• Korean Journal of Plant Taxonomy
• /
• v.46 no.1
• /
• pp.1-12
• /
• 2016

DNA sequences of nrITS regions obtained from 49 accessions representing 12 species and one variety within the section Adonanthe of the genus Adonis were analyzed to test the previous intra-sectional classification system and to determine their phylogenetic relationships. The results showed that the seven accessions of A. amurensis Regel et Radde included in the present study did not form a monophyletic group, as some of the accessions showed a close relationship with the Japanese endemic species A. ramosa Franch., which implies that the current species delimitation and identification of A. amurensis is problematic. Adonis pseudoamurensis W. T. Wang, which is frequently misidentified as A. ramosa in Korea, formed a segregated group, which suggests that they should not be considered as conspecific taxa. Accessions from A. shikokuensis Nishikawa et Koji Ito, A. multiflora Nishikawa et Koji Ito, and A. pseudoamurensis formed a clade, but monophyly of each species was not evident. The nrITS data did not support the classification system proposed by Wang, who classified sect. Adonanthe into four series, as most of these were found to be either polyphyletic or paraphyletic.

• Korean Journal of Ichthyology
• /
• v.25 no.2
• /
• pp.53-58
• /
• 2013

Seven individuals (16.1~29.1 mm in length) which were estimated with fishes of genus Abudefduf were collected in Seogwipo, Jeju Island in the summer of 2011 and 2012. Among them, five individuals (20.8~29.1 mm SL) are similar to Abudefduf notatus, based on morphological characters such as yellow transverse band on the body, one small black spot on the base of the pectoral fin, and yellow caudal fin. On the other hand, two individuals (16.1 mm, 17.0 mm SL) differ from them in several light transverse bands and transparent rays of all fins except for pelvic fin, and anterior transparent head with only one (16.1 mm). According to the results of molecular analyses of 578 base pairs of mtDNA 16S rRNA sequences, these individuals correspond to A. notatus adult, with a high bootstrap value of 95% (genetic distance, d=0.002). Therefore, this study shows that the individuals more than 20.8 mm similar to adult body color but the 16.1 mm individual differs to that of adult. We confirm that this species changes to body color during their early life stages. This result regards as a survival strategy to protect themselves against their predator during their early life stages.

• Korean Journal of Microbiology
• /
• v.45 no.4
• /
• pp.397-403
• /
• 2009

For the research of the natural antioxidant from marine sources, an antioxidant-producing marine actinomycetes was isolated from sea water in Jeju coastal area. The strain was identified based on 16S rDNA sequencing, the morphology by a method of scanning electron microscopy, physiological and biochemical characteristics and cellular fatty acid analysis. The isolated strain ACT-1 cell size was $0.5\sim1.0{\mu}m$ and gram positive, aerobic, nonmotile, substrate mycelium are red and gray aerial mycelium. 16S rRNA sequence analysis showed that were Gram-positive bacteria grouped on Streptomyces genus. Results of cellular fatty acid analysis showed that major cellular fatty acids were $C_{15:0}$ anteiso (39.33%), $C_{16:1}$ cis 9 (11.96%), $C_{16:0}$ (13.08%) and $C_{17:0}$ anteiso (10.99%). Finally, strain was identified Streptomyces sp. ACT-1. The antioxidant activity of methanol extract from Streptomyces sp. ACT-1 was evaluated by measuring DPPH, hydroxyl, and alkyl radical scavenging activity using an electron spin resonance (ESR) spectrometer. DPPH radical scavenging activity of SBME-1 (Streptomyces broth methanol extract) was 67% at $1,000{\mu}g$/ml. Hydroxyl radical scavenging activity of SBME-1 was 84% at $500{\mu}g$/ml. Alkyl radical scavenging activity of SBME-1 was 71% at $1,000{\mu}g$/ml.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.8
• /
• pp.1383-1391
• /
• 2016

