Carrageenan Industry Research Articles

Effect of Adding Carrageenan Processing Solid Waste from Eucheuma cottonii to Art Paper Manufacture from Water Hyacinth

The carrageenan industry produces solid waste E. cottonii of 65% to 70%, so it had the potential to be used as a paper material. The aimed of this study was to analyze the effect of the concentration of E. cottonii waste which was added in the production of art paper from water hyacinth stems on the quality of the paper. The experimental design used was Complete Randomized Design with 1 factor, namely the difference of Eucheuma cottonii waste concentration (0%, 10%, 15%, and 20% (w/w)). The results showed that the addition of carrageenan processing from E. cottonii with difference concentration gave significantly different (p<0.05) on the value of grammage, tensile strength, tear resistance, density, and lightness of the paper. The best concentration of Eucheuma cottonii was 15% because it had the highest tear resistance value (p<0.05) and higher of lightness than the concentration of 0% and 10% (p<0.05). Paper with waste E. cottonii 15% had a grammage 148.93 g/m2; tensile resistance 1.28 kN/m; tear resistance 2497.37 mN; density 1.52 g/cm3; and lightness L* 80.19. The results of microstructure observations using Scanning Electron Microscopy (SEM) were the paper with E. cottonii waste 15% seen less free space (tighter) than other papers. Based on the grammage and tensile resistance value, paper with E. cottonii waste 10% according to Indonesian National Standard 8218:2015 regarding paper and cardboard for food packaging requirements.

Analysis of yield and types of carrageenan from different strains at Kupang Bay seaweed production center, East Nusa Tenggara

Kappaphycus alvarezzi is a species widely cultivated by the seaweed farmers surrounding Kupang Bay since the early 2000s. K. alvarezzi is sold as raw materials for the carrageenan industry as its hydrocolloid properties are used as emulsion and suspension stabilizers in the food and pharmaceutical industries. This study determines the yield and identifies the type of carrageenan from algal farms at Kupang Bay. Samples are collected from five production centers, then extracted at the Wet Laboratory at the Undana Faculty of Animal Husbandry, Marine and Fisheries in Kupang; and the extracted carrageenan is then analyzed using infrared spectroscopy at the Laboratory of the Faculty of Advanced and Multidisciplinary Technology Universitas Airlangga in Surabaya. The results showed that the highest yield of carrageenan was seaweed from Sulamu (25.72%) then, followed by Oenaek (19.6%), Tablolong A (13.48%), South Semau (11%), and Tablolong B as the lowest yield (9.6% ). Both the presence of functional groups such as D-galactose-4-sulphate and 3,6 anhydro D-galactose groups and the absence of D-galactose-2-sulfate and the 3,6 anhydrogalactose-2-sulfate group, concluded that the type of carrageenan produced in Kupang Bay is the kappa carrageenan.

Use of macroalgal waste from the carrageenan industry as feedstock for the production of polyhydroxybutyrate

AbstractThe industrial waste generated in the extraction of carrageenan from red seaweed, Eucheuma spinosum, was tested in this study to produce fermentable sugars that could be used for the production of high‐value‐bioproducts with a biorefinery approach. A sequential process was used: thermochemical pretreatment with HCl and enzymatic hydrolysis. Hydrogen chloride concentrations in the range from 0 mol L−1 to 0.5 mol L−1 and pretreatment times from 15 to 100 min were assayed. The best conditions found for pretreatment were HCl 0.3 mol L−1 for 60 min, leading to reducing sugar concentrations of 21.4 g L−1 (274 mg of reducing sugars per gram of algal residue). The hydrolysates coming from the sequential process under the pretreatment conditions of HCl 0.3 mol L−1 for 60 and 80 min have been used successfully for the production of polyhydroxyalkanoates by Cupriavidus necator. The yields of polyhydroxybutyrate were 0.21–0.26 g PHB g−1 reducing sugar consumed and the accumulation of the biopolymer was of the order of 58% dry cell weight. © 2023 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

