• 대한환경공학회지
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• 제22권7호
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• pp.1243-1252
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• 2000

휘발성 훈증제인 cis-와 trans-1,3-D의 각각에 대한 분해력 향상은 몇몇 연구자들에 의해 이루어져왔다. 본 연구는 cis-와 trans-1,3-D에 대해 서로 다른 속도에서 각각의 분해력 증진과 미생물과의 관련성을 조사한 것으로, 미생물이 휘발성을 갖는 독성 유기화합물의 분해를 향상시키는 데 관여하고 있음이 관찰되었다. 1,3-D로 야외(field)처리되어 적응되어 왔던 토양으로부터, 1,3-D의 분해가 확인된 토양시료를 채취하여 1,3-D를 분해할 수 있는 혼합 배양세균을 분리하였다. 이렇게 분리된 혼합 배양세균은 cis-1,3-D보다는 trans-1,3-D를 더 빨리 분해 시켰으나, 미생물 성장을 위한 탄소원으로 cis-와 trans-1,3-D만이 제공되었을 때는 분해가 일어나지 않는 반면, 적절한 2차 탄소원들이 존재할 때에는 cis-와 trans-1,3-D를 분해시켰다. 따라서, cis-와 trans-1,3-D의 분해는 공동대사과정(cometabolism)인 것으로 판단된다. 두 이성질체는, 토양여과액(soil leachate), tryptone, tryptophan, alanine이 포함된 시료가 2차 탄소원으로 제공되었을 때에는 분해가 이루어졌으나, 고온고압하에서 멸균시킨 토양추출액(soil extract), glucose, yeast extract 및 indole이 포함된 시료가 2차 탄소원으로 제공되었을 때는 두 이성질체 모두를 분해시키지 못했다. 상업용 훈증제로 이용되는 cis-와 trans-1,3-D를 다른 속도로 개별적으로 분해하는 혼합 미생물군은 형태학적인 구별방법에 의해 4개의 독립된 순수 colony로 구성되어 있는 것으로 관찰되었다.

• 공업화학
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• 제19권1호
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• pp.122-128
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• 2008

본 연구에서는 J 하수 처리장의 최종 방류수를 대상으로 종속영양세균의 증식과 수중 물리, 화학적 영향인자와의 관계를 고찰하였다. 하수 중의 용존 유기물질 농도는 종속영양세균의 성장과 가장 밀접한 관계를 보였다. 미생물의 영양원인 단백질, 지방, 전분, 섬유소, 팩틴의 분해 세균 분포를 파악한 결과 하수 중 단백질 및 지방세균의 비율은 전체의 81%로 가장 높았다. 종속영양세균은 연중 8월에 가장 높은 수치를 나타냈다. 하수 방류수에 대해 10 mg/L의 유리염소를 주입하여 15 min간 접촉시 THMs의 농도는 $71{\mu}/L$ (< $100{\mu}/L$- 먹는 물 수질기준)의 값을 나타내어 높지 않았다.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.909-915
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• 2002

The biodegradation of BTEX components (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene) individually and in mixtures was investigated using the o-xylene-degrading thermo-tolerant bacterium Ralsronia sp. strain PHS1 , which utilizes benzene, toluene, ethylbenzene, or o-xylene as its sole carbon source. The results showed that as a single substrate for growth, benzene was superior to both toluene and ethylbenzene. While growth inhibition was severe at higher o-xylene concentrations, no inhibition was observed (up to 100 mg $l^-1$) with ethylbenzene. In mixtures of BTEX compounds, the PHS1 culture was shown to degrade all six BTEX components and the degradation rates were in the order of benzene, toluene, o-xylene, ethylbenzene, and m- and p-xylene. m-Xylene and p-xylene were found to be co-metabolized by this microorganism in the presence of the growth-supporting BTEX compounds. In binary mixtures containing the growth substrates (benzene, toluene, ethylbenzene. and o-xylene), PHS1 degraded each BTEX compound faster when it was alone than when it was a component of a BTEX mixture, although the degree of inhibition varied according to the substrates in the mixtures. p-Xylene was shown to be the most potent inhibitor of BTEX biodegradation in binary mixtures. On the other hand, the degradation rates of the non-growth substrates (m-xylene and p-xylene) were significantly enhanced by the addition of growth substrates. The substrate utilization patterns between PHS1 and other microorganisms were also examined.