The fungal strain EML-DML3PNa1 isolated from leaf of white dogwood (Cornus alba L.) showed strong nematicidal activity with juvenile mortality of 87.6% at a concentration of 20% fermentation broth filtrate at 3 days after treatment. The active fungal strain was identified as Aspergillus oryzae, which belongs to section Flavi, based on the morphological characteristics and sequence analysis of the ITS rDNA, calmodulin (CaM), and β-tubulin (BenA) genes. The strain reduced the pH value to 5.62 after 7 days of incubation. Organic acid analysis revealed the presence of citric acid (515.0 mg/kg), malic acid (506.6 mg/kg), and fumaric acid (21.7 mg/kg). The three organic acids showed moderate nematicidal activities, but the mixture of citric acid, malic acid, and fumaric acid did not exhibit the full nematicidal activity of the culture filtrate of EML- DML3PNa1. Bioassay-guided fractionation coupled with ¹H- and ¹³C-NMR and EI-MS analyses led to identification of kojic acid as the major nematicidal metabolite. Kojic acid exhibited dose-dependent mortality and inhibited the hatchability of M. incognita, showing EC₅₀ values of 195.2 μg/ml and 238.3 μg/ml, respectively, at 72 h post-exposure. These results suggest that A. oryzae EML-DML3PNa1 and kojic acid have potential as a biological control agent against M. incognita.

• The Korean Journal of Mycology
• /
• v.42 no.4
• /
• pp.262-268
• /
• 2014

A fungal isolate DUCC5000 from a garden plant Pachysandra terminalis was identified as Paraconiothyrium brasiliense based on the results of morphological and molecular studies. The fungus formed brown to black conidiomata of (0.2-0.7)-2(-3.5) mm singly or as a group on PDA. Conidia measured $2-5{\times}1.8-3{\mu}m$ in size, hyaline, ellipsoid to short-cylindrical, and rounded at both ends. The internal transcribed spacer (ITS) DNA of the isolate shared 100% nucleotide sequence homology with those of known P. brasiliense isolates. Phylogenetic tree inferred from the ITS sequence analysis showed that the DUCC5000 isolate formed a clade with known isolates of P. brasiliense. The fungal mycelia grew better on oatmeal agar than on MEA and PDA. On PDA media under various pH conditions, fungal mycelial growth was observed at pH 9. Colony morphology of the fungus tended to alter depending on the kinds of nutrient media and pH condition. On chromagenic media, the fungus demonstrated its ability to produce extracellular enzymes including amyalse, avicelase, ${\beta}$-glucosidase, protease, and xylanase. However, in pathogenicity testing, no disease symptoms were observed on the leaves of P. terminalis. This strain is the first report on P. terminalis in Korea.

• Parasites, Hosts and Diseases
• /
• v.57 no.4
• /
• pp.341-357
• /
• 2019

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hotspring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.

• Journal of Life Science
• /
• v.29 no.10
• /
• pp.1126-1135
• /
• 2019

From a sample of bamboo byproduct, the protease-producing yeast strain CO-1 was newly isolated. Strain CO-1 is spherical to ovoid in shape and measures $3.1-4.0{\times}3.8-4.4{\mu}m$. For the growth of strain CO-1, the optimal temperature and initial pH were $30^{\circ}C$ and 4.0, respectively. The strain was able to grow in 0.0-15.0%(w/v) NaCl and 0.0-9.0%(v/v) ethanol. Based on a phylogenetic analysis of its 18S rDNA sequences, strain CO-1 was identified as Pichia anomala. The extracellular protease produced by P. anomala CO-1 was partially purified by ammonium sulfate precipitation, which resulted in a 14.6-fold purification and a yield of 7.2%. The molecular mass of the protease was recorded as approximately 30 kDa via zymogram. The protease activity reached its maximum when 1.0%(w/v) CMC was used as the carbon source, 1.0%(w/v) yeast extract was used as the nitrogen source, and 0.3%(w/v) $MnSO_4$ was used as the mineral source. The protease revealed the highest activity at pH 7.0 and $30^{\circ}C$. This enzyme maintained more than 75% of its stability at a pH range of 4.0-10.0. After heating at $65^{\circ}C$ for 1 hr, the neutral protease registered at 60% of its original activity. The protease production coincided with growth and attained a maximal level during the post-exponential phase.

