• Korean Journal of Ecology and Environment
• /
• v.36 no.2 s.103
• /
• pp.108-116
• /
• 2003

To investigate bacteria with algal Iytic activities against Anabaena cylindrica when water blooming occurs and to study enzyme profiles of alga-Iytic bacteria, various bacterial strains were isolated from surface waters and sediments in eutrophic lakes or reservoirs in Korea. Abacterial strain AK-07 was characterized and identified as Acinetobacter johnsonii based on its16S rDNA base sequence. When AK-07 was co-cultivated with A. cylindrica, bacterial cells propagated to $8\;{\times}\;10^8$ cfu $ml^{-1}$ and Iyses algal cells. However, culture filtrates of AK-07 did not exhibit algal Iytic activities. That suggesting the enzymes on the surfaces of the bacterium might be effective algal Iytic agents to cause Iyses of cells. Acinetobacter johnsonii AK-07 exhibited high degradation activities against A. cylindrica, and formed alginase, caseinase, lipase, fucodian hydrolase, and laminarinase. Moreover, glycosidases for example ${\beta}$-galatosidase, ${\beta}$-glucosidase, ${\beta}$-glucosaminidase, and ${\beta}$-xylosidase, which hydrolyzed ${\beta}$-0-glycosidic bonds, were found in cell-free extracts of A. johnsonii AK-07. Other glycosidase such as ${\alpha}$-galctosidases, ${\alpha}$-N-Ac-galctosidases, ${\alpha}$-mannosidases, and ${\alpha}$- L-fuco-sidases, which cleavage ${\alpha}$-0-glycosidic bondsare not detected. In the results, enzyme systemsof A. johnsonii AK-07 were very complex to do-grade cell walls of cyanobacteria. The polysaccharides or peptidoglycans of A. cylindrica maybe hydrolyzed and metabolized to a range of easily utilizable monosaccharides or other low molecular weight organic substances by strain AK-07 of A. johnsonii.

• Journal of Life Science
• /
• v.15 no.6 s.73
• /
• pp.1005-1012
• /
• 2005

Endophytic Bacillus sp. CY22 was previously isolated from the interior of balloon flower root and showed strong antifungal activity against phytopathogenic fungi such as Rhizoctonia solnni, Fusarium oxysporum, and Phythium ultimum. Many Bacillus strains produce antifungal compound such as iturin, fengycin, and mycosubtilin. We isolated and identified antifungal compound from cell supernatant of the endophytic strain. By the MALDI-TOF mass result, the antifungal compound was similar to the known antifungal lipopeptide iturin. It was found that the purified iturin had three isoforms with protonated masses of m/z 1,043.39, 1,057.42, and 1,071.42 and different structures in combination with $Na^{+}$ ion using MALDI-TOF MS. The ita22 gene, which transacylase gene is associated with production of antifungal iturin, had an open reading frame (ORF) of 1,200 bp encoding 400 amino acids. Results of deduced amino acids sequence homology search, Ita22 was homologous with FenF (BAB69697) of Bacillus subtilis 168.

• Journal of Food Hygiene and Safety
• /
• v.30 no.3
• /
• pp.289-294
• /
• 2015

The aim of this study was to develop rapid screening method for the identification of Chinese herbal medicine species with similar appearance, Polygonum multiflorum, Cynanchum wilfordii and C. auriculatum, by using genetic markers. As a genetic marker, psbA-trnH gene in chloroplast was selected due to differences in sequence among the three species. Species-specific primers were designed based on the sequences of the marker gene of P. multiflorum, C. wilfordii, and C. auriculatum, and the expected size of PCR products was 160, 147, and 119 bp, respectively. Under the developed conditions, cross-reaction was not detected among these three plant species. To confirm the efficiency of our species-specific primers, the optimized method was applied to a variety of processed products composed of mostly P. multiflorum and C. wilfordii, demonstrating that our method was a rapid and easy screening assay. Our findings suggest this screening method can be utilized to prevent the distribution of economically motivated adulteration food and to improve consumer's right.

• Journal of fish pathology
• /
• v.25 no.3
• /
• pp.189-197
• /
• 2012

A survey was conducted to investigate infection of anisakid nematode larvae in 243 wild marine fishes caught from the southern coastal area of Korea between 2010 and 2012. The samples comprised fishes from 9 orders, 30 families and 50 species. Total infection rate of anisakid nematode larvae was 10.7% (26/243 fish), which comprised from Yeosu, 7.4% (7/95) in 2010 and 22.7% (5/22) in 2011; from Jeju, 8.2% (5/61) in 2011; from Wando, 40.9% (9/22) in 2012. Anisakid nematode larvae were not detected in Tongyoung and Wando samples in 2011. Molecular identification of the 89 worms from 26 fish was conducted by PCR-RFLP and/or sequence analysis of internal transcribed spacer (ITS) region of ribosomal DNA. From the results, 6 kinds of anisakis species were identified: Anisakis pegreffii (infection rate: 53.9%, 48/89 worms), Hysterothylacium aduncum (38.2%, 34/89), H. fabri (3.4%, 3/89), hybird (A. simplex X A. pegreffii) (2.4%, 2/89), A. simplex (1.1%, 1/89) and Raphidascaris lophii (1.1%, 1/89). The rate of single infection was 80.8% (21/26 infected fish), while 19.2% (5/26) showed mixed infection with 2 to 3 different anisakis species.

