• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.394-402
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• 2001

In order to investigate the composition of dried layer, Porphyra yezoensis cultured at the south coast of Korea, the dried laver was analyzed separately for extractive nitrogen, free and combined amino acids, ATP and related compounds and quaternary ammonium basis using specimens collected monthly from January to April 1998. The extractive nitrogen contents of dried layer extracts were $976\~1,196\;mg/100\;g$ (on dry basis). Twenty-eight to thirty-one kinds of free amino acids were found in the dried laver extracts and their total amounts were 5,648-6,845 mg/100 g (on dry basis). The extracts were rich in free amino acids such as alanine, glutamic acid, taurine, phosphoserine and aspartic acid. Eighteen to twenty-two kinds of combined amino acids from oligopeptides were found in the extracts and their total amounts were $1,194\~1,406\;mg/100\;g$ (on dry basis). The amounts of ATP and related compounds were $111.6\~195.5\;mg/100\;g\;(3.30\~6.00{\mu}mol/g$ on dry basis). Homarine was detected in all samples but glycinebetaine, $\beta$-alaninebetaine and $\gamma$-butyrobetaine disappeared during processing, TMAO was detected in all samples but low TMA was found in some. During processing of dried layer, P. yezoensis, free amino acids, ATP and its related compounds were increased but the other constituents such as combined amino acids, TMAO and TMA and betaines were decreased in all specimens.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.633-640
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• 2001

This study investigated the effects of lipid metabolism on male Sprague Dawley rats given porphyran diet extracted from Porphyra yezoensis for 4 weeks. We divided into 5 diet groups which were normal diet, control diet fed high fat, cholesterol and sodium cholate, control and 1% porphyran diet (1% PD), control and 5% porphyran diet (5% PD), control and 10% of porphyran diet (10% PD). Feed intake and weight gain were not significantly different between control and porphyran diet. Serum triglyceride, total cholesterol and LDL-cholesterol contents were significantly (p<0.05) lower in porphyran diet groups than control group. However, serum HDL-cholesterol contents increased by the addition of porphyran in experimental diet. Hepatic triglyceride and total cholesterol concentrations were proportionally decreased by the addition of porphyran in control diet compared to control diet. A number of lipid particles were shown in liver tissue of control group and the same appearance was shown in the group fed with 1% porphyran diet, whereas lipid particles was reduced in the group fed with 5% and 10% porphyran diet compared to control group. Especially, liver tissue of 10% porphyran diet group was shown similar appearance to normal diet group. These results indicated that supplementation of porphyran in hyperlipidemic rats has an effect on the improvement of serum lipids.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.100-101
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• 2002

Red seaweeds contain considerable amounts of polysaccharides often having peculiar structures. The major soluble polysaccharide in Porphyra species is porphyran, which usually has a linear backbone composed of alternating 3-O-linked $\beta$-D-galactopyianose and 4-O-linked $\alpha$-L-galactopyranose(or 3,6 anhydro-L-galacto pyranose) residues. But the substituting patterns are very complex. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1166-1172
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• 1998

A method for the isolation and purification of DNA from a red algae, Porphyra was innovated. The innovation of the method consists mainly of three steps that include sodium acetate treatment, chloroform extraction, and 0.2 volume isopropanol precipitation step. The sodium acetate treatment was designed to remove polysaccharide contamination, and the isopropanol step to remove proteins and salts contaminents. Genomic DNA,s of several species(for example, P. tenera, P. yezoensis, P. seriata, and P. pseudolinearis) was successfully isolated by the innovated method. The amount of DNA purified from one g of sample material with the innovated method was 53 g in average. The resulting DNA was characterized to include high molecular weight and showed no nuclease activity. The DNA was pure enough to be digested directly by various restriction enzymes without any difficulties. Porphyra DNA was pure enough and adequate for amplification reaction through the polymerase chain reaction (small nuclear rDNA PCR amplification).