Coastal Communities’ Empowerment through Seaweed (Eucheuma cottoni): Potency, Suitability, and Local Participation

Indonesia is the largest producer of seaweed contributed by coastal communities, but they still live in precarious conditions. To bolster the seaweed cultivation and alleviate poverty, a coastal community’s empowerment was studied in Salabangka archipelagoes through the evaluation of its largely produced seaweed (Eucheuma cottoni) potency (total production and investment opportunities), suitability for seaweed cultivation (environmental parameter and suitability), and local participation (interviews) in 2011. Seaweed production in Salabangka archipelagoes was estimated from 2009 to 2010 data. For the investment opportunities of seaweed cultivation, initial investments were assessed for the medium-scale semi refined carrageenan (SRC) model and the Carrageenan industry model. Subsequently, the profit and loss were projected for the upcoming five years. To estimate the investment qualification, several criteria were used, i.e., Net Present Value (NPV), Internal Rate Return (IRR), Net Benefit Ratio (Net B/C), Pay Back Period (PBP), and Profitability Index Methods (PI). The factors that influence the local participation and perceptions of coastal communities in Salabangka archipelagoes were analyzed based on the degree of perception and participation obtained from interviews in substation sites. The seaweed potency reveals a good prospect indicated by the increase of seaweed production and profitable investment. The environmental condition and qualifications support the suitable habitat for seaweed cultivation. Local participation shows a good indication of the support of the coastal communities. In the future, the government must secure the policy, allocate funding, and forge a partnership with the local bank to bolster the seaweed cultivation in the Salabangka archipelagoes.

STRATEGI PENETAPAN BEA KELUAR EKSPOR RUMPUT LAUT SEBAGAI UPAYA OPTIMALISASI INDUSTRI KARAGINAN DALAM NEGERI

Indonesia is one of the best seaweed producers in Asia. With this, Indonesia should be able to optimize various kinds of seaweed processing industries, one of which is the carrageenan industry. Carrageenan is a derivative product of seaweed which in the international market the price can be much higher than the commodity of seaweed without any added value. Continuing to increase the volume of primary seaweed exports makes the domestic carrageenan processing industry experience difficulties in raw materials, especially during the Covid-19 pandemic. So in this study, panel data analysis was used with a gravity model to analyze what factors affect the demand for Indonesian seaweed exports to export destinations of China, the Philippines, Vietnam, the Republic of Korea, Chile, United Kingdom, USA, Hong Kong, Germany and France. .To find out the amount of Seaweed Export Duty that can be applied in an effort to reduce the export of seaweed commodities. The results showed that the factors that affect the volume of seaweed exports to destination countries include export prices that have a negative and significant effect, real GDP has a positive and significant effect, and economic distance has a negative and significant effect. The determination of export duty for seaweed raw materials by up to 18 percent can reduce export demand from the top ten export destinations for seaweed raw materials.

Science Interventions for Sustainable Marine Products Production: The Case of Sardines and Seaweeds

This paper presents two cases of scientific interventions to address pressing sustainable production of marine products in the Philippines such as the sardine fishery and seaweed production. The Philippine sardine fishery accounts for about 25% of commercial and 11% of municipal fisheries. Due to dwindling catch, the biology, ecology, fish catch and environmental factors were investigated in Northern Zamboanga Peninsula where upwelling during the northeast monsoon supports a significant sardine population. The study resulted in a resource management program that remains adaptive and spatially explicit to ensure sustainability of the sardine fishery. On the other hand, the Philippine seaweed production contributes about 50% of the annual fishery production volume, of which 70% comes mainly from carrageenophytes or carrageenan-bearing seaweeds. Production of these seaweeds made the Philippines the world’s top supplier of the raw dried seaweed for carrageenan production until 2007 after which seaweed production for the carrageenan industry placed second only to a neighboring country. Government agencies and academic institutions, thus, initiated studies to improve the productivity of this marine plant. For sustainability, tissue culture techniques were developed, and gene and seedlings banks were established in strategic parts of the country to ensure continued supply of quality seaweed seedlings to the farmers. Philippine standard specifications for raw material and carrageenan were formulated to comply with international standards. Continued science interventions to marine fishery industries are called for and should be intensified to promote further the country’s progress.

