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Lee D.-W.,Pacific Ocean Research Center | Abu Affan M.D.,King Abdulaziz University | Lee H.-Y.,Seowon University | Ma C.W.,Korea University | And 3 more authors.
Ocean and Polar Research | Year: 2013

One of the most important challenges facing the Spirulina mass cultivation industry is to find a way to reduce the high production costs involved in production. Although the most commercial medium (Zarrouk's medium) for Spirulina cultivation is too expensive to use, it contains higher amount of NaHCO3 (16.80 g L-1), trace metals and vitamin solutions. The purpose of this study was to increase the efficiency of Spirulina platensis biomass production by developing a low-cost culture medium at an isolated tropical island such as Chuuk State, Federated States of Micronesia (FSM). This study set out to formulate a lowcost medium for the culture of S. platensis, by substituting nutrients of Zarrouk's medium using fertilizer- grade urea and soil extract with a different concentration of carbon source under natural weather condition. In order to select a low-cost culture medium of S. platensis, 10 culture media were prepared with different concentrations of nitrogen (urea and NaNO3) and NaHCO3. The highest maximum specific growth rate (μmax) and mass production were 0.50 day-1 and 1.05 g L-1 in modified medium (NaHCO3 7.50 g L-1, urea 2.00 g L-1 without NaNO3) among all the synthesized media. Protein (56.14%) and carbohydrate (16.21%) concentrations of the lyophilized standard samples were estimated with highest concentration of glutamic acid (14.93%). This study revealed that the use of a low concentration of urea and NaHCO3 with soil extract was an affordable medium for natural mass cultivation in the FSM.

Choi Y.-U.,Korea South Pacific Ocean Research Center | Park M.,Kookmin University | Lee K.-W.,Korea South Pacific Ocean Research Center | Oh C.,Global Bioresources Research Center | Park H.-S.,Korea South Pacific Ocean Research Center
Ocean Science Journal | Year: 2014

This study was conducted to investigate the reproductive characteristics of the humbug damselfish, Dascyllus aruanus, through the measurement of gonadosomatic indices (GSI) and histological examination of the gonads. Fish were collected from Chuuk Lagoon, Micronesia (7°27′N; 151°53′E), between August 2009 and July 2010. Overall, the functional sex ratio was approximately 1:1; however, there was a female bias in the smaller size range (35–40 mm standard length [SL]) and male bias in the larger size range (45–60 mm in SL). The process of oocyte development exhibited a group synchronous pattern, from the vitellogenic phase oocytes in the gonads following the two clutches of oocytes, as the primary growth stage and yolk vesicle stage. The testis with an ovarian lumen exists as a central slit, and the sperm ducts extend into the medial hilar region of the gonads, indicating that males of D. aruanus have a secondary testis of protogynous species. Monthly variations in the GSI and evolution of gonad status indicated that reproductive activity in this species occurs throughout the year in Chuuk Lagoon, Micronesia. © 2014, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

Cho M.L.,East Sea Research Institute | Lee D.-J.,Gangneung - Wonju National University | Lee H.-S.,Global Bioresources Research Center | Lee Y.-J.,Global Bioresources Research Center | You S.G.,Gangneung - Wonju National University
Ocean Science Journal | Year: 2013

