• 대한수의학회지
• /
• 제21권2호
• /
• pp.93-97
• /
• 1981

It has long been believed for the presence of infectious coryza affecting serious economic loss in domestic poultry industry. However, the etiologic agent has not been isolated until quite recently. From 1979, several strains of Haemophilus-like organism were isolated from chickens with symptoms similar to infectious coryza, and their colonial morphology, growth requirement, biochemical properties and pathogenicity were assessed. In addition, serological properties of the isolates by cross hemagglutination inhibition test was also investigated. The results indicated that all the isolates were identified as Haemophilus gallinarum which had similar characteristics to the reference strains.

• Fisheries and Aquatic Sciences
• /
• 제27권3호
• /
• pp.159-170
• /
• 2024

Research to obtain molecular markers related to the major histocompatibility complex (MHC) gene in both strains of gourami is essential to increase the success of the selection program of disease resistance traits. Using a completely randomized design (CRD), the challenge test consists of four treatments and seven replications. The treatment was Jambi gourami injected with PBS (KJ), Kalimantan gourami injected with PBS (KK), Jambi strain injected with Aeromonas hydrophila (GJ), and Kalimantan strain injected with A. hydrophila (GK). The GJ population was more resistant to A. hydrophila than the GK population. The MHC II gene was detected in both test strains (GJ and GK), both resistant and susceptible fish. However, there were differences in the results of amplifying the MHC II gene in susceptible and resistant fish. Two DNA fragments approximately 400 and 585 bp were detected in the genome of susceptible fish, while in the genome of susceptible fish, only one DNA fragment was detected (400 bp). Therefore, the MHC II gene fragment with a size of about 585 bp can be used as a potential candidate for specific molecular markers to obtain resistance to A. hydrophila bacteria in the giant gourami.

• 한국버섯학회지
• /
• 제12권3호
• /
• pp.171-180
• /
• 2014

느타리버섯류(Pleurotus spp.) 우량 품종개발에 많이 이용되는 교잡육종법 중에서 단핵-단핵간(mono-mono) 교잡에 관한 특성을 구명하기 위하여 느타리 6계통 및 사철느타리 1계통으로 단핵-단핵간 7조합 85개 교잡주를 얻어 교잡율, 핵 DNA 패턴 양상, 자실체의 갓 색깔과 수량성을 분석한 결과는 다음과 같다. 단핵-단핵간 교잡율은 50~93.75%로 나타났으며, 단핵간 85 교잡주의 핵 DNA 양상을 분석한 결과 양친주의 핵을 공유하고 있어 DNA 패턴은 양친의 중간이지만 유전유사도는 어느 한쪽 친주와 조금 더 가까운 양상을 나타냈다. 계통간교잡주 모두 양친의 핵이 공존하는 DNA 패턴을 나타내었지만 양친 중 한쪽 친과 유연관계가 가까운 것으로 나타났다. 사철느타리와 느타리간 교잡주는 유사도가 사철느타리에 가까웠고, 느타리간의 교잡주도 한쪽 모균주에 가까운 유연관계로 나타났다. 단핵-단핵간 교잡에서 자실체 갓 색은 사철느타리와 느타리간 교잡주는 대부분 양친주의 중간정도의 색을 나타냈으나 양친주 중 어느 한 쪽 친주에 좀 더 가까운 갓 색을 띄는 경향을 나타냈다. 자실체 수량성은 느타리간의 교잡주는 양친과 유사한 것이 82 %, 양친보다 높은 것이 0%, 양친보다 낮은 것이 18%였다. 본 연구는 느타리 계통간 교잡주의 핵 DNA 양상과 자실체 특성을 구명하였다. 단핵-단핵간 교잡법의 장점을 충분히 활용하여 앞으로 육종방법으로서 느타리버섯류의 우량 품종을 개발하는데 유용하게 이용될 수 있을 것으로 기대된다.

• BMB Reports
• /
• 제37권3호
• /
• pp.282-291
• /
• 2004

Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyI1) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyI1 and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyI1 and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyI1s, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pastoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of P. pastoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that ~4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and an optimum temperature of $60^{\circ}C$.