• Asian Journal of Turfgrass Science
• /
• v.21 no.2
• /
• pp.147-154
• /
• 2007

In March of 2004, gray snow mold (Typhula blight) caused by Typhula spp. occurred on perennial ryegrass (Lolium perenne L.) and Kentucky bluegrass (Poo pratensis L.) at MuJu golf courses in Jeonbuk Province. Leaves in the affected areas were matted together and frequently covered with white to grayish mycelia. Sclerotia were formed on the leaf blade, leaf sheath, or crown regions. The fungus isolated from the diseased leaf formed whitish mycelium, clamp connections, and light pink to brown, irregular-shaped small sclerotia of less than 1.4 mm in diameter, which are characteristic to Typhula incarnata. Optimum temperature ranges for mycelial growth were $5^{\circ}C$ to $15^{\circ}C$. The causal organism was confirmed to be T. incarnata as the partial sequence of its ribosomal RNA ITS1 (internal transcribed spacer) region was 91% homologous to those of T. incarnata in GenBank database. Out of the 14 fungicides tested fur antifungal activity in vitro, 10 fungicides including iprodione, tebuconazole, polyoxin D, flutolanil, hexaconazole, tolclofos-methyl, fosetyl-Al, mepronil, pencycuron+tebuconazole, and fenarimol completely inhibited fungal growth at their recommended concentrations. In the field test, these fungicides and others such as thifluzamide and thiram effectively controlled the gray snow mold of turfgrass with some variable degrees of control efficacies.

• Animal cells and systems
• /
• v.15 no.2
• /
• pp.161-168
• /
• 2011

Siberian chipmunks, Tamias sibiricus, are one of several popular companion animals found in the pet shops of South Korea. At present, however, there have been no studies done in South Korea examining their origin even though they could be potential carriers of zoonotic diseases, and are a species of concern for efficient conservation and management strategies. Sequences of the mitochondrial cytochrome b gene (1140 bp) were determined to investigate the origin of Siberian chipmunks sold in four South Korean pet shops through comparison with sequence data from animals of known locality. Nine Siberian chipmunks were collected from pet shops in South Korea, which resulted in nine haplotypes. One (AR) of these coincided with the haplotype previously described. Phylogenetic and network analyses using 53 haplotypes including 45 haplotypes from GenBank showed three phylogenetic groups in South Korea, almost concordant to locality, designated as northern, central, and southern parts as described in a previous study. Of the nine individuals examined from the pet shops, eight were clustered into the northern phylogroup but one (cgrb9153) was grouped with the southern phylogroup, implying that at least the Siberian chipmunks examined in this study did not originate from other countries. It is likely that most individuals sold in the pet shops of Seoul were caught in the wild in Gyeonggi-do and Gangwon-do, or are maternal descendants of captive-bred individuals originating from the northern part of South Korea. It is recommended that conservation and management units of Korean chipmunks should be examined in further detail.

• Food Science and Preservation
• /
• v.14 no.2
• /
• pp.188-193
• /
• 2007

The purpose of this study was to isolate lactic acid bacteria, useful in the fermentation industry from Hahyangju Nuruk. Five strains were isolated, and identified as Lactobacillus based on growth inhibition by 10% (v/v) alcohol at pH 4.0. Isolated strains were identified to species, and named Lactobacillus plantarum L-3, L. sakei L-10, and L. curvatus strains L-8, L-11, and L-12. Morphological characteristics, physiological data, carbohydrate fermentation patterns, and 16S rRNA sequence data, were all used to characterize the bacterial isolates. L. plantarum L-3 showed the highest lactic acid productivity of all isolates, but grew only poony in the presence of 10% (v/v) alcohol at pH 4.0. The other strains exhibited lower lactic acid productivity than did L. plantarum L-3 and did not grow in the presence of 10% (v/v) alcohol at pH 4.0. The optimal temperature and pH for lactic acid production were $30^{\circ}C$ and pH 6.0 7.0, respectively. The lactic acid productivity of L. plantarum L-3, L. sakei L-10 and the three L. curvatus strains L-8, L-11, and L-12 were (% v/v of culture supematant) 1.55, 1.0, 1.06, 1.0, and 0.99, respectively, at $30^{\circ}C$ and pH 6.0. While L. plantarum L-3 suffered growth inhibition in the presence of 10% (v/v) alcohol, growth of the other strains was inhibited at 8% (v/v) alcohol.

