Academic literature on the topic 'Seaweed-based extract'

We explored two methods for obtaining aqueous extracts: boiling and soaking of Baltic seaweeds (EB and ES, resp.). Algal extracts were characterized in terms of polyphenols, micro- and macroelements, lipids content, and antibacterial properties. The utilitarian properties were examined in the germination tests onLepidium sativumfor three extract dilutions (0.5, 2.5, and 10%). It was found that the extracts were similar in micro- and macroelement concentrations. Water was proved to be a good solvent to extract phenolic compounds. The algal extract produced by soaking biomass did not show inhibitory effect onEscherichia coliandStaphylococcus aureus. Only the boiled extract had an inhibitory activity againstE. coli. Germination tests revealed a positive influence of the bioproducts on the cultivated plants. In the group treated with 10% EB, plants were 13% longer than in the control group; the content of elements B, Mo, Zn, and Na in the group treated with 10% ES was higher by 76%, 48%, 31%, and 59% than in the control group, respectively; the content of chlorophyll was 2.5 times higher in 0.5% ES than in the control group. Extracts showed the slight impact on the morphology of plants.

In this research, we develop Indonesia marine resource of seaweed Gracilaria verrucosa as an anti-colorectal cancer agent. Seaweed Gracilaria verrucosa which was collected from east Lombok beach, Nusa Tenggara Barat, Indonesia, were extracted into four different organic solvents, that is n-hexane, ethylacetate, chloroform and ethanol. The extracts were analyzed by Phytochemical test and Thin Layer Chromatography (TLC). Subsequently, anticancer activity of n-hexane, ethyl acetate, chloroform and ethanol extracts of Gracilaria verrucosa were evaluated against colorectal HCT-116 cells by MTT cell proliferation assay. Based on Phytochemical analysis, the extracts of Gracilaria verrucosa containing secondary metabolite of saponin, while TLC analysis indicated that the extracts were composed by five chemical compounds. Among four concentrated extracts of Gracilariaverrucosa, ethanolic extract showed the strongest anticancer activity against colorectal HCT-116 cells with IC50 of 43.9 μg/mL.Ethanolic extract of seaweed Gracilaria verrucosa is potential to be further developed as a promising anti-colorectal cancer agents.

Seaweed has been gaining global interest in agriculture for the development of marine-based plant biostimulants. This research aimed to study the effect of three different liquid extracts of Sargassum sp., acidic, alkaline, and water extract, on the germination and early growth of maize and to evaluate the phytohormones content responsible for the growth. Phytohormones content including Indole-3-acetic acid (IAA), gibberellins (GA), kinetin and zeatin were analyzed using high-performance liquid chromatography (HPLC) and bioassay was performed twice on maize. Parameters observed on the bioassay were germination percentage, number of roots, shoot length, shoot weight and root weight under 4 different concentrations with 0.5; 1.5; 3.5; and 5% in the first bioassay and 3.5% concentration in the second bioassay. Both bioassays following randomized complete design and the data were analyzed using one-way ANOVA using post hoc test of Duncan Multiple Range Test (DMRT) at error probability of 5% in Genestat software. Phytohormones content in the seaweed extract indicated that alkaline extract was rich in IAA, gibberellin, and zeatin content, while water extract showed the highest kinetin content. The first bioassay indicated that lower concentration of the seaweed extracts gave better growth in all extracts, therefore a 3.5% concentration was chosen for the second bioassay with higher replication for each treatment. The second bioassay confirmed alkaline extract resulted in the highest germination while the highest seedling height, number of roots, shoot and root weight were resulted from acidic extract treatment. In conclusion, Sargassum sp. extracts obtained from acidic, alkaline, and water-based extraction methods, were able to improve the shoot and root growth of maize plants. The acidic extract showed the highest growth promotion among other extracts with the lowest phytohormones content.

