Abstract
The yield and gel properties of agar from Gelidium robustum, harvested in Baja California for industrial production is affected by season of collection and epiphyte loading. The alga is epiphytized to various extents by the bryozoan Membraniphora tuberculata ('conchilla') and the resulting calcareous crust on the alga diminishes the price of the seaweed biomass. Classification of the algal biomass quality by the agar industry is based on the apparent 'conchilla' content from visual examination. The different quality classes can be categorized quantitatively into premium class (30–40% w/w of 'conchilla' load), 2nd class (∼ 50% w/w) and 3rd class (> 60% w/w). For samples collected at two exploited beds, the biomass obtained from Bahía de Tortugas had a lower epiphytic coverage than that from Bahía Asunción. The agar yield from different quality classes of G. robustum was strongly affected by the bryozoan epiph ytic coverage, while its gel characteristics were not. Algae collected at Punta Prieta, an unexploited bed not affected by 'conchilla', showed seasonality in agar yield. It ranged between 17.5 and 44.2% with two maximum values observed, one in summer and the other in winter. Gel strength ranged between 515 and 665 g cm−2, reaching a maximum during autumn.
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References
Armisén, R. & F. Galatas, 1987. Production, properties and uses of agar. In McHugh, D. J. (ed.), Production and Utilization of Products from Commercial Seaweeds. FAO Fish. Tech. Pap. 288: 1–57.
Barilotti, C. D. & W. Silverthorne, 1972. A resource management study of Gelidium robustum. Proc. int. Seaweed Symp. 7: 255–261.
Bird, K. T., M. D. Hanisak & J. Ryther, 1981. Chemical quality and production of agars extracted from Gracilaria tikvahiaegrown in different nitrogen enrichment conditions. Bot. mar. 24: 441–444.
Cancino, J. M., J. Muñoz, M. Muñoz & M. C. Orellana, 1987. Effects of the bryozoan Membraniphora tuberculata(Bosc.) on the photosynthesis and growth of Gelidium rexSantelices et Abbott. J. exp. mar. Biol. Ecol. 113: 105–112.
Casas-Valdez, M. M. & C. Fajardo, 1990. Análisis preliminar de la explotación de Gelidium robustum(Gardner) Hollenberg et Abbott en Baja California Sur, México. Inv. Mar. CICIMAR 5(1): 83–86.
Cooper, G. L. & G. R. Johnstone, 1944. The seasonal production of agar in Gelidium cartilagineuma perennial red alga. Am. J. Bot. 31: 638–640.
Espinoza, J. & H. Rodríguez, 1992. Rendimiento y fuerza de gel de Gelidium robustum(Gelidiales, Rhodophyta) de la parte central de la península de Baja California. Rev. Inv. Cient. 3: 1–10.
Freile-Pelegrín, Y., D. Robledo & G. García-Reina, 1995. Seasonal agar yield in Gelidium canariensis(Grunow) Seoane-Camba (Gelidiales, Rhodophyta) from Gran Canaria, Spain. J. appl. Phycol. 7: 141–144.
Freile-Pelegrín, Y., D. Robledo, R. Armisén & G. García-Reina, 1996. Seasonal changes in agar characteristics of two populations of Pterocladia capillaceain Gran Canaria, Spain. J. appl. Phycol. 8: 236–246.
García, I., 1988. Estudio de la variación estacional de la calidad y el rendimiento del agar obtenido del alga roja Gelidium sesquipedale(Clem.) Born. et Thur. en la costa guipuzcoana (N. de España). Inf. Tecn. Inv. Pesq. 146: 3–19.
Guzmán del Próo, S. & S. De la Campa Guzmán, 1979. Gelidium robustum(Florideophyceae), an agarophyte of Baja California, México. Proc. int. Seaweed Symp. 9: 303–308.
McHugh, D. J., 1991. Worldwide distribution of commercial resources of seaweeds including Gelidium. Hydrobiologia 221: 19–29.
Mouradi-Givernaud, A., T. Givernaud, H. Morvan & J. Cosson, 1992. Agar from Gelidium latifolium(Rhodophyceae, Gelidiales): biochemical composition and seasonal variations. Bot. mar. 35: 153–159.
Onraët, A. C. & B. L. Robertson, 1987, Seasonal variation in yield and properties of agar from sporophytic and gametophytic phases of Onikusa pristoides(Turner) Akatsuka (Gelidiaceae, Rhodophyta). Bot. mar. 30: 491–495.
Robledo, D., 1998. Seaweed resources from Mexico. In Critchley, A. & M. Ohno (eds), Seaweed Resources of the World, JICA, Nagai, Yokosuka, Japan: 331–342.
Santelices, B., 1988. Synopsis of biological data of the seaweed genera Gelidiumand Pterocladia(Rhodophyta). FAO Fish. Synops. 145, 55 pp.
Torres, M., F. X. Niell & P. Algarra, 1991. Photosynthesis of Gelidium sesquipedale: effects of temperature and light on pigment concentration, C/N ratio and cell wall polysaccharides. Hydrobiologia 221: 77–82.
Zertuche-González, J., 1993. Situación actual de la industria de las algas marinas productoras de ficocoloides en México. In Zertuche-González, J. A. (ed.), Situación Actual de la Industria de Macroalgas Productoras de Ficocoloides en América Latina y el Caribe. D. C. No. 13. FAO-AQUILA, Mexico DF, Mexico: 33–37.
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Freile-Pelegrín, Y., Robledo, D. & Serviere-Zaragoza, E. Gelidium robustum agar: quality characteristics from exploited beds and seasonality from an unexploited bed at Southern Baja California, México. Hydrobiologia 398, 501–507 (1999). https://doi.org/10.1023/A:1017029915910
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DOI: https://doi.org/10.1023/A:1017029915910