• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1672-1676
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• 2010

The Actinomycete strain KH29 is antagonistic to the multidrug-resistant Acinetobacter baumannii. Based on the diaminopimelic acid (DAP) type, and the morphological and physiological characteristics observed through the use of scanning electron microscopy (SEM), KH29 was confirmed as belonging to the genus Streptomyces. By way of its noted 16S rDNA nucleotide sequences, KH29 was found to have a relationship with Streptomyces cinnamonensis. The production of an antibiotic from this strain was found to be most favorable when cultured with glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. The antibiotic produced was identified, through comparisons with reported spectral data including MS and NMR as a cyclo(L-tryptophanyl-L-tryptophanyl). Cyclo(L-Trp-L-Trp), from the PY cultures of KH29, was seen to be highly effective against 41 of 49 multidrug-resistant Acinetobacter baumannii. Furthermore, cyclo(L-Trp-L-Trp) had antimicrobial activity against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger, and Candida albicans, However, it was ineffective against Streptomyces murinus.

• 한국식품과학회지
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• 제40권6호
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• pp.656-660
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• 2008

예로부터 전통 장류는 먹거리로 많이 이용되어 왔으며, 최근에는 장류의 다양한 영양 성분 및 생리 활성 능력이 밝혀지면서 관심이 증대되고 있다. 본 연구에서는 전통 방식으로 제조된 어육장의 발효에 관여하는 미생물을 숙성 기간별로 분석하고 이를 통해 안전성을 평가하였으며, 이와 함께 국내에서 시판되고 있는 간장의 미생물을 분석하여 어육장의 미생물분석과 비교하였다. 어육장은 2개월 단위로 샘플링하여 분석하였으며, 분리된 미생물은 API kit와 16S rDNA sequencing을 이용하여 동정하였다. 어육장의 발효에 전반적으로 관여하는 미생물은 Bacillus 균류와 Saccharomyces cerevisiae였으며, 숙성 초기에는 Aspergillus flavus가 발효에 관여하는 것으로 확인되었다. 어육장은 최종적으로 섭취 전에 달이는 과정을 거치게 되는데 실험결과 달인 후에는 미생물이 존재하지 않았다. 현재 국내에서 시판되고 간장의 경우 총 균수가 0-42 CFU/mL였고, 동정결과 B. subtilis, B. licheniformis, B. pumilus로 확인되었다. 분리된 Bacillus 균류에 대하여 독소여부를 분석한 결과 어육장 및 시판 장류에서 검출된 Bacillus균류는 본 실험에서 분석된 3가지 설사형 독소와 1종의 구토형 독소를 생성하지 않는 균주들인 것으로 확인되었다.

• 대한유전성대사질환학회지
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• 제6권1호
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• pp.15-23
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• 2006

Purpose: Glycogen storage disease type III (GSD-III), is a rare autosomal recessive disorder of glycogen metabolism. The affected enzyme is amylo-1,6-glucosidase, 4-alpha-glucanotransferase (AGL, glycogen debranching enzyme), which is responsible for the debranching of the glycogen molecule during catabolism. The disease has been demonstrated to show clinical and biochemical heterogeneity, reflecting the genotype-phenotype heterogeneity among different patients. In this study, we analyzed mutations of the AGL gene in three unrelated Korean GSD-III patients and discussed their clinical and laboratory implications. Methods: We studied three GSD-III patients and the clinical features were characterized. Sequence analysis of 35exons and part exon-intron boundaries of the AGLgene in patients were carried out by direct DNA sequencing method using genomic DNA isolated from patients' peripheral leukocytes. Results: The clinical features included hepatomegaly (in all patients), seizures (in patient 2), growth failure (in patients 1), hyperlipidemia (in patients 1 and 3), raised transaminases and creatinine kinase concentrations (in all patients) and mild EKG abnormalities (in patients 2). Liver transplantation was performed in patient 2due to progressive hepatic fibrosis. Administration of raw-corn-starch could maintain normoglycemia and improve the condition. DNA sequence analysis revealed mutations in 5 out of 6 alleles. Patient 1 was a compound heterozygote of c.1282 G>A (p.R428K) and c.1306delA (p.S603PfsX6), patient 2 with c.1510_1511insT (p.Y504LfsX10), and patient 3 with c.3416 T>C (p.L1139P) and c.l735+1 G>T (Y538_R578delfsX4) mutations. Except R428K mutation, 4 other mutations identified in3 patients were novel. Conclusion: GSD-III patients have variable phenotypic characteristics resembling GSD-Ia. The molecular defects in the AGL gene of Korean GSD-III patients were genetically heterogeneous.