Drought is one of the major abiotic stresses causing severe damage and losses in economically important crops worldwide. Drought decreases the plant water status, leading to a disruptive metabolic reprogramming that negatively affects plant growth and yield. Seaweed extract-based biostimulants show potential as a sustainable strategy for improved crop health and stress resilience. However, cellular, biochemical, and molecular mechanisms governing the agronomically observed benefits of the seaweed extracts on plants are still poorly understood. In this study, a liquid chromatography–mass spectrometry-based untargeted metabolomics approach combined with computational metabolomics strategies was applied to unravel the molecular ‘stamps’ that define the effects of seaweed extracts on greenhouse-grown maize (Zea mays) under drought conditions. We applied mass spectral networking, substructure discovery, chemometrics, and metabolic pathway analyses to mine and interpret the generated mass spectral data. The results showed that the application of seaweed extracts induced alterations in the different pathways of primary and secondary metabolism, such as phenylpropanoid, flavonoid biosynthesis, fatty acid metabolism, and amino acids pathways. These metabolic changes involved increasing levels of phenylalanine, tryptophan, coumaroylquinic acid, and linolenic acid metabolites. These metabolic alterations are known to define some of the various biochemical and physiological events that lead to enhanced drought resistance traits. The latter include root growth, alleviation of oxidative stress, improved water, and nutrient uptake. Moreover, this study demonstrates the use of molecular networking in annotating maize metabolome. Furthermore, the results reveal that seaweed extract-based biostimulants induced a remodeling of maize metabolism, subsequently readjusting the plant towards stress alleviation, for example, by increasing the plant height and diameter through foliar application. Such insights add to ongoing efforts in elucidating the modes of action of biostimulants, such as seaweed extracts. Altogether, our study contributes to the fundamental scientific knowledge that is necessary for the development of a biostimulants industry aiming for a sustainable food security.

The time when plant biostimulants were considered as “snake oil” is erstwhile and the skepticism regarding their agricultural benefits has significantly faded, as solid scientific evidences of their positive effects are continuously provided. Currently plant biostimulants are considered as a full-fledged class of agri-inputs and highly attractive business opportunity for major actors of the agroindustry. As the dominant category of the biostimulant segment, seaweed extracts were key in this growing renown. They are widely known as substances with the function of mitigating abiotic stress and enhancing plant productivity. Seaweed extracts are derived from the extraction of several macroalgae species, which depending on the extraction methodology lead to the production of complex mixtures of biologically active compounds. Consequently, plant responses are often inconsistent, and precisely deciphering the involved mechanism of action remains highly intricate. Recently, scientists all over the world have been interested to exploring hidden mechanism of action of these resources through the employment of multidisciplinary and high-throughput approaches, combining plant physiology, molecular biology, agronomy, and multi-omics techniques. The aim of this review is to provide fresh insights into the concept of seaweed extract (SE), through addressing the subject in newfangled standpoints based on current scientific knowledge, and taking into consideration both academic and industrial claims in concomitance with market’s requirements. The crucial extraction process as well as the effect of such products on nutrient uptake and their role in abiotic and biotic stress tolerance are scrutinized with emphasizing the involved mechanisms at the metabolic and genetic level. Additionally, some often overlooked and indirect effects of seaweed extracts, such as their influence on plant microbiome are discussed. Finally, the plausible impact of the recently approved plant biostimulant regulation on seaweed extract industry is addressed.

