Brown Alga Laminaria Japonica Research Articles

An α type gluco-oligosaccharide from brown algae Laminaria japonica stimulated the growth of lactic acid bacteria encoding specific ABC transport system components.

Glucan is the most widely distributed glycan. Many probiotics such as lactic acid bacteria (LAB) encoded corresponding hydrolytic enzymes, which could use these glucans as energy substances. Brown alga is rich in glucan and has high edible and medicinal value, but research on its regulation to probiotics is not detailed enough. In this study, we determined a novel neutral α type gluco-oligosaccharide from the brown alga Laminaria japonica with a degree of polymerization (DP) of 2-8 and a structure that mainly consists of α-(1→4)-linked glycosidic bonds called Laminaria japonica gluco-oligosaccharide (LJGO). Fermentation in vitro and gene-phenotype correlation analyses revealed that LJGO selectively stimulated the growth of the LAB strain encoding a specific ATP-binding cassette (ABC) transport system in a GH13 gene cluster, with apparent differences among 14 tested species. Comparative genomics further revealed that this transport system is species-specific, implying a potential contribution to species evolution. Transcriptomic analysis based on LAB strains cultured on LJGO and 1H-NMR findings of LJGO residues after strain utilization showed that the GH13 gene cluster contains functional LAB genes involved in LJGO utilization. Further verification by gene knockout studies is needed to expand our findings.

Effects of whole plant brown algae (Laminaria japonica) on zootechnical performance, apparent total tract digestibility, faecal characteristics and blood plasma urea in weaned piglets

ABSTRACTTwo trials were conducted with 48 newly weaned piglets (28 d old) each 8.6 ± 0.05 kg to study how Laminaria japonica plants (LJ) affect zootechnical performance, feed conversion and the apparent total tract digestibility (ATTD) of crude nutrients. All basal diets consisted of cereals, soybean meal, skim milk powder and premixes according to recommendations (no growth promoters or enzymes). For Trial 1, piglets from 16 litters (50% male-castrated, 50% female) were assigned to three treatment groups (n = 16) in a completely randomised block design. Groups received either 2.5% supplementation with sun dried (SD) or drum dried (DD) LJ powder or 2.5% of diatomaceous earth (control). For Trial 2, piglets from 12 litters received either 5% of diatomaceous earth (control) or one of three mixtures of diatomaceous earth + DD LJ powder (3.3%+1.7%, 1.7%+3.3% or 0.0%+5%; n = 12). Data collection included zootechnical performance, faecal consistency, blood plasma urea (Trial 1 and 2) and ATTD (Trial 2). Metabolisable energy (ME) of DD LJ and diets in Trial 2 was estimated using digestible nutrients. Statistical analysis included two-way ANOVA (treatment, block) and mixed linear regression. During both trials, LJ at dosages ≥2.5% significantly reduced feed:gain ratio compared to control (p ≤ 0.0001, = 0.01 for Trial 1, Trial 2) irrespective of the drying method. ATTD from Trial 2 significantly increased digestibilities of dry matter (DM) and crude ash (CA) (p ≤ 0.01) and significantly decreased digestibilities of organic matter and crude fibre in animals fed ≥3.33% DD LJ (p = 0.01). Fractional digestibility of the DD LJ resulted in limited ME of ~9.3 ± 2.5 MJ/kg DM. Dietary conversion ratios of ME and digestible DM of DD LJ diets from Trial 2 decreased linearly with increasing algal supplementation (R2 = 0.93, 0.94 and pslope = 0.002, 0.002 for MCR, DCR). In conclusion, dried LJ powder was included up to 5% into diets without impairing zootechnical performance. The improved feed conversion in the presence of LJ was partly due to slightly higher ME within the algae diets compared to control. However, piglets receiving LJ during Trial 2 needed significantly lower dietary ME and digestible DM to maintain growth performance. Thus, LJ exerted a performance enhancing effect on weaned piglets. The precise mode-of-action is yet unclear.