• Interdisciplinary Bio Central
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• 제3권3호
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• pp.10.1-10.8
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• 2011

Introduction: Hash functions are computer algorithms that protect information and secure transactions. In response to the NIST's "International Call for Hash Function", we developed a biological hash function using the computing capabilities of bacteria. We designed a DNA-based XOR logic gate that allows bacterial colonies arranged in a series on an agar plate to perform hash function calculations. Results and Discussion: In order to provide each colony with adequate time to process inputs and perform XOR logic, we designed and successfully demonstrated a system for time-delayed bacterial growth. Our system is based on the diffusion of ${\ss}$-lactamase, resulting in destruction of ampicillin. Our DNA-based XOR logic gate design is based on the op-position of two promoters. Our results showed that $P_{lux}$ and $P_{OmpC}$ functioned as expected individually, but $P_{lux}$ did not behave as expected in the XOR construct. Our data showed that, contrary to literature reports, the $P_{lux}$ promoter is bidirectional. In the absence of the 3OC6 inducer, the LuxR activator can bind to the $P_{lux}$ promoter and induce backwards transcription. Conclusion and Prospects: Our system of time delayed bacterial growth allows for the successive processing of a bacterial hash function, and is expected to have utility in other synthetic biology applications. While testing our DNA-based XOR logic gate, we uncovered a novel function of $P_{lux}$. In the absence of autoinducer 3OC6, LuxR binds to $P_{lux}$ and activates backwards transcription. This result advances basic research and has important implications for the widespread use of the $P_{lux}$ promoter.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.560-570
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• 2007

The effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. Accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. Community profiling using PCR targeting the l6S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE) revealed an alteration in the bacterial community profiles with time. Exposure to cis- and trans-dichloroethenes led to the disappearance of certain genospecies that were initially observed in the untreated samples. A cluster analysis of the bacterial DGGE community profiles at various sampling times during the degradation process indicated that the community profile became stable after day 10 of the enrichment. DNA sequencing and phylogenetic analysis of selected DGGE bands revealed that the genera Acinetobacter, Pseudomonas, Bacillus, Comamonas, and Arthrobacter, plus several other important uncultured bacterial phylotypes, dominated the enrichment cultures. Thus, the identified dominant phylotypes may play an important role in the degradation of cis- and trans-dichloroethenes.

• 한국미생물·생명공학회지
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• 제35권4호
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• pp.310-315
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• 2007

민속주 안동소주 발효에 있어서, 젖산균의 영향 분석과 효율적 제어를 위해, 안동소주 자가 제조 누룩 및 알코올 발효액으로부터 젖산균을 분리하였다. 분리된 젖산균들 중 ADS-L1 균주가 가장 젖산 생성이 우수하였으며, 균체 집락의 특성으로 안동소주 자가제조 누룩 및 안동소주 발효액에서 우점종으로 판단되었으며, 생리, 생화학적 특성과 16S rDNA 염기배열 분석결과 Pediococcus acidilactici로 동정되었다. ADS-L1 균주는 $40{\sim}50^{\circ}C$의 온도와 pH $5{\sim}7$의 범위에서 우수한 생육을 보여, 최고온도가 $50^{\circ}C$까지 상승하는 누룩 띄움 과정 및 pH 6의 안동소주 발효초기의 주요 젖산균으로 판단되었다. 한편 12%(w/v)의 알코올 농도 및 0.01N HCl 처리시 낮은 생존율을 나타내어 안동소주 발효진행에 따라 발효 후기에는 급격한 생육저해가 나타날 것으로 판단되었다. MRS 배지에서의 발효특성 실험 결과, ADS-L1 균주는 충분한 탄소원이 존재시 24시간 이내에 발효액의 pH를 산성화하며, 지속적인 젖산 생성을 통해 발효액의 집균염 방지 등의 긍정적 효과를 나타내며, 발효후기 $10^5\;CFU/ml$ 이하로 감소되어 안동소주 발효동안 별도의 문제를 유발하지 않을 것으로 판단되었다.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.140-144
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• 2016

