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논문검색은 역시 페이퍼서치

한국미생물·생명공학회지검색

Microbiology and Biotechnology Letters


  • - 주제 : 자연과학분야 > 생물
  • - 성격 : 학술지
  • - 간기: 계간
  • - 국내 등재 : KCI 등재
  • - 해외 등재 : - / SCOPUS
  • - ISSN : 1598-642x
  • - 간행물명 변경 사항 : 산업미생물학회지(~2001)→한국미생물·생명공학회지(2002~)
논문제목
수록 범위 : 48권 1호 (2020)
초록보기
The aim of this study was to investigate the effects of Torulaspora delbrueckii and Saccharomyces cerevisiae, as pure fermenters and mixed fermenters (simultaneous and sequential culture), on the production of nonvolatiles and volatiles, and on the antioxidant activity in Golden Dried Longan juice and Golden Dried Longan wines. Alanine, arginine, glutamic acid, leucine, proline, and gamma-aminobutyric acid (GABA) were the most prominent amino acids that were found in these wines. The Golden Dried Longan Wine fermented with monocultures of S. cerevisiae and T. delbrueckii produced a total volatile aroma content of 393.21 mg/l and 383.20 mg/l, respectively. Simultaneous culture of the two organisms produced the highest total volatile aroma content, that affected most volatile compounds including isobutanol, ethyl acetate, ethyl decanoate, ethyl heptanoate, ethyl hexanoate, ethyl pentanoate, isoamyl acetate, and isobutyl acetate. Of the four treatments, the sequential culture possessed the highest total phenolic content (5.80 mg gallic acid equivalents (GAE)/ml). In addition, the total phenolic content significantly correlated with the antioxidant activity of the Golden Dried Juice and Golden Dried Longan Wine. These results suggest that co-cultures of the two organisms used in the production of the Golden Dried Longan Wine may improve the intensity and complexity of its aroma.
초록보기
Edible films containing antimicrobial agents can be used as safe alternatives to preserve food products. Essential oils are well-recognized antimicrobials. However, their low water solubility, volatility and high sensitivity to oxygen and light limit their application in food preservation. These limitations could be overcome by embedding these essential oils in complexed product matrices exploiting the encapsulation efficiency of β-cyclodextrin. This study focused on the maximization of β-cyclodextrin production using cyclodextrin glucanotransferase (CGTase) and the evaluation of its encapsulation efficacy to fabricate edible antimicrobial films. Response surface methodology (RSM) was used to optimize CGTase production by Brevibacillus brevis AMI-2 isolated from mangrove sediments. This enzyme was partially purified using a starch adsorption method and entrapped in calcium alginate. Cyclodextrin produced by the immobilized enzyme was then confirmed using high performance thin layer chromatography, and its encapsulation efficiency was investigated. The clove oil/β-cyclodextrin inclusion complexes were prepared using the coprecipitation method, and incorporated into chitosan films, and subjected to antimicrobial testing. Results revealed that β-cyclodextrin was produced as a major product of the enzymatic reaction. In addition, the incorporation of clove oil/β-cyclodextrin inclusion complexes significantly increased the antimicrobial activity of chitosan films against Staphylococcus aureus, Staphylococcus epidermidis, Salmonella Typhimurium, Escherichia coli, and Candida albicans. In conclusion, B. brevis AMI-2 is a promising source for CGTase to synthesize β-cyclodextrin with considerable encapsulation efficiency. Further, the obtained results suggest that chitosan films containing clove oils encapsulated in β-cyclodextrin could serve as edible antimicrobial food-packaging materials to combat microbial contamination.

Engineering of Recombinant Escherichia coli Towards Methanol Sensing Using Methylobacterium extroquens Two-component Systems

( Vidhya Selvamani ) , ( Irisappan Ganesh ) , ( Sowon Chae ) , ( Murali Kannan Maruthamuthu ) , ( Soon Ho Hong )
4,500
초록보기
Five genes (mxbDM, mxcQE and mxaB) are responsible for the transcription of methanol oxidation genes in Methylobacterium strains. Among these, MxbDM and MxcQE constitute the two-component system (TCS) regulating methanol metabolism. In this study, we integrated the methanol-sensing domain of MxbD and MxcQ with the EnvZ/OmpR from Escherichia coli. The domain-swapping strategy resulted in chimeric histidine kinases (HK’s) MxbDZ and MxcQZ AM1 containing recombinant E. coli. Real-time quantitative PCR was used to monitor OmpC expression mediated by the chimeric HK and response regulator (RR) OmpR. Further, an ompC promoter based fluorescent biosensor for sensing methanol was developed. GFP fluorescence was studied both qualitatively and quantitatively in response to environmental methanol. GFP measurement also confirmed ompC expression. Maximum fluorescence was observed at 0.05% methanol and 0.01% methanol using MxbDZ and MxcQZ AM1, respectively. Thus the chimeric HK containing E. coli were found to be highly sensitive to methanol, resulting in a rapid response making them an ideal sensor.
4,500
초록보기
We improved on a unified saccharification and fermentation (USF) system for the direct production of ethanol from agarose by increasing total agarase activity. The pGMFα-NGH plasmid harboring the NABH558 gene encoding neoagarobiose hydrolase and the AGAG1 and AGAH71 genes encoding β-agarase was constructed and used to transform Saccharomyces cerevisiae 2805. NABH558 gene transcription level was increased and total agarase activity was increased by 25 to 40% by placing the NABH558 gene expression cassette upstream of the other gene expression cassettes. In the 2805/pGMFα-NGH transformant, three secretory agarases were produced that efficiently degraded agarose to galactose, 3,6-anhydro-L-galactose (AHG), neoagarobiose, and neoagarohexaose. During the united cultivation process, a maximum of 2.36 g/l ethanol from 10 g/l agarose was produced over 120 h.