Characterization of a seafood-flavoring enzymatic hydrolysate from brown alga Laminaria japonica

A seafood-flavoring enzymatic hydrolysate was prepared from brown alga Laminaria japonica. Response surface method was utilized to optimize the degree of hydrolysis and yield of the preparation process. The results indicated that the optimal conditions for the seafood flavoring production were as follows: temperature 50 °C, pH 7.5, solid–liquid ration 1:7 (g/mL), enzyme concentration 9.34%, and reaction time 21.3 h. Under this condition, the yield achieved was 29.90 ± 0.07%, and the degree of hydrolysis was 8.91 ± 0.24%. Amino acids and volatile aromatic substances of the enzymatic hydrolysate were subsequently determined by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry, respectively. Electronic tongue and electronic nose were used to assess the taste and flavor of the hydrolysate, respectively. Hexanal (43.31 ± 0.57%), (E)-2-octenal (10.42 ± 0.34%), nonanal (6.91 ± 0.65%), pentanal (6.41 ± 0.97%), heptanal (4.64 ± 0.26) and 4-ethylcyclohexanol (4.52 ± 0.21%) were the most abundant flavor compounds in the enzymatic hydrolysate with % peak areas in GC–MS. The contents of aspartic acid (11.27 ± 1.12%) and glutamic acid (13.79 ± 0.21%) were higher than other free amino acids in the enzymatic hydrolysate. Electronic tongue revealed a taste profile characterized by high scores on umami and saltiness, consistent with the HPLC results.

Diterpenes and Sesquiterpenes from the Marine Algicolous Fungus Trichoderma harzianum X-5.

Six new terpenes, including one harziane diterpene, 3 R-hydroxy-9 R,10 R-dihydroharzianone (1), one proharziane diterpene, 11 R-methoxy-5,9,13-proharzitrien-3-ol (2), three cyclonerane sesquiterpenes, 11-methoxy-9-cycloneren-3,7-diol (3), 10-cycloneren-3,5,7-triol (4), and methyl 3,7-dihydroxy-15-cycloneranate (5), and one acorane sesquiterpene, 8-acoren-3,11-diol (6), were isolated from the culture of Trichoderma harzianum X-5, an endophytic fungus obtained from the marine brown alga Laminaria japonica. Their structures and relative configurations were established by analysis of 1D/2D NMR, HREIMS, and IR data, and the absolute configurations were assigned on the basis of ECD curves or biogenetic considerations. These terpenes possess four different carbon skeletons, and compound 2, with a rarely occurring bicyclic framework, represents a possible precursor of tetracyclic harzianes. Compounds 1-6 exhibited growth inhibition of some marine phytoplankton species.

All-in-one electrochromic devices with biological tissues used as electronic components

Two novel all-in-one electrochromic devices have been fabricated on the basis of low-cost and environmentally benign marine brown algae laminaria japonica, and jellyfish, which were both utilized as electronic component (gel electrolytes) in combination with electrochromic viologen bis(3-hydroxypropyl) viologen dibromide, and electron mediators 1,1′-ferrocene dicarboxylic acid and 1,1′-ferrocenedimethanol. The electrochromic performance of the as-fabricated devices was tested. The two biological ECDs exhibited driving voltages as low as 1.1 V, which is superior to many traditional viologen-based ECDs. Moreover, following the principles of green chemistry, no waste and organic solvents were introduced during the room-temperature device assembly. Based on abundant content of biological tissues, the device can be presented as a proof-of-concept to find potential applications in the fields of low-cost, green and large-scale ECDs.

Utilization of different macroalgae by abalone Haliotis discus hannai Ino: Evidence from analyses of fatty acid profiles

The use of different algal species by the abalone Haliotis discus hannai was investigated by using fatty acids (FAs) as trophic markers. Each of six groups of abalones was fed a different diet consisting of powdered algae over an 84-day period. Of the six diets, three consisted of a single algal species, i.e., the brown alga Laminaria japonica (L), the green alga Ulva lactuca (U), and the red alga Gracilaria lemaneiformis (G). The remaining three diets had different 1:1 mixtures of the algal species, i.e., L. japonica and U. lactuca (LU), L. japonica and G. lemaneiformis (LG), and U. lactuca and G. lemaneiformis (UG). The FA profiles of the abalone soft body showed clear changes over the experimental period and differed significantly between the different diet groups. Analyses of variation of specific FAs and multidimensional scaling ordination of overall FA profiles showed that H. discus hannai absorbed L. japonica preferentially over G. lemaneiformis in the dietary group LG and discriminated against U. lactuca in groups LU and UG. Additionally, abalone in group LG had the highest specific growth rate (SGR = 0.73 ± 0.06% d−1), while those in group U had the lowest (0.36 ± 0.07% d−1). Our results for dietary preferences and growth performance suggest that G. lemaneiformis might be used as an alternative to the kelp L. japonica in the diet of farmed H. discus hannai, while U. lactuca may not be suitable.

