• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.8-15
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• 2021

More and more available fungal genome sequence data reveal a large amount of secondary metabolite (SM) biosynthetic 'dark matter' to be discovered. Heterogeneous expression is one of the most effective approaches to exploit these novel natural products, but it is limited by having to clone entire biosynthetic gene clusters (BGCs) without errors. So far, few effective technologies have been developed to manipulate the specific large DNA fragments in filamentous fungi. Here, we developed a fungal BGC-capturing system based on CRISPR/Cas9 cleavage in vitro. In our system, Cas9 protein was purified and CRISPR guide sequences in combination with in vivo yeast assembly were rationally designed. Using targeted cleavages of plasmid DNAs with linear (8.5 kb) or circular (8.5 kb and 28 kb) states, we were able to cleave the plasmids precisely, demonstrating the high efficiency of this system. Furthermore, we successfully captured the entire Nrc gene cluster from the genomic DNA of Neosartorya fischeri. Our results provide an easy and efficient approach to manipulate fungal genomic DNA based on the in vitro application of Cas9 endonuclease. Our methodology will lay a foundation for capturing entire groups of BGCs in filamentous fungi and accelerate fungal SMs mining.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 춘계학술대회
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• pp.19-25
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• 2002

Biotechnology in the 21st century will be driven by three emerging technologies: genomics, high-throughput biology, and bioinformatics. These technologies are complementary to one another. A large number of economically important crops are currently subjected to whole genome sequencing. Functional genomics for determining the functions of the genes comprising the given plant genome is under progress by using various means including phenotyping data from transgenic mutants, gene expression profiling data from DNA microarrays, and metabolic profiling data from LC/mass analysis. The aim of plant molecular breeding is shifting from introducing agronomic traits such as herbicide and insect resistance to introducing quality traits such as healthful oils and proteins, which will lead to improved and nutritional food and feed products. Plant molecular breeding is also expected to aim to develop crops for producing human therapeutic and industrial proteins.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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• pp.13-16
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• 2000

Microorganisms have been widely employed for the production of useful bioproducts including primary metabolites such as ethanol, succinic acid, acetone and butanol, secondary metabolites represented by antibiotics, proteins, polysaccharides, lipids and many others. Since these products can be obtained in small quantities under natural condition, mutation and selection processes have been employed for the improvement of strains. Recently, metabolic engineering strategies have been employed for more efficient production of these bioproducts. Metabolic engineering can be defined as purposeful modification of cellular metabolic pathways by introducing new pathways, deleting or modifying the existing pathways for the enhanced production of a desired product or modified/new product, degradation of xenobiotics, and utilization of inexpensive raw materials. Metabolic flux analysis and metabolic control analysis along with recombinant DNA techniques are three important components in designing optimized metabolic pathways, This powerful technology is being further improved by the genomics, proteomics, metabolomics and bioinformatics. Complete genome sequences are providing us with the possibility of addressing complex biological questions including metabolic control, regulation and flux. In silico analysis of microbial metabolic pathways is possible from the completed genome sequences. Transcriptome analysis by employing ONA chip allows us to examine the global pattern of gene expression at mRNA level. Two dimensional gel electrophoresis of cellular proteins can be used to examine the global proteome content, which provides us with the information on gene expression at protein level. Bioinformatics can help us to understand the results obtained with these new techniques, and further provides us with a wide range of information contained in the genome sequences. The strategies taken in our lab for the production of pharmaceutical proteins, polyhydroxyalkanoate (a family of completely biodegradable polymer), succinic acid and me chemicals by employing metabolic engineering powered by genomics, proteomics, metabolomics and bioinformatics will be presented.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 추계학술대회
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• pp.19-25
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• 2002

Biotechnology in the 21st century will be driven by three emerging technologies: genomics, high-throughput biology, and bioinformatics. These technologies are complementary to one another. A large number of economically important crops are currently subjected to whole genome sequencing. Functional genomics for determining the functions of the genes comprising the given plant genome is under progress by using various means including phenotyping data from transgenic mutants, gene expression profiling data from DNA microarrays, and metabolic profiling data from LC/mass analysis. The aim of plant molecular breeding is shifting from introducing agronomic traits such as herbicide and insect resistance to introducing quality traits such as healthful oils and proteins, which will lead to improved and nutritional food and feed products. Plant molecular breeding is also expected to aim to develop crops for producing human therapeutic and industrial proteins.

• Journal of Plant Biotechnology
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• 제29권3호
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• pp.145-150
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• 2002

Biotechnology in the 21st century will be driven by three emerging technologies: genomics, high-throughput biology, and bioinformatics. These technologies are complementary to one another. A large number of economically important crops are currently subjected to whole genome sequencing. Functional genomics for determining the functions of the genes comprising the given plant genome is under progress by using various means including phenotyping data from transgenic mutants, gene expression profiling data from DNA microarrays, and metabolic profiling data from LC/mass analysis. The aim of plant molecular breeding is shifting from introducing agronomic traits such as herbicide and insect resistance to introducing quality traits such as healthful oils and proteins, which will lead to improved and nutritional food and feed products. Plant molecular breeding is also expected to aim to develop crops for producing human therapeutic and industrial proteins.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.135-137
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• 2008