Assessment of genetic diversity within eucheumatoid cultivars in east Sabah, Malaysia

Studies have shown that cultivars of the carrageenophytes Kappaphycus and Eucheuma are clones of a limited number of strains originally domesticated from wild populations. For the development and selection of new cultivars, it is important that a comprehensive record of available variants exists. This study was conducted to provide up-to-date analysis and compilation of the current state of cultivars as the last list of cultivars was compiled nearly a decade ago. The present study analyzed the cox2–3 spacer and cox1 (1356 bp) genetic diversity of cultivars collected from 2019 to 2020 from the east coast of Sabah where the seaweed farms are concentrated. These data were compared with cultivars reported from 2010 to 2012 to assess changes, if any, to the gene pool of farmed eucheumatoid in Malaysia. Kappaphycus alvarezii, K. striatus, and K. malesianus are currently cultivated while Eucheuma denticulatum is no longer an important cultivar compared to a decade ago, probably due to its lower price. Analysis of the cox2–3 spacer revealed a new haplotype, LBT10, and, by including published GenBank data, a further four previously unnamed haplotypes were recognized from Sabah. This study confirms that there is a limited gene pool within cultivars in Malaysia and suggests the need for new or genetically diverse cultivars which can adapt to a changing environment, to ensure a more sustainable carrageenan industry.

Neuritogenic Activities of Various Kappaphycus alvarezii Extracts in Hippocampal Neurons

The carrageenophyte Kappaphycus alvarezii seaweed is known to have neuritogenic activities. Post-harvest treatment of seaweed affects its biological activities. Five drying treatments of K. alvarezii, including oven-drying, sun-drying, freeze-drying, shade-drying, and salting followed by shade-drying, were evaluated for their effects on neuritogenic activities. We also evaluated the neuritogenic activity of different parts of K. alvarezii thalli and its carrageenan waste. Neuron cells of the 19th day pregnant rat fetuses were collected from the hippocampus by brain dissection. Neuron cells were isolated by dissociation of the hippocampal tissue. Cells were plated onto poly-DL-lysine-coated glass coverslips in 24-well plates and treated with extracts. All tested extracts were obtained from maceration using 95% ethanol. Freeze and shade-drying extracts exhibited significantly higher neuritogenic activities (p 0.05) compared to that of the vehicle control. Carrageenan waste also significantly promoted the neuritogenic activities (p 0.05) with an optimal dose at 1 µg mL-1. Old and young thalli showed insignificant differences in neuritogenic activities. The carrageenan waste extract retained neuritogenic activities. Thus, the utilization of carrageenan waste for neuritogenic material provides added value to the waste in the carrageenan industry. Freeze and shade dried K. alvarezii can be used as a neuritogenic agent to provide optimum biological activity.

Antioxidant properties of different strains of Kappaphycus alvarezii (Rhodophyta) farmed on the Brazilian coast

ABSTRACT Kappaphycus alvarezii is one of the most farmed algae globally. It is used almost exclusively for the carrageenan industry, although there is increasing interest in its biotechnological application as a natural product with biological properties. This cultivated species produces different strains with distinct chemical and physiological properties. Despite this, K. alvarezii has been marketed as a single biomass. The aim of this study was to evaluate differences in antioxidant capacities among green, red, brown and G11 strains of K. alvarezii cultivated in southeastern Brazil, assessed by Folin–Ciocalteu reducing potential, DPPH, ABTS and FRAP assay methods. Methanolic and aqueous extracts yielded from 2.67% to 3.43% and 26.25% to 32.90%, respectively. Nevertheless, methanolic extracts showed higher total phenolic content (40.80 mg GAE 100 g−1 DW to 58.49 mg GAE 100 g−1 DW) than aqueous ones (7.77 mg GAE 100 g−1 DW to 12.51 mg GAE 100 g−1 DW), and a similar trend was found for DPPH (7.15% to 31.21%), for ABTS (60.29% to 100.39%), and for FRAP (27.24% to 95.95%). Antioxidant activity of aqueous extracts was lower than 17% for all spectrophotometric assays. The green strain had the highest index of antioxidant capacity, suggesting that this strain may be suitable as a natural source of antioxidants. This is the first report evaluating antioxidant potential of four strains of K. alvarezii, supporting the need for further research to identify and select for its value as a viable natural antioxidant source.