• Journal of Veterinary Science
• /
• v.22 no.4
• /
• pp.43.1-43.10
• /
• 2021

Background: The H5 avian influenza viruses (AIVs) of clade 2.3.4.4 circulate in wild and domestic birds worldwide. In 2017, nine strains of H5N6 AIVs were isolated from aquatic poultry in Xinjiang, Northwest China. Objectives: This study aimed to analyze the origin, reassortment, and mutations of the AIV isolates. Methods: AIVs were isolated from oropharyngeal and cloacal swabs of poultry. Identification was accomplished by inoculating isolates into embryonated chicken eggs and performing hemagglutination tests and reverse transcription polymerase chain reaction (RT-PCR). The viral genomes were amplified with RT-PCR and then sequenced. The sequence alignment, phylogenetic, and molecular characteristic analyses were performed by using bioinformatic software. Results: Nine isolates originated from the same ancestor. The viral HA gene belonged to clade 2.3.4.4B, while the NA gene had a close phylogenetic relationship with the 2.3.4.4C H5N6 highly pathogenic avian influenza viruses (HPAIVs) isolated from shoveler ducks in Ningxia in 2015. The NP gene was grouped into an independent subcluster within the 2.3.4.4B H5N8 AIVs, and the remaining six genes all had close phylogenetic relationships with the 2.3.4.4B H5N8 HPAIVs isolated from the wild birds in China, Egypt, Uganda, Cameroon, and India in 2016-2017, Multiple basic amino acid residues associated with HPAIVs were located adjacent to the cleavage site of the HA protein. The nine isolates comprised reassortant 2.3.4.4B HPAIVs originating from 2.3.4.4B H5N8 and 2.3.4.4C H5N6 viruses in wild birds. Conclusions: These results suggest that the Northern Tianshan Mountain wetlands in Xinjiang may have a key role in AIVs disseminating from Central China to the Eurasian continent and East African.

• Genes and Genomics
• /
• v.40 no.12
• /
• pp.1319-1329
• /
• 2018

SSRs were successfully isolated from the Perilla crop in our current study, and used to analyze Perilla accessions from East Asia. Analyses of the clear genetic diversity and relationship for Perilla crop still remain insufficient. In this study, 40 new simple sequence repeat (SSR) primer sets were developed from RNA sequences using transcriptome analysis. These new SSR markers were applied to analyze the diversity, relationships, and population structure among 35 accessions of the two cultivated types of Perilla crop and their weedy types. A total of 220 alleles were identified at all loci, with an average of 5.5 alleles per locus and a range between 2 and 10 alleles per locus. The MAF (major allele frequency) per locus varied from 0.229 to 0.943, with an average of 0.466. The average polymorphic information content (PIC) value was 0.603, ranging from 0.102 to 0.837. The genetic diversity (GD) ranged from 0.108 to 0.854, with an average of 0.654. Based on population structure analysis, all accessions were divided into three groups: Group I, Group II and the admixed group. This study demonstrated the utility of new SSR analysis for the study of genetic diversity and population structure among 35 Perilla accessions. The GD of each locus for accessions of cultivated var. frutescens, weedy var. frutescens, cultivated var. crispa, and weedy var. crispa were 0.415, 0.606, 0.308, and 0.480, respectively. Both weedy accessions exhibited higher GD and PIC values than their cultivated types in East Asia. The new SSR primers of Perilla species reported in this study may provide potential genetic markers for population genetics to enhance our understanding of the genetic diversity, genetic relationship and population structure of the cultivated and weedy types of P. frutescens in East Asia. In addition, new Perilla SSR primers developed from RNA-seq can be used in the future for cultivar identification, conservation of Perilla germplasm resources, genome mapping and tagging of important genes/QTLs for Perilla breeding programs.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.7
• /
• pp.967-972
• /
• 2018

The genus Chattonella belonging to the class raphidophyceae, is a harmful algal bloom species. Recently, its occurrence has been increasing and expanding along the Korean coast. Species identification of the genus Chattonella only by morphological observation is difficult due to the lack of rigid cell walls. In this study, the morphological characteristics and genetic affinity of Chattonella sp. isolated from Deungnyang Bay in 2017 were examined. We carried out single-cell isolation from field samples then sequenced three different areas using the single-cell PCR method: 1) parts of ribosomal operon, the large subunit (LSU) of the rDNA, 2) the chloroplast-encoded subunit psaA of Photosystem I, and 3) rbcL encoding the large subunit of the Rubisco gene. The cells were morphologically very similar to the general genus Chattonella ($74.0{\pm}10.1{\mu}m$ in length, $33.1{\pm}3.6{\mu}m$ in width). The three partial gene sequences were insufficient to justify distinction at the species rank. However, they clustered at 99-100 % sequence similarity with C. marina, C. marina var. antiqua and C. marina var. ovata.