Brown seaweed phlorotannins have shown the potential to promote several health benefits. Durvillaea incurvata and Lessonia spicata—species that are widely distributed in central and southern Chile—were investigated to obtain phlorotannin extracts with antioxidant and antihyperglycemic potential. The use of an environmentally friendly and food-grade glycerol-based pressurized hot liquid extraction (PHLE) process (15% v/v glycerol water) was assessed for the first time to obtain phlorotannins. Multiple effects were analyzed, including the effect of the species, harvesting area (Las Cruces and Niebla), and anatomical part (holdfast, stipe, and frond) on the extracts’ polyphenol content (TPC), antioxidant capacity (AC), and carbohydrate-hydrolyzing enzyme—α-glucosidase and α-amylase—inhibitory activity. Contaminants, such as mannitol, heavy metals (As, Cd, Pb, Hg, and Sn), and 5-hydroxymethylfurfural (HMF), were also determined. The anatomical part used demonstrated a significant impact on the extracts’ TPC and AC, with holdfasts showing the highest values (TPC: 95 ± 24 mg phloroglucinol equivalents/g dry extract; DPPH: 400 ± 140 μmol Trolox equivalents/g dry extract; ORAC: 560 ± 130 μmol TE/g dry extract). Accordingly, holdfast extracts presented the most potent α-glucosidase inhibition, with D. incurvata from Niebla showing an activity equivalent to fifteen times that of acarbose. Only one frond and stipe extract showed significant α-glucosidase inhibitory capacity. No α-amylase inhibition was found in any extract. Although no HMF was detected, potentially hazardous cadmium levels (over the French limit) and substantial mannitol concentrations—reaching up to 50% of the extract dry weight—were found in most seaweed samples and extracts. Therefore, further purification steps are suggested if food or pharmaceutical applications are intended for the seaweed PHLE extracts obtained in this study.

Seaweed-based biodegradable films were studied with incorporation of different concentrations of neem (Azadirachta indica) leaf extract. The films were fabricated via a hot casting method and were subjected to physical, mechanical, and morphological examinations to investigate the effect of the neem extract reinforcement in the edible film. There was moderate improvement in the tensile strength, contact angle values, and elongation at break values, while the water vapour permeability was reduced with the addition of neem leaves extract beyond 5 w/w %. Analysis of the morphology of the fabricated films confirmed that there was good dispersion of the neem leaves extract in the seaweed matrix films, which resulted in the enhanced mechanical strength of the fabricated films. Moreover, the fabricated composite films showed excellent antimicrobial activity towards both Gram-positive bacterium subclasses (coccus and bacillus), which is highly desirable for the packaging material in the current scenario. So far, this is the first report on neem leave based seaweed films with enhanced antimicrobial activity, which makes them suitable for sustainable packaging application. The experiments showed that the seaweed-based film incorporated with neem leaves extract has potential application as an active packaging material due to its enhanced mechanical properties and antimicrobial activity.

Genetic, biochemical and physiological parameters can be changed by applying seaweed extract-based products. However, there is scarce information about the influence of seaweed extract on yarrow performance (Achillea millefolium L.), which is widely used in the folk medicine. Therefore, this study aimed to evaluate the effects of Ascophyllum nodosum extract on plant development (leaf and root biomass, and leaf area), physiological indexes (leaf weight ratio, and root: leaf ratio), secondary metabolite (phenolic compounds) content and antioxidant activity of yarrow. The experiment was carried out in a completely randomized design with 4 treatments (seaweed extract concentrations 0, 3, 6 and 9 mL L-1) and 10 replications. The higher concentration of seaweed extract caused higher total dry weight of plants (from 17.8 to 19%), especially due to increases in the root biomass (up to 28.5%). Only plants that received the highest concentration of seaweed-based product presented increments in the number of leaves when compared to the control plants (18.3 %). Furthermore, the use of A. nodosum extract 9 mL L-1 provided increases in the antioxidant activity and content of phenolic compounds in leaves (up to 30.44%). In conclusion, application of A. nodosum is a potential tool strategy to improve the quality of raw material from yarrow plants, since it increased the phenolic compound content and antioxidant activity in leaves, which are the plant organs commonly used in folk medicine.

