ABSTRACT The use of bioactive compounds from macroalgae in agricultural formulations is an emerging technology with great potential to reduce dependence on synthetic agrochemicals. Currently, seaweed extracts are considered a sustainable resource due to their biodegradable nature. This review discusses their potential to replace or reduce a variety of synthetic molecules in economically important crops, such as synthetic nitrogen and phosphate fertilisers, synthetic hormone growth regulators, and organochlorine and organophosphate pesticides. Due to the presence of a wide range of bioactive substances already reported in certain algae, they are foreseen as good candidates for the production of plant bioformulations. In this sense, the commercial and biotechnological exploitation of macroalgae could benefit the local economy. However, despite the potential of algae, there is very little information on their total metabolomic or chemical content. This literature review summarises information proposing the use of the macroalgae Kappaphycus alvarezii, Acanthophora spicifera and Hypnea spinella in the Ecuadorian agricultural sector as an alternative for pesticide reduction.

RESUMEN El empleo de compuestos bioactivos extraídos de macroalgas en forma de formulaciones agrícolas representa una tecnología emergente con gran potencial para reducir la dependencia de agroquímicos sintéticos. Al presente, los extractos de algas marinas se consideran un recurso sostenible debido a su carácter biodegradable. En esta revisión se discute su potencial para reemplazar o reducir a una variedad de moléculas sintéticas en cultivos económicamente importantes, tales como fertilizantes sintéticos nitrogenados y fosfatados, reguladores del crecimiento hormonales sintéticos y plaguicidas organoclorados y organofosforados. Por la presencia de una extensa gama de sustancias bioactivas ya registradas en ciertas algas se prevén como buenos candidatos para la producción de bioformulaciones vegetales. En este sentido, el aprovechamiento comercial y biotecnológico de las macroalgas podría beneficiar la economía local. Sin embargo, pese a todo el potencial de las algas existe muy poca información de su contenido metabolómico o químico total. Esta revisión bibliográfica resume información que propone el uso de las macroalgas Kappaphycus. alvarezii, Acanthophora spicifera e Hypnea spinella dentro del sector agrícola ecuatoriano como alternativa para la reducción de pesticidas.

ABSTRACT Background: Kappaphycus alvarezii seaweed is a major commodity of important economic value fishery cultivation that has been developed in many countries. The demand for K. alvarezii seaweed continues to increase because it produces carrageenan which is commonly used as the main raw material in many industrial activities. However, K. alvarezii seaweed farming is inseparable from several obstacles. In the seaweed culture system, ice-ice disease is a major obstacle because it can harm the cultivation business. Ice-ice disease causes a decrease in seaweed production. Bacteria play a role in the development of ice-ice disease in seaweed cultivation. Aquatic organisms infected with bacteria indirectly cause damage to tissue. The spread of bacterial diseases in aquatic organisms can occur vertically or horizontally. Goals: This research aims to study the horizontal transmission of ice-ice disease on growth, carrageenan content, and changes in the structure of the K. alvarezii seaweed tissue which were tested in-vivo. Methods: This study uses healthy seaweed thalus weighing 35g and seaweed thallus affected by ice-ice weighing 30g (A), 35g (B), 40g (C) and 45g (D).The parameters observed were morphological changes, carrageenan content and tissue changes with histological analysis. Result: The results of this research indicate that the transmission of ice-ice disease can occur horizontally from thallus affected by ice-ice to healthy thallus. This transmission causes discoloration that shows symptoms of ice-ice attack on healthy seaweed K. alvarezii. This discoloration is accompanied by a decrease in thallus weight. Transmission also causes changes in the structure of the tissue in the form of lysis in the tissue and reduce the content of carrageenan in K. alvarezii seaweed. Conclusions: Based on this research, it can be concluded that the spread of ice-ice disease in seaweed causes color change, weight loss, changes in tissue structure, and reduce the quality of carrageenan.