Potential of brown algae for sustainable electricity production through anaerobic digestion

This paper assesses the economics of heat and power production from the anaerobic digestion (AD) of brown algae (Laminaria japonica) at a plant scale of 400,000 dry tons/year. The conversion process was simulated in Aspen Plus v.8.6 to obtain rigorous heat and material balance for energy assessments and the development of a techno-economic model. The breakeven electricity selling price (BESP) was found to be 18.81 ¢/kWh assuming 30years of plant life and a 10% internal rate of return. The results show that the AD unit has the highest energy demand in the entire process and consumes approximately 14% of all electricity produced. In addition, the seaweed cost of 11.95 ¢/kWh is the largest cost component that contributes to the calculated BESP, which means that a reduction in the cost of seaweed cultivation can significantly decrease the electricity production cost. A sensitivity analysis was performed on the economic and process parameters in order to assess the impact of possible variations and uncertainties in these parameters. Results showed that solids loading, anaerobic digestion yield, and time, respectively, have the highest impact on BESP.

СРАВНЕНИЕ РАДИАЦИОННОЙ СТАБИЛЬНОСТИ ХЛОРОФИЛЛОВЫХ ФРАКЦИЙ В СПИРТОВЫХ И АЦЕТОНОВЫХ ЭКСТРАКТАХ ВОДОРОСЛЕЙ LAMINARIA JAPONICA (МЬЯНМЫ)

В работе выделены этанольные и ацетоновые экстракты из бурых водорослей Laminaria Japonica Jemo (D) и Jenit (M). Методом UV-VIS спектрофотометрии зарегистрированы спектры оптического поглощения исходных экстрактов и их изменения при различном разбавлении растворителями. Показано, что природа водорослей, способ их культивирования, природа растворителей влияют на эффективность экстракции ценных биологически активных соединений (БАС), включая наиболее важные из них – каротиноиды и хлорофиллы. Особое внимание в этой работе было уделено изучению радиационно-химических превращений спиртовых (этанол), ацетоновых, водно-этанольных (50%) и водно-ацетоновых (50%) растворов экстрактов водорослей при различных условиях моделирования окислительно-восстановительных реакций за счет насыщения облучаемых растворов разными газами: кислородом воздуха, аргоном или закисью азота. Определена радиационно-химическая стабильность хлорофилловых фракций в разных видах водорослей в зависимости от условий радиолиза. Известно, что хлорофиллы часто используются в фармакологии, в качестве пищевого красителя, а в настоящее время в качестве компонентов светочувствительных слоев в нанофотонике. Данные по радиационной чувствительности биологических соединений из морских водорослей можно использовать для оценки их стабильности при радиационной стерилизации сырья и медицинских препаратов.

Effect of Sulfated Polysaccharides from Brown Algae on Apoptosis of Human Peripheral Blood Lymphocytes.

We studied the influence of fucoidans from brown algae Fucus evanescens, Laminaria cichorioides and Laminaria japonica on apoptosis of human peripheral blood lymphocytes. It was demonstrated that fucoidans induced lymphocyte apoptosis, increased the proportion of cells with low mitochondrial transmembrane potential, and inhibit expression of Bcl-xL gene in blood lymphocytes. These findings suggest that lymphocyte apoptosis induced by the analyzed sulfated polysaccharides is mediated by mitochondrial pathway.

Effect of sulfated polysaccharides from brown seaweed Laminaria japonica on the morfology of lymfoid organs and functional characteristics of immunocompetent cells

The effect of sulfated polysaccharide fucoidan from the brown alga Laminaria japonica on morphological characteristics of mouse lymphoid organs, subpopulations of spleen mononuclear leukocytes, cytokine production and cytotoxic activity of splenocytes has been investigated. Fucoidan promoted activation and proliferation of lymphoid hematopoietic cells in primary and secondary immunogenesis bodies, increased expression of markers CD19, NK, NKT, CD25, MHC II, TCR, TLR2 and TLR4, the cytotoxic activity of splenocytes and production of immunoregulatory and proinflammatory cytokines (IL- 2, IL-12, IFN-g, TNF-a, IL-6). This suggests activation of effector mechanisms of innate immunity and adaptive immune responses via the Th-1 type.