Research has been carried out on formulation and stability test of hand body lotion from ethanolic extract of seaweed (Euchema cottonii). This study aims to obtain a hand body lotion formulation from seaweed extract (Eucheuma cottonii) that meets the requirements for the physical quality of the lotion, where the formula made consists of 4 formulas with extract concentrations of 5%, 10%, 15% and formulas without extracts. The evaluation of lotion preparations included organoleptic tests, pH tests, homogeneity tests and dispersibility tests. Data analysis was carried out by testing the physical quality of each formula compared to the quality standard of lotion preparations according to theory. From the research that has been done, it shows that the composition of the 4 formulas shows homogeneous results. The pH values of the formulas with extract concentrations of 5%, 10% and 5% and formulas without extracts were 5,8;5,3;5,1 and 6.6 (quality requirements 4,5 -6.6). Meanwhile, the pH distribution of the formula with 5%, 10% and 5% extract concentrations and the formula without extract was 5.2, respectively; 4.8; 4,4 and 5 (quality requirements 5-7). Based on the results obtained, it can be concluded that the formula with an extract concentration of 5% has the most physical stability that meets the requirements for the quality of lotion preparations.

Neem leaves extract was incorporated into the matrix of seaweed biopolymer, and the seaweed-neem biocomposite films were irradiated with various doses of gamma irradiation (0.5, 1.5, 2.5, 3.5, and 4.5 kGy). The physical, barrier, antimicrobial, and mechanical properties of the films were studied. The incorporation of 5% w/w neem leaves extract into a seaweed-based film, and gamma irradiation dose of 2.5 kGy was most effective for improved properties of the film. The results showed that the interfacial interaction of the seaweed-neem improved with physical changes in colour and opacity. The water solubility, moisture content, and water vapour permeability and biodegradability rate of the film reduced. The contact angle values increased, which was interpreted as improved hydrophobicity. The tensile strength and modulus of the films increased, while the elongation of the composite films decreased compared to the control film. The film’s antimicrobial activities against bacteria were improved. Thus, neem leaves extract in combination with the application of gamma irradiation enhanced the performance properties of the film that has potential as packaging material.

Throughout the Mediterranean region, V. vinifera are subjected to a wide range of environmental stresses, especially during the summer, when prolonged dry periods are combined with high radiation load and high temperatures. Furthermore, given the strong influence of the atmospheric factors on this species, seasonal weather pattern can significantly affect grapevine physiology and wine quality under future climate change projections. Although grapevines have multiple acclimation strategies to environmental constrains, the evidence for significant climate change in the upcoming decades urges adaptation and mitigation measures to be taken by the whole viticulture and winemaking sectors. Short‐term adaptation measures can be considered as a first protection strategy and should be focused at specific threats, mostly changes in agronomical practices, such as the application of biostimulants to enhance nutrition efficiency, abiotic stress tolerance and quality traits of plants. Seaweed-based extracts have been recently employed as sustainable tools to improve abiotic stress tolerance and increase grape quality. However, the effect of these extracts on secondary metabolism compounds, that are fundamental for grape and wine quality, is still scarce. Under this scenario, the objectives of the present PhD project were: 1) to investigate the physiological performances of V.vinifera and the biochemical adjustments induced in grape berry skins by A. nodosum foliar treatments under field conditions; 2) to evaluate if these treatments affect grapevine water relations and berry phenylpropanoid metabolism, mitigating the effects of a post-véraison drought in potted vines. An enhancement in the biosynthesis of secondary metabolites in berry skins and in leaves in response to these treatments, effective to improve grape quality and help vines to cope with abiotic stresses, was hypothesized. In order to achieve these goals, two experiments were arranged. The comparison between vines treated with A. nodosum extract and non-treated ones was set up in a field experiment carried out in 2016 and 2017 in a commercial vineyard in the Chianti Classico area (Tuscany, Italy), on 18-year-old vines of the red cv. Sangiovese (V. vinifera). Furthermore, in order to deeply investigate if A. nodosum treatments are effective in help vines to cope with drought stress, a second study was performed in 2017 on potted vines (cv. Pinot noir), subjected to two irrigation regimes (well watered and water stressed) associated with A. nodosum foliar treatments, performed with the same protocol as the field experiment. In both experiments, gas exchanges, chlorophyll fluorescence and water potentials on leaves treated with A. nodosum extract and non-treated control leaves, were monitored at three phenological stages. In addition, at the same stages, anthocyanins, flavonols and hydroxycinnamic acids were quantified in berry skins. In general, this PhD thesis provides evidence of A. nodosum treatments-induced changes in eco-physiological traits and berry skin metabolism of V. vinifera, resulting in different physiological adjustments to counteract environmental stress. Furthermore, in both experiments, the biochemical berry skin analyses revealed that the A. nodosum extract likely acted selectively in the phenylpropanoid pathway. In particular A. nodosum extract may influence anthocyanin biosynthesis by affecting the activity of enzymes involved in the phenylpropanoid pathway, thus resulting in changes in the content of methoxylated compounds in treated vines. Moreover, the increases in the phenolic and flavonoid profiles have a significant effect on enhancing multiple stress tolerance as well as improving plant water status and photosynthetic performances. Overall, these results support previous findings on the beneficial effects of A. nodosum treatments on plant acclimation to stressful environmental condition. For the first time, this study shows the potential effect of seaweed extracts in promoting higher tolerance to stress in vines. Considering the challenges posed by climate change in the Mediterranean basin, the use of seaweed extracts might represent a sustainable tool to mitigate the negative effects caused by increasing severity of drought events, often associated to heat-waves, in the viticulture sector.