The nitric oxide inhibitory (NOI) and antioxidant (ABTS and DPPH radical scavenging effects with reducing power) activities of the ethanol (EtOH) extracts and solvent partitioned fractions from Scytosiphon lomentaria, Chorda filum, Agarum cribrosum, and Desmarestia viridis were investigated, and the correlation between biological activity and total phenolic (TP) and phlorotannin (TPT) content was determined by PCA analysis. The yield of EtOH extracts from four brown seaweeds ranged from 2.6 to 6.6% with the highest yield from D. viridis, and the predominant compounds in their solvent partitioned fractions had medium and/or less polarity. The TP and TPT content of the EtOH extracts were in the ranges of 25.0-44.1 mg GAE/g sample and 0.2-4.6 mg PG/g sample, respectively, which were mostly included in the organic solvent partitioned fractions. Strong NOI activity was observed in the EtOH extracts and their solvent partitioned fractions from D. viridis and C. filum. In addition, the EtOH extract and its solvent partitioned fractions of D. viridis exhibited little cytotoxicity to Raw 264.7 cells. The most potent ABTS and DPPH radical scavenging capacity was shown in the EtOH extracts and their solvent partitioned fractions from S. lomentaria and C. filum, and both also exhibited strong reducing ability. In the PCA analysis the content of TPT had a good correlation with DPPH (r = 0.62), ABTS (r = 0.69) and reducing power (r = 0.65), however, an unfair correlation was observed between the contents of TP and TPT and NOI, suggesting that the phlorotannins might be responsible for the DPPH and ABTS radical scavenging activities. © 2013 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

Ye B.-R.,Global Bioresources Research Center | Ye B.-R.,Hanyang University | Kim J.,Jeju National University | Kim M.-S.,Global Bioresources Research Center | And 7 more authors.
Ocean Science Journal | Year: 2013

We demonstrated that an extract from Pylaiella littoralis, collected from the Federate States of Micronesia (FSM), could inhibit the proliferation of tumor cells. P. littoralis extract (PLE) showed anti-proliferative activities in the tumorigenic cells tested, ranging from 20.2% to 67.9%. The highest inhibitory activity, in HT-29 cells, was selected for further experiments. PLE showed no cytotoxic effect in normal cells and inhibited the growth of HT-29 cells depending on concentration and incubation time. PLE-treated HT-29 cells showed the typical morphological characteristics of apoptosis, such as apoptotic body formation and DNA fragmentation. PLE also induced mitochondrial membrane potential depolarization and resulted in increased mitochondrial membrane permeability, compared with untreated cells. PLE decreased Bcl-2 protein and increased Bax protein expression, activating caspase-3 and poly (ADP-ribose) polymerase (PARP) expression via the caspase pathway. PLE also increased the phosphorylation of c-Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK), and it reduced cell viability in treatment cells with specific inhibitors such as PD98059 (a specific inhibitor of ERK), SP600125 (a specific inbibitor of JNK), and SB 203580 (a specific inbibitor of p38 MAPK). via the the mitogen-activated protein kinases (MAPKs) pathway. These results suggest that PLE inhibits the proliferation of HT-29 cells by affecting the caspase and MAPK pathways involved in the induction of apoptosis. Thus, we suggest that P. littoralis extract might be potential candidate agents for the treatment of human colorectal cancer. © 2013 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

Lee Y.,Global Bioresources Research Center | Lee J.-H.,Global Bioresources Research Center | Shim W.-B.,Global Bioresources Research Center | Shim W.-B.,Texas A&M University | And 7 more authors.
Ocean Science Journal | Year: 2014

Glucanases are involved in degradation of glucans. Here, we report a new endo-β-1,3-glucanase Mzl86 identified in Mesoflavibacter zeaxanthinifaciens S86. The deduced amino-acid sequence of Mzl86 showed highest similarity (45.1%) with Leeuwenhoekiella blandensi and thus placed in glycosyl hydrolase family 16. Purified recombinant protein (rMz186) showed an optimum enzyme activity against laminarin at 50℃ and pH 8. The enzyme was stable at 50℃ for 1 hour (maintaining 80% of its maximum activity) and was strongly activated (187%) in the presence of 2.5 mM manganese. Substrate-specific activities of rMzl86 against laminarin, barley β-glucan and lichenan were 261, 128 and 115 unit/mg, respectively. rMzl86 degraded laminarioligosaccharides (lager than biose) and laminarin while producing mainly biose and glucose. Molecular and biochemical properties reveal that rMzl86 shares typical features of β-1,3-glucanase (EC and thus is a potential candidate for use in agriculture, drug, chemical and bioethanol industries. © 2014, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

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