토양에서 분리한 Pseudomonas geniculata ANG3, Exiguobacterium acetylicum ANG40 및 Burkholderia stabilis ANG51의 식물 생장촉진 활성 및 식물병 방제활성

김지윤 ( Ji-youn Kim ) , 김희숙 ( Hee Sook Kim ) , 이송민 ( Song Min Lee ) , 박혜정 ( Hye-jung Park ) , 이상현 ( Sang-hyeon Lee ) , 장정수 ( Jeong Su Jang ) , 이문현 ( Mun Hyon Lee )
4,500
초록보기
본 연구는 토양으로부터 분리한 균주를 대상으로 식물병 방제활성 및 식물 생장촉진 활성을 확인하고자 하였다. 식물병원성 곰팡이에 대한 길항능을 통해 방제기능을 확인할 수 있었으며, 이는 siderophore 및 항생물질 생성 등에 기인되는 것으로 판단된다. 또한 ANG40의 경우에는 amylase, cellulase, xylanase와 같은 세포외 효소활성을 갖고 있음을 확인하였다. 이 외에도 질소 고정능, 인산 가용화능, siderophore 생성능 등 다양한 실험을 통해 식물 생장에 필수적인 질소, 인, 철 등을 식물이 흡수 가능한 형태로 변화시켜 식물 생장에 도움을 줄 수 있을 것으로 기대된다. 또한 6종의 분리균주는 모두 에틸렌 생성과 연관된 IAA를 생성하였으며, 그 중에서도 ANG51의 경우에는 ACC deaminase 활성도 갖고 있음을 확인하였다. 따라서, 최종 선별된 Pseudomonas geniculata ANG3, Exiguobacterium acetylicum ANG40, Burkholderia stabilis ANG51을 이용하여 식물 생장촉진 활성과 식물 병원성 곰팡이에 항진균 활성을 갖는 새로운 생물학적 제제로써 이용 가능성을 제시하였다.
4,500
초록보기
This study aimed to optimize the culture conditions to improve the crude biosurfactant activity of Bacillus pumilus IJ-1, using a 33 full-factorial design of response surface methodology (RSM). It was found that submerged fermentation of B. pumilus improved the activity of the crude biosurfactant. The factors selected for optimization were NaCl concentration, temperature, and tryptone concentration. Response surface analysis revealed that the fitted quadratic model was statistically significant and produced an adequate R2 value (0.9898) and a low probability value (<0.0001). The optimum level for each factor was found to be 0.567% (w/v) NaCl, 21.851℃ and 0.765% (w/v) tryptone, respectively. Crude biosurfactant activity was found to be most affected by tryptone concentration; then temperature, and finally NaCl concentration. Our results may potentially facilitate large-scale biosurfactant production from B. pumilus IJ-1.