본 연구에서는 극지 연구소로부터 분양 받은 Arthrobacter sp. PAMC 27388 균주에서 생산되는 아밀라아제(amylase)를 물리적 요인(physical factor)들의 변화를 통하여 생산배지 최적화를 수행하였다. 한천 배지 상에서 lugol solution을 이용한 클린환의 확인을 통하여 아밀라아제가 생산됨을 확인하였으며, 16S rDNA를 이용하여 동정한 결과 Arthrobacter sp. 임을 확인할 수 있었다. 최적화 이전의 아밀라아제 생산량은 1.66 mU/L로 확인되었다. 최적화 결과, 2.49 mL의 접종부피, pH 6.85, 42.87 mL의 배지 부피의 조건에서 가장 많은 양의 아밀라아제가 생산될 것으로 예상되었으며, 생산량은 2.84 mU/L로 예상되었다. 확인 실험을 통하여 최적화 이전과 비교하여 생산량이 약 150% 증가한 2.50 mU/L의 아밀라아제가 생산됨을 확인할 수 있었다.

• Fisheries and Aquatic Sciences
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• 제11권3호
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• pp.172-176
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• 2008

To develop a potent strain for the production of coenzyme $Q_{10}$, a photosynthetic bacterium was isolated from silt of the Nakdong River in Korea. Using l6S-rDNA sequence analysis, the isolated strain was identified as Rhodobacter sphaeroides. A stable improvement in its $CoQ_{10}$ content was achieved by chemical mutation, upon which the content of $CoQ_{10}$(2.94 mg/g dry cell) was increased by approximately 1.9-fold, comparable to that of R. sphaeroides reported in other studies. The isolate is a potentially valuable microorganism for mass production of $CoQ_{10}$, and may provide an appropriate model for further study of economical mass production.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.583-587
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• 2004

The 7 sheep microsatellite markersOarFCB48, OarAE101, MAF33, OarFCB11, MAF70, OarFCB304 and OarFCB128, which were located on chromosomes 2, 4, 6, 9, 17 and 19, were selected to PCR in Hu sheep, Tong sheep and their closely related species,the goat. They were studied with the amplifying result of 7 microsatellite sites of Hu Sheep, Tong Sheep and goats, the data of allele number and range of allele' size of amplifying were analyzed with ANOVA. The results showed that there were no significant differences (p<0.05) in microsatellite DNA sites among 3 populations. Concerning the conservation of microsatellites in closely related species, selecting microsatellite sites located on the chromosome where the Robertsonian fusion was caused between sheep and goat, may be used in research into genetic differentiation and evolutionary relationships between sheep and goats.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.545-555
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• 2011

The diversity elucidation by amplified ribosomal DNA restriction analysis and 16S rDNA sequencing of 96 associative diazotrophs, isolated from the feeder roots of tea on enriched nitrogen-free semisolid media, revealed the predominance of Gram-positive over Gram-negative bacteria within the Kangra valley in Himachal Pradesh, India. The Gram-positive bacteria observed belong to two taxonomic groupings; Firmicutes, including the genera Bacillus and Paenibacillus; and Actinobacteria, represented by the genus Microbacterium. The Gram-negative bacteria included ${\alpha}$-Proteobacteria genera Brevundimonas, Rhizobium, and Mesorhizobium; ${\gamma}$-Proteobacteria genera Pseudomonas and Stenotrophomonas; and ${\beta}$-Proteobacteria genera Azospira, Burkholderia, Delftia, Herbaspirillum and Ralstonia. The low level of similarity of two isolates, with the type strains Paenibacillus xinjiangensis and Mesorhizobium albiziae, suggests the possibility of raising species novum. The bacterial strains of different phylogenetic groups exhibited distinct carbon-source utilization patterns and fatty acid methyl ester profiles. The strains differed in their nitrogenase activities with relatively high activity seen in the Gramnegative strains exhibiting the highest similarity to Azospira oryzae, Delftia lacustris and Herbaspirillum huttiense.