• The Korean Journal of Quaternary Research
• /
• v.17 no.2
• /
• pp.157-159
• /
• 2003

Much of northern Asia is lacking in high-resolution palaeoclimatic data coverage. This vast region thus represents a sizeable gap in data sets used to reconstruct hemispheric-scale temperature trends for the past millennium. To improve coverage, we present a regional-scale composite of four tree-ring width records of Siberian pine and Siberian larch from temperature-sensitive alpine timber-line sites in Mongolia. The chronologies load closely in principal components analysis (PCA) with the first eigenvector accounting for over 53% of the variance from ad 1450 to 1998. The 20-year interval from 1974 to 1993 is the highest such growth period in this composite record, and 17 of the 20 highest growth years have occurred since 1946. Thus these trees, unlike those recently described at some northern sites, do not appear to have lost their temperature sensitivity, and suggest that recent decades have been some of the warmest in the past 500 years for this region. There are, however, comparable periods of inferred, local warmth for individual sites, e.g., in 1520-1580 and 1760-1790. The percent common variance between chronologies has increased through time and is highest (66.1%) in the present century. Although there are obvious differences among the individual chronologies, this result suggests a coherent signal which we consider to be related to temperature. The PCA scores show trends which strongly resemble those seen in recent temperature reconstructions for the Northern Hemisphere, very few of which included representation from Eurasia east of the Ural Mountains. The Mongolia series therefore provides independent corroboration for these reconstructions and their indications of unusual wanning during the twentieth century.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.4
• /
• pp.379-388
• /
• 1983

The subtidal benthic algal communities of Dolsan-island in the southern coast of Korea were surveyed by means of SCUBA diving. The vertical zonation is recognized into three groups; upper, middle and lower subtidal zones. The representative species in each group throughout the year are Ulva pertusa, Codium fragile, Chondria crassicaulis and Gigartina tenera in the upper, Myagropsis myagroides and Sargassum tortile in the middle, and Plocamium telfairiae, Callophyllis japonica and Symphyocladia linearis in the lower zone. According to the normal association analysis by $2{\times}2$ contingency table and chi-square calculation among 29 quadrats, the algal communities are divided into 9 groups which are dominated by Sargassum tortile, Myagropsis myagroides, Chondria crassicaulis, Codium fragile, Pterocladia tenuis, Gigartina tenera, Gracilaria textorii. The thallus length and standing crops of Myagropsis myagroides show the highest value in spring and the lowest in summer.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.16
• /
• pp.6773-6779
• /
• 2014

Background: Nanotechnology opens new applications in many fields including medicine. Among all metallic nanoparticles, silver nanoparticles (silver NPS) have proved to be the most effective against a large variety of organisms including toxic cyanobacteria. Materials and Methods: Silver NPs were biosynthesized in vivo with different alga species namely, Spirulina piatensis, Chlorella vulgaris and Scenedesmus oh/iquus following two scenarios. First: by suspending a thoroughly washed algae biomass in 1 mM aqueous $AgN0_3$ solution. Second: by culturing them individually in culture media containing the same concentration of $AgN0_3$. Silver NPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FfIR) spectroscopy. The biosynthesized silver NPs were tested for cytotoxic activity against a cancer promoter cyanobacteruim Microcystis aeruginosa, considering effects on cell viability and chlorophyll content. Results: The surface plasmon band indicated the biosynthesis of silver NPs at ~400 nm. Transmission electron microscopy (TEM) revealed that the silver NPs had a mean average size below 100 nm. Energy-dispersive analysis X-ray (EDX) spectra confirmed the presence of silver element. FfIR spectral analyses suggested that proteins and or polysaccharides may be responsible for the biosynthesis of silver NPs and (-COO-) of carboxylate ions is responsible for stabilizing them. The toxic potentialities ofthe biosynthesized silver NPs against the cancer promoter cyanobacterium, Microcystis aeruginosa showed high reduction in viable cells count and the total chlorophyll content. Conclusions: The potential activity of the biosynthesized silver NPs from the studied algae species against Microcystis aernginosa cells is expected to be mainly mediated by the release of silver ions (Ag+) from the particle surface and bioactive compounds as indicated by FfIR analysis.