Seaweed are an abundant and sustainable source for the production of nutritious and healthy food, presenting bioactive compounds useful for several industries. Macroalgae have numerous applications, but they are still an underexploited resource that has to reach its full application potential. With consumers' increasing environmental awareness, the demand for more sustainable products is also increasing, pressuring the packaging industry to develop more sustainable alternatives to single-use plastic. There are several studies that successfully report the use of seaweed polysaccharides-based films in maintaining the properties of food products, but few are those that use seaweed extracts in the formulation of the film matrix. In this work bioactive films were developed for food applications using aqueous extracts of the brown marine macroalga Bifurcaria bifurcata and the red marine macroalgae Porphyra sp. and Osmundea pinnatifida. The composition of the initial biomass of the algae was determined in terms of polysaccharide, protein and ash content. B. bifurcata presented the highest amount of carbohydrates (50 % w/w) and inorganic material (16 % w/w), while the red macroalgae showed the highest amount of protein (29 and 31 % w/w for Porphyra sp. and O. pinnatifida, respectively). Aqueous extracts were obtained from the initial biomass, with room temperature water and hot water (90 ºC). Both red algae extracts showed an increase in the total carbohydrate content, in relation to the sugar content of the initial biomass, being similar to each other in the amount and composition of sugars. The hot water extract from B. bifurcata showed an increase in the content of sugars obtained. In addition, all extracts showed higher amounts of sulfated compounds (Porphyra sp. 12 and 10 %; O. pinnatifida 19 and 16 %; B. bifurcata 16 and 8 %) than the initial biomass and B. bifurcata extracts showed also higher amounts of soluble protein (30 and 50 %). The greatest antioxidant activity was observed for the B. bifurcata extracts followed by Porphyra sp. and O. pinnatifida. The films produced using aqueous extracts of O. pinnatifida were less resistant, less elastic and less plastic, while those of Porphyra sp. were more resistant and flexible. The contact angle results showed that Porphyra sp. have a more hydrophobic surface. However, Porphyra sp. and O. pinnatifida films are very soluble in aqueous medium, while those of B. bifurcata presented solubility values below 50%, even after 7 days immersed in water. All films showed antioxidant activity, but the brown alga had a higher value. Taking into account the characteristics of the extracts and films obtained, we can consider that we have obtained films with mechanical properties and the potential to promote food preservation due to their antioxidant capacity to be applied in the food industry, namely in the development of packaging.
