Carrageenophyte-attached and planktonic bacterial communities in two distinct bays of Vietnam: Eutrophication indicators and insights on ice-ice disease

The composition of the bacterial community of carrageenophyte-attached and planktonic bacteria was studied in two bays of Vietnam with contrasting anthropogenic inputs to assess their role as ecological indicators. Clear differences (~73% dissimilarity) between carrageenophyte-attached bacteria and bacterioplankton were detected in terms of genus composition: mainly Agaribacter, Ruegeria, Alteromonas, the Pir4 lineage and Vibrio for the carrageenophytes and Candidatus Actinomarina, HIMB 11, NS groups and SAR clades for the bacterioplankton. The copiotrophic nature, potential for complex-polymer degradation, and ability to form and defend biofilms were common features inferred for the carrageenophyte-attached microbiome. Significant differences between the bays were detected in the concentration of most inorganic nutrients. More eutrophic conditions and presumptive wastewater pollution in Cam Ranh (CR) bay were primarily indicated by the dominance of Rubripirellula, Leptobacterium, Hypnocyclicus and Porphyrobacter and their correlations with phosphate. In terms of bacterioplankton, the influence of intensive aquaculture in CR bay was suggested by the dominance of the NS5 and NS4 marine groups, the SUP05 cluster, Flavobacteriaceae unclassified and SAR 11 clade III as well as their strong correlations with ammonium and phosphate. The link between silicate and other inorganic nutrients suggests freshwater input in CR bay. Arenicellaceae unclassified and Formosa were also potential indicators of eutrophication. Operational taxonomic units (OTUs) of Marinagarivorans, Cobetia, Vibrio, Alteromonas and Pseudoalteromonas were typical of the carrageenophytes showing ice-ice disease symptoms. Vibrio and Alteromonas were also common among healthy macroalgae, and differences at the OTU level suggested potential succession of species from the healthy to the diseased state. The probable beneficial roles of some bacteria, such as Ruegeria, Cutibacterium and unidentified members of the family Rhizobiaceae, were discussed. This study provides pioneering insights into the bacterial community composition of carrageenophytes and highlights their ecological value as strong indicators of the sources of organic matter, anthropogenic impacts and health status of marine systems.Fil: Kopprio, Germán Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Leibniz - Institute of Freshwater Ecology and Inland Fisheries; Alemania. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Cuong, Le Huu. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; Vietnam. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Luyen, Nguyen Dinh. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; Vietnam. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; VietnamFil: Duc, Tran Mai. Vietnam Academy of Science and Technology. Nhatrang Institute of Technology Research and Application; VietnamFil: Ha, Tran Hong. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; VietnamFil: Huong, Le Mai. Vietnam Academy of Science and Technology. Institute of Natural Product Chemistry; Vietnam. Vietnam Academy of Science and Technology. Graduate University of Science and Technology; VietnamFil: Gärdes, Astrid. Leibniz - Institute of Freshwater Ecology and Inland Fisheries; Alemania. University of Applied Sciences; Alemania. Alfred-Wegener-Institut. Helmholtz-Zentrum für Polar und Meeresforschung; Alemani

The potential of Grateloupia filicina (Lamouroux) J. Agardh. for mariculture: culture experiments and observations on shore phenology

Grateloupia filicina is a carrageenophytic red alga which is in demand as a carrageenan raw material and for use in food. There is therefore interest in developing a technique for mariculturing this species. Since vegetative propagation from thallus fragments has not been successful, the present study was initiated to determine suitable conditions for spore liberation and growth of G. filicina from spores. It was also attempted to propagate G. filicina sporelings from crust and thallus fragments. In addition, the proportions of plants in different life history phases were determined in August and September to test for seasonal differences in shore phenology, and whether G. filicina is monoecious or dioecious, since there is disagreement on this in the literature. Spore release was easy to achieve, even without stressing the parent plant. Growth of crusts was found to be fastest at 50 μM.m⁻².s⁻¹ and at 20°C. Carposporelings (i.e. young tetrasporophytes) grew slightly but significantly faster than tetrasporelings (i.e. young carposporophytes). Crust fragments were able re-attach to the substrate and gave rise to new upright thalli within 1-2 weeks, compared to 4-5 weeks between spore release and thallus initiation. Attachment was weak, however, and only a small proportion of the crust fragments placed into culture regenerated. Thallus regeneration was not successful. There were seasonal differences in shore phenology during the study period: while two thirds of the plants collected in August were carposporophytes, only tetrasporophytes were found in September. No male gametophytes or spermatangia were found. It did not emerge from this study whether G. filicina in an annual, or what phenotypic differences are found throughout the year. Information of this kind is important for mariculture as it affects the supply of parent plants (and therefore spores) and the growth of young plants on ropes if these are released into the sea. The culturing experiments look promising; techniques (seeding ropes directly with spores or using regenerated crust fragments) still need to be refined