• Parasites, Hosts and Diseases
• /
• v.58 no.6
• /
• pp.653-660
• /
• 2020

Spirometra tapeworms (Cestoda: Diphyllobothriidae) collected from carnivorous mammals in Tanzania were identified by the DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and internal transcribed spacer 1 (ITS1), and by morphological characteristics. A total of 15 adult worms were collected from stool samples and carcasses of Panthera leo, Panthera pardus, and Crocuta crocuta in the Serengeti and Selous ecosystems of Tanzania. Three Spirometra species: S. theileri, S. ranarum and S. erinaceieuropaei were identified based on morphological features. Partial cox1 sequences (400 bp) of 10 specimens were revealed. Eight specimens showed 99.5% similarity with Spirometra theileri (MK955901), 1 specimen showed 99.5% similarity with the Korean S. erinaceieuropaei and 1 specimen had 99.5% similarity with Myanmar S. ranarum. Sequence homology estimates for the ITS1 region of S. theileri were 89.8% with S. erinaceieuropaei, 82.5% with S. decipiens, and 78.3% with S. ranarum; and 94.4% homology was observed between S. decipiens and S. ranarum. Phylogenetic analyses were performed with 4 species of Spirometra and 2 species of Dibothriocephalus (=Diphyllobothrium). By both ML and BI methods, cox1 and ITS1 gave well supported, congruent trees topology of S. erinaceieuropaei and S. theileri with S. decipiens and S. ranarum forming a clade. The Dibothriocephalus species were sisters of each other and collectively forming successive outgroups. Our findings confirmed that 3 Spirometra species (S. theileri, S. ranarum, and S. erinaceieuropaei) are distributed in the Serengeti and Selous ecosystems of Tanzania.

• Korean journal of applied entomology
• /
• v.59 no.4
• /
• pp.281-293
• /
• 2020

The Korean thistle (Cirsium setidens) is grown in Gangwon province as a food ingredient called gondre. Based on regular monitoring of Korean thistle cultivation, we detected local outbreaks of a stick insect causing severe damage. Here we report the identification of the stick insect and its ecological characteristics. The survey involved 3 farms located in Jeongeon-gun, Gangwon province and lasted from May 28 to October 1 in 2019. According to morphological and DNA analyses the stick insect was identified as Ramulus koreanus Kwon Ha and Lee. a member of the family Phasmatidae. Its outbreak in the Korean thistle farms was observed from June 11 to August 22 with peak density on July 23. Spatial distribution analyses, using Taylors power law and Greens index showed that R. koreanus was uniformally distributed. Food consumption rate of Korean thistle leaves was estimated as 60.98±4.35 ㎠/day/adult. The main food plants were identified as Juglans mandshurica and Aronia melanocarpa. Further study needs to pursue the mechanism of the outbreak and its possible impact on agricultural and forest ecosystems. Additionally, means to relieve crop damage need to be identified.

• Animal Bioscience
• /
• v.35 no.2
• /
• pp.281-289
• /
• 2022

Objective: The aim of this study was to characterize the exopolysaccharides (EPS)-producing lactic acid bacteria from Taiwanese ropy fermented milk (TRFM) for developing a clean label low-fat fermented milk. Methods: Potential isolates from TRFM were selected based on the Gram staining test and observation of turbid suspension in the culture broth. Random amplified polymorphic DNA-polymerase chain reaction, 16S rRNA gene sequencing, and API CHL 50 test were used for strain identification. After evaluation of EPS concentration, target strains were introduced to low-fat milk fermentation for 24 h. Fermentation characters were checked: pH value, acidity, viable count, syneresis, and viscosity. Sensory evaluation of fermented products was carried out by 30 volunteers, while the storage test was performed for 21 days at 4℃. Results: Two EPS-producing strains (APL15 and APL16) were isolated from TRFM and identified as Lactococcus (Lc.) lactis subsp. cremoris. Their EPS concentrations in glucose and lactose media were higher than other published strains of Lc. lactis subsp. cremoris. Low-fat fermented milk separately prepared with APL15 and APL16 reached pH 4.3 and acidity 0.8% with a viable count of 9 log colony-forming units/mL. The physical properties of both products were superior to the control yogurt, showing significant improvements in syneresis and viscosity (p<0.05). Our low-fat products had appropriate sensory scores in appearance and texture according to sensory evaluation. Although decreasing viable cells of strains during the 21-day storage test, low-fat fermented milk made by APL15 exhibited stable physicochemical properties, including pH value, acidity, syneresis and sufficient viable cells throughout the storage period. Conclusion: This study demonstrated that Lc. lactis subsp. cremoris APL15 isolated from TRFM had good fermentation abilities to produce low-fat fermented milk. These data indicate that EPS-producing lactic acid bacteria have great potential to act as natural food stabilizers for low-fat fermented milk.