Arsenic Species in Edible Seaweeds Using In Vitro Biomimetic Digestion Determined by High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry.

Arsenite [As (III)], arsenate [As (V)], methylarsonate (MMA), and dimethylarsinate (DMA) in five edible seaweeds (the brown algae Laminaria japonica, red algae Porphyra yezoensis, brown algae Undaria pinnatifida, brown algae Hizikia fusiformis, and green algae Enteromorpha prolifera) were analyzed using in vitro digestion method determined by high-performance liquid chromatography inductively coupled plasma mass spectrometry. The results showed that DMA was found in the water extracts of all samples; As (III) were detected in L. japonica and U. pinnatifida and about 23.0 and 0.15 mg/kg of As (V) were found in H. fusiformis and E. prolifera respectively. However, after the gastrointestinal digestion, As (V) was not detected in any of the five seaweeds. About 0.19 and 1.47 mg/kg of As (III) was detected in the gastric extracts of L. japonica and H. fusiformis, respectively, and about 0.31 and 0.10 mg/kg of As (III) were extracted from the intestinal extracts of Porphyra yezoensis and U. pinnatifida, respectively. The present results successfully reveal the differences of As species and levels in the water and biomimetic extracts of five edible seaweeds. The risk assessment of the inorganic arsenic in the five edible seaweeds based on present data showed almost no hazards to human health.

Antitumor activity of a polysaccharide fraction from Laminaria japonica on U14 cervical carcinoma-bearing mice.

In the present study, we investigated the in vitro and in vivo antitumor effects of a sulfated polysaccharide fraction from the brown alga Laminaria japonica (LJSP) on cervical carcinoma. In vitro, the results showed that LJSP exhibited the highest cell growth inhibitory effect on cervical carcinoma U14 cells among five tumor cell lines. In vivo, the results showed that LJSP could not only inhibit the growth of the tumor but also enhance the spleen and thymus indexes, as well as the body weight of U14 tumor-bearing mice. Moreover, the white blood cell count of H22 tumor-bearing mice showed no change in the LJSP-treated groups and little toxicological effects were observed on hepatic function and renal function in LJSP-treated mice bearing U14 tumor cells. Besides, LJSP induced apoptosis of transplanted tumor tissues by increasing the ratio of Bax/Bcl-2. These data showed that LJSP exhibited prominent antitumor activities and low toxic effects; thus, it could be developed to a safe and effective anticancer agent.

Modulation of platelet aggregation-related eicosanoid production by dietary F-fucoidan from brown alga Laminaria japonica in human subjects.

Laminaria japonica is traditionally eaten in Japan as a beneficial food for thrombosis. The alga contains two specific ingredients, a xanthophyll fucoxanthin (FX) and a polysaccharide, F-fucoidan (FD). The aim of the present study was to investigate whether FX or FD exhibited anti-thrombotic effects. For this purpose, three types of capsules, containing 1 mg FX, 400 mg fucoidan, and both, were prepared from the alga and administered to volunteers for 5 weeks. The dose of FD or FD+FX significantly shortened lysis time (LT) of the thrombus measured by a global thrombosis test in the blood, but FX did not. Examining the mechanism, dietary FD increased H2O2 and the secretion of prostacyclin (PGI2), a potent inhibitor of platelet aggregation, in the blood, although FD was under the detection limit in the blood, determining with its monoclonal antibody. Furthermore, in mouse experiments, dietary FD was totally excreted into the faeces and was not incorporated into the blood. We then employed a co-culture system of a Caco-2 cell monolayer with fresh human blood. The addition of FD to Caco-2 cells stimulated the expression of NADPH oxidase 1 (NOX1) and dual oxidase 2 (DUOX2) mRNA and secreted H2O2 onto the blood side accompanied by a significant increase in serum PGI2 production. These effects were invalidated by the combined addition of FD with its monoclonal antibody. The results suggested that dietary FD stimulated the expression of H2O2-producing enzymes in intestinal epithelial cells and released H2O2 into the blood, which played a signalling role to increase PGI2 production and then shortened LT for thrombi.

