Comparison of Ethanol Yield Coefficients Using Saccharomyces cerevisiae, Candida lusitaniae, and Kluyveromyces marxianus Adapted to High Concentrations of Galactose with Gracilaria verrucosa as Substrate

( Yurim Park ),( In Yung Sunwoo ),( Jiwon Yang ),( Gwi-teak Jeong ),( Sung-koo Kim ) 한국미생물 · 생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.6

The red seaweed Gracilaria verrucosa has been used for the production of bioethanol. Pretreatment for monosaccharide production was carried out with 12% (w/v) G. verrucosa slurry and 500 mM HNO3 at 121℃ for 90 min. Enzymatic hydrolysis was performed with a mixture of commercial enzymes (Cellic C-Tec 2 and Celluclast 1.5 L; 16 U/ml) at 50℃ and 150 rpm for 48 h. G. verrucosa was composed of 66.9% carbohydrates. In this study, 61.0 g/L monosaccharides were obtained from 120.0 g dw/l G. verrucosa. The fermentation inhibitors such as hydroxymethylfurfural (HMF), levulinic acid, and formic acid were produced during pretreatment. Activated carbon was used to remove HMF. Wildtype and adaptively evolved Saccharomyces cerevisiae, Candida lusitaniae, and Kluyveromyces marxianus were used for fermentation to evaluate ethanol production.

Recombinant agarase increases the production of reducing sugars from HCl-treated <i>Gracilaria verrucosa</i>, a red algae

Kim, Se Won,Kim, Yong-Woon,Hong, Chae-Hwan,Lyo, In-Woong,Lim, Ho-Dong,Kim, Geun-Joong,Shin, Hyun-Jae Elsevier 2018 Algal research Vol.31 No.-

<P><B>Abstract</B></P> <P>One of the most intensively studied species in red algae is <I>Gracilaria</I> spp., which is also a highly abundantly produced species annually in Asian countries including Korea and Japan. Much of the recent work on production of reducing sugars from <I>Gracilaria</I> spp. has concentrated on a combined process of physicochemical and biochemical treatments using acids and commercial enzymes. To the best of our knowledge, this study is first demonstration of combined acid and enzymatic hydrolysis using recombinant agarase to produce total reducing sugar (TRS) from <I>Gracilaria verrucosa</I>. By performing acid hydrolysis under the specified condition (2% biomass, 0.1N HCl, 121°C, 15min), a 34.9% TRS yield was obtained. Subsequent enzymatic hydrolysis using two recombinant agarases (aga 50D 0.5U/mg+NABH 0.5U/mg), resulted in a 47.4% TRS yield was achieved. The TRS yield obtained from acid and enzymatic hydrolysates was 5% higher than that of previous study with commercial enzyme. These results served to demonstrate that feasibility of enzymatic hydrolysis using the recombinant agarases to produce TRS from <I>G. verrucosa</I> for bio-refinery applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recombinant agarases were used to produce reducing sugar from <I>Gracilaria verrucosa</I>. </LI> <LI> Three agarases from <I>Saccharophagus degradans</I> were successfully expressed in <I>E. coli.</I> </LI> <LI> A higher yield (47.4%) of reducing sugar was obtained than with commercial enzyme. </LI> <LI> This study proposes combined hydrolysis using weak acids and recombinant enzymes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Introduction of alkali soaking and microwave drying processes to improve agar quality of Gracilaria verrucosa

김용운,신현재 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.12

Gracilaria species produce agars with low quality due to their high sulfate concentrations. For this reason, the gel properties of many Gracilaria agars must be improved by appropriate processes. In this study, we developed an improved agar extraction process for Gracilaria verrucosa by alkali soaking extraction and microwave thawing and drying. Variables such as the seaweed to alkali volume ratio, extraction time, and alkali concentration were adjusted to optimize the yield and agar quality. The yield of the agar was maximized (34.5±0.6%) using 3% alkali concentration; the lowest yield (17.0±1.7%) was obtained with 1% alkali concentration. Agar gel strengths ranged from 462.0±7 to 627.3±11 g·cm−2. We have developed a process for quickly producing an agar gel through thawing and drying using microwave radiation. This study shows the possibility of producing a high-value agar using alkali soaking extraction methods for nonedible G. verrucosa.