Développement D’un Stock De Semences (Seedstocks) De L’algue Rouge Gelidium Corneum (Gelidiaceae, Rhodophyta)

Gelidium corneum is a species of red algae notable for its commercial important as an agarophyte in Morocco. Several regions from the Moroccan Atlantic show that this alga is an endangered species due to the excessive tearing. Hence, the repopulation of these areas is necessary. The in vitro culture of the species was carried out in three media: enriched seawater medium (PES medium (Provasoli Enriched Seawater, Provasoli 1968)), medium with seawater (SW) and medium with artificial seawater, with the addition of polyamines (putrescine (put), spermidine (spd), and spermine (spr)) as a growth regulator in the three media. The results obtained are very significant, especially in PES medium with a growth rate of 95%. Rhizoid formation and attachment of explants have been noted, especially in PES + Put medium

Genetic Identification and Mass Propagation of Economically Important Seaweeds

Seaweeds are a primary source of hydrocolloids, which can be processed into various food additives, cosmetics, and pharmaceuticals. The inability of current commercial seaweed farming projects to meet industrial demands is underscored by a plethora of challenges, which include the lack of high-quality germplasm with the desired cultural characteristics. This chapter describes the current trends in commercial seaweed production and the potential technological advances in production methods and genetic selection strategies, which can be applied to raise the productivity of seaweed farms. Molecular markers have become increasingly relevant to the selection of a diverse range of wild varieties for domestication, and this augurs well for strain identification. The development of high-density linkage maps based on molecular markers offers an avenue for the implementation of molecular breeding strategies based on quantitative trait loci (QTLs). Concurrently, productivity of existing varieties can be enhanced by the analysis of exogenous factors known to affect the growth and survival of tissue-cultured seedlings. The application of photobioreactors for tissue culture is another important development, which will be digressed upon. In addition to this, quality control which focuses on the comparison of chemical and physical qualities of the tissue-cultured and conventional cultivated seaweeds will become increasingly relevant to the development of industry standards for sustainable seaweed production to fulfill the increasing demands of seaweed-related industries

PEMBUATAN EDIBLE FILM DARI SEMIREFINE CARRAGEENAN (KAJIAN KONSENTRASI TEPUNG SRC DAN SORBITOL)

Semi refine flour carrageenan is produced from Eucheuma seaweed species cottoni. Yellowish-white, are to form a gel that was instrumental in the food industry and medicine, which is a stabilizer, thickening agents and emulsifiers. Edible films made ​​from hydrocolloid has the mechanical properties are good, but the texture is fragile and therefore need the addition of plasticizer which serves to increase elasticity, reduce the risk of rupture, tears and destruction of the edible film is formed. Sorbitol is one effective plasticizer used because it can increase the elasticity of the film. This study aims to determine the influence of starch concentration of SRC and sorbitol concentration on the characteristics of edible films produced, determine the best treatment combination between SRC and flour concentration of sorbitol concentration so that the resulting edible film with good quality. Making edible film of this SRC flour using Completely Randomized Design (CRD) with factorial pattern and 2 factors repeated 2 times: Factor I Concentrations flour SRC 1,, 5%, 2%, 2.5% (w / v), Factor II Sorbitol concentration of 0%, 3%, 5%, 7% (w / v total). The results showed that the best treatment is the concentration of flour SRC sorbitol concentration of 2.5% and 7% that produce edible film with the criteria of water content 8.35%, 0.079 mm thickness, tensile strength 7.39 N, 64.41% percent extension and water vapor transmission rate of 0.115 g / hr. Results of financial analysis shows the BEP 21.19%, NPV Rp.74.358.273, 00, PP 3.4 yr, the Net B / C 1.1247 and 22.46% IRR

Aproveitamento do efluente da carcinicultura de Litopenaeus vannamei em sistema biofloco pela macroalga Kappaphycus alvarezii