Expressed sequence tag analysis and cloning of trehalose-6-phosphate synthase gene from marine alga Laminaria japonica (Phaeophyta)

A high quality cDNA library was constructed from the brown alga Laminaria japonica, with the titer of 1.2×105 pfu/ml. The average insert size of the cDNA library is about 1.6 kb. From the cDNA library, 591 cDNA clones were randomly selected and sequenced. As a result, 574 EST (expressed sequence tag) sequences were generated. All of the 574 ESTs were submitted to the dbEST database section of GenBank with the accession numbers from CX942625 to CX943198. The cDNA library was screened with a α-32p labeled 453 bp TPS gene probe, which is a partial sequence yielded from Porphyra yezoensis. Four positive cDNA clones were screened and the sequencing data showed that these four cDNA clones covered majority of L. japonica TPS cDNA sequence. After PCR amplification, sequencing and assembling, the entire ORF (open reading frame) sequence of the TPS gene was obtained, which was named LjTPS. LjTPS encodes a protein containing 908 amino acids with a calculated molecular mass of 101 674 Daltons. The LjTPS gene was successfully expressed in E. coli and rice. The LjTPS gene has potential application both in plant breeding to stress tolerance and in deciphering the TPS gene function and mechanism to stress tolerance.

Inhibitory activities of the edible brown alga Laminaria japonica on glucose-mediated protein damage and rat lens aldose reductase

Increased aldose reductase (AR)-related polyol pathway activity and the subsequent formation of advanced glycation end-products (AGEs) have been implicated in the onset of diabetic complications. We have evaluated the inhibitory effects of the methanolic extract and its fractions of Laminaria japonica on rat lens AR (RLAR) and AGE formation. The CH2Cl2 fraction was separated by high-performance liquid chromatography to yield active porphyrin derivatives, including pheophorbide a (1) and pheophytin a (2), which were assayed for their anti-diabetic complications and yield. Compound 1 exhibited potent inhibitory activities against both AGE formation and RLAR, with respective half-maximal inhibitory concentration (IC50) values of 49.4 and 12.3 μM. Conversely, compound 2 was found to be active against AGE formation, with an IC50 of 228.7 μM. For further elucidation of the structure–inhibitory activity relationship of the porphyrin derivatives, the inhibitory activities of four commercially available porphyrin derivatives on AGE formation and RLAR were measured. The presence of a carboxyl group and the absence of a phytyl group at the C-172 position of the porphyrin were found to contribute to the inhibitory effects towards both AGE formation and RLAR. These results suggest that the L. japonica and its porphyrin derivatives may represent a potential functional food resource for further prevention of diabetic complications.

Metal bioavailability and risk assessment from edible brown alga Laminaria japonica, using biomimetic digestion and absorption system and determination by ICP-MS.

A new biomimetic digestion and absorption system, including in vitro bionic digestion and biomimetic membrane extraction, was used for the first time for the pretreatment of edible Laminaria japonica . After bionic digestion, 11 species of trace metals (V, Cr, Mn, Fe, Ni, Cu, Zn, Se, As, Cd, and Pb) in the resulting chyme were transformed into their final coordinated complexes and then absorbed by the biomembrane. Similar to the biomembrane between gastrointestinal tract and blood vessels, monolayer liposome was used for the first time as a biomembrane model. Affinity-monolayer liposome metals (AMLMs) were separated, determined by ICP-MS, and then used for the metal bioavailability assessment as the bioassimilated part. The action of gastrointestinal acidity and components (including digestive enzymes) was assessed on the basis of the concentration of AMLMs; the safe dosage and tolerable upper intake level of L. japonica for adults were proposed as 33.3 and 230.8 g/day, respectively.