As algas marinhas são uma abundante e sustentável fonte para a produção de produtos alimentares nutritivos e saudáveis, apresentando na sua composição compostos bioativos úteis para diversas indústrias. As macroalgas têm inúmeras aplicações, mas ainda são um recurso pouco explorado com o seu máximo potencial de utilização por atingir. Com o aumento da consciência ambiental dos consumidores, a procura por produtos mais sustentáveis está também a aumentar, pressionando a indústria de embalagens a desenvolver alternativas mais sustentáveis ao plástico de uso único. Vários são os estudos que relatam com sucesso o uso de filmes à base de polissacarídeos obtidos de algas marinhas na manutenção das propriedades de produtos alimentares, mas poucos são os que usam extratos de algas marinhas na formulação da matriz do filme. Neste trabalho foram desenvolvidos filmes bioativos para aplicações alimentares usando extratos aquosos da alga castanha Bifurcaria bifurcata e das algas vermelhas Porphyra sp. e Osmundea pinnatifida. A composição da biomassa inicial das algas foi determinada em termos de conteúdo em polissacarídeos, proteína e cinzas. B. bifurcata apresentou a maior quantidade de carbohidratos (50% m/m) e material inorgânico (16% m/m), enquanto as macroalgas vermelhas apresentaram maior quantidade de proteína (29 e 31% m/m para a Porphyra sp. e O. pinnatifida, respetivamente). Os extratos foram obtidos a partir da biomassa, com água à temperatura ambiente e água quente (90ºC). Os extratos das algas vermelhas apresentaram um aumento no teor de carbohidratos totais, em relação ao teor de açúcares da biomassa inicial, sendo semelhantes entre si na quantidade e composição em açúcares. O extrato obtido com água quente de B. bifurcata teve um aumento na quantidade de açúcares obtidos. Além disso, todos os extratos apresentaram maiores quantidades de compostos sulfatados (Porphyra sp. 12 e 10%; O. pinnatifida 19 e 16%; B. bifurcata 16 e 8%) do que a biomassa inicial e os extratos de B. bifurcata apresentaram também maiores quantidades de proteína solúvel (30 e 50%). A maior atividade antioxidante foi observada nos extratos de B. bifurcata seguidos de Porphyra sp. e O. pinnatifida. Os filmes produzidos usando os extratos aquosos de O. pinnatifida eram os menos resistentes, menos elásticos e menos plásticos, enquanto que os de Porphyra sp. foram os mais resistentes e flexíveis. Os resultados do ângulo de contacto mostraram que os filmes de Porphyra sp. têm uma superfície mais hidrofóbica. No entanto, os filmes de Porphyra sp. e de O. pinnatifida são muito solúveis em meio aquoso, enquanto que os de B. bifurcata apresentaram valores de solubilidade abaixo de 50%, mesmo após 7 dias imersos em água. Todos os filmes apresentaram atividade antioxidante, porém o da alga castanha apresentou um valor superior. Tendo em conta as características dos extratos e dos filmes obtidos podemos considerar que obtivemos filmes com propriedades mecânicas e potencial para promover a conservação dos alimentos devido à sua capacidade antioxidante para serem aplicados na indústria alimentar, nomeadamente no desenvolvimento de embalagens.
Mestrado em Biologia Molecular e Celular