A value chain analysis of Malaysia\u2019s seaweed industry

A global shortfall in protein supply from capture fisheries has motivated the Malaysian government to revise its aquaculture strategy, focusing on three commodities: seaweed, fish and marine shrimp. However, the performance of the Malaysian aquaculture sector, particularly seaweed production, is poorly documented. This is the first empirical study to undertake a value chain analysis (VCA) of the Malaysian seaweed sector using stakeholder perceptions and secondary data that encompass members of seaweed farming cooperatives (the Semporna Area Farmers’ Association and the governments’ flagship Seaweed Cluster Project). Fieldwork was conducted between April and June 2015 among seaweed stakeholders involved in the value chain using a mixed methods approach—in-depth interviews with key informants, focus group discussions, household surveys, personal observation and secondary data. Qualitative and quantitative data were collected from both upstream (seaweed farming, marketing structure and the Malaysian Good Aquaculture Practices [MyGAP] certification programme) and downstream (seaweed processing) activities involving farmers, intermediaries/middlemen (buyers), processors and officials. Kappaphycus spp. was sold in two forms: (1) dried seaweed to be used as raw materials in carrageenan processing (approximately 90% of total harvest) and (2) fresh seaweed to be used as a source of seedlings (approximately 10% of total harvest). The value chain ended with the carrageenan form, which is exported to international markets. The price of dried seaweed varied according to a combination of seaweed quality, the strength of farmer’s relationships with intermediaries and processors and in response to demand from the carrageenan industry. The prices obtained by Malaysian farmers for dried seaweed and carrageenan remained low, US$ 0.60 and US$ 4.43 per kg, respectively, despite efforts by the government to enhance the value chain by imposing seaweed standards (via MyGAP) for farm management, dried seaweed and semi-refined carrageenan. The VCA was a useful tool to identify and map the market, with the results providing a better understanding of the seaweed sector, which could be helpful in supporting further aquaculture development in Malaysia.

Sequential acid and enzymatic hydrolysis of carrageenan solid waste for bioethanol production: a biorefinery approach

The seaweed industry has developed rapidly over the last decade, and carrageenan is the leading hydrocolloid in the seaweed industry. Approximately 57,500 t of carrageenan is produced annually throughout the world. As a consequence of the increase in carrageenan production, the enormous amount of waste resulting from the carrageenan industry has also increased. This study investigated the possibility of ethanol production using carrageenan solid waste from the carrageenan extraction of Kappaphycus alvarezii, the principal species used in the carrageenan industry. Optimum acid hydrolysis followed by enzymatic hydrolysis enhanced the production of both galactose and glucose. Fermentation of the enzymatic hydrolysate using Saccharomyces cerevisiae ATCC 200062 resulted in an ethanol yield of 13.8 g L−1.

Spore release and germling development on different substrates in the carrageenophyte Sarcothalia crispata from the southwestern Atlantic coast

