• ALGAE
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• v.21 no.1
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• pp.91-101
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• 2006

Despite continued studies on red algal flora in Korea, the taxonomy of the tiny ceramiaceous algae has received little attention. We report for the first time Griffithsia okiensis from Korea on the basis of morphology and molecular data. The species is small in thalli height (0.3-1.5 cm), and in diameter of vegetative cells (50-500 μm), and the ratio of cell length/breadth is 2-3 times. It has two carpogonial branches from the supporting cell of procarp. We generated psbA and rbcL sequences from ten specimens of G. okiensis isolated from Korea and Japan and from one G. japonica species isolated Japan. Eight specimens of G. okiensis from Korea were almost identical in both psbA and rbcL regions, nevertheless they differed from Japanese specimens by 4 ucleotides in psbA and 7 in rbcL. In all analyses of psbA, rbcL, and psbA + rbcL data sets, G. okiensis was determined to be a different species from G. japonica isolated from Japan, although both species showed a sister relationship. For all that extensive collection trips, we found no evidence for the occurrence of G. japonica in Korea.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.234-241
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• 2017

Morphological and molecular information about two microfilamentous endophytic algae of the Grateloupia lanceolata or Bryopsis sp. from Korea is given. Of two endophytes, Phaeophila dendroides is endophytic in Grateloupia lanceolata. It is green in color and composed of uniseriate branched filaments with long setae. Each cell had several pyrenoids. Undulate or twisted Phaeophila-type hair developed from vegetative cells. Dilabifilum arthropyreniae is endophytic in Bryopsis sp. The frond of this species consists of frequently irregular, branching uniseriate filaments. Each cell had a single pyrenoid without hairs. Sporangia were not observed. The ends of the filaments were curved. In the phylogenetic tree, based on tufA and ITS sequences, these two species are nested in the same clade as Phaeophila dendroides and Dilabifilum arthropyreniae, respectively. In this study, these two species are newly recorded in the Korean marine algal flora, based on the morphological and molecular data.

• ALGAE
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• v.18 no.4
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• pp.239-253
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• 2003

The morphotaxonomic characters of the genus Spirogyra were investigated to clarify their taxonomic category and the variation range among species on the basis of comparative morphological and numerical analyses by unialgal cultures and field samples collected from various freshwater habitats in Korea. 25 characters selected on morphological feature of the species were examined on 568 individuals for morphological comparisons and numerical analyses. Width, length and their length/width ratio of vegetative cell, shape of septum, chloroplast number, maximum width, width, length and their length/width ratio of female gametangium, length of male gametangium, size and shape of zygospore, and cell wall ornamentation of the spore showed a comparatively high vector in principal component analysis. In cluster analysis, 15 taxa analysed were divided into 8 major groups by the average taxonomic distance 1.0 level. Considering the morphology and numerical analysis, Spirogyra crassoidea could not be recognized as an independent species, therefore it was treated as a variety of S. ellipsospora. S. koreana (nom. invalidum), recognized as a new taxon, is under the investigation for its clear taxonomic category.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.27-31
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• 1993

Certain bacterial species possess the capability of differentiation through several morphogenetic changes which enable them to adapt to certain internal and external stimuli(Losick and Shapiro 1984). Upon induction, cells of A. vinelandii undergo a morphological process which leads to the production of one cyst per cell (Sadoff, 1975). The cysts are considerably resistant to desiccation, which confers a survival advantages upon the organism(Socolofsky and Wyss 1962). Like other prokaryotic differentiations encystment provides a relatively simple model of cellular differentiation. Like in other differentiating bacteria, vegetative growth can be separated from differentiation. Furthermore, the differentiation cycle can be synchronized by specific inducer. There have been a great deal of morphological and physiological studies on this process. However, the mechanisms used to regulate cell differentiation can be clearly defined by careful genetic analysis of the process. Unfortunately, A. vinelandii has proven to be difficult for genetic analysis (Sadoff 1975). For example, it has been shown that a variety of metabolic mutants of Azotobacter speicies are difficult to isolate after mutagenesis with chemical mutagens or UV irradiation. Nevertheless recent advances in molecular genetics in Azotobacter species, especially in the nitrogen fixation research area, appear to be able to overcome this difficulty (Robinson et al. 1986; Kennedy et al. 1986).

• KSBB Journal
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• v.18 no.6
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• pp.435-439
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• 2003

Plant cell culture can be divide into two classes non-organic culture and organic culture. Non-organic culture such as suspension culture has many researches, however organic culture about recombinant protein production has little researches. Recombinant protein produced through organ culture is quite stable and it can make proteins by itself without any grow regulators. Therefore organ culture is much easier than other methods. In this research, we used transformed tobacco seed. At first we germinated the seed then separated stems and leaves from the grown plant. And raised in liquid medium by in vitro vegetative reproduction. Continuing most suitable conditions, we compared the Quantities of recombinant protein from intra cellular with from extra cellular. And adding some permeabilizing agents (Pluronic F-68, Triton X-100, DMSO, PEG8000), we increased the productivity of the recombinant protein.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.83-83
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• 1995

