Study the Effect of P. minor Seaweed Crude Extract as a Biostimulant on Soybean.

<b>Background and Objective:</b> Seaweed biostimulants are often used in agriculture because of their benefits in increasing growth, production and quality of plants and are safe for the environment. <i>Padina minor</i> is one of the potential seaweeds that contains high macro and micronutrients and has also been shown to increase the vegetative growth of several plants. This study aims to determine the effect of <i>P. minor</i> seaweed extract in various concentrations and frequencies as a biostimulant on the growth and production of soybean plants. <b>Materials and Methods:</b> <i>Padina minor</i> extract was applied to soybean plants with several concentrations (0, 10, 20, 30 and 40%) at three different application times. Where 1 application (2 weeks after planting), 2 applications (2 and 4 weeks after planting) and 3 applications (2, 4 and 5 weeks after planting). <b>Results:</b> <i>Padina minor</i> extract with a concentration of 40% with 1 application was able to increase plant height and shorten soybean harvest life. While the <i>P. minor</i> extract with a concentration of 40% with two and three applications was able to increase the gross and dry weight of plants, the number of pods, gross and dry mass of whole seeds. <b>Conclusion:</b> <i>Padina minor</i> seaweed extract with a concentration of 40% was able to increase the growth and production of soybean plants.

Propiedades hepatoprotectoras de las algas marinas: estrés oxidativo en modelos animales intoxicados con xenobióticos / Hepato-protective properties of seaweeds: oxidative stress in animal models intoxicated with xenobiotics

Resumen Desde épocas ancestrales, las algas marinas han sido empleadas con fines medicinales. En la actualidad, las algas han atraído la atención como fuentes de compuestos bioactivos, debido a su alto contenido en metabolitos secundarios. En numerosos estudios epidemiológicos e investigaciones experimentales se han demostrado diferentes propiedades terapéuticas. Diversos autores han demostrado actividades antioxidantes en especies de algas marinas y su relación con las propiedades hepatoprotectoras, explicadas en la mayoría de los casos por su composición polifenólica. Por otra parte, existen pocos fármacos disponibles que estimulen la función hepática, ofrezcan protección al hígado de posibles daños y/o ayuden a regenerar las células hepáticas. Por este motivo resulta interesante buscar fármacos alternativos para el tratamiento de enfermedades hepáticas. Durante dos décadas, el Grupo de Farmacología y Toxicología de la Universidad de La Habana (UH), en coordinación con el Laboratorio de Lípidos de la Facultad de Ciencias Farmacéuticas (FCF-USP) de la Universidad de San Pablo, Brasil, han investigado varias especies de algas marinas como fuentes de sustancias neuro y hepatoprotectoras con resultados alentadores. En la presente revisión se analizó un conjunto de investigaciones de extractos y moléculas de algas marinas como posibles agentes hepatoprotectores y su relación con la actividad antioxidante. Se presentan diferentes metodologías con varios modelos animales, inductores de daño hepático y variables experimentales. A partir de estas consideraciones, el objetivo de este artículo de revisión fue resumir el estado de la ciencia hasta la fecha acerca del papel de las algas marinas como fuentes naturales de hepatoprotectores y su relación con las propiedades antioxidantes.

Abstract Since ancient times, seaweed has been used for medicinal purposes. At present, seaweeds have attracted attention as sources of bioactive compounds, due to their high content of secondary metabolites. In numerous epidemiological studies and experimental investigations, different therapeutic properties cuidahave been shown. Several authors have demonstrated antioxidant activities in seaweeds species and their relationship with hepato-protective properties, explained in most cases by their polyphenolic composition. On the other hand, there are few drugs available that stimulate liver function, offer protection to the liver from possible damage and/or help to regenerate liver cells, so it is interesting to look for alternative drugs for the treatment of liver diseases. For two decades, the Pharmacology and Toxicology Group of University of Havana (UH) in coordination with the Lipids Laboratory, School of Pharmaceutical Sciences of the University of Sao Paulo (FCF-USP) (Brazil) have investigated various species of seaweeds as sources of neuro- and hepato-protectors with encouraging results. In this review a set of investigations of extracts and molecules of seaweed is analysed as possible hepato-protective agents and their relationship with antioxidant activity. Different methodologies are presented with various animal models, liver damage inducers and experimental variables. Based on these considerations, the objective of this review article was to summarise the state of science to date about the role of seaweeds as natural sources of hepato-protectors and their relationship with antioxidant properties.