Sarcothalia crispata is a carrageenophytic red alga from South America. The gametophytes produce kappa/iota carrageenan and the tetrasporophytes, lambda carrageenan, each with different properties and uses. The aims of this study were to determine the most effective method for obtaining S. crispata carpospores and tetraspores from southern Argentina, to evaluate the germination process of these spores, and to assess their survival and growth on different substrates. Desiccation, osmotic shock, low temperature, and spontaneous discharge were tested in the laboratory as spore release methods. The settlement and growth of sporelings were assessed on glass, ropes, shells, and gravel. No differences were found among induction methods, obtaining a higher output of tetraspores per frond area than of carpospores. After 3 months, shells and gravel showed the highest densities of carposporelings and tetrasporelings, while the lowest were observed on ropes and glass, respectively. Carposporeling survival varied between 88% on gravel and 13% on ropes; for tetrasporelings, mean survival was 5%. Sporelings attained the largest basal discs and longest erect portions on glass, and the smallest and shortest ones on ropes, those on shells and gravel being of intermediate in size. Based on these results, it can be concluded that carpospores and tetraspores from S. crispata obtained by spontaneous discharge and inoculated on shells and gravel will result in good densities, allowing germlings to develop and grow. This is the first study on reproductive aspects of S. crispata from the southwestern Atlantic coast, presenting valuable information for reliably initiating specific spore cultures. Obtaining this specific raw material separately for the extraction of kappa/iota or lambda carrageenan would lead to a better management of the resource by the carrageenan industry.

Great potency of seaweed waste biomass from the carrageenan industry for bioethanol production by peracetic acid–ionic liquid pretreatment

Seaweed waste biomass from the carrageenan industry (SWBC) is a potential biomass feedstock for producing sustainable biofuel because it increases the product value and reduces the pollutant risk. Peracetic acid (PAA) followed by ionic liquid (IL) pretreatment has been used to increase the enzymatic saccharification of pretreated SWBC. The SWBC cellulose content was comparable with that of terrestrial biomasses. PAA + 1-hexylpyridinium chloride ([Hpy][Cl]), and PAA + 1-ethyl-3-methylimidazolium diethylphosphate ([Emim][DEP]) pretreatments produced saccharide and unknown oligosaccharide fractions in regenerated water (∼4–6% SWBC cellulose content). For 48 h of saccharification, the untreated SWBC and the SWBC pretreated using PAA followed by [Hpy][Cl], [Emim][DEP] or 1-ethyl-3-methylimidazole acetate ([Emim][OAc]) produced cellulose conversions of 77, 91, 84 and 62%, respectively. The untreated SWBC had a high cellulose conversion, which may be caused by the low lignin and hemicellulose contents of the SWBC. PAA + IL pretreatment could yield pretreated SWBCs with more amorphous cellulose structures, which lead to an almost-complete cellulose conversion.

Risk analysis using species distribution modeling to support public policies for the alien alga Kappaphycus alvarezii aquaculture in Brazil

Abstract The native tropical seaweed Kappaphycus alvarezii from the Indo-Pacific region has been introduced in many countries because it is the main source of raw material for the carrageenan industry. In Brazil, K. alvarezii aquaculture is allowed in 300 km of the southeastern coast. The aim of this study was to analyze the risk of invasion of this species along the entire Brazilian coast to design public policies and to minimize environmental risks associated with aquaculture. The risk analysis was based on: K. alvarezii suitability models (GARP and MAXENT), coral reef presence, substrate preferences for establishment, and the probability of occurrence of nine species of herbivores that are potential feeders. An invasibility index was created from these parameters and published data of field experiments were used for calibration. The maximum values of suitability corresponded to regions with low temperature ranges, low nitrate availability, high irradiance, and high salinity. Three invasion risk classes were established. The areas of high risk are the eastern and northeastern regions, where the main Atlantic coral reefs are found. This is a priority area for global marine conservation. K. alvarezii introduction is not recommended in this area and the cultivation of native species must be prioritized. The area of medium risk is mainly in the northern region, where local field scale experiments are recommended before widespread introduction. The area of low risk is the southeastern region, where K. alvarezii farming has been established since 2004 with no evidence of invasion. However, considering the high capacity of acclimation of this species, permanent monitoring is recommended, even in areas having a low risk of invasion. Statement of relevance We state the relevance of our paper in commercial aquaculture since we presented a consistent environmental risk analysis for K. alvarezii that according to FAO is the most cultivated seaweed in the world. Our aim is to contribute for development of sustainable seaweed aquaculture, subsiding data to minimize environmental risks associated with K. alvarezii introduction. This kind of analysis also can be adapted to other countries. Our results indicate safe areas to extend K. alvarezii cultivation, areas where the native seaweed should be cultivated and with those conclusions encouraging the expansion of the commercial seaweed aquaculture and highlight for high environmental risks in coral reef areas.