• Journal of Microbiology and Biotechnology
• /
• 제22권9호
• /
• pp.1218-1223
• /
• 2012

${\varepsilon}$-Poly-$_L$-lysine (${\varepsilon}$-PL), produced by Streptomyces or Kitasatospora strains, is a homo-poly-amino acid of $_L$-lysine, which is used as a safe food preservative. The present study investigates the combined use of cell immobilization and in situ adsorption (ISA) to produce ${\varepsilon}$-PL in shaken flasks. Loofah sponge-immobilized Streptomyces ahygroscopicus GIM8 produced slightly more ${\varepsilon}$-PL than those immobilized on synthetic sponge, and sugarcane bagasse. Moreover, loofah sponge supported the maximum biomass. Hence, loofah sponge was chosen for cell immobilization. Meanwhile, the ion-exchange resin D152 was employed for ISA. The loofah sponge-immobilized cells produced $0.54{\pm}0.1g/l$ ${\varepsilon}$-PL, which significantly increased to $3.64{\pm}0.32g/l$ after combining with ISA through the addition of resin bags. The free cells with ISA using the dispersed resin yielded $2.73{\pm}0.26g/l$ of ${\varepsilon}$-PL, an increase from $0.82{\pm}0.08g/l$. These data illustrate that the proposed combination method improved production most significantly compared with either immobilization or ISA only. Moreover, the immobilized cells could be repeatedly used and an ${\varepsilon}$-PL total amount of $8.05{\pm}0.84g/l$ was obtained. The proposed combination method offers promising perspectives for ${\varepsilon}$-PL production.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2015년도 춘계학술대회 및 임시총회
• /
• pp.53-53
• /
• 2015

Agrobacterium tumefaciens-mediated transformation(ATMT) of Flammulina velutipes was used to produce a diverse number of transformants to discover the functions of gene that is vital for its variation color, spore pattern and cellulolytic activity. Futhermore, the transformant pool will be used as a good genetic resource for studying gene functions. Agrobacterium-mediated transformation was conducted in order to generate intentional mutants of F. velutipes strain KACC42777. Then Agrobacterium tumefaciens AGL-1 harboring pBGgHg was transformed into F. velutipes. This method is use to determine the functional gene of F. velutipes. Inverse PCR was used to insert T-DNA into the tagged chromosomal DNA segments and conducting sequence analysis of the F. velutipes. But this experiment had trouble in diverse morphological mutants because of dikaryotic nature of mushroom. It needed to make monokaryotic fruiting varients which introduced genes of compatible mating types. In this study, next generation sequencing data was generated from 28 strains of Flammulina velutipes with different phenotypes using Illumina Hiseq platform. Filtered short reads were initially aligned to the reference genome (KACC42780) to construct a SNP matrix. And then we built a phylogenetic tree based on the validated SNPs. The inferred tree represented that white- and brown- fruitbody forming strains were generally separated although three brown strains, 4103, 4028, and 4195, were grouped with white ones. This topological relationship was consistently reappeared even when we used randomly selected SNPs. Group I containing 4062, 4148, and 4195 strains and group II containing 4188, 4190, and 4194 strains formed early-divergent lineages with robust nodal supports, suggesting that they are independent groups from the members in main clades. To elucidate the distinction between white-fruitbody forming strains isolated from Korea and Japan, phylogenetic analysis was performed using their SNP data with group I members as outgroup. However, no significant genetic variation was noticed in this study. A total of 28 strains of Flammulina velutipes were analyzed to identify the genomic regions responsible for producing white-fruiting body. NGS data was yielded by using Illumina Hiseq platform. Short reads were filtered by quality score and read length were mapped on the reference genome (KACC42780). Between the white- and brown fruitbody forming strains. There is a high possibility that SNPs can be detected among the white strains as homozygous because white phenotype is recessive in F. velutipes. Thus, we constructed SNP matrix within 8 white strains. SNPs discovered between mono3 and mono19, the parental monokaryotic strains of 4210 strain (white), were excluded from the candidate. If the genotypes of SNPs detected between white and brown strains were identical with those in mono3 and mono19 strains, they were included in candidate as a priority. As a result, if more than 5 candidates SNPs were localized in single gene, we regarded as they are possibly related to the white color. In F. velutipes genome, chr01, chr04, chr07,chr11 regions were identified to be associated with white fruitbody forming. White and Brown Fruitbody strains can be used as an identification marker for F. veluipes. We can develop some molecular markers to identify colored strains and discriminate national white varieties against Japanese ones.

• 한국균학회지
• /
• 제39권1호
• /
• pp.48-52
• /
• 2011

본 연구에서는 표고 교잡균주들의 생화학적 특성을 이해하기 위한 하나의 시도로서 교잡균주간의 laccase 효소의 활성을 비교하는 빠르고 간편한 방법을 모색하고자 균사체 배양 배지의 성상과 염색물질이 laccase 활성 검출에 미치는 영향을 조사 비교하였다. 고체배지와 액체배지 모두에서 발색시약이 Remazol Brilliant Blue R(RBBR)일 경우는 potato dextrose 성분 보다 malt extract 성분 배지를 사용하는 것이 표고버섯균 균사가 분비하는 세포외 laccase 활성 검출이 용이하였다. Guaiacol을 발색시약으로 사용하는 경우는 potato dextrose 성분과 malt extract 성분 배지 모두 세포외 laccase 활성 검출이 용이하였다. 2ml microfuge tube를 이용한 액체 배양 방법은 RBBR와 Guaiacol 모두 malt extract 성분배지에서 3일만에 표고 교잡균주간의 세포외 laccase 활성 검출과 정량적 비교를 가능케 하였다.