Resumo Desde épocas ancestrais, as algas marinhas são utilizadas para fins medicinais. Atualmente, as algas têm chamado a atenção como fontes de compostos bioativos, devido ao alto teor de metabólitos secundários. Em muitos estudos epidemiológicos e investigações experimentais, diferentes propriedades terapêuticas foram demonstradas. Vários autores têm demonstrado atividades antioxidantes em espécies de algas marinhas e sua relação com propriedades hepato-protetoras, explicadas na maioria dos casos por sua composição polifenólica. Por outro lado, existem poucos medicamentos disponíveis que estimulem a função hepática, ofereçam proteção ao fígado de possíveis danos e/ou ajudem a regenerar as células hepáticas, por isso é interessante procurar medicamentos alternativos para o tratamento de doenças hepáticas. Há duas décadas, o Grupo de Farmacologia e Toxicologia de la Universidade de la Habana (UH) em coordenação com o Laboratório de Lipídios da Faculdade de Ciências Farmacêuticas (FCF-USP) da Universidade de São Paulo, Brasil tem investigado várias espécies de algas marinhas como fontes de neuro- e hepato-protetores com resultados animadores. Nesta revisão foi analisado um conjunto de investigações de extratos e moléculas de algas marinhas como possíveis agentes hepato-protetores e sua relação com a atividade antioxidante. Diferentes metodologias são apresentadas com vários modelos animais, indutores de dano hepático e variáveis experimentais. Com base nessas considerações, o objetivo deste artigo de revisão era resumir o estado da ciência até o momento sobre o papel das algas marinhas como fontes naturais de hepatoprotetores e sua relação com propriedades antioxidantes.

Optimization of Porphyran Extraction from Pyropia yezoensis by Response Surface Methodology and Its Lipid-Lowering Effects.

Macroalgae polysaccharides are phytochemicals that are beneficial to human health. In this study, response surface methodology was applied to optimize the extraction procedure of Pyropia yezoensis porphyran (PYP). The optimum extraction parameters were: 100 °C (temperature), 120 min (time), and 29.32 mL/g (liquid-solid ratio), and the maximum yield of PYP was 22.15 ± 0.55%. The physicochemical characteristics of PPYP, purified from PYP, were analyzed, along with its lipid-lowering effect, using HepG2 cells and Drosophila melanogaster larvae. PPYP was a ß-type sulfated hetero-rhamno-galactan-pyranose with a molecular weight of 151.6 kDa and a rhamnose-to-galactose molar ratio of 1:5.3. The results demonstrated that PPYP significantly reduced the triglyceride content in palmitic acid (PA)-induced HepG2 cells and high-sucrose-fed D. melanogaster larvae by regulating the expression of lipid metabolism-related genes, reducing lipogenesis and increasing fatty acid ß-oxidation. To summarize, PPYP can lower lipid levels in HepG2 cells and larval fat body (the functional homolog tissue of the human liver), suggesting that PPYP may be administered as a potential marine lipid-lowering drug.

Sulfated Polysaccharides from Macroalgae Are Potent Dual Inhibitors of Human ATP-Hydrolyzing Ectonucleotidases NPP1 and CD39.

Extracellular ATP mediates proinflammatory and antiproliferative effects via activation of P2 nucleotide receptors. In contrast, its metabolite, the nucleoside adenosine, is strongly immunosuppressive and enhances tumor proliferation and metastasis. The conversion of ATP to adenosine is catalyzed by ectonucleotidases, which are expressed on immune cells and typically upregulated on tumor cells. In the present study, we identified sulfopolysaccharides from brown and red sea algae to act as potent dual inhibitors of the main ATP-hydrolyzing ectoenzymes, ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) and ecto-nucleoside triphosphate diphosphohydrolase-1 (NTPDase1, CD39), showing nano- to picomolar potency and displaying a non-competitive mechanism of inhibition. We showed that one of the sulfopolysaccharides tested as a representative example reduced adenosine formation at the surface of the human glioblastoma cell line U87 in a concentration-dependent manner. These natural products represent the most potent inhibitors of extracellular ATP hydrolysis known to date and have potential as novel therapeutics for the immunotherapy of cancer.