Effects of a commercial extract of the brown alga Ascophyllum nodosum on the biomass production of Kappaphycus alvarezii (Doty) Doty ex P. C. Silva and its carrageenan yield and gel quality cultivated in Brazil

Despite of its success, the carrageenan industry has had to cope with difficulties due to epiphyte infestations and diseases known as ice-ice. Some promising results in respect of biomass production, carrageenan yield, and protection epiphytes were obtained using a powdered extract of the brown alga Ascophyllum nodosum in Kappaphycus alvarezii seedling production. This study focused on the effects of the A. nodosum extract on the treatment of K. alvarezii cultivated on commercial floating rafts not only to evaluate improvements demonstrated in vitro but also the effects on the quality of the carrageenan. The seedlings were treated in an A. nodosum extract solution and placed alongside their controls on commercial floating rafts using the tubular net technique. Daily growth rate, carrageenan yield, gel strength, and gel viscosity were obtained over 20 and/or 40 days. After 20 days, daily growth rates showed no significant difference (p = 0.44), while the carrageenan yield was higher in samples that were treated with the A. nodosum solution (p < 0.001). After 40 days, both daily growth rate (p = 000.7) and carrageenan yield (p = 0.009) were higher in treated samples; however, gel strength was higher in control samples (p = 0.03) as viscosity was also highest in the samples which had not been treated (p < 0.001). The use of the A. nodosum extract treatment on the cultivation in situ of K. alvarezii was positive since after 40 days when the daily growth rate and carrageenan yield increased. In spite of the negative effect on the quality of the semi-refined carrageenan, the values were within commercial standards.

Effect of the commercial extract of the brown alga Ascophyllum nodosum Mont. on Kappaphycus alvarezii (Doty) Doty ex P.C. Silva in situ submitted to lethal temperatures

Kappaphycus alvarezii is being introduced in several countries and in some of them there is a need to adapt this cultivation to periods with lethal temperatures, such as the 16–18 °C that occurs in the winter in southern Brazil. Moreover, there is the need to maintain the seedlings during this lethal temperature period. Considering the promising results obtained with the commercial powder extract of Ascophyllum nodosum (Acadian marine plant extract powder—AMPEP) treatment in the cultivation of K. alvarezii in vitro and in the sea allowing more resistance to epiphytes and increasing the growth rate and carrageenan yield, it was hypothesized that seedlings previously subjected to an AMPEP treatment could be more resilient to lethal temperatures. The daily growth rate and carrageenan yield and gel quality (gel strength and gel viscosity) of K. alvarezii in vitro previously treated with AMPEP were analyzed under temperature stress. The daily growth rates and the gel strengths of the AMPEP-treated samples were increased. In spite of the lower carrageenan yield and lower gel viscosity, the values were within the ones accepted by the carrageenan industry. Thus, the treatment of the seedlings of the K. alvarezii with AMPEP solution can be used as an alternative to lower temperature effects on crops as a preventive action for the cultivation of the seedlings in tanks and in the sea in periods of low temperatures at sea.

Cultivation of the red algae Kappaphycus alvarezii in Brazil and its pharmacological potential

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.

Phylogenetic relationship of Kappaphycus Doty and Eucheuma J. Agardh (Solieriaceae, Rhodophyta) in Malaysia