Anoikis induction by glycoprotein from <i>Laminaria japonica</i> in HT-29 cells

We extracted a glycoprotein from the brown alga Laminaria japonica (LJGP). We previously demonstrated that LJGP induced apop- tosis in HT-29 colon cancer cells via the Fas- and the mitochondrial signaling pathway, and cell-cycle arrest. However, its effect on the cell membrane remained unknown. In this study, we identified the involvement of matrix metalloproteinase (MMP), integrin, and Epi- thelial (E)-cadherin in LJGP-induced apoptosis in HT-29 cells. LJGP treatment increased the expression and activity of MMP-2 and MMP-9. Furthermore, LJGP decreased the expression of integrin αν, β3, β5, β6 and E- cadherin. Consistent with a decreased expression of E-cadherin, LJGP inhibited the Wnt signaling pathway. Moreover, activation of downstream molecules of integrin, including focal adhesion kinase (FAK), the Src family of protooncogenic tyrosine kinases, extracellular signal-related kinase (ERK), and phosphatidyl inositol 3 kinase (PI-3K) were also decreased. These findings suggest that LJGP-induced apoptosis of HT-29 cells involves possible ECM disruption and cell detachment, which are executed principally through the activation of MMPs and by a decrease of adhesion molecules, contributing to a down-regulation of the PI-3K, MAPK, and Wnt signaling pathways. Apoptosis induced by ECM disruption or cell detachment is also known as anoikis. We can say that LJGP induces anoikis in HT-29 cells.

A glycoprotein from Laminaria japonica induces apoptosis in HT-29 colon cancer cells

We isolated a novel glycoprotein from the brown alga Laminaria japonica that has antiproliferative effects on HT-29 colon cancer cells. We also identified the mechanism by which this glycoprotein, named LJGP, induces apoptosis. MTS assays showed that LJGP inhibited the proliferation of several cancer cell lines (AGS, HepG2, HT-29) in a dose-dependent manner. Especially in HT-29 cells, proliferation was significantly decreased. LJGP treatment on HT-29 displayed several apoptotic features, such as DNA fragmentation, sub-G1 arrest, caspase-3 activation, and PARP degradation. Consistent with sub-G1 arrest, LJGP decreased the expression of Cdk2, cyclin E, cyclin D1, PCNA, E2F-1, and phosphorylated pRb. Furthermore, the increase of p27 expression was observed. We also determined that LJGP-induced apoptosis leads to the formation of a death-induced signaling complex of Fas, FADD, and procaspase-8. LJGP induced the reduction of mitochondrial membrane potential with activation of the Bcl-2 family of proteins and caspase-9. These findings suggest that LJGP inhibits HT-29 cell proliferation by inducing apoptosis, which may be mediated via multiple pathways, including the Fas signaling pathway, the mitochondrial pathway, and cell cycle arrest. Therefore, LJGP can be a useful treatment option for colon cancer in humans.

Extraction of the polysaccharides from five algae and their potential antioxidant activity in vitro

The sulfated polysaccharides extracted from algae possess excellent antioxidant activities. In this study, we prepared five polysaccharides extracted from five algae including one brown alga Laminaria japonica , one red alga Porphyra haitanensis and three green algae Ulva pertusa , Enteromorpha linza and Bryopsis plumose . And then the antioxidant activities of all the samples were investigated including scavenging effects of superoxide and hydroxyl radicals, and reducing power. The chemical analysis and FT-IR spectrum showed these extracts were polysaccharides. And in addition, we found that certain polysaccharide exhibited stronger antioxidant activity in certain antioxidant activity. Factors effecting and attributing to radical scavenging effect need to be further studied.

Bio-hydrogen production from a marine brown algae and its bacterial diversity

The aim of this study was to determine how bio-hydrogen production was related to the composition of the bacterial community in a dark fermentation fed with marine brown algae (Laminaria japonica). The bacterial di- versity was ascertained by 16S rDNA PCR-sequencing. A total of 444 mL of bio-hydrogen was produced from 10 g/ L of dry algae in a 100 mL of culture fluid for 62 h. The pH varied from 8.74 to 7.05. Active bio-hydrogen production was observed from 24 to 48 h, and maximum bio-hydrogen production was 106 mL over 1 L gas. The bacterial com- munity of the activated sludge consisted of 6 phyla, where H2 producing and consuming bacteria coexisted. The only detectable bacterial phylum after bio-hydrogen generation with heat-treated (65 o C, 20 min) seeding was Firmicutes. Clostridium and Bacillus species constituted 54% and 46%, respectively, of the bacterial mixture and the most abundant species was Clostridium beijierinckii (34%). These results may provide a better understanding of how different bio- hydrogen communities affect hydrogen production and aid in the optimization of bio-hydrogen production.