Seaweed-Based Compounds and Products for Sustainable Protection against Plant Pathogens.

Sustainable agricultural practices increasingly demand novel, environmentally friendly compounds which induce plant immunity against pathogens. Stimulating plant immunity using seaweed extracts is a highly viable strategy, as these formulations contain many bio-elicitors (phyco-elicitors) which can significantly boost natural plant immunity. Certain bioactive elicitors present in a multitude of extracts of seaweeds (both commercially available and bench-scale laboratory formulations) activate pathogen-associated molecular patterns (PAMPs) due to their structural similarity (i.e., analogous structure) with pathogen-derived molecules. This is achieved via the priming and/or elicitation of the defense responses of the induced systemic resistance (ISR) and systemic acquired resistance (SAR) pathways. Knowledge accumulated over the past few decades is reviewed here, aiming to explain why certain seaweed-derived bioactives have such tremendous potential to elicit plant defense responses with considerable economic significance, particularly with increasing biotic stress impacts due to climate change and the concomitant move to sustainable agriculture and away from synthetic chemistry and environmental damage. Various extracts of seaweeds display remarkably different modes of action(s) which can manipulate the plant defense responses when applied. This review focuses on both the similarities and differences amongst the modes of actions of several different seaweed extracts, as well as their individual components. Novel biotechnological approaches for the development of new commercial products for crop protection, in a sustainable manner, are also suggested.

Alienimonas chondri sp. nov., a novel planctomycete isolated from the biofilm of the red alga Chondrus crispus.

The phylum Planctomycetes comprises bacteria with peculiar and very unique characteristics among prokaryotes. In marine environments, macroalgae biofilms are well known for harboring planctomycetal diversity. Here, we describe a novel isolate obtained from the biofilm of the red alga Chondrus crispus collected at a rocky beach in Porto, Portugal. The novel strain LzC2T is motile, rosette-forming with spherical- to ovoid-shaped cells. LzC2T forms magenta- to pinkish-colored colonies in M13 and M14 media. Transmission and scanning electron microscopy observations showed a division by polar and lateral budding. Mother cells are connected to the daughter cells by a tubular neck-like structure. The strain requires salt for growth. Vitamins are not required for growth. Optimal growth occurs from 15 to 30°C and within a pH range from 5.5 to 10.0. Major fatty acids are anteiso-C15:0 (54.2%) and iso-C15:0 (19.5%). Phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid represent the main lipids and menaquinone 6 (MK-6) is the only quinone present. 16S rRNA gene-based phylogenetic analysis supports the affiliation to the phylum Planctomycetes and family Planctomycetaceae, with Alienimonas as the closest relative. Strain LzC2T shares 97% 16S rRNA gene sequence similarity with Alienimonas californiensis. LzC2T has a genome size of 5.3 Mb and a G+C content of 68.3%. Genotypic and phenotypic comparison with the closest relatives strongly suggest that LzC2T (=CECT 30038T=LMG XXXT) is a new species of the genus Alienimonas, for which we propose the name Alienimonas chondri sp. nov., represented by LzC2T as type strain. 16S rRNA gene accession number: GenBank=MN757873.1. Genome accession number: GenBank=WTPX00000000.

Anti-Alzheimer's Materials Isolated from Marine Bio-resources: A Review.

The most common type of dementia found in the elderly population is Alzheimer's disease. The disease not only impacts the patients and their families but also the society therefore, the main focus of researchers is to search new bioactive materials for treating AD. The marine environment is a rich source of functional ingredients and to date, we can find sufficient research relating to anti- Alzheimer's compounds isolated from marine environment. Therefore, this review focuses on the anti- Alzheimer's material from marine bio-resources and then expounds on the anti-Alzheimer's compounds from marine seaweed, marine animal and marine microorganisms. Moreover, because of the complexity of the disease, different hypothesizes have been elaborated and active compounds have been isolated to inhibit different stages of pathophysiological mechanisms. Sulfated polysaccharides, glycoprotein, and enzymatic hydrolysates from marine seaweeds, peptides, dietary omega-3 polyunsaturated fatty acids and skeletal polysaccharide from marine animals and secondary metabolites from marine microorganism are summarized in this review under the anti-Alzheimer's compounds from the marine.