제주 연안의 가시복(Diodon holoanthus)에서 분리된 세균의 다양성 및 항균활성 효과

문채윤 ( Chae-yun Moon ) , 고준철 ( Jun-cheol Ko ) , 김민선 ( Min-seon Kim ) , 허문수 ( Moon-soo Heo )
4,500
초록보기
지구 온난화로 인한 제주도의 해양 생태계는 지난 20년동안 온대에서 아열대로 변화되었다. 이러한 기후 변화는 난대성 어류가 서식할 수 있는 환경이 되며, 최근 제주 연안에서는 가시복(diodon holoanthus)이 발견되고 있다. 본 연구에서는 가시복의 장내미생물의 다양성을 파악하였다. 그리고 다양한 균주 중 어류 또는 인체 유해세균 가능성을 확인하고자 항균 활성 탐색을 수행하였다. Proteobacteria는 분리 된 균주 중 91%를 차지한 우점문으로 γ-proteobacteria강은 11속 142종으로 Vibrio속 35%, Photobacterium속 32%, Shewanella속 6%, Psychrobacter속 4%, Acinetobacter속 3% 및 나머지 Enterovibrio, Moraxella_g2속이 각각 1%를 차지했다. α-proteobactera강은 5속 5종으로 Brevundimonas속, Allorhizobium속, Pseudoceanicola속, Erythrobacter속 및 Methylobacterium 속이 각각 1%로 나타났다. Firmicutes문 Bacilli강은 6속 10종으로 Bacillus속 5%가 가장 높았고 나머지 Terribacillus속, Paenibacillus속, Salinicoccus속, Staphylococcus속 및 Streptococcus속은 1%로 관찰됐다. Actinobacteria문 Actinobacteria강은 3속 3종으로 Janibacter속, Micrococcus속 및 Isoptericola속이 각각 1%를 차지했다.

Isolation and Characterization of Microbial Strains with Hydrolytic Enzyme Profile from Clay Minerals

( Sulhee Lee ) , ( Eui-sang Cho ) , ( Young-do Nam ) , ( So-lim Park ) , ( Seong-il Lim ) , ( Dong-ho Seo ) , ( Jae-hwan Kim ) , ( Myung-ji Seo )
4,500
초록보기
A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.

질산화-탈질 연계공정에서 질소화합물 및 기능성 유전자 거동

권지현 ( Ji-hyeon Kwon ) , 박형주 ( Hyung-joo Park ) , 이윤영 ( Yun-yeong Lee ) , 조경숙 ( Kyung-suk Cho )
4,500
초록보기
The dynamics of nitrogen compounds and RNA-based functional genes were characterized in the nitrification-denitrification coupling process. For the removal of residual ammonium, intermittent aeration was introduced in the denitrification reactor. N2O production was not observed in both reactors. In both reactors, the nitrifying genes (achaeal-amoA, bacterial-amoA and hor) and denitrifying genes (narG, nirK, norB and nosZ) had a copy number of 3.92 × 102 -7.25 × 105 and 2.85 × 102 -3.06 × 104 per ng of DNA, respectively. These results suggest that denitrification and nitrification reactions occur in both the nitrification and denitrification reactors, respectively. Therefore, the coupling process is a promising one for the conversion of ammonium to nitrogen without generating N2O.

RAW 264.7 세포에서의 단풍잎돼지풀 추출물의 항염증 활성 검증

유단희 ( Dan-hee Yoo ) , 이진영 ( Jin-young Lee )
5,100
초록보기
본 연구는 단풍잎돼지풀 70% 에탄올 추출물의 항염증 활성을 검증하기 위해 수행되었다. 단풍잎돼지풀 70% 에탄올 추출물의 전자공여능 측정과 ABTS+ 라디칼 소거능을 측정한 결과, 1,000 μg/ml 농도에서 각각 84.1%와 92.5%의 효과를 나타냈고, 수렴활성 측정을 한 결과 1,000 μg/ml 농도에서 94.7%의 효과를 보였다. 단풍잎돼지풀 70% 에탄올 추출물의 항염증 효과를 측정하기 위해 lipopolysaccharide (LPS)로 유도된 RAW 264.7세포를 사용하여 효과를 측정하였다. 세포에서 단풍잎돼지풀 추출물의 세포독성을 측정하기 위해 MTT assay를 수행하였다. 그 결과, 500 μg/ml 농도에서 90% 이상의 생존율을 보였다. Nitric oxide 생산을 억제하는 효과를 측정한 결과, 단풍잎돼지풀 추출물에서 농도가 증가할수록 NO 생성이 감소되는 효과를 확인하였다. 단풍잎돼지풀 추출물의 단백질 발현효과를 western blot을 통해 25, 50, 100 μg/ml 농도에서 측정하였고, 양성 대조군으로 β-actin을 사용하였다. 그 결과, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 단백질 발현효과는 100 μg/ml 농도에서 8.6%, 25.1%의 감소됨을 확인하였다. ERK1/2, p38, JNK와 Iκ-Bα의 단백질발현 효과는 인산화를 통해 확인하였고, 농도의존적으로 감소하였음을 확인 하였다. mRNA 발현 억제 효과를 RT-PCR을 통해 25, 50, 100 μg/ml의 농도에서 측정하였고, 양성 대조군으로 GAPDH를 사용하였다. 그 결과, LPS로 유도된 대식세포에서 iNOS, COX-2, interleukin (IL)-1β, IL-6, TNF-α의 mRNA 발현 억제 효과는 농도가 증가할수록 발현이 감소됨을 확인하였다. 결론적으로 단풍잎돼지풀 추출물은 염증을 억제할 수 있는 가능성이 있는 항염증 소재의 가능성을 증명하였다.
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