RESUMEN Antecedentes: Kappaphycus alvarezii es un importante producto en la acuicultura de valor económico en muchos países. La demanda de algas K. alvarezii continúa aumentando porque produce carragenina, que se usa comúnmente como la principal materia prima en muchas actividades industriales. Sin embargo, el cultivo de algas marinas de K. alvarezii es inseparable de varios obstáculos. En el sistema de cultivo de algas marinas, la enfermedad de hielo-hielo una problemática importante porque puede dañar el negocio del cultivo. La enfermedad de hielo-hielo causa una disminución en la producción de algas. Las bacterias juegan un papel en el desarrollo de la enfermedad de hielo-hielo en el cultivo de algas. Los organismos acuáticos infectados con bacterias causan daños indirectos en los tejidos. La propagación de enfermedades bacterianas en organismos acuáticos puede ocurrir vertical u horizontalmente. Objetivos: Esta investigación tiene como objetivo estudiar la transmisión horizontal de la enfermedad de hielo-hielo en el crecimiento, el contenido de carragenina y los cambios en la estructura de la red de algas marinas K. alvarezii que se probaron in vivo. Métodos: Este estudio utilizó talos de algas sanas que pesaron 35 g y talos de algas marinas afectadas por la enfermedad del hielo-hielo que pesaron 30 g (A), 35 g (B), 40 g (C) y 45 g (D). Los parámetros observados fueron cambios morfológicos, contenido de carragenano y cambios tisulares con análisis histológico. Resultados: Los resultados de esta investigación indican que la transmisión de la enfermedad de hielo-hielo puede ocurrir horizontalmente desde el talo afectado por el hielo hasta el talo sano. Esta transmisión provoca decoloración y una disminución en el peso del talo. La transmisión también provoca cambios en la estructura del tejido en forma de lisis en la red y reduce el contenido de carragenina en las algas K. alvarezii. Conclusiones: Con base en esta investigación, se puede concluir que la propagación de la enfermedad del hielo-hielo en las algas marinas causa cambios de color, pérdida de peso, cambios en la estructura de los tejidos y reducción de la calidad de la carragenina.

Las especies carragenófitas están definidas como macroalgas miembro del Phylum Rodophyta, Clase Rodophyceae, Subclase Florideophycidae, Orden Gigartinales. Las especies de mayor importancia comercial a nivel internacional son de los géneros Betaphycus, Eucheuma y Kappaphycus; y a nivel nacional especies de los géneros Gigartina, Mazzaella y Sarcothalia. Debido a su importancia comercial, el género Gigartina, ha sido objeto de investigaciones como: Ecología de las poblaciones de las costas estuarinas y abiertas de la especie del noreste del Atlántico; ha sido investigado por Mathieson y Tveter (1976) con relación a las cantidades y calidad de su carragenina. Estudios de las respuestas a fotoperíodos (Guiry, 1984; Guiry et al., 1984) han identificado "ventanas" reproductivas, sugiriendo que las explicaciones de multiplicación vegetativa son cada vez más exclusivas, a diferencia de la producción y gametangial o tetrasporangial, en las poblaciones de las altas latitudes de una especie europea generalizada. La determinación genética de los patrones de ramificación y límites de tolerancia a la temperatura se han establecido para varias especies de (Guiry et al., 1987.; Buschmann, 2001). La viabilidad del cultivo de especies en sustratos artificiales ha sido evaluada por Mumford y Waaland (1980), y demostró tener potencial comercial. Este género tiene distribución en todo el mundo en mares templados a fríos, sin embargo, muy pocas especies ocurren en las regiones subtropicales. Los centros de diversidad de especies particularmente rica son California, Japón, Nueva Zelanda, Chile y Sudáfrica (Guiry, M.D & Guiry, G.M. 2011).