Gracilariopsis hommersandii, a red seaweed, source of agar and sulfated polysaccharides with unusual structures.

Red seaweed Gracilariopsis hommersandii produces important amounts of non-gelling galactans, which were extracted with hot water (GrC, yield, 37%, viscosity average molecular weight, Mv 109 kDa), comprising agarose and sulfated galactan structures. The alkali modified derivative, GrCTr (Mv 95 kDa), gave a galactose:3,6-anhydrogalactose molar ratio of 1.0:0.9, and a more regular structure, favouring gelation (melting and gelling temperatures 64 and 14 °C, respectively). The rheological properties of this product suggest possible applications as hydrocolloid. G. hommersandii also biosynthesizes non gelling sulfated galactan fractions with diads constituted by ß-d-galactose and partially cyclized α-l-galactose units or non-cyclized α-d-galactose residues. Sulfation was mainly detected on C6 or C4 of the ß-d-galactose units, and on C6 and, in minor amounts, on C3 of the α-l-galactose units. The presence of ß-apiuronic acid was demonstrated for these fractions as side chains of the galactan backbone. Carrageenan structures were found for the first time in an agarophyte of the Gracilariales.

Cladophora glomerata methanolic extract decreases oxidative stress and improves viability and mitochondrial potential in equine adipose derived mesenchymal stem cells (ASCs).

Reactive oxygen species (ROS) are key mediators of several cellular damage and thus associated with equine diseases such as inflammation and metabolic syndrome. This study aimed to evaluate the protective and antioxidant activities of methanolic extract prepared from Cladophora glomerata (C. glomerata) biomass, on equine adipose derived mesenchymal stem cells (EqASCs), under experimental oxidative stress induced by H2O2. Pre-treatment of EqASCs cells with different concentrations of C. glomerata methanolic extract (1% and 5%) provided a clear protection against cellular damage triggered by H2O2. The cell's apoptotic status was significantly regulated, with promotion of cell viability, down-regulation of pro-apoptotic (p21, p53, Bax and Casp-9) genes expression, concomitant to up-regulation of the survival gene Bcl-2, this being supported by a mitigation of the endoplasmic reticulum (ER) stress and significant minimization of mitochondrial dysfunction. The results also showed that C. glomerata extract significantly increased the antioxidant enzymes Superoxide dismutase (SOD) and Catalase (CAT) activities, positively regulated the enzymes genes expression, and markedly reduced the protein carbonyls derivatives production. Finally, RT-qPCR analysis of the inflammatory related genes allowed to highlight a promising anti-inflammatory and immunomodulatory effect of this extract. Due to the valuable antioxidant and anti-inflammatory activities, C. glomerata may have potential benefits for the prevention of equine diseases associated with oxidative stress, including metabolic syndrome.

A multi-indicator approach for identifying shoreline sewage pollution hotspots adjacent to coral reefs.

Sewage pollution is contributing to the global decline of coral reefs. Identifying locations where it is entering waters near reefs is therefore a management priority. Our study documented shoreline sewage pollution hotspots in a coastal community with a fringing coral reef (Puako, Hawai'i) using dye tracer studies, sewage indicator measurements, and a pollution scoring tool. Sewage reached shoreline waters within 9 h to 3 d. Fecal indicator bacteria concentrations were high and variable, and δ15N macroalgal values were indicative of sewage at many stations. Shoreline nutrient concentrations were two times higher than those in upland groundwater. Pollution hotspots were identified with a scoring tool using three sewage indicators. It confirmed known locations of sewage pollution from dye tracer studies. Our study highlights the need for a multi-indicator approach and scoring tool to identify sewage pollution hotspots. This approach will be useful for other coastal communities grappling with sewage pollution.

The diversity of ice algal communities on the Greenland Ice Sheet as revealed by oligotyping.