• 생명과학회지
• /
• 제30권11호
• /
• pp.1007-1011
• /
• 2020

본 연구는 우리나라 고유의 재래흑염소 집단인 당진, 장수, 통영 및 경상대 계통과 교잡종 염소 계통 또는 해외품종의 개체 식별을 위한 유전적 다양성과 관계 조사 및 검증을 위해 수행하였다. 각 염소 집단에 존재하는 Monomorphic SNP를 수집한 이후 공통적으로 존재하는 SNP 133개를 선발하여 분석에 이용하였다. Monomorphic SNP 133개를 통한 재래흑염소와 교잡종 염소의 유전적 구조 차이를 나타냈으며, 주성분 분석 결과 재래흑염소와 교잡종 염소가 명확히 구분되는 것으로 나타났다. 또한, 참조집단 이외의 70두(Native Korean goat = 24, Cross breed = 46)로 구성된 검증집단을 분석한 결과 국내 재래흑염소 계통의 참조집단과 동일한 유전적 구조를 나타냈으며, 교잡종 염소의 경우 참조집단의 일부 유전적 구성을 공유하는 것으로 나타났다. 국내 재래흑염소의 경우는 하나의 군집을 형성한 반면 해외 품종 및 교잡종 계통의 경우 재래흑염소 계통에 비해 넓게 퍼져 군집을 형성하는 것으로 나타났다. 따라서, 본 연구 결과는 국내 재래흑염소 유전자원 집단을 보존을 위한 기초자료로 활용하고 추후 유전적 다양성을 고려한 염소의 개량을 위한 기초자료로 유용하게 활용 할 수 있을 것으로 판단된다.

• 식물병연구
• /
• 제12권2호
• /
• pp.129-133
• /
• 2006

2003년 수원의 팥 재배 포장에서 새로운 병해가 발견되었다. 처음에는 잎에서 수침상 점무늬가 형성되고 점점 커져 주위로 노란색의 테두리를 형성하는 진갈색의 반점을 형성한다. 심해지면 잎이 떨어지고 잎자루 및 꼬투리에도 진갈색의 병반이 형성된다. YDC 배지에서 병원세 균을 순수 분리하였을 때 Xanthomonas속 세균의 전형적인 특징인 노란색 색소를 띤 세균이 형성되었다. 분리된 세균을 $10^8 cfu/ml$로 현탁한 후 3 주 동안 자란 팥과 콩에 분무 접종하여 병원성을 확인하였다. 지방산 조성 및 함량과 다양한 탄소원 이용정도를 이용하여 분리세균 SL4311은 X. axonopodis pv. phaseoli로 SL4309와 SL4310 은 X. axonopodis pv. phaseoli var. fuscans로 동정하였으며 이 병을 팥의 세균성잎마름병으로 명명하였다.

• Journal of Microbiology and Biotechnology
• /
• 제33권6호
• /
• pp.831-839
• /
• 2023

Tylosin is a potent veterinary macrolide antibiotic produced by the fermentation of Streptomyces fradiae; however, it is necessary to modify S. fradiae strains to improve tylosin production. In this study, we established a high-throughput, 24-well plate screening method for identifying S. fradiae strains that produce increased yields of tylosin. Additionally, we constructed mutant libraries of S. fradiae via ultraviolet (UV) irradiation and/or sodium nitrite mutagenesis. A primary screening of the libraries in 24-well plates and UV spectrophotometry identified S. fradiae mutants producing increased yields of tylosin. Mutants with tylosin yield 10% higher than the wild-type strain were inoculated into shake flasks, and the tylosin concentrations produced were determined by high-performance liquid chromatography (HPLC). Joint (UV irradiation and sodium nitrite) mutagenesis resulted in higher yields of mutants with enhanced tylosin production. Finally, 10 mutants showing higher tylosin yield were re-screened in shake flasks. The yield of tylosin A by strains UN-C183 (6767.64 ± 82.43 ㎍/ml) and UN-C137 (6889.72 ± 70.25 ㎍/ml) was significantly higher than that of the wild-type strain (6617.99 ± 22.67 ㎍/ml). These mutant strains will form the basis for further strain breeding in tylosin production.