The carragenophytas species are defined as macro-algae, members of the Phylum Rodophyta, Rodophyceae Class, Florideophycidae Subclass, Gigartinales Order. The most important commercial species at the international level are the Betaphycus, Eucheuma and Kappaphycus genera and at the national level the species belonging to the Gigartina, Mazzaella and Sarcothalia genera. Because of its commercial importance, the Gigartina genus has been the object of investigations such as: Ecology of populations in estuaries and open coast in the North-East Atlantic species; it has been studied by Mathieson and Tveter (1976) in relation with its carragenine quantity and quality. Studies about the response to photoperiods (Guiry, 1984; Guiry et al., 1984) have identified reproductive "windows" suggesting that the explanations for vegetative multiplication are more exclusive each time, different from gametangial or tetra-sporangial production in populations of high latitudes from a generalized European species. Genetic determination of ramification patterns and tolerance limits to temperature has been established for several species (Guiry et al., 1987; Buschmann, 2001). Species cultivation viability in artificial substrates has been evaluated by Mumford y Waaland (1980), and it showed commercial potential. This genus has distribution worldwide in warm and cold seas. However, very few species happen in subtropical regions. The particularly rich species biodiversity centers are California, Japan, New Zealand, Chile y South Africa (Guiry, M.D & Guiry, G.M. 2011).

Este estudo tem como objetivo otimizar um método alternativo para extração de carragenana sem tratamento alcalino prévio e sem precipitação com etanol através da Metodologia de Superfície de Resposta (RSM). A fim de inovar a etapa de isolamento, a secagem por atomização foi adaptada, o que reduziu o tempo para a obtenção do pó seco. Os efeitos da temperatura e do tempo de extração sobre o rendimento, força do gel e de viscosidade foram avaliados. Além disso, o material extraído foi submetido a análises estruturais por espectroscopia de infravermelho e de ressonância magnética nuclear, e composição química. Os resultados mostraram que os modelos de regressão gerados explicam adequadamente a variação de dados. Apenas a temperatura de extração afetou o rendimento e a viscosidade do gel. Entretanto, a força do gel foi influenciada tanto pelo tempo como pela temperatura de extração. As condições ótimas de extração foram 74 ºC durante 4 horas. Nessas condições, as propriedades da carragenana bruta determinadas pelo modelo polinomial foram 31,17%, 158,27 g.cm-2 e 29,5 cP, para rendimento, força do gel e viscosidade, respectivamente, enquanto que em condições experimentais foram 35,8 ± 4,68%, 112,50 ± 4,96 g.cm-2 e 16,01 ± 1,03 cP. A composição química e as análises estruturais mostraram que a carragenana extraída é principalmente κ-carragenana.

This study aims to optimize an alternative method of extraction of carrageenan without previous alkaline treatment and ethanol precipitation using Response Surface Methodology (RSM). In order to introduce an innovation in the isolation step, atomization drying was used reducing the time for obtaining dry carrageenan powder. The effects of extraction time and temperature on yield, gel strength, and viscosity were evaluated. Furthermore, the extracted material was submitted to structural analysis, by infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR), and chemical composition analysis. Results showed that the generated regression models adequately explained the data variation. Carrageenan yield and gel viscosity were influenced only by the extraction temperature. However, gel strength was influenced by both, extraction time and extraction temperature. Optimal extraction conditions were 74 ºC and 4 hours. In these conditions, the carrageenan extract properties determined by the polynomial model were 31.17%, 158.27 g.cm-2, and 29.5 cP for yield, gel strength, and viscosity, respectively, while under the experimental conditions they were 35.8 ± 4.68%, 112.50 ± 4.96 g.cm-2, and 16.01 ± 1.03 cP, respectively. The chemical composition, nuclear magnetic resonance spectroscopy, and infrared spectroscopy analyses showed that the crude carrageenan extracted is composed mainly of κ-carrageenan.

O trabalho avaliou o efeito da administração oral dos polissacarídeos sulfatados (PS) extraídos da macroalga marinha Kappaphycus alvarezii na sobrevivência e ganho de peso de pós-larvas da tilápia do Nilo, durante a reversão sexual em situação de estresse. Os PS foram extraídos por digestão enzimática e incorporados à ração antes da adição do hormônio 17-α-metiltestosterona, sendo administrados nas doses de 0,05; 0,1 e 0,2 mg g-1 de peso vivo e um controle (sem PS), durante 28 dias. Na última semana da reversão sexual foi estabelecida uma situação de estresse, pela supressão da aeração e renovações de água. Os dados de sobrevivência e ganhos de peso foram submetidos à análise de variância (Anova) e teste de Tukey para diferenciação das médias, aos níveis de significância de 1 e 5%. Os ganhos de peso foram maiores nos animais que receberam os PS, independente da dose utilizada e as melhores sobrevivências obtidas quando os PS foram administrados nas doses de 0,05 e 0,1 mg g-1, com valores de 79,90 ± 5,68 e 77,60 ± 1,80%, respectivamente. O estudo revelou que pequenas doses dos PS, foram capazes de melhorar a sobrevivência, o ganho de peso diário e o peso médio final das tilápias submetidas a situações de estresse.