The Arctic is being disproportionally affected by climate change compared with other geographic locations, and is currently experiencing unprecedented melt rates. The Greenland Ice Sheet (GrIS) can be regarded as the largest supraglacial ecosystem on Earth, and ice algae are the dominant primary producers on bare ice surfaces throughout the course of a melt season. Ice-algal-derived pigments cause a darkening of the ice surface, which in turn decreases albedo and increases melt rates. The important role of ice algae in changing melt rates has only recently been recognized, and we currently know little about their community compositions and functions. Here, we present the first analysis of ice algal communities across a 100 km transect on the GrIS by high-throughput sequencing and subsequent oligotyping of the most abundant taxa. Our data reveal an extremely low algal diversity with Ancylonema nordenskiöldii and a Mesotaenium species being by far the dominant taxa at all sites. We employed an oligotyping approach and revealed a hidden diversity not detectable by conventional clustering of operational taxonomic units and taxonomic classification. Oligotypes of the dominant taxa exhibit a site-specific distribution, which may be linked to differences in temperatures and subsequently the extent of the melting. Our results help to better understand the distribution patterns of ice algal communities that play a crucial role in the GrIS ecosystem.

Enhancement of Biochemical and Nutritional Contents of Some Cultivated Seaweeds Under Laboratory Conditions.

Six species of macroalgae belonging to the Chlorophyta, Phaeophyta, and Rhodophyta divisions were cultivated in a closed system with Guillard's f/2, Walne's, Provasoli Enriched Seawater (PES) medium, and seawater (control) for 6 weeks. The growth rate and parameters of the tested seaweeds showed that all used media enhanced the growth rate and chemical content as compared with other seaweeds cultivated in seawater without addition of any nutrients. There are significant differences in the effect of the used media on the seaweed composition at p = .01; PES is more effective than the f/2 and Walne's media. The results indicate that the cultivation technique of some macroalgae was an efficient tool for increasing the seaweeds' biomass and increasing their chemical compounds, calories, and energy under laboratory conditions.

Antimicrobial properties of cultivable bacteria associated with seaweeds in the Gulf of Mannar on the southeast coast of India.

In this study, 234 bacterial strains were isolated from 7 seaweed species in the Gulf of Mannar on the southeast coast of India. The strains having consistent antimicrobial activity were chosen for further studies, and this constituted about 9.8% of the active strains isolated. Phylogenetic analysis using 16S rDNA sequencing with the help of classical biochemical identification indicated the existence of 2 major phyla, Firmicutes and Proteobacteria. Antimicrobial activity analysis combined with the results of amplifying genes encoding for polyketide synthetase and nonribosomal peptide synthetase showed that seaweed-associated bacteria had broad-spectrum antimicrobial activity. These epibionts might be beneficial to seaweeds by limiting or preventing the development of competing or fouling bacteria. Phylogenetic analysis of ketosynthase (KS) regions with respect to the diverse range of KS domains showed that the KS domains from the candidate isolates were of Type I. The bacterial cultures retained their antimicrobial activities after plasmid curing, which further suggested that the antimicrobial activity of these isolates was not encoded by plasmid, and the genes encoding the antimicrobial product might be present within the genome. Seaweed-associated bacteria with potential antimicrobial activity suggested that the seaweed species are an ideal ecological niche harboring specific bacterial diversity representing a largely underexplored source of antimicrobial secondary metabolites.

Benthic algal assessment of ecological status in European lakes and rivers: Challenges and opportunities.

This opinion paper introduces a special series of articles dedicated to freshwater benthic algae and their use in assessment and monitoring. This special series was inspired by talks presented at the 9th International Congress on the Use of Algae for Monitoring Rivers and Comparable Habitats (Trento, Italy, 2015), the latest of a series of meetings started in 1991. In this paper, we will first provide a brief overview of phytobenthos methods in Europe. Then, we will turn towards the 'dark side' of phytobenthos and describe four particular problems for phytobenthos assessment in the European Union: (1) over-reliance on a single group of algae (mostly diatoms) to the exclusion of other groups; (2) relatively low adoption of benthic algae for ecological assessments in lakes; (3) absence of measures of phytobenthos abundance; (4) approaches used to define boundaries between ecological classes. Following this, we evaluate the strengths and limitations of current phytobenthos assessment methods against 12 criteria for method evaluation addressing four areas: ecological rationale, performance, feasibility of implementation, and use in communication and management. Using these criteria, we identify and discuss three general challenges for those developing new methods for phytobenthos-based assessment: a weak ecological rationale and insufficient consideration of the role of phytobenthos as a diagnostic tool and for communicating ecosystem health beyond a narrow group of specialists. The papers in the special series allow a comparison with the situation and approaches in the USA, present new methods for the assessment of ecological status and acidification, provide tools for an improved management of headwaters and petrifying springs, discuss the utility of phytobenthos for lake assessments, and test the utility of functional measures (such as biofilm phosphorus uptake capacity, PUC).

