• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.178-182
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• 1998

Bioremediation techniques have proved to be effective for restoring petroleum-contaminated soils. however some limitations still exist, especially biodegradation of hydrophobic organic compounds(HOCs) in soil is limited by their low solubility and sorption to solid surfaces. The principal objective of this study was to evaluate the effectiveness of biosurfactant sophorolipid on the biodegradation of hydrocarbons in soil. Experimental results showed that sophorolipid was not toxic to the HOC-degrading bacteria and enhanced biodegradation of HOCs in soil better than synthetic surfactants. when these models were treated with 1000mg/soil kg sophorolipid.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.342-349
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• 2017

Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권spc호
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• pp.51-63
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• 2022

In this study, the TPH(Total Petroleum Hydrocarbon) contamination and microbial ecological characteristics in petroleum-contaminated site were investigated through the correlation among the vertical TPH contamination distribution of the site, the geochemical characteristics, and the indigenous microbial ecology. The high TPH concentration showed in the vicinity of 3~4 m or less which is thought to be affected by vertical movement due to the impervious clay layer. In addition, the TPH concentration was found to have a positive correlation with Fe²⁺, TOC concentration, and the number of petroleum-degrading bacteria, and a negative correlation with the microbial community diversity. The microbial community according to the vertical distribution of TPH showed that Proteobacteria and Firmicutes at the phylum level were dominant in this study area as a whole, and they competed with each other. In particular, it was confirmed that the difference in the microbial community was different due to the difference in the degree of vertical TPH contamination. In addition, the genera Acidovorax, Leptolinea, Rugoshibacter, and Smithella appeared dominant in the samples in which TPH was detected, which is considered to be the microorganisms involved in the degradation of TPH in this study area. It is expected that this study can be used as an important data to understand the contamination characteristics and biogeochemical and microbial characteristics of these TPH-contaminated sites.

• 한국미생물·생명공학회지
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• 제33권3호
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• pp.169-177
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• 2005

본 연구는 어업이나 농업 등의 인간활동에 의하여 상당한 영향을 받고 있는 순천만 갈대의 근권에서 이루어지는 정화작용에 있어 미생물의 역할을 조사하는 것에 중점을 두었다. 일반적으로 만은 환경 스트레스로 인한 갑작스런 충격을 감소시키는 완충지역으로서의 역할을 하는 것으로 알려져 있다. 갈대근권에서 이루어지는 정화기능에 있어 미생물의 역할을 밝히기 위한 첫 번째 노력의 일환으로 벤젠, 톨루엔, 또는 자일렌이 단일 탄소 및 에너지원으로 첨가된 농화배양법을 사용하여 BTEX를 분해할 수 있는 두 종류의 그람양성 세균을 순수분리하였다. 다양한 온도조건의 BTEX배지에서 이들 세균을 배양하는 동안 BTEX의 분해율 및 성장률을 주기적으로 조사한 결과 $37^{\circ}C$에서 가장 빠른 기질 분해율을 보였고 $42^{\circ}C$의 고온에서도 두 균 모두 잘 성장하는 것으로 나타났다. 본 연구에서 시험한 수은, 카드뮴, 납, 바륨, 철 대부분의 중금속에 강한 내성뿐만 아니라 ampicillin을 비롯한 시험한 5종류의 항생제 모두에 강한 내성을 나타냈다. 16S rRNA 유전자 서열과 다양한 표현형 및 형태학적 특성을 기초로 한 동정의 결과 BTEX를 분해할 수 있는 두 균주는 $95{\%}$상의 신뢰도로 Microbacterium sp.와 Rhodococcus sp.로 나타났고, 각 균주는 Microbacterium sp. EMB-1과 Rhodococcus sp. EMB-2로 명명하였다. 이러한 결과는 주요한 염습지 식물중의 하나인 갈대의 근권에서 살아가는 이들 균주들이 BTEX와 같은 석유로 오염된 근권 환경의 정화작용에 중요한 역할을 할 수 있음을 제시해주었다.

• 한국환경과학회지
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• 제8권4호
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• pp.451-456
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• 1999

Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected stains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% $NH_4NO_3$, 1-1.5% $MgSO_4$.$7H_2O$, 0.05-0.15% KCl, 0.1-0.15% $CaCl_2$.$2H_2O$, 2.5-3.5% NaCl, initial pH 8-9, temperature 3$0^{\circ}C$ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected stains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.

• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.431-436
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• 2002

Effects of fertilizer additions for oil degradation were examined in sand seashore mesocosms. Within 37 days, up to $85\%$ removal was achieved by the addition of slow-release type fertilizer (SRF) with the initial degradation rate of 423.3 mg oil $(kg sand)^-1\;day^-1$. The removal was mostly of biological origin based on the changes of $C_17$ /pristane and $C_18$/phytane ratios from 2.60 to 0.81 and from 3.55 to 1.29, respectively. The addition of oleophilic fertilizer (Inipol EAP22) was less effective and resulted in the removal of $64\%$ of the added oil ($3\%$, v/v) with a lower initial degradation rate. Petroleum-degrading bacteria had achieved a value of $1{\times}10^8$ CFU $(g sand)^-1$ at Day 3 and this peak exactly coincided with the initial degradation in the SRF-treated mesocosm. In this mesocosm, surface tension values were decreased drastically during Days 3 and 8, suggesting that microbially-produced surface-active agents actively enhanced the oil degradation rate and cell proliferation. Although the Inipol-treated mesocosm appeared to show significantly enhanced oil degradation compared to that of the untreated control mesocosm, Inipol was found to be less effective than SRF in enhancing a true oil-degrader when compared under similar experimental conditions.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권6호
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• pp.70-77
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• 2007

토양에 존재하는 다핵방향족탄화수소(Polycyclic Aromatic Hydrocarbons, PAHs)의 처리를 위하여 자연계로부터 분리된 균주는 Pseudomonas sp.로 동정되었으며, 이 균주를 KM1으로 명명하였다. 균주의 최적 성장조건은 회분식 배양에서 $35^{\circ}C$, pH 7로 나타났다. 분리균주 Pseudomonas sp. KM1에 의한 7-PAHs(naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene)의 분해실험결과 배양 1일 만에 fluoranthene을 제외한 naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and pyrene 이 분해됨을 확인할 수 있었다. 그리고 토양유무에 따른 PAHs 분해실험 결과, 흡착분배계수와 유기물함량(%)이 큰 신동방이 경방이나 봉동보다 분리균주에 의한 생분해율(%)이 낮았다. 토양에 오염된 유기화합물의 분배특성과 토양 내 유기물함량(%)이 오염된 토양의 생물학적 처리효과에 영향을 미치는 중요한 인자인 것으로 나타났다.