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2017.Este trabalho avaliou a capacidade da macroalga Kappaphycus alvarezii remover os nutrientes dissolvidos do efluente da carcinicultura de Litopenaeus vannamei em sistema de bioflocos (Biofloc Technology ? BFT) e a influência deste efluente sobre o rendimento e a qualidade da carragenana. Talos da linhagem tetrasporofítica marrom foram cultivados durante 35 dias em condições controladas. Dois meios de cultura foram testados: solução von Stosch a 50% (V) e efluente BFT a 25% (B), ambos diluídos em água do mar esterilizada. Como controle, foi utilizado apenas água do mar esterilizada (C). Ambos os tratamentos e o controle foram feitos em triplicatas. Os talos foram fertilizados por 7 dias conforme seus respectivos tratamentos e na sequência foram cultivados apenas em água do mar esterilizada até o término do cultivo. Amostras de meio de cultura foram coletadas antes e após o período de fertilização para análise de remoção de nutrientes. Ao final do período experimental, a taxa de crescimento média final dos tratamentos V e B não apresentaram diferenças significativas (0,87 %dia-1; 0,95 %dia-1, respectivamente) e foram superiores ao controle (0,62 %dia-1). O nitrato foi a fonte de nitrogênio com maior taxa de remoção, 58,39% no tratamento V e 22,97% no tratamento B. Em relação ao fosfato, 100% foi removido no tratamento V e 83,58% no tratamento B. A concentração de nitrogênio tecidual foi significativamente maior no tratamento V (8,12%). Embora não tenha afetado o rendimento da carragenana kappa, foi observado força de gel e viscosidade significativamente maior no tratamento B (248,85 g cm-² e 19,89 mPa.s, respectivamente). Estes resultados comprovam que a macroalga K. alvarezii pode auxiliar no tratamento do efluente BFT e que este pode substituir a solução von Stosch sem prejudicar o rendimento e a qualidade da carragenana.Abstract : This work aims to evaluate the capacity of the seaweed Kappaphycus alvarezii to remove dissolved nutrients from effluent of Litopenaeus vannamei shrimp rearing in Biofloc Technology (BFT), and its influence over yield and carrageenan quality. Brown tetrasporophyte thalli were cultivated for thirty-five days under controlled conditions. Two culture media were tested: 50% von Stosch solution (V) and 25% BTF effluent (B), both diluted in sterilized sea water. As control, only sterilized sea water was used (C). Both treatments and the control were made in triplicates. During seven days, thalli were fertilized in the respective treatments and then cultivated in sterilized sea water until the end of the experiment. Culture media samples were taken before and after the fertilization period for nutrient removal analysis. At the end of the experimental period, the average growth rate of the treatments V and B did not show significant differences (0,87 %day-1; 0,95 %day-1, respectively) and both were higher than the control (0,62 %day-1). Nitrate showed the higher removal rate between the nitrogen sources (58,39% for V and 22,97% for B). 100% of the phosphate was removed in the treatment V and 83,58% in the treatment B. The tissue nitrogen content was higher in the treatment V (8,12%). Despite no significant differences in the kappa carrageenan yield, a significant higher gel strength and viscosity for the treatment B was observed (248,85 gcm-² and 19,89 mPa.s, respectively). Those results show that the seaweed Kappaphycus alvarezii can be used in the treatment of BFT effluent. The BFT can also substitute the use of von Stosch solution, avoiding losses in the carrageenan yield and quality

Functional properties of the isomorphic biphasic algal life cycle

Many species of marine algae have life cycles that involve multiple separate, free-living phases that frequently differ in ploidy levels. These complex life cycles have received increasing scientific attention over the past few decades, due to their usefulness for both ecological and evolutionary studies. I present a synthesis of our current knowledge of the ecological functioning and evolutionary implications of the isomorphic, biphasic life cycles commonly found in many species of marine algae. There are both costs and benefits to life cycles with 2 morphologically similar but separate, free-living phases that differ in ploidy levels (haploids and diploids). Evolutionary theory predicts that the existence of subtle yet important differences between the phases may be what allows these life cycles to be maintained. Different phases of the same species can vary in abundance, in demographic parameters such as mortality and fecundity, in their physiology, and in their resistance to herbivory. Some taxonomic groups within the red algae have received significant attention toward these issues, while our knowledge of these properties for brown and green algae remains limited

Large scale Mariculture of Seaweeds - Need of the Hour

Seaweeds are marine macroalgae consisting of taxonomically distinguished groups of Chlorophyta (Green seaweeds), Phaeophyta (Brown seaweeds) and Rhodophyta (Red seaweeds). They are generally found attached to rocks, pebbles or other aquatic plants in the intertidal or subtidal regions of the sea. Seaweeds are the natural source of phycocolloids such as agar-agar, algin and carra2eenan. A number of tropical seaweeds including green algae (Ulva, Enteromorpha, Monostroma, Caulerpa) brown seaweeds (Dictyota, Laminaria, Cladosiphon, Padina) and red seaweed (Gracilaria, Porphyra, Eucheuma) are eaten directly (sea vegetables) for their minerals, vitamins, proteins, essential amino acids and low fat content