Redundancy in the ecological assessment of lakes: Are phytoplankton, macrophytes and phytobenthos all necessary?

Although the Water Framework Directive specifies that macrophytes and phytobenthos should be used for the ecological assessment of lakes and rivers, practice varies widely throughout the EU. Most countries have separate methods for macrophytes and phytobenthos in rivers; however, the situation is very different for lakes. Here, 16 countries do not have dedicated phytobenthos methods, some include filamentous algae within macrophyte survey methods whilst others use diatoms as proxies for phytobenthos. The most widely-cited justification for not having a dedicated phytobenthos method is redundancy, i.e. that macrophyte and phytoplankton assessments alone are sufficient to detect nutrient impacts. Evidence from those European Union Member States that have dedicated phytobenthos methods supports this for high level overviews of lake condition and classification; however, there are a number of situations where phytobenthos may contribute valuable information for the management of lakes.

Roseimaritima ulvae gen. nov., sp. nov. and Rubripirellula obstinata gen. nov., sp. nov. two novel planctomycetes isolated from the epiphytic community of macroalgae.

Four isolates, belonging to the deep-branching phylum Planctomycetes, were recovered from the biofilm of two marine macroalgae, Ulva sp. and Laminaria sp., from the Northern coast of Portugal. These strains were light pink- or red-pigmented; the cells were variable in shape and usually organized in rosettes. They had a dimorphic cell cycle with budding reproduction. The organisms were chemoheterotrophic, strictly aerobic and mesophilic. The 16S rRNA gene sequence analysis showed that the strains belong to the family Planctomycetaceae with Rhodopirellula as the closest genus. The isolates form two separate branches (strain LF1(T) forms one branch and the strains UC8(T), UF3 and UF42 form a second branch) clearly separated from Rhodopirellula baltica with 94.2% and 93.8% 16S rRNA gene sequence similarity, respectively. Based on differential characteristics that distinguish the novel genera from R. baltica, such as cell size and shape, ultrastructure, enzymatic activities, substrate utilization pattern, fatty acid composition, phospholipid profiles and phylogeny we propose that the isolates represent two novel genera of the order Planctomycetales, Roseimaritima ulvae gen. nov., sp. nov. (type strain is UC8(T)=DSM 25454(T)=LMG 27778(T)) and Rubripirellula obstinata gen. nov., sp. nov. (type strain is LF1(T)=LMG 27779(T)=CECT 8602(T)).

Genetic affinities between trans-oceanic populations of non-buoyant macroalgae in the high latitudes of the Southern Hemisphere.

Marine biologists and biogeographers have long been puzzled by apparently non-dispersive coastal taxa that nonetheless have extensive transoceanic distributions. We here carried out a broad-scale phylogeographic study to test whether two widespread Southern Hemisphere species of non-buoyant littoral macroalgae are capable of long-distance dispersal. Samples were collected from along the coasts of southern Chile, New Zealand and several subAntarctic islands, with the focus on high latitude populations in the path of the Antarctic Circumpolar Current or West Wind Drift. We targeted two widespread littoral macroalgal species: the brown alga Adenocystisutricularis (Ectocarpales, Heterokontophyta) and the red alga Bostrychiaintricata (Ceramiales, Rhodophyta). Phylogenetic analyses were performed using partial mitochondrial (COI), chloroplast (rbcL) and ribosomal nuclear (LSU / 28S) DNA sequence data. Numerous deeply-divergent clades were resolved across all markers in each of the target species, but close phylogenetic relationships - even shared haplotypes - were observed among some populations separated by large oceanic distances. Despite not being particularly buoyant, both Adenocystisutricularis and Bostrychiaintricata thus show genetic signatures of recent dispersal across vast oceanic distances, presumably by attachment to floating substrata such as wood or buoyant macroalgae.