The genera Kappaphycus Doty and Eucheuma J. Agardh are important sources of carrageenan in Malaysia, offering lucrative revenues to the carrageenan industry, economy, and the local community. The extensive range of morphotypes and the lack of distinct morphological characteristics led to the application of molecular systematics in elucidating this taxonomic confusion. Local varieties of Kappaphycus and Eucheuma, identified using putative external morphology, were analyzed using the mitochondrial cox2–3 spacer and plastid RuBisCO spacer molecular markers. Phylogenetic analysis of these and non-local specimens indicate that Kappaphycus and Eucheuma are genetically distinct. Three main genotypes of Kappaphycus alvarezii were identified, of which two are extant in Hawaii. Morphological and color variations are not supported by molecular data, indicating that most of the local names are not genetically based. Both the cox2–3 spacer and RuBisCO spacer generated phylogenetic trees with similar topology except in variation of nodal supports. The two markers showed clear separation between Kappaphycus and Eucheuma and the existence of three Malaysian Kappaphycus cultivars. Cox2–3 spacer data is more variable and provides better resolution than the RuBisCO spacer, showing that Kappaphycus is more diversified with a larger number of genotypes, strains, and species which are unique to Southeast Asia. Kappaphycus sp. “Aring-aring” appeared to be phenotypically and genotypically different from other Kappaphycus congeners, whereas Kappaphycus striatum exhibited two different genotypes. Our data indicate that Eucheuma denticulatum is the dominant species in Malaysian waters and also suggested paraphyly in Eucheuma which will require further studies. The application of molecular taxonomy on Malaysian Kappaphycus and Eucheuma proves useful, offering valuable insights into the taxonomy and distribution of these commercially important Rhodophytes.

Does salinity affect growth and carrageenan yield of Kappaphycus alvarezii (Gigartinales/Rhodophyta)?

Kappaphycus alvarezii (Doty) Doty ex. P. C. Silva is one of the most important sources of raw material for the carrageenan industry (Ask & Azanza 2002). In Brazil, onlyHypneamusciformis (Wulfen) J.V. Lamouroux is used as raw material and its natural stocks are not su⁄cient to supply the Brazilian demand (Bulboa & Paula 2005; Reis, Yoneshigue-valentin & Santos 2008). This was one of the reasons why, in 1995, K. alvarezii was introduced at the Brazilian Southeastern coast, in Sa o Paulo State (Bulboa & Paula 2005). The carrageenan yield (CY) can change in accordance to environmental parameters as a mechanism of prevention against stressful situations like salinity £uctuations (Hayashi, Oliveira, Bleicher-lhonneur, Boulenguer, Pereira,Von Seckendori, Shimoda, Le£amand,Valle¤ e & Critchley 2007; Reis et al. 2008). Few works discuss the salinity eiects on daily growth rate (DGR) and CYof eucheumatoids in spite of its importance (Ask & Azanza 2002).This information could help the identi¢cation of good sites for cultivation and would help mitigation activities (Ask, Batibasaga, Zertuche-gonzaŁ lez & De San 2003).Thus, the aim of this study was to analyse the eiect of the salinity on DGRand CYvalues of K. alvarezii in vitro.

Does biofouling influence Kappaphycus alvarezii (Doty) Doty ex Silva farming production in Brazil?

The commercial cultivation of Kappaphycus alvarezii is the main source of raw material for the carrageenan industry. Brazilian commercial farming uses floating rafts that serve as substrata for fouling organisms that may affect production of the carrageenophyte seedlings. The aim of this work was to identify and quantify the biofouling on floating rafts at Sepetiba Bay, Rio de Janeiro State (23° 02′ 25″ S and 43° 53′ 39″ W), and to evaluate seedling damage caused by epibionts and endobionts. Samples were collected from August 2006 to August 2007. In each assessment, organisms contained in random sampling areas of 18 quadrats of 0.10 m2 (n = 18) were removed from floating rafts. K. alvarezii seedling samples were collected to verify the presence of epibionts or endobionts (n = 30). Twenty-four taxa belonging to seven groups of animals and three groups of seaweed were found. The percentage occurrence estimated 13 dominant organisms and amphipod tubes: e.g., Chondracanthus tedii, Cladophora vagabunda, Gracilariopsis tenuifrons, Hypnea spinella, Hypnea musciformis, Hincksia mitchelliae, Spyridia spp., Ulva spp., Bowerbankia sp., Bugula neritina, Botryllus sp., Haplosclerida sp., and Perna perna. Richness, equitability, diversity, and total biomass varied significantly during the study period (p 0.05).