• 유기물자원화
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• 제14권4호
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• pp.141-150
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• 2006

음식물류폐기물의 친환경적 처리를 위한 소재를 개발하기 위하여 지렁이로부터 유기물 분해 및 응집능을 갖는 기능성 미생물을 분리하였다. 분리된 균주 중 음식물류폐기물을 처리하는데 적합한 것으로 판단되는 균주를 최종 선별하여 JS-01균주로 명명하였으며 16s rDNA 염기서열분석에 의한 최종결과, Bacillus pumilus로 동정되었다. 0.5% Kaolin clay을 대상으로 JS-01균주의 응집능을 조사한 결과 응집을 위한 최적 생장조건은 MRS 액체배지에서 온도 $37^{\circ}C$ 및 pH 7.0으로 나타났다. 유기물분해능 중에서는 특히, 음식물류폐기물의 대표적 성분인 섬유소에 대한 분해능을 확인하였다. 따라서 JS-01균주는 음식물류폐기물의 친환경적 처리 및 재활용을 위한 미생물 소재 및 음식물 침출수의 효과적인 응집 처리를 위한 생체량 생성에 이용할 수 있을 것으로 사료된다.

• 농업과학연구
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• 제10권1호
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• pp.146-155
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• 1983

색소로 인한 수질오염의 방지책에 대한 기초자료를 얻고자 대전근교의 토양을 분리원으로 하여 amaranth를 분해하는 미생물을 분리하고 그의 균학적 성질을 검토하여 동정하였다. 또한 색소 분해에 대한 몇가지 주요한 요인등을 검토하고 분해산물을 TLC로 검정하여 다음과 같은 결과를 얻었다. 1. Amaranth의 분해능이 가장 강한 A12-은 Pseudomonas속으로 동정되었다. 2. A12-1 균주의 생육최적온도는 $35^{\circ}C$, pH 7.5이었으며 통기배양에서 더욱 생육이 촉진되었다. 3. Amaranth를 분해하는 최적조건은 생육최적조건과 비슷하였으나 통기는 생육을 촉진하는데 비해 색소분해는 저해하였다. 4. Amaranth 농도가 높을수록 균의 생육 및 색소분해는 저하되었다. 5. A12-1 균주의 배양으로 얻은 조효소의 amaranth에 대한 최적반응조건은 온도 $35^{\circ}C$, pH 7.5이었다. 6. Amaranth의 분해산해물은 TLC로 검토해본 결과 sodium naphthionate와 R -amino salt로 추정되었다.

• 한국환경과학회지
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• 제23권4호
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• pp.681-695
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• 2014

In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 ${\mu}m$, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were $7.5{\times}10^4$ and $1.25{\times}10^5$ cells/ml, respectively, and dominant species were Entosiphon sulcatus var sulcatus in PEMT A and Chlamydomonas reinhardtii in PEMT B, respectively. Flask experiments using the two media revealed that the percentages of color removal were 25.8% in PEMT A and 27.1% in PEMT B after 72-h cultivation, indicating the necessity of bioaugmentation. Experiments for bioaugmentation effect on color removal were carried out in the pilot-scale treatment for 75 d by three-step operation under the control of wastewater loading rate and microbial input rate. Dye degradation occurred mainly in the second reaction tank, and the attachment of augmented dye-degrading microorganisms to media took at least 35 d. Final value of chromaticity in effluent was 227, meeting the required standard. Therefore bioaugmentation onto media was good for color treatment. In summary, thickness of biofilm formed on the media depended upon the size of media, resulting in different ecosystem inside the media. Hence, this affected microbial community and color treatment further. Accordingly, the reduction of operation cost is expected by efficient color-treatment process using bioaugmented media.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.27-36
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• 2022

Ever since bioplastics were globally introduced to a wide range of industries, the disposal of used products made with bioplastics has become an issue inseparable from their application. Unlike petroleum-based plastics, bioplastics can be completely decomposed into water and carbon dioxide by microorganisms in a relatively short time, which is an advantage. However, there is little information on the specific degraders and accelerating factors for biodegradation. To elucidate a new strain for biodegrading poly-3-hydroxybutyrate (PHB), we screened out one PHB-degrading bacterium, Microbulbifer sp. SOL03, which is the first reported strain from the Microbulbifer genus to show PHB degradation activity, although Microbulbifer species are known to be complex carbohydrate degraders found in high-salt environments. In this study, we evaluated its biodegradability using solid- and liquid-based methods in addition to examining the changes in physical properties throughout the biodegradation process. Furthermore, we established the optimal conditions for biodegradation with respect to temperature, salt concentration, and additional carbon and nitrogen sources; accordingly, a temperature of 37℃ with the addition of 3% NaCl without additional carbon sources, was determined to be optimal. In summary, we found that Microbulbifer sp. SOL03 showed a PHB degradation yield of almost 97% after 10 days. To the best of our knowledge, this is the first study to investigate the potent bioplastic degradation activity of Microbulbifer sp., and we believe that it can contribute to the development of bioplastics from application to disposal.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.245-254
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• 2022