홍조 꼬시래기(Gracilaria verrucosa) 유래의 글리세로당 Floridoside의 화학구조

盧連淑,孫炳華,任光植,崔洪大 동의대학교 기초과학연구소 1995 基礎科學硏究論文集 Vol.5 No.1

As part of search for new biologically active substances from marine organism, we have isolated a glyecrol glycoside from the marine red alga Gracilaria verrucosa. The structure of the glycerol glycoside was elucidated as 2-O-α-_D-galactopyranosylglycerol〔floridoside(4)〕 on the basis of spectroscopic and physicochemical evidences.

홍조 꼬시래기(Gracilaria verrucosa) 유래의 글리세로당 Floridoside의 화학구조

노연숙,손병화,임광식,최홍대,Roh, Yeon-Suk,Son, Byeng-Wha,Im, Kwang-Sik,Choi, Hong-Dae 한국생약학회 1994 생약학회지 Vol.25 No.2

As part of search for new biologically active substances from marine organism, we have isolated a glyecrol glycoside from the marine red alga Gracilaria verrucosa. The structure of the glycerol glycoside was elucidated as 2-O-${\alpha}-_D$-galactopyranosylglycerol[floridoside(4)] on the basis of spectroscopic and physicochemical evidences.

해양 홍조류 에탄올 추출물의 항균 및 항산화 활성

김세율,김일철,이숙영 대한미용학회 2020 대한미용학회지 Vol.16 No.3

The aims of the current study were to analyze the bioactive substances of ethanol extracts from domestic marine red algae strains G. verrucosa, G. vermiculophylla, C. tenellus, and G. furcata, and to evaluate their antioxidant and antibacterial activities. Analysis indicated that the contents of total polyphenols and flavonoids were higher than other red algae extracts, with total polyphenols and flavonoids of 8.08±1.04 mg/g and 66.94±6.12 mg/g, respectively. Results of tests of SOD-like activity in the four species of red algae found that C. tenellus had the highest activity at 121.76±1.92 unit/mg. Similar to SOD-like activity, ascorbate peroxidase (APX) activity was the highest at 6.13±0.68 units/mg in stone agar, as a result of H2O2 scavenging. The catalase (CAT) activity of G. furcata was the highest among the four red algae extracts at 0.66±0.11 unit/mg. All four red algae extracts showed DPPH radical scavenging activities in a concentration-dependent manner. At 100 mg/mL, G. furcata had the highest activity at 9.05±4.20% followed by G. vermiculophylla at 8.09±6.16%. In addition, the antimicrobial activity of the ethanol extracts of all four types of red algae indicated minimum inhibitory concentration (MIC) of 0.4 to 6.25 mg/mL for the experimental strains. In the case of S. epidermidis, G. verrucosa had the greatest antibacterial activity in gram-positive bacteria at 0.625 mg/mL. Ethanol extracts of all four types of red algae demonstrated stronger antibacterial activity in gram negative bacteria. The MIC showed the strongest antimicrobial spectrum in the extract of G. verrucosa. Minimum bacterial concentration (MBC) for the ethanol extracts of four types of red algae was found to be in the range of 0.4 to 6.25 mg/mL, with the strongest activity in G. verrucosa and G. vermiculophylla at 1.25 ~ 5 and 0.8 ~ 6.25 mg/mL, respectively. Taken together, these results indicate that ethanol extracts of domestic marine red algae G. verrucosa, G. vermiculophylla, C. tenellus, and G. furcata have high antimicrobial and antioxidant activities, and should be considered for use as a functional cosmetic compound.

