Propiedades antibióticas de algunas especies de algas marinas bentónicas

Twenty eight species of marine benthic algae were collected in three different localities, in order to have representatives from: warm temperature, subtropical and tropical regions; aquose and alcoholic extracts were prepared and tested for antibiosis against two puretrains of bacteria, Eschericha coli and Micococcus Iysodeikticus.The action of the ranged from active (antibiosis against both bacteria) to non active. The 62% of the analized species showed some antibiotic effect. The highest number of algal species with antibiotic activity were collected in the warm temperate region.Se colectaron veintiocho especies de algas marinas bentónicas en tres diferentes localidades, con el objeto de tner especies representativas de: zonas templadas, subtropicales y tropicasles; de ellas se hicieron extractos acuosos y alcohólicos, que fueron rpobados para determinar sus efectos antibióticos, en contra de dos cepas de bacterias: Escherichia coli y Micrococcus Iysodeikticus. La acción de los extractos varió de activa (efecto sobre las dos cepas bacterianas) a no activa. El 62% de las especies analizadas presentaron alguna actividad, correspondiendo el mayor porcentaje de algas con actividad a las recolectadas en la zona templada

Crecimiento poblacional de tres microalgas en diferentes medios de cultivo

In this research work it was studied the answer of three species of microalgae from the Chlorophyte Division growing in three different culture media, in order to determinate if a differential growth exists related to the chemical composition of the media. To realize the study it was chosen pure strains of Chlorella vulgaris Beijerinck, Chlamydomonas debaryana Goroschankin Monoraphidium griffithii (Berkeley) Komárková-Legnerová and the culture media: Bristol, Knop and Waris, the last one specific for Chlorophytes. The experimental tests were done by triplicates using 250 ml flasks with 90ml of media plus 10ml of the algal culture. Qualitative and quantitative observations were done every other day in order to determine the population growth curve. The highest population ¡increase for Chlamydomonas debaryana was founded in the Bristol medium; Chlorella vulgaris, grew better in the Knop medium and Monoraphidium griffithii in Waris medium. About the results obtained we can concluded that it exists a selectivity of the species to the culture media due to their nutritional requirements

Inhibición de la actividad hemaglutinante de algunas macroalgas marinas de las cosas de México

Lectins are proteins or glycoproteins that selective hind sugars. The inhibition of hemaglutination activity has been used as a detection probe for this molecules. Agglutination assays were done with human erythrocytes O, A and B positive groups, testing 44 algal extracts (32 species) as aglutinants. Four extracts showed evident agglutination, 3 Chlorophyta: Codium giraffa Silva, Codium istmocladum Vickers and Ulva lactuca Linnaeus, one Rhodophyta Hypnea spinella (C. Ag.) Kützing. The inhibition of hemagglutinat activity in Codium giraffa, Codium isthmocladum y Ulva latuca were due to N­ acetylglucosamine. No inhibition was observed by none of the sugars used in this work for Hypnea spinella extract

Historia taxonómica del género Gracilaria Greville (Gracilariaceae, Rhodophyta)

Genus Gracilaria Greville (Gracilariales, Rhodophyta) and its commercial importance are briefly described. An analysis of the taxon's history, since its first decription until today shows a constant and characteristic taxonomic unstability; an explanation for this is provided. These, together with the available data for Mexican shores, as an example, makes c1early evident the necesity of a historical research, previous to the monographic step, in order to establish which are the taxonomic problems to resolve, if present, and define properly the scope and logistics of subsecuents surveys

Tecnologías de cultivo de microalgas con fines acuiculturales

In 1993 the world aquaculture production reached around 15 millions of metric tons of fishes, mollusks and crustacean, and it is possible in the next years to increase remarkably this value. Every day the requirement of microalgae as live food growth and it is necessary to improve massive production technologies. The use of microalgae as food source for aquaculture, are described in this paper. Fourteen genera of six different families have been used in commercial aquaculture. as direct and indirect food in all over the world. Microalgae culture is mainly realized in three systems: a) batch, b) semi-continuos and c) continuos. On the other hand, the importance of the autotrophic chain management induced by fertilizers in semi-intensive cultures is described, which promote the growth of the phytoplankton biomass

Detección antimicótica en extractos de algas marinas

En el presente trabajo se obtuvieron extractos de 37 especies de macroalgas marinas recolectadas en dos localidades de la costa de Veracruz, preparados con cuatro mezclas de disolventes: cloroformo-metanol-agua, cloroformo-alcohol etílico- agua, éter-metanol-agua y éter-alcohol etílico-agua, estos extractos fueron probados mediante la técnica de dilución, contra seis cepas de hongos patógenos a plantas y al hombre: Aspergillus niger, Rhyzopus nigricans, Candida albicans, Rhyzopus oryzae, Alternaria alternata y Beauveria bassiana, Los resultados mostraron que todas las especies algales, excepto dos, inhibieron alguna cepa con alguno de sus extractos (96 %). Solamente se observó ausencia de actividad antifúngica en dos especies recolectadas en la estación de secas, estas algas volvieron a presentar actividad al final de la época de lluvias. Este es el primer estudio en este campo de la Ficología Aplicada en México y debido a los resultados obtenidos podemos concluir que las macroalgas marinas son una fuente potencial para proveernos con moléculas novedosas, capaces de inhibir el crecimiento de hongos patógenos

Ichtyotoxic activity of extracts from Mexican marine macroalgae

Seventy-three species of macroalgae from the Mexican Pacific, Atlantic and Caribbean coast were screened for ichtyotoxic activity. Ethanolic, acetonic and aqueous extracts were prepared and tested against the fish Carassius auratus. The extracts were classified on the basis of their effects as: toxic if the fish died in two hours or les