagenesis on Bacillus subtilis SPB1 using a combination of UV irradiation and nitrous acid treatment. Following mutagenesis and screening on blood agar and subsequent formation of halos, the mutated strains were examined for emulsifying activity of their culture broth. A mutant designated B. subtilis M2 was selected as it produced biosurfactant at twice higher concentration than the parent strain. The potential of this biosurfactant for industrial uses was shown by studying its stability to environmental stresses such as pH and temperature and its applicability in the oil recovery process. It was practically stable at high temperature and at a wide range of pH, and it recovered above 90% of motor oil adsorbed to a sand sample.

• KSBB Journal
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• 제13권5호
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• pp.606-614
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• 1998

In this study, biodegradation rate of Arabian light crude oil by mixed cultures of selected petroleum-degraders was determined. Their modes of hydrocarbon uptake were then observed to determine whether there are differences in biodegradation rate by the mixed cultures. By the mixed cultures of petroleum-degraders having same modes of hydrocarbon uptake, such as strain US1 and K1 (using pseudo-solubilized hydrocarbons by a biosurfactants), K2-2 and P1(using hydrocarbons by direct contact), CL 180 and IC-10 (mixed type of uptake modes), the biodegradation rates of aliphatics in the crude oil were increased more than those by their pure cultures, about 40%, 25% and 20%, respectively. Biodegradation rate of strain KH3-2 (using only water- dissolved hydrocarbons) was increased by mixed cultures with strain K1, CL180 or IC-10 possessing high emulsifying activity. However, the biodegradation rate of the crude oil was decreased about 20%-40% by the mixed cultures of petroleum-degraders having different mode of hydrocarbon uptake, such as addition of strain US1 or K1 in the cultures of K2-2 or P1. Biosurfactants produced by US1 or K1 seems to enhance the emulsification of crude oil in aqueous phase but inhibit the attachment of K2-2 or P1 to crude oil. As same phenomena, the addition to Triton X-100 into the culture of strain US1, K1, CL180, IC-10 or KH3-2 increased the biodegradation rate, but the addition in the culture of strain K2-2 or P1 decreased the biodegradation rate. The mixed culture made of CL180, IC-10 and KH3-2 degraded 61.5% of aliphatics and 69% of aromatics in 3% (v/v) of Arabian light crude oil added.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.497-500
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• 2000

유류오염토양에서 분리한 유류분해균주 중 계면장력 저하능이 우수한 균주를 분리하여 동정한 결과 Pseudomonas aeruginosa D2D2로 판명되었다. 탄소원으로 glucose와 olive oil을 각 1.5%씩 첨가하였을 때 표면장력이 27.9 dyne/cm로 표면장력 저하능력이 가장 우수한 것으로 나타냈다. 생산된 biosurfactant로 ethly acetate 추출하여 crude biosurfactant를 얻었으며, TLC 분석한 결과 glycolipid계열의 biosurfactant임을 확인하였다.

• KSBB Journal
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• 제10권1호
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• pp.71-77
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• 1995

Penicillium spiculisporum으로부터 생산한 S-acid 와 그의 유도체를 만들고 이들의 계면활성제로서의 특성을 살펴 보았다. S-lNa 엽 이 우수한 표면장력 저하능 (31.6dyne/때)과 기존의 SDS, Tween 80을 능가하는 분산능력을 보였다. 또한 칼슐 존재 하에 서도 유화능력을 유지할 수 있었고 침투력에서도 기존의 LAS와 유사한 결과를 보였다. 반면 대전방지 능력은 거의 없었고 세척력은 LAS의 70%를 보였다. 생분해측면에서는 모든 유도체가 기존의 계연활 성제보다 월등히 빨리 분해되었으며 방청력변에서는 S-3Na 엽이 기존의 방청제와 유사한 우수한 결과를 보였다.