Temperature and Light Responses in Growth of Gracilaria verrucosa(Rhodophyta) and Its Potential for Mariculture in Korea

Kim, Young Sik,Kim, Han Gilx,Kim, Hyung Geun,Nam, Ki Wan,Sohn, Chul Hyun 한국수산학회 2002 Fisheries and Aquatic Sciences Vol.5 No.2

Apical and subapical fragments of Gracilaria verrucosa (Judson) Papenfuss (Rhdophyta) were cultured on a temperature-light gradient table with four temperature (15, 20, 25 and 30℃) and five light intensity (20, 40, 60, 80, and 100 μmol photons m^-2s^-1) regimes to examine growth responses. Their growth was measured weekly. Plant weight and lateral branch formation were affected by temperature and light intensity. As compared with other reports, relative growth rate (RGR) in both fragments was more or less high with 6.27 to 11.95% day^-1. It was lowest at 15℃ with 20 μmol photons m^-2s^-1, whereas, the highest value was recorded at 25℃ with 100 μmol photons m^-2s^-1. During the experimental period, the growth pattern in G. verrucosa was significantly different between apical and subapical fragments, even though RGR based on weight was similar. Growth in apical fragments depended on elongation by apical growth. By contrast, subapical fragments mainly increased their weights by proliferation of lateral branch. This suggests that intercalary activity (e.g. lateral branch formation) is also an important means for growth of the thallus in Korean G. verrucosa. In conclusion, the relatively high growth potential with intercalary activity in G. verrucosa will be helpful for mariculture in Korea.

Biosugar Production from Gracilaria verrucosa with Sulfamic Acid Pretreatment and Subsequent Enzymatic Hydrolysis

박미라,김성구,정귀택 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.3

In this study, sulfamic acid-catalyzed pretreatment and subsequent enzymatic hydrolysis was conducted to produce biosugar from the marine macro-alga Gracilaria verrucosa. Sulfamic acid has dual active sites and is a green catalyst. Optimized sulfamic acid pretreatment at 130°C with 7.5% biomass and 100 mM sulfamic acid for 90 min yielded 39.9% total reducing sugar (TRS). Subsequent enzymatic hydrolysis yielded 69.1% TRS. These results indicate the potential of sulfamic acidcatalyzed pretreatment and subsequent enzymatic hydrolysis in producing biosugars using a biorefinery process.

The Occurrence of 15-keto-Prostaglandins in the Red Alga Gracilaria verrucosa

Dang, Hung-The,Lee, Hye-Ja,Yoo, Eun-Sook,Hong, Jong-Ki,Choi, Jae-Sue,Jung, Jee-H. 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.9

New 15-keto-prostaglandins (1-4) were isolated from the MeOH extract of the red alga, Gracilaria verrucosa. Their structures were determined to be prostaglandin B congeners (1-3) and a prostaglandin E congener (4) based on the NMR and MS data. Prostaglandins with a C-15 keto function are rare from natural sources. The presence of these metabolites in the alga is notable because 15-keto-prostaglandins (15-keto-PGs) are considered to be the metabolic products of regular prostaglandins in mammals. The occurrence of different prostaglandins in this alga might be due to the existence of different oxidative enzymes, as previously mentioned for oxygenated fatty acids of the red alga Gracilariopsis lemaneiformis. The anti-inflammatory activity of these prostaglandins was examined by evaluating their inhibitory effects on nitric oxide production in lipopolysaccharide (LPS)-activated RAW264.7 murine macrophage cells. These prostaglandins showed weak activity on nitric oxide production.

Indolyl Alkaloid Derivatives, Nb-Acetyltryptamine and Oxaline from a Marine-Derived Fungus

YongLi,XiFengLi,DongSooKim,HongDaeChoi,ByengWhaSon 대한약학회 2003 Archives of Pharmacal Research Vol.26 No.1

Indolyl alkaloids, Nb-acetyltryptamine (1) and the known oxaline (2) have been isolated from the organic extract of the broth of an unidentified fungus collected from the surface of the marine red alga Gracilaria verrucosa. The structure of Nb-acetyltryptamine (1) was assigned on the basis of comprehensive spectroscopic analyses.