• Microbiology and Biotechnology Letters
• /
• v.45 no.3
• /
• pp.209-217
• /
• 2017

In the enduring investigation of the bioactive microbes, Pseudomonas aeruginosa strain (referred to as CGK-KS-1 (ICTB-315)), isolated from Chumathang hot spring, Ladakh, and India, was identified to possess a major bioactive fraction with antimicrobial and anti-biofilm properties. This bioactive metabolite was purified through bioactivity-guided fractionation. The chemical structure of this major compound was elucidated as phenazine-1-carboxamide (PCN) based on $^1H$ and $^{13}C$ NMR, FT-IR, EI-HR-MS and 2D NMR spectroscopic techniques. In the current study, PCN exhibited antimicrobial activity with MIC values ranging between $1.9-3.9{\mu}g/ml$ against various test human pathogens and Xanthomonas spp. PCN showed the anti-biofilm property with the $IC_{50}$ values ranging from 17.04 to $60.7{\mu}M$ against different test pathogens. The in silico docking studies showed PCN strongly interacted with various proteins of different Xanthomonas spp. with high binding energies. We report herein for the first time the anti-biofilm property and the docking studies of PCN. The extrolite from P. aeruginosa strain CGK-KS-1 showed promising bioactivities and may be considered as a potential candidate for application in various biocontrol strategies.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.10
• /
• pp.1500-1509
• /
• 2020

Drought is a major abiotic factor and has drastically reduced crop yield globally, thus damaging the agricultural industry. Drought stress decreases crop productivity by negatively affecting crop morphological, physiological, and biochemical factors. The use of drought tolerant bacteria improves agricultural productivity by counteracting the negative effects of drought stress on crops. In this study, we isolated bacteria from the rhizosphere of broccoli field located in Daehaw-myeon, Republic of Korea. Sixty bacterial isolates were screened for their growth-promoting capacity, in vitro abscisic acid (ABA), and sugar production activities. Among these, bacterial isolates YNA59 was selected based on their plant growth-promoting bacteria traits, ABA, and sugar production activities. Isolate YNA59 highly tolerated oxidative stress, including hydrogen peroxide (H₂O₂) and produces superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities in the culture broth. YNA59 treatment on broccoli significantly enhanced plant growth attributes, chlorophyll content, and moisture content under drought stress conditions. Under drought stress, the endogenous levels of ABA, jasmonic acid (JA), and salicylic acid (SA) increased; however, inoculation of YNA59 markedly reduced ABA (877 ± 22 ng/g) and JA (169.36 ± 20.74 ng/g) content, while it enhanced SA levels (176.55 ± 9.58 ng/g). Antioxidant analysis showed that the bacterial isolate YNA59 inoculated into broccoli plants contained significantly higher levels of SOD, CAT, and APX, with a decrease in GPX levels. The bacterial isolate YNA59 was therefore identified as Variovorax sp. YNA59. Our current findings suggest that newly isolated drought tolerant rhizospheric Variovorax sp. YNA59 is a useful stress-evading rhizobacterium that improved drought-stress tolerance of broccoli and could be used as a bio-fertilizer under drought conditions.

• Proceedings of the SCSK Conference
• /
• 2003.09a
• /
• pp.645-658
• /
• 2003

We evaluated activities of various plant leaf extracts and found the availability against skin aging in the leaf extract of star fruit (Averrhoa carambola L), and developed Star Fruit Leaf Extract BG30 as an ingredient of cosmetics. Star Fruit Leaf Extract BG30 was found to show scavenging activities of reactive oxygen species and an inhibitory effect on the activity of matrix metalloproteinase-1. It showed increasing activity of type I collagen and recovery effect from damage of UV-B irradiation in human fibroblast. We performed the separation of the active principal from Star Fruit Leaf Extract BG30 to give isofurcatin 2"-Ο-$\alpha$-L-rhamnopyranoside, which showed increasing activity of type I collagen. To examine the anti-wrinkle effect of Star Fruit Leaf Extract BG30, seven volunteers applied a Star Fruit Leaf Extract BG30 1 ％ cream in double blind manner to one-side of the corner of their eye and the placebo cream to the opposite side. Clinical evaluation of wrinkling was performed every week for 5 weeks using a silicone rubber replica. A statistically significant improvement of Star Fruit Leaf Extract BG30-treated site was seen in decreased wrinkles. Star Fruit Leaf Extract BG30 results in clinically visible improvement in wrinkling when used topically for 5 weeks.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.4
• /
• pp.522-527
• /
• 2010

Gibberellic acid ($CA_3$) is used in many industries and constitutes the primary gibberellins produced by fungi and bacteria. However, there is no information on $CA_3$ production by Methylobacterium oryzae CBMB20, a novel plant growth promoting bacterium. We investigated the favorable carbon (C) and nitrogen (N) sources and ratios and cultural conditions, such as incubation temperature, pH of the culture medium, and incubation period for the maximum production of $CA_3$ by Methylobacterium oryzae CBMB20. Maximum $CA_3$ production was observed in ammonium mineral salt (AMS) broth supplemented with Na-succinate and $NH_4Cl$ as C and N sources, respectively. The maximum $CA_3$ production was found at the C/N ratio of 5:0.4 g $L^{-1}$. The highest $CA_3$ production was obtained when the bacterial culture was incubated at $30^{\circ}C$ for 96 h at pH 7.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.21-21
• /
• 2003