A new method to quantify macroalgae and a practical sampler for experimentation in lotic habitats / Um novo método para quantificar macroalgas e um prático amostrador para experimentação em ecossistemas lóticos

Experimental studies in rivers and streams are extremely difficult to run due to the fact that the conditions of these environments are very complex and provide a high level of heterogeneity, which hinders the precise control and standardization of variables. In this study, we present a practical sampler that was designed to make it easier to conduct research projects involving benthic communities of lotic environments, as well as a new nondestructive technique for quantification of the macroalgal communities typically found in these habitats. The sampler consists of an acrylic square tube in which water flows normally inside. This structure carries a removable glass plaque with a known area and can simulate various ecological situations by changing both biotic and abiotic conditions. Thus, it can mitigate the differences between environmental characteristics where each sampler is exposed. The new technique involves capturing digital images that can monitor a unique macroalgal community in development throughout time and a more precise quantification when compared with other techniques that are widely applied. The sampler is easy to build and the images simple to quantify, allowing the detection of spatial and temporal variations in richness and abundance of investigated communities.

Os estudos experimentais em rios e riachos são extremamente difíceis de serem executados, visto que as condições desses ambientes são muito complexas e proporcionam um alto nível de heterogeneidade, o que dificulta o controle e a padronização precisa das variáveis. Nesse contexto, um prático amostrador foi desenvolvido para facilitar a execução de projetos de pesquisas envolvendo comunidades bentônicas de ambientes lóticos, além de constituir uma nova técnica não destrutiva para quantificação das macroalgas tipicamente encontradas nesses habitats. O amostrador consiste de um tubo de acrílico de seção quadrada, pelo qual a água corrente flui normalmente em seu interior. Tal estrutura porta uma placa de vidro removível com área conhecida e permite simular diversas situações ecológicas, variando tanto as condições abióticas como as bióticas, além de amenizar as diferenças entre as características ambientais a que está submetido cada um dos amostradores. Diversamente, a nova técnica consiste na captura de imagens digitais que permitem o acompanhamento temporal de uma mesma comunidade de macroalgas em desenvolvimento e uma quantificação mais precisa quando comparada com técnicas amplamente aplicadas na área. O amostrador é fácil de construir e as imagens são simples para quantificar, permitindo a detecção de variações espaço-temporais na riqueza e abundância das comunidades investigadas.

A new method to quantify macroalgae and a practical sampler for experimentation in lotic habitats.

Experimental studies in rivers and streams are extremely difficult to run due to the fact that the conditions of these environments are very complex and provide a high level of heterogeneity, which hinders the precise control and standardization of variables. In this study, we present a practical sampler that was designed to make it easier to conduct research projects involving benthic communities of lotic environments, as well as a new nondestructive technique for quantification of the macroalgal communities typically found in these habitats. The sampler consists of an acrylic square tube in which water flows normally inside. This structure carries a removable glass plaque with a known area and can simulate various ecological situations by changing both biotic and abiotic conditions. Thus, it can mitigate the differences between environmental characteristics where each sampler is exposed. The new technique involves capturing digital images that can monitor a unique macroalgal community in development throughout time and a more precise quantification when compared with other techniques that are widely applied. The sampler is easy to build and the images simple to quantify, allowing the detection of spatial and temporal variations in richness and abundance of investigated communities.

Development of an eco-friendly agar extraction technique from the red seaweed Gracilaria lemaneiformis.

The red seaweed, Gracilaria lemaneiformis growing as an aquaculture bioremediator along the coasts of Liaodong Peninsula, China, was investigated for the agar production. An eco-friendly method called agar photobleaching extraction process was developed for the benefit of workers' health and safety of the environment. The native agar (NA), alkali-modified agar (AA), chemical-bleached agar (CA) and photobleached agar (PA), which were extracted using different processes, were evaluated for their physical and chemical properties. The PA showed most desirable performances in terms of gel strength, gelling temperature, sulfate content and 3,6-anhydro-l-galactose content. Among the different processed agars, PA gel strength was 1913 g/cm2, the highest among the different processed agars, which increased 8.6% on the basis of the AA. Further we applied this new technique to extract agars from Gracilaria asiatica, and similar results were obtained with that of G. lemaneiformis. This indicates that the agar photobleaching extraction process is a feasible method for Gracilaria species and has a potential application. During the whole agar photobleaching extraction process the pigment content of G. lemaneiformis declined gradually and the TOC concentration in photobleaching solution increased along with the increase in the irradiation time. The mechanism of agar photobleaching could be elucidated by the photolysis theory.