In the current study, a total of 102 common Todarodes pacificus squid caught in the East Sea were investigated for parasitological research. The results revealed that 33 (32.35%) out of 102 squid were infected by Nybelinia surmenicola, the mean intensity was 5.58 parasites per squid, and the maximum abundance was 11. Morphological analysis using a field emission scanning electron microscope showed the characteristic features of N. surmenicola. Molecular identification based on the 28S rRNA gene confirmed the isolated parasite as N. surmenicola, while phylogenetic analysis revealed that N. surmenicola isolated in this study was clustered with N. surmenicola isolated from Japan. This is the first report of phylogenetic characterization of N. surmenicola isolated from Korea.
The squid Todarodes pacificus is a commercially important fishery species in East Asia. As East Asians consume raw or lightly cooked squids, there has been growing concern about parasitic infections associated with squid consumption. In the current study, five squids caught in the East Sea were sampled for parasitological research from the biggest fishery market in Seoul, Republic of Korea. They were dissected and examined for parasites using a light microscope. Proteocephalus sp. was isolated and identified using field emission scanning electron microscopy, PCR, and sequencing. Given that Proteocephalus spp. can be affected by water temperature and geographical characteristics, further research on Proteocephalus spp. with respect to changes in water temperature in the East Sea is important.
In DNA barcoding, the DNA degradation of old museum specimens has been limited full-length (658bp) sequencing. The challenges associated with the retrieval and authentication of degraded DNA extracts from fossil and old museum specimens were principally limited to analyze the relatively short sequences (<300 bp). Furthermore, almost protocols in other to analyzed the degraded DNA contained the cloning process after PCR causing the time-consuming and the rising costs. To overcome these problematic circumstances, we tried a modified method to analyze full-length of DNA barcoding region in 30~60 year-old butterfly specimens (225 samples in 28 species), using direct sequencing after PCR with species-specific overlapping primer sets per each species. As a result, all of 28 species have been successfully analyzed, although 178 samples (79%) are completely generated barcoding sequences ranged from 640 to 658 bp and 47 samples (21%) are partially sequenced ranged from 100 to 500 bp. Thus, the result showed that the direct PCR sequencing using the overlapping primer sets per species appears to have great potential efficiency for analysis of degraded DNA without incorrect sequences.
The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.
본 연구에서는 4대강 살리기 사업 후 퇴적현상이 지배적으로 발생하는 남한강과 섬강 합류부 구간을 대상으로 2차원 수치모형인 CCHE2D 모형을 이용하여 하천의 흐름 및 하상변동에 대한 해석을 수행하였다. 대상지점 합류부는 남한강 본류의 만곡부에 지류 섬강이 유입되는 특성을 갖는다. CCHE2D 모형은 비평형 유사이송을 해석하며 소류사와 부유사 조정거리가 중요한 입력변수로 대상지점에서는 소류사 조정거리가 하상변동에 가장 큰 영향을 주는 것으로 나타났다. 수치모의 결과 유량비(Qr) 변화가 남한강과 섬강 합류부 지점에서 흐름 및 하상변동에 영향을 미쳤으며, Qr≤ 2.5인 경우에는 합류전 본류의 유속이 증가하여 흐름박리구역을 감소시켰으며 이로 인해 합류부 내측의 퇴적이 감소하였다. Qr>2.5이면 합류부 구간에 퇴적이 증가하여 사주가 형성될 가능성이 높은 것으로 나타났다. 수치모의를 통해 2013년에 발생한 유량비 변화에 의해 합류부에 고정사 주가 형성된 것을 알 수 있었다.
Background : Nasturtium officinale, belongs to the Brassicaceae, is a perennial plant growing in and around natural watersystem. It is commonly called watercress and commercially consumed as a salad crop in many countries. Hairy root cultures (HRCs), transformed by Agrobacterium rhizogenes (A. rhizogenes), have been noted for an experimental model system in plant metabolic engineering for the synthesis of natural products since hairy roots have fascinating properties including biochemical and genetic stability, high biosynthetic capacity for secondary metabolites and rapid growth rates. Methods and Results : The dry weights (DW) of watercress hairy roots was measured after 4-days freeze dryer. The highest weight was recorded after HRCs in SH and half-strength SH medium, followed by the levels of DW in MS and half-strength medium. However, the level of DW after HRCs in half-strength medium was lowest. SH medium is the most suitable for the growth of watercress hairy roots. Glucosinolate contents in the hairy roots varied responding to the basal media. 1/2 SH basal media resulted in the lowest value of total glucosinolate. MS basal media, however, resulted in the highest value of total glucosinolate, as well as the highest accumulation of each glucosinolate. The hairy roots cultured in 1/2 MS basal media showed the second highest value of total glucosinolate, followed by B5, SH and 1/2 B5. The accumulation of 4-Methoxyglucobrassicin and gluconasturtiin was also secondly higher in the hairy roots in 1/2 MS. In contrast, the level of 4-Hydroxyglucobrassicin and glucobrassicin were the second highest after culturing in SH and B5, respectively. Conclusion : In this study, media played a main role in growth and glucosinolate accumulation in watercress hairy roots. SH and half-strength SH media enabled the rate growth of hairy roots to be highest. In contrast, the highest accumulation of glucosinolate was recorded after HRCs in MS media. The current study suggests HRCs of watercress could be one of an effective alternative approaches for the enhanced production of glucosinolates