The three chitin synthetases of Saccharomyces cerevisiae, Chs1, Chs2, and Chs3, participate in septum and cell wall formation of vegetative cells and in wall morphogenesis of conjugating cells and spores. Because of the differences in the nature and in the time of execution of their functions, the synthetases must be specifically and individually regulated. The nature of that regulation has been investigated by measuring changes in the levels of the three synthetases and of the messages of the three corresponding gnes, CDSI, CHS2, and CAL1/CSD2/DITl0l(referred to below as CAL1), during the budding cycles. For Chs1 and Chs3, posttranslational regulation, probably by activation of latent forms, appears to be predominant. Since Chs2, like Chs1, is found in the cell in the zymogenic form, a posttranslational activation step appears to be necessary for this synthetase also. The regulation mechanism was investigated to search the relationship of CAL1, CAL2 and CALJ which is involved in Chs3 activity us ing different assay methods other than previous one. Treatment of Chs3-containing membranes with detergents drastically reduced the enzymatic activity. Activity could, however, be restored by subsequent incubation with trypsin or other pro teases in the presence of UDPGlcNAc. Experiments wi th mutants in the three genes invoIved in Chs3 activity-CAL1, CAL2, and CALJ-showed that only CAL1 and CALJ are required for the proteaseelicited (zymogenic) activity. It is concluded that Chs3 IS a zymogen and that the CAL2 product funct ions as its activator.ivator.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.188-193
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• 2022

The Korean mint (Agastache rugosa Kuntze) is used as a leaf vegetable. Therefore, it is important to improve the quality and quantity of leaves by maintaining vegetative growth. When the development of a plant is switched from vegetative to reproductive growth, leaf development may be lowered, leading to a decrease in marketability. Therefore, this study was conducted to investigate the effect of the photoperiod on the flowering characteristics and inflorescence development of the Korean mint to select an appropriate photoperiod for leaf production. The seeds were sown in 105-cell trays on 29 November 2021, and planted in each pot on 27 December 2021, when four main leaves appeared. After planting, the light/dark period was adjusted to 10/14hrs, 12/12hrs, 14/10hrs, 16/8hrs. After 19 days of planting, the first flowering occurred in 10/14hrs, which had a short photoperiod, and the 12/12hrs had 20 days for flowering, and other treatments had 21 days. In addition, it was confirmed that the Korean mint has the characteristics of facultative quantitative short-day plant, through the increase in the development of inflorescences as the light period is shorter than the dark period. As for the growth of Korean mint, the longer the photoperiod, the higher values were shown with leaf length, number of leaves, fresh weight, dry weight, and leaf area of the shoot. Therefore, it is considered that 14 h or more light period is suitable for increasing the productivity of Korean mint as a leafy vegetable.

• Journal of Microbiology
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• v.35 no.4
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• pp.284-289
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• 1997

A Gram (-), rod-shaped bacterium $2.3{\sim}2.8{\times}0.45{\mu}m$ in size which exhibited growth-inhibiting effects against a cyanobacterium (Anabaena cylindrica) was isolated from Daechung Dam Reservoir. This isolate was identified as Moraxella sp. and designated Moracella sp. CK-1. Hollow zones formed around bacterial colonies on the cyanobacterial lawn. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells completely disappeared within 24 hours. On treatment with Moraxella sp. CK-1, cell walls of A. cylindrica disappeared, but sheathes remained in a more electron dense form. The unit membrane such as thylakoidal membrane was stable to bacterial lysing activity. This bacterium showed a broad action spectrum against cyanobacteria. The growth-inhibiting activity of Moracella sp. CK-1 against A. cylindrica is believed to be performed through the excretion of active substances.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.611-618
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• 2015

Spirogyra is a zygnematalean green algal genus that is ubiquitous in a broad range of freshwater habitats throughout the world. Samples collected throughout Korea from October 2004 to July 2015 were examined using light microscopy. Morphological characteristics (e.g., size of vegetative cells, number of chloroplasts in each cell, type of end walls of adjacent cells, details of conjugation, shape of female gametangia, dimensions and shape of zygospores, color and ornamentation of median spore walls) were used as diagnostic characteristics for species identification. In this study, five species of Spirogyra (i.e., S. emilianensis Bonhomme, S. jaoensis Randhawa, S. pascheriana Czurda, S. weberi var. farlowii (Transeau) Petlovany, and S. weberi var. grevilleana (Hassall) Kirchner) were described as newly recorded in Korea.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.293-302
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• 2013

The present study summarizes the occurrence, distribution and autecology of 12 taxa of the class Cyanophyceae collected from several swamps, reservoir and highland wetlands in South Korea from 2009 to 2012. A new species, Anabaena koreana sp. nov. and 11 taxa of blue-green algae newly recorded are described and illustrated. Anabaena koreana is similar to A. oumiana, A. spiroides and A. crassa in that the trichomes form regular coils. However, A. koreana is distinguished from these three species by the morphological characteristics of the vegetative cell, heterocyst, and akinet shape and size. This study considers 12 blue-green algal species, including a new species, Anabaena koreana sp. nov. and 11 species that are recorded for the first time in the Korean freshwater algal flora. Among them, the genus Nostochopsis Wood ex Bornet et Flahault 1886 had not previously been recorded in Korea.