The study evaluated the effect of oral administration of sulfated polysaccharides (SP) extracted from the marine macroalga Kappaphycus alvarezii on survival and weight gain of Nile tilapia post larvae during sex reversal in a stress situation. SP were extracted from the seaweed by enzymatic digestion and incorporated into the diet before the addition of the hormone 17-α-methyltestosterone, and administered at the doses of 0.05, 0.1 and 0.2 mg g-1 of body weight and a control (without SP), for 28 days. In the last week of sex reversal a stress situation was established by removing the aeration and water renewal. Survival and weight gains data were subjected to a variance analysis (ANOVA) and Tukey's test for averages differentiation at significance levels of 1 and 5%. Weight gains were greater in animals that received SP, regardless of the used dose and better survivals were obtained when SP were administered at the doses of 0.05 and 0.1 mg g-1, with values of 79.90 ± 5.68 and 77.60 ± 1.80%, respectively. The study revealed that small doses of the SP were able to improve survival, daily weight gain and final average weight of tilapias submitted to a stress situation.

Kappaphycus alvarezii (Rhodophyta, Gigartinales) is a red algae widely cultivated as the main source of raw material for the carrageenan industry. This hydrocolloid is normally used in the food industry as a gelling and stabilizing agent. The facility of its commercial farming based on vegetative propagation promoted the success of the aquaculture of this macroalgae that consequently stimulated studies focusing on new potential uses of this resource. This work presents a brief review of the studies related to K. alvarezii cultivation in southern and southeastern Brazil, the latest discoveries in the world concerning pharmacological studies with this species and the advantages of the use of carrageenan as a source of dietary fiber, cholesterol reducer, and antioxidant, anti-viral and anti-cancer compounds, as well as the effects in hemagglutination activity.

En este estudio se realizó la evaluación bromatológica dos especies de algas nativas (Gracilariopsis tenuifrons y Sargassum filipendula) y una exótica (Kappaphycus alvarezii) provenientes de cultivos algales en La Guajira, costa Caribe de Colombia. Por los resultados obtenidos se pudo concluir que K. alvarezii es una fuente importante de potasio, sodio y fósforo y S. filipendula de fibra, calcio, magnesio, manganeso, fósforo y potasio; teniendo en cuenta que la primera tiene un sobresaliente aporte en potasio, y la segunda en fibra y calcio. Los análisis muestran la riqueza en minerales que tienen las tres algas, en K. alvarezii predomina el contenido de potasio, en cambio en S. filipendula y en G. tenuifrons es el calcio. La cantidad de proteína bruta en G. tenuifrons es casi siete veces la contenida en K. alvarezii y dos veces la de S. filipendula, siendo para estas dos últimas, baja. Los valores estimados de la proteína cruda para S. filipendula se encuentran dentro de los intervalos registrados en la literatura. En el caso del hierro, las concentraciones obtenidas en G. tenuifrons y S. filipendula están muy por encima de las cantidades aportadas por otros alimentos energéticos. Igualmente, la fibra contenida S. filipendula es muy elevada, ya que la mayor parte de los polisacáridos estructurales y de reserva, comunes en las algas pardas, como alginatos, furanos y celulosa pueden ser considerados como compuestos fibrosos. Similar consideración puede hacerse sobre la concentración de fibra en G. tenuifrons, ya que la contiene en un valor mayor al 80%. En cuanto a grasa total, fósforo y zinc los contenidos en las tres especies son similares. En las proteínas, es evidente la alta concentración de G. tenuifrons, sobre las otras dos especies. Por último, llama la atención la ausencia de cobre y manganeso en G. tenuifrons y K. alvarezii, mientras que en S. filipendula, son altas especialmente en cuanto al manganeso.