An efficient plant regeneration system was developed for Hordeum vulgare L. cv Baegdong - an important Korean cultivar. The protocol was based on a series of experiments involving the sizes of mature embryos and the culture media. The embryo size is found to be critical for the establishment of embryogenic callus. Embryos of 1.1-1.5 mm size showed a much higher ability to produce embryogenic callus capable of regenerating green plants. The auxins picloram and dicamba proved effective in inducing callus from mature embryos. 2.5 mg $I^{-1}$ dicamba and 4.0 mg $I^{-1}$ picloram in Murashige and Skoog's (MS) medium was optimum for the induction of primary callus. The induced primary callus was loose and friable which ultimately developed into creamy white and compact callus after transferring into the fresh medium. Multiple shoots were induced in the MS medium supplemented with 6.0 g $I^{-1}$ maltose, 20 mg $I^{-1}$ sorbitol, 0.5 mg $I^{-1}$ 2,4-D and 1.0 mg $I^{-1}$ kinetin and the rate was 6.5 shoots per embryo. Regenerated plants were hardy and developed roots rapidly in the medium containing 0.2 $I^{-1}$ IBA. This efficient plant regeneration system provides a foundation for generating transgenic plants of this important barley cultivar.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.22-22
• /
• 2018

Based on medicinal plant references from Vietnam, 1884 flowering plant species (194 families, 956 genera) can be used to treat 30 diseases or have 4 valuable uses such as Tranquillizer, Detoxify, Galactopoietic and Diuretic. 23 species (15 families, 18 genera) for Tranquillizer, 94 species (50 families, 79 genera) for Vaginitis, 18 species (13 families, 15 genera) for Paralytic, 6 species (6 families, 6 genera) for Obese, 60 species (28 families, 50 genera) for Flu, 63 species (37 families, 56 genera) for Eyesore, 96 species (45 families, 77 genera) for Toothache, 97 species, (50 families, 86 genera) for Detoxify, 18 species (18 families, 18 genera) for Syphilis, 80 species (50 families, 71 genera) for Asthma, 17 species (8 families, 11 genera) for HIV AIDS, 56 species (41 families, 54 genera) for Gonorrhoea, 378 species (108 families, 56 genera) for Dysentery, 31 species (22 families, 29 genera) for Galactopoietic, 131 species (69 families, 116 genera) for Diuretic, 11 species (9 families, 9 genera) for Mump, 737 species (129 families, 626 genera) for "Snack bite", 23 species (18 families, 22 genera) for Urolithiasis, 134 species (56 families, 122 genera) for Malaria, 462 species (113 families, 323 genera) for Rheumatism, 55 species (34 families, 49 genera) for Diabetes, 87 species (42 families, 70 genera) for Heart and blood pressure diseases, 70 species (46 families, 63 genera) for Haemorrhoids, 21 species (16 families, 20 genera) for Cancer, 42 species (27 families, 38 genera) for Gastritis, 154 species (66 families, 129 genera) for Hepatitis, 5 species (5 families, 5 genera) for Keratitis, 81 species (42 families, 75 genera) for Sore throat, 11 families (9 families, 11 genera) for Encephalitis, 72 species (41 families, 66 genera) for Nephritis, 10 species (6 families, 8 genera) for Sinusitis, 22 species (17 families, 20 genera) for Sterile, 19 species (14 families, 17 genera) for Cirrhosis, 3 species (3 families, 3 genera) for Brain hemorrhage. Each species can be used to treat some diseases. The information of species can be used to orient researches fast and effectively.

• Journal of Plant Biotechnology
• /
• v.5 no.4
• /
• pp.225-231
• /
• 2003

The hormonal requirement suiting micropropagation of Morus alba during any season throughout the year was studied. Sprouting frequency from axillary buds of M. alba was greatly influenced by the time of explant collection, the highest value was achieved when nodal explants were collected at the end of bud dormancy period (late in March) and cultured on Murashige and Skoog (MS) medium supplemented with low concentration (0.5 mg/L) of BAP, kinetin or IBA (85-68%). In addition, they showed higher axillary bud sprouting on growth-regulators-free medium (49%) than others collected in autumn or winter and cultured on medium supplemented with various growth regulators (47-48%). Regardless of that period, young explants with greenish buds collected in summer exhibiting high sprouting frequency (66%) on MS medium supplemented with 0.5 mg/L kinetin and 0.5 mg/L GA3. Shoot multiplication via adventitious bud formation was achieved when the nodal explants were cultured on MS medium supplemented with 2 mg/L BAP and 0.2 mg/L IBA. Further multiplication via nodal explants of in vitro grown shoots was obtained on MS medium supplemented with 0.5 mglL BAP and 0.5 mg/L GA3. While half strength MS medium supplemented with low concentration (0.5 mg/L) of IBA, IAA or 2,4-D stimulated adventitious root formation, IBA was the best. After transfer the plantlets to the soil, acclimatization for three weeks was essential prerequisite for survival in high frequency (92%). Peroxidase activity is related to break of bud dormancy where maximum enzyme activity was detected when the lateral buds were induced to commence growth under field condition (early in spring) or in vitro.