The metabolic engineering of epothilones, as secondary metabolites, was investigated using Sorangium cellulosum to achieve the selective production of epothilone B, a potent anticancer agent. Thus, the propionyl-CoA synthetase gene (prpE) from Ralstonia solanacearum was heterologously expressed in S. cellulosum to increase the production of epothilone B. Propionyl-CoA synthetase converts propionate into propionyl-CoA, a potent precursor of epothilone B. The recombinant S. celluloslim containing the prpE gene exhibited a significant increase in the resolution of epothilones B/A, with an epothilone B to A ratio of 127 to 1, which was 100 times higher than that of the wild-type cells, demonstrating its potential use for the selective production of epothilone B.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.297-303
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• 2013

Phylogenetic analysis of the groEL1 and xynB1 gene sequences from Sorangium cellulosum strains isolated in Korea previously revealed the existence of at least 5 subgroups (A-E). In the present study, we used sequence analysis of polymerase chain reaction-amplified biosynthetic genes of strains from the 5 subgroups to indicate correlations between S. cellulosum subgroups and their secondary metabolic gene categories. We detected putative biosynthetic genes for disorazol, epothilone, ambruticin, and soraphen in group A, group C, group D, and group E strains, respectively. With the exception of KYC3204, culture extracts from group A, group B, and group C strains exhibited no noticeable antimicrobial inhibitory activities. By contrast, culture extracts from group D strains inhibited the growth of Candida albicans, whereas culture extracts from group E strains inhibited the growth of C. albicans and Staphylococcus aureus. High performance liquid chromatography analysis of the culture extracts from the strains of each subgroup revealed unique peak patterns. Our findings indicate the existence of at least 5 subgroups of S. cellulosum strains, each of which has the potential to produce a unique set of secondary metabolites.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.294-300
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• 2009

Activation tagging that uses T-DNA vectors containing multimerized transcriptional enhancers from the cauliflower mosaic virus (CaMV) 35S gene is a powerful tool to determine gene function in plants. This approach has been successfully applied in screening various types of mutations and cloning the corresponding genes. We generated an activation tagged hairy root pool of ginseng (Panax ginseng C.A. Meyer) in an attempt to isolate genes involved in the biosynthetic pathway of ginsenoside (triterpene saponin), which is known as the major active ingredient of the root. Quantitative and qualitative variation of ginsenoside in activation tagged hairy root lines were profiled using LC/MS. Metabolic profiling data enabled selection of a specific hairy root line which accumulated ginsenoside at a higher level than other lines. The relative expression level of several genes of triterpene biosynthetic pathway in the selected hairy root line was determined by real time RT-PCR. Overall results suggest that the activation tagged ginseng hairy root system described in this study would be useful in isolating genes involved in a complex metabolic pathway from genetically intractable plant species by metabolic profiling.

• 미생물학회지
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• 제54권3호
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• pp.175-187
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• 2018

점액세균은 포식활동, 자기방어, 세포 간 신호전달 및 아직까지 알려지지 않은 다른 기능을 위해 다양한 이차대사산물을 생산한다. 점액세균에서 분리된 많은 이차대사산물들은 독특한 작용기작을 가지며 항암, 항세균, 항진균 등과 같은 약학적으로 유용한 생리활성을 보인다. 따라서 전 세계적으로 많은 점액세균 균주들이 분리되었고 이들로부터 다양한 생리활성물질들이 탐색되었다. 하지만 16S rRNA 데이터베이스 분석에 의하면 야생에는 지금까지 분리된 종류 이외에도 다양한 점액세균 종류들이 존재할 것으로 추정되며, 유전체 서열 분석에 의하면 각 점액세균들은 기존에 알려진 물질보다 더 많은 물질을 생산할 수 있는 능력이 있는 것으로 나타났다. 본 총설에서는 점액세균 유래 이차대사산물들과 이들의 유전자, 점액세균에서의 기능, 생합성 유전자의 발현을 조절하는 전사조절인자 등에 대한 최근까지의 연구 현황을 살펴보았다.

• 생명과학회지
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• 제24권10호
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• pp.1055-1062
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• 2014

본 연구는 떡잎의 발달 동안 지방의 유동 및 대사와 관련된 오이 유전자들의 발현을 조사하여 유전자의 활성을 비교하고자 하였으며, 글라이옥시좀과 미토콘드리아 사이의 탄소원(아세틸 단위)의 가능한 경로를 탐색하고자 하였다. 네 곳의 세포 내 소기관인 글라이옥시좀(퍼옥시좀), 미토콘드리아, 엽록체 및 세포질에서 작동하는 중요 대사경로의 10개 유전자들이 조사되었다. 나아가 암소에서 발아한 유식물체의 발아 초기 반응과 이후 3일간 빛을 주었을 때의 반응을 조사하였다. 역전사-중합효소연쇄반응(RT-PCR)에 따르면, 유식물체의 발달 동안에 저장지방의 유동과 관련된 Thio2, ICL 및 MS 유전자는 항상 유사한 유전자 발현 양상을 나타냈다. 오이의 발아 초기에 BOU 유전자와 함께 ICL 및 MS 유전자의 공조된 발현은 퍼옥시좀과 미톤콘드리아 사이에 아세틸 단위의 2차 통로의 존재 가능성에 대한 강한 증거이다. 앞서 보고된 연구에서 보여준 BOU 활성에서처럼 BOU 유전자는 빛 의존성으로 암소에서는 세포막의 미약한 발달로 인하여 활성이 저하됨을 암시한다. 나머지의 유전자들은 떡잎이 초록색으로 발달하고 노쇠화 할 때까지 떡잎의 전 발달 기간 동안에 활성을 나타냈다. 본 연구에서는 아세틸 단위의 운반에 대한 새로운 추가적 제안으로써 지방 저장 종자의 발아와 오이 떡잎의 발달과 관련된 유전자의 발현을 통해 처음으로 확인하였다.