This study presents the bromatological evaluation of two species of native (Gracilariopsis tenuifrons and Sargassum filipendula) and exotic (Kappaphycus alvarezii) algae from algal cultures in La Guajira, located on the Colombian Caribbean coast. From the results obtained, it was concluded that K. alvarezii is an important source of potassium, sodium and phosphorus, and S. filipendula is a source of fiber, calcium, magnesium, manganese, phosphorus and potassium; emphasizing that the first significantly contributes potassium, while the second contributes fiber and calcium. The analysis shows the richness in minerals of the three algae, in K. alvarezii the potassium content is dominant; while in S. filipendula the calcium content predominates; and G. tenuifrons is rich in iron. The amount of crude protein in G. tenuifrons is almost seven times more than that found in K. alvarezii, and twice that of S. filipendula.. The estimated values of crude protein in S. filipendula are within the ranges found in the scientific literature. In the case of iron, concentrations found in G. tenuifrons and S. filipendula are well above the amounts provided by other energetic food. Similarly, the fiber contained in S. filipendula is very high, since most of the structural and reserve polysaccharides, common in brown algae, such as alginates, cellulose and furans can be considered as fibrous compounds. Similar consideration can be made regarding the concentration of fiber in G. tenuifrons, since it contains over 80%. As for total fat, phosphorus and zinc contents in the three species are similar. Regarding proteins, the high concentration found in G. tenuifrons, over the other two species is evident. Finally, the absence of copper and manganese in G. tenuifrons and K. alvarezii is notorious, whereas S. filipendula is particularly high in manganese.

Kappaphycus alvarezii, uma das principais fontes de matéria prima para produção de carragenana, vem sendo cultivada em balsas flutuantes, na baía de Sepetiba, sem estudos de monitoramento ambiental. A ocorrência e o estabelecimento de esporos e de mudas desta alga exótica no ambiente marinho foram avaliados e a praticidade da metodologia aplicada foi verificada, visando à proposta de um protocolo de monitoramento ambiental para cultivos liberados para o Brasil, entre a baía de Sepetiba (RJ) e a Ilha Bela (SP). Este estudo foi realizado no maior cultivo desta espécie no país, na baía de Sepetiba (23º03'50"S e 043º52'50"N), entre maio e julho/2006. Neste período, não foi observada ocorrência de mudas férteis sob cultivo tampouco estabelecimento de esporos. A ocorrência de mudas fora do sistema de cultivo foi ínfima, frente à biomassa cultivada, e restrita aos limites da fazenda marinha. Além disso, a sobrevivência de mudas transplantadas fora das balsas foi suprimida em detrimento da baixa incidência luminosa provocada pelo alto teor de material particulado em suspensão na água do mar. Concluiu-se, portanto, que a introdução de Kappaphycus alvarezii não ocasionou danos ambientais nesta baía até o momento e que o método utilizado foi adequado à avaliação do estabelecimento desta espécie no ambiente. Neste sentido, recomenda-se a aplicação permanente do método apresentado como protocolo para o cultivo de Kappaphycus alvarezii na área permitida para o Brasil, visando à manutenção da biodiversidade marinha.

Kappaphycus alvarezii, one of the most important sources of raw material for carrageenan production, has been cultivated in a floating-raft system, at Sepetiba Bay, southeast Brazil, with no environmental monitoring studies. The aim of this research was to verify the occurrence and establishment of Kappaphycus alvarezii plantlets and spores in the benthic communities around the biggest Brazilian Kappaphycus alvarezii farm, at Sepetiba Bay (23º03'50"S; 043º52'50"N), to analyze the applicability of the methodology and to propose an environmental monitoring protocol for areas where this cultivation is permitted in Brazil. From May to July/2006, the occurrence of fertile cultivated branches as well the recruitment and establishment of spores were not observed. The occurrence of plantlets outside the system was restricted to the farm boundaries and lost biomass was insignificant in relation to cultivated biomass. Futhermore, the establishment of transplanted seedlings through vegetative growth was suppressed by high suspended particulate material in the water column. These results suggest that Kappaphycus alvarezii introduction has not yet provoked environmental damage in Sepetiba Bay and the methodology used was adequate for this kind of evaluation. Constant application of the method is recommended as a protocol for growing Kappaphycus alvarezii where permitted in Brazil in order to maintain marine biodiversity.