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.562-569
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• 2010

This study was conducted to investigate the hypocholesterolemic effects of porphyran and insoluble dietary fiber isolated from laver in rats fed high fat diet containing 1% cholesterol, 0.25% sodium cholate and 12% lard. Rats were fed, ad libitum, diets containing 5% diet fiber as cellulose(normal control or high fat control), porphyran or insoluble dietary fiber for 4 weeks. Among the groups fed high fat diet, liver weight was significantly lower in high fat porphyran group than high fat control. Plasma GOT, GPT, total cholesterol, cholesteryl ester, LDL-cholesterol and liver total cholesterol concentration were significantly lower in high fat porphyran group than high fat control. The feeding of porphyran significantly increased fecal cholesterol and bile acid excretion. The feeding of insoluble dietary fiber had no significant effect on either plasma or liver cholesterol levels, although fecal cholesterol level in the insoluble dietary fiber group was significantly higher than that in the high fat control. The results indicate that porphyran isolated from the laver may exert their hypocholesterolemic effect by increasing excretion of fecal bile acid and cholesterol.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.1-8
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• 2012

The objective of the present study was carried out to clarify the effects of deep sea water on the growth and maturation of $Porphyra$ (Rhodophyta, Bangiales). Foliose thalli for indoor culture were collected from Yeongok ($P.$ $okamurae$) in Gangwon Prefecture, Tongyeong ($P.$ $suborbiculata$ f. $latifolia$) and Namhae ($P.$ $yezoensis$ f. $narawaensis$) in Gyongnam Prefecture respectively. Monospores were cultured at five temperatures (5, 10, 15, 20 and $25^{\circ}C$) with a photon irradiance of $80{\mu}m^{-2}s^{-1}$ under photoperiods of 14L:10D and 10L:14D in surface, deep and mixed seawater in respectively. The fast growth of foliose thalli were observed in $P.$ $suborbiculata$ f. $latifolia$ cultured at deep seawater under $15^{\circ}C$ and 10L:14D. In three species, the optimum growth occurred at 10 and $15^{\circ}C$ under deep and mixed seawater and short day-length. In general, monospores from the cultured thalli were liberated within three weeks after incubation under $10-25^{\circ}C$ and both photoperiods. From the result of this study, deep seawater is considered that the natural species of the genus $Porphyra$ can be useful for the development as the new cultivars.

• Journal of Microbiology
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• v.45 no.6
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• pp.541-546
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• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.127-131
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• 1998

The effect of extraction temperature ($60\~100^{\circ}C$) and pH ($2.0\~13.5$) on the yield and chemical compositions of crude porphyran from Porphyra Yezoensis was investigated. The yield and chemical compositions of crude porphyran were greatly affected by extraction pH and temperature. Yield was highest between pH $3\~4$ at all temperature ranges. Crude porphyran extracted in acidic conditions showed more sulfate and less protein content than extracted in neutral conditions, but molecular weights was decreased. Crude porphyran extracted in alkaline conditions showed low sulfate and high protein content. For high yield and low molecular weight, acidic condition, particulary pH $3\~4$, was effective. But in order to avoid molecular weight degradation, neutral conditions were effective.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.682-687
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• 2018

We investigated the effects of a highly saline solution (HS) containing hypochlorous acid, calcium chloride ($CaCl_2$), and phosphoric acid ($H_3PO_4$) on cell death and growth rate of laver Porphyra yezoensis and green laver Ulva intestinalis. Cell death rates of laver treated with HS and HS plus hypochlorous acid (HS + HOCl) in the harvesting stage were less than 0.5%, and there were no significant differences between the HS and HS + HOCl treatments. However, cell death of green laver treated with HS + HOCl in the harvesting stage was greater than 81.2%. These results indicate that the addition of HOCl is highly effective to eradicate noxious green laver without causing damage to laver. The addition of HOCl and $H_3PO_4$ to HS did not increase the area or weight of laver blades. A combination treatment of $CaCl_2$ and HS, however, significantly increased the area and weight of laver lades compared to controls (P<0.05).