Accumulation of non-biodegradable plastics is causing high levels of environmental pollution. Currently, edible and biodegradable films and coatings for food and nutraceutical applications are a fast emerging technology with increased attention among researchers and consumers, which acts as an alternative to these synthetic plastics. Edible coatings are most commonly developed from polysaccharides and proteins. Among polysaccharides, seaweed-based polysaccharides play a vital role. These seaweed-based polysaccharides, which are utilized in the development of edible coatings and films, include Agar, Alginate, and carrageenan. Alginates are extracted from brown algae, while agar and carrageenan are extracted from red algae varieties. These developed coatings and films are commonly applied to extend the shelf life and maintain the desired quality level in food. These films or coatings can be applied to foods such as fruits, vegetables, meat, poultry, seafood, and dairy products. They improve the quality of the product by retarding moisture loss, reducing lipid oxidation and discoloration, sealing in volatile flavors, and functioning as carriers of food additives such as antimicrobial and antioxidant agents. This book chapter discusses the application of seaweed-based biodegradable films and coatings for food and nutraceuticals.

Edible seaweeds (macroalgae and microalgae) are considered superfoods of our waterways. Based on pigmentation seaweeds, macroalgae are classified into three groups, green seaweeds (Chlorophyta), brown seaweeds (Phaeophyta) and red seaweeds (Rhodophyta). Seaweeds are rich in macro and micro nutrients. They contain protein, dietary fiber, minerals, vitamins, polyphenols, peptides, sterols and polyunsaturated fatty acids. Apart from being a major nutritional source in the human diet, seaweed is considered a functional and nutraceutical due to its extra nutritional and physiological properties. Plethora of bioactive compounds with potential applications in food, medicinal, health and pharmaceutical industries are included in extensive research and industries. For example, phycocolloids from seaweeds are widely used in the food industry. Medicinal and pharmaceutical properties of edible seaweeds include anti-tumor property, anti-viral property, anti-coagulant property, anti-Alzheimer’s property, and anti-oxidant property. Thus, a vast scope of investigating and understanding bioactive compounds from edible seaweeds is welltimed.

In order to remove the excessive nutrient salt at Port of Amagasaki, we have established the method to utilize the cycle of life: by cultivating seaweed at the port, removing shellfish from the upright sea walls, and turning them into compost. In cooperation with the local junior high school students, local citizens, experts, and administration, the junior high schools of Amagasaki provided the environmental study through this activity, based on the theme of “Cycle of Life”. In this report, we describe about the effects of this study. 1) Before the study, a survey showed that most of the students had bad impression toward Amagasaki Sea, such as “dirty” and “smelly”. However, after the study, the impression turned into better impression such as “fun” and “more familiar”. 2) In the Technology class, the students successfully cultivated more than 50 kinds of vegetation. As the students cooked and ate the vegetables and fruits they grew, the study also developed into “Food Education”-learning the connection between their health, environment, and food. 3) The students cooked using the oil extracted from the seeds of rape blossoms cultivated with their compost. Then they watched waste oil being refined and turned into bio diesel fuel, which activated car engine. Through such experiences, many students realized the cycle of life as “the life continues in different forms”, and the respect for life as well as developing their awareness to improve the natural environment.

In order to remove the excessive nutrient salt at Port of Amagasaki, we have established the method to utilize the cycle of life: by cultivating seaweed at the port, removing shellfish from the upright sea walls, and turning them into compost. In cooperation with the local junior high school students, local citizens, experts, and administration, the junior high schools of Amagasaki provided the environmental study through this activity, based on the theme of “Cycle of Life”. In this report, we describe about the effects of this study. 1) Before the study, a survey showed that most of the students had bad impression toward Amagasaki Sea, such as “dirty” and “smelly”. However, after the study, the impression turned into better impression such as “fun” and “more familiar”. 2) In the Technology class, the students successfully cultivated more than 50 kinds of vegetation. As the students cooked and ate the vegetables and fruits they grew, the study also developed into “Food Education”-learning the connection between their health, environment, and food. 3) The students cooked using the oil extracted from the seeds of rape blossoms cultivated with their compost. Then they watched waste oil being refined and turned into bio diesel fuel, which activated car engine. Through such experiences, many students realized the cycle of life as “the life continues in different forms”, and the respect for life as well as developing their awareness to improve the natural environment.