Devido aos potenciais problemas ambientais na baía de Sepetiba, sítios de monitoramento ambiental nesta baía se tornam necessários. A praia do Kutuca foi selecionada para este propósito por possuir dados pretéritos sobre a sua estrutura da comunidade, com coletas realizadas em 1999, que detectou alta diversidade. Durante 21 meses, dezembro de 2003 a julho de 2005, foram coletados 63 táxons (Chlorophyta, 22%; Ochrophyta, 16% e Rhodophyta, 62%). Na amostragem destrutiva, foram usados seis quadrados aleatórios (25×25 cm), colocados em cada uma das duas linhas de 20 m horizontais ao costão. Os resultados de 1999 foram comparados com estes e se observou que a biomassa passou de 490,9±201,2 g.m-2 para 199,57±29,33 g.m-2, a riqueza de 13,0±4,5 para 5,06±1,72, a diversidade H'=2,2±0,41 para H'=1,3±0,39 e a equitabilidade J'= 0,65± 0,06 para J'= 0,55±0,17.Quatro táxons (Sargassum spp., Caulerpa sertularioides (S.G. Gmel.) M. Howe, Hypnea musciformis (Wulfen in Jacquin) J.V. Lamour. e Gracilaria cervicornis (Turner) J. Agardh) mais representativos contribuíram com 15 a 33% de biomassa, enquanto que em 1999, oito táxons (Caulerpa sertularioides,Dictyopteris delicatula J.V. Lamour., Gracilaria cervicornis, Sargassum spp., Codium taylorii P.C. Silva, Padina gymnospora (Kützing) Sonder, Galaxaura marginata (Ellis & Solander) J.V. Lamouroux e Hypnea spinella (C. Agardh) Kütz.) contribuíram com 5 a 20% de biomassa. Esses resultados mostraram a existência de distúrbios, provavelmente decorrentes das dragagens para aumento do canal de navegação para o Porto de Sepetiba, além da entrada de frentes meteorológicas. Apesar da avaliação do potencial invasivo da espécie exótica Kappaphycus alvarezii (Doty) Doty ex Silva ter sido negativo neste período, se recomenda que o seu monitoramento seja permanente.

Due to potential environmental problems in Sepetiba Bay, it is necessary to identify sites for environmental monitoring. Kutuca Beach was chosen for this purpose since community structure data from collections in 1999 detected high diversity. Over a period of 21 months, 63 taxa were collected (Chlorophyta, 22%; Ochrophyta, 16%; Rhodophyta, 62%). The destructive sampling used six random plots (25x25 cm) in each of two 20-meter long lines horizontal to the rocky shore. When the 1999 results were compared with these, it was observed that biomass went from 490.9±201.2 g.m-2 to 199.57±29.33 g.m-2, richness from 13.0±4.5 to 5.06±1.72, diversity H'=2.2±0.41 to H'=1.3±0.39 and equitability J'= 0.65± 0.06 to J'=0.55±0.17. Four taxa (Sargassum spp., Caulerpa sertularioides (S.G. Gmel.) M. Howe, Hypnea musciformis (Wulfen in Jacquin) J.V. Lamour. and Gracilaria cervicornis (Turner) J. Agardh) contributed 15% to 33% of the biomass, while in 1999, eight taxa (Caulerpa sertularioides,Dictyopteris delicatula J.V. Lamour., Gracilaria cervicornis, Sargassum spp., Codium taylorii P.C. Silva, Padina gymnospora (Kützing) Sonder, Galaxaura marginata (Ellis & Solander) J.V. Lamouroux and Hypnea spinella (C. Agardh) Kütz.) contributed 5% to 20% of the biomass. These results showed the existence of disturbance that probably is a consequence of dredging to increase the navigation channel to Sepetiba Port, as well as the entrance of cold fronts. In spite of fact that the invasive potential of the exotic species Kappaphycus alvarezii (Doty) Doty ex Silva was assessed as negative during this period, permanent monitoring of this species is recommended.