Cellulases are a group of biocatalyst enzymes that are capable of degrading cellulosic biomass present in the natural environment and produced by a large number of microorganisms, including bacteria and fungi, etc. In the current study, we isolated, screened and characterized cellulase-producing bacteria from soil. Three cellulose-degrading species were isolated based on clear zone using Congo red stain on carboxymethyl cellulose (CMC) agar plates. These bacterial isolates, named as HB2, HS5 and HS9, were subsequently characterized by morphological and biochemical tests as well as 16S rRNA gene sequencing. Based on 16S rRNA analysis, the bacterial isolates were identified as Bacillus cerus, Bacillus subtilis and Bacillus stratosphericus. Moreover, for maximum cellulase production, different growth parameters were optimized. Maximum optical density for growth was also noted at pH 7.0 for 48 h for all three isolates. Optical density was high for all three isolates using meat extract as a nitrogen source for 48 h. The pH profile of all three strains was quite similar but the maximum enzyme activity was observed at pH 7.0. Maximum cellulase production by all three bacterial isolates was noted when using lactose as a carbon rather than nitrogen and peptone. Further studies are needed for identification of new isolates in this region having maximum cellulolytic activity. Our findings indicate that this enzyme has various potential industrial applications.

• Journal of Microbiology and Biotechnology
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• 제31권5호
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• pp.756-763
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• 2021

Agarose is a linear polysaccharide composed of ᴅ-galactose and 3,6-anhydro-ʟ-galactose (AHG). It is a major component of the red algal cell wall and is gaining attention as an abundant marine biomass. However, the inability to ferment AHG is considered an obstacle in the large-scale use of agarose and could be addressed by understanding AHG catabolism in agarolytic microorganisms. Since AHG catabolism was uniquely confirmed in Vibrio sp. EJY3, a gram-negative marine bacterial species, we investigated AHG metabolism in Streptomyces coelicolor A3(2), an agarolytic gram-positive soil bacterium. Based on genomic data, the SCO3486 protein (492 amino acids) and the SCO3480 protein (361 amino acids) of S. coelicolor A3(2) showed identity with H2IFE7.1 (40% identity) encoding AHG dehydrogenase and H2IFX0.1 (42% identity) encoding 3,6-anhydro-ʟ-galactonate cycloisomerase, respectively, which are involved in the initial catabolism of AHG in Vibrio sp. EJY3. Thin layer chromatography and mass spectrometry of the bioconversion products catalyzed by recombinant SCO3486 and SCO3480 proteins, revealed that SCO3486 is an AHG dehydrogenase that oxidizes AHG to 3,6-anhydro-ʟ-galactonate, and SCO3480 is a 3,6-anhydro-ʟ-galactonate cycloisomerase that converts 3,6-anhydro-ʟ-galactonate to 2-keto-3-deoxygalactonate. SCO3486 showed maximum activity at pH 6.0 at 50℃, increased activity in the presence of iron ions, and activity against various aldehyde substrates, which is quite distinct from AHG-specific H2IFE7.1 in Vibrio sp. EJY3. Therefore, the catabolic pathway of AHG seems to be similar in most agar-degrading microorganisms, but the enzymes involved appear to be very diverse.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.583-591
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• 2002

Biodegradation of fat, oil, and grease (FOGs) plays an Important role in wastewater management and water pollution control. However, many industrial food-processing and food restaurants generate FOG-containing waste waters for which there Is no acceptable technology for their pretreatment. To solve these problems, this study evaluated the feasibility of effective FOG-degrading microorganisms on the biodegradation of olive oil and FOG-containing wastewater. Twenty-two strains capable of degrading FOGs were isolated from five FOG-contaminated sites for the evaluation of their FOG degradation capabilities. Among twenty-two strains tested, the lipase-producing Pseudomonas sp. strain D2D3 was selected for actual FOG wastewater treatment. Its biodegradability was performed at 3$0^{\circ}C$ and pH 8. The extent of FOG removal efficiency was varied for each FOG tested, being the highest for olive oil and animal fat (94.5% and 94.4%), and the lowest for safflower oil (62%). The addition of organic nitrogen sources such as yeast extract, soytone, and peptone enhanced the removal efficiency of FOGs, but the addition of the inorganic nitrogen nutrients such as $NH_4$Cl and $(NH_4)_2SO_4$ did not increase. The $KH_2PO_4$ sources in 0.25% to 0.5% concentrations showed more than 90% degradability. As a result, the main pathway for the oxidation of fatty acids results in the removal of two carbon atoms as acetyl-CoA with each reaction sequence: $\beta$-oxidation. Its lipase activity showed 38.5 U/g DCW using the optimal media after 9 h. Real wastewater and FOGs were used for determining the removal efficiency by using Pseudomonas sp. strain D2D3 bioadditive. The degradation by Pseudomonas sp. strain D2D3 was 41% higher than that of the naturally occurring bacteria. This result indicated that the use of isolated Pseudomonas sp. strain D2D3 in a bioaugmentating grease trap or other processes might possibly be sufficient to acclimate biological processes for degrading FOGs.