ABSTRACT
Introducción: los géneros Furcraea y Agave comprenden un gran número de plantas xerófitas que se explotan principalmente en México, Colombia y Brasil. La producción de bebidas, cordeles, sacos, artículos artesanales, alimentación animal, fármacos, biomasa, refuerzo para construcciones, abono y sustrato para cultivos, son solo algunas de las aplicaciones directas de estas plantas. Sus extractos contienen una gran variedad de compuestos químicos muchos de los cuales tienen aplicaciones potenciales en el tratamiento de enfermedades como el cáncer. Entre los compuestos encontrados están las saponinas, hecogeninas, fructanos, celulosa y hemicelulosa. Objetivos: explorar la información publicada sobre los géneros Furcraea y Agave sus cualidades medicinales y agroindustriales e inferir sus posibilidades futuras de investigación y explotación. Métodos: la búsqueda bibliográfica se realizó en las bases de datos ScienceDirect, SpringerLink, Academic Search Complete (EBSCO) y Redalyc, en los documentos encontrados entre los años de 1995 y 2012, seleccionando aquellos artículos que involucraban la caracterización química de las plantas, usos alternativos y algunos métodos de análisis químico realizados. Resultados: se muestra la información compilada sobre 4 especies del género Furcraea y 9 especies del género Agave. Algunas de las especies analizadas poseen saponinas, compuestos químicos con uso potencial en el tratamiento de cáncer. También se reporta la presencia de carbohidratos libres como glucosa y fructosa y poliméricos como los fructanos, estos últimos se clasifican como prebióticos. La celulosa, hemicelulosa y lignina que conforman la fibra principalmente de las hojas de las plantas, pueden emplearse como quelantes de origen biológico. Conclusiones: las plantas de los géneros Furcraea y Agave, consideradas en esta revisión, poseen sustancias químicas que pueden ser útiles en diversos campos médicos e industriales, aunque algunas especies no se han estudiado exhaustivamente.
Introduction: the genera Furcraea and Agave comprise a large number of xerophytic plants which are exploited mainly in Mexico, Colombia and Brazil to obtain beverages, twine, sacks, handicrafts, animal feed, pharmaceuticals, biomass, construction reinforcements, fertilizers and cultivation substratum, among other direct uses. Their extracts contain a great variety of chemical compounds, many of which have potential applications in the treatment of diseases such as cancer. Among such compounds are saponins, hecogenins, fructans, cellulose and hemicellulose. Objectives: explore the information published about the genera Furcraea and Agave and their medicinal and agroindustrial properties, and infer their future research and exploitation possibilities. Methods: a bibliographic search was conducted in the databases ScienceDirect, SpringerLink, AcademicSearch Complete (EBSCO) and Redalyc of documents published from 1995 to 2012. A selection was made of papers including the chemical characterization of the plants, their alternative uses and the methods of chemical analysis employed. Results: a presentation is provided of the information gathered about 4 species of the genus Furcraea and 9 of the genus Agave. Some of the species analyzed contain saponins, which are chemical compounds potentially useful in the treatment of cancer. A report is included of the presence of free carbohydrates, such as glucose and fructose, and polymeric carbohydrates like fructanes. The latter are classified as prebiotic. Cellulose, hemicellulose and lignin, which constitute the fiber mainly of leaves, may be used as chelating agents of biological origin. Conclusions: plants of the genera Furcraea and Agave, considered in this review, contain chemical substances potentially useful in a variety of medical and industrial fields, though some species have not been studied exhaustively.
ABSTRACT
Los Polihidroxialcanoatos (PHAs) son biopolímeros con características similares a los plásticos sintéticos, pero rápidamente biodegradables dado su origen microbiano. En esta investigación se aislaron 248 colonias bacteriales de suelos contaminados con residuos del beneficio de fique en Guarne (Antioquia), evaluándose su capacidad como productoras de PHAs. Se realizaron tinciones con rojo y azul de Nilo y detección por PCR del gen PhaC. Las bacterias positivas a dichas pruebas, fueron identificadas utilizando análisis filogenético de secuencias de 16S del ADNr y pruebas bioquímicas. Finalmente, se evaluó, mediante cromatografía de gases con detector selectivo de masas GC-MS/SIM, la naturaleza química del biopolímero, a partir de la biomasa generada en un ensayo de fermentación en cultivo sumergido, con medio mínimo de sales suplementado con glucosa como fuente de carbono. Cuatro cepas de los morfotipos bacteriales encontrados, presentaron potencial para producir PHAs, de los cuales dos fueron identificados como miembros de la especie Bacillus megaterium, uno como B. mycoides y el otro como Gordonia sp. El gen PhaC se detectó en los dos aislamientos de B. megaterium. El análisis cromatográfico permitió detectar al Polihidroxibutirato (PHB) como el principal componente de los PHAs presentes en B. megaterium, cuantificándose entre 63.8 mg/g y 95.3 mg/g de PHB en los ensayos de fermentación. Las bacterias aisladas tienen potencial en la producción de PHAs a partir de residuos agroindustriales, incluyendo el jugo de fique, lo que contribuiría a la reducción de su condición contaminante.
Polyhydroxyalkanoates (PHAs) are biodegradable biopolymers of bacterial origin with properties similar to conventional plastics. In this work, bacteria were isolated from soils contaminated with fique wastes in the municipality of Guarne (Antioquia) and their ability to produce PHAs was evaluated. Bacteria were stained with Nile blue and Nile red and the PhaC gene detected by PCR. Positive bacteria were identified by phylogenetic analysis of 16S rDNA and biochemical tests. The chemical nature of the biopolimers was determined by gas chromatography GC-MS/SIM using biomass produced in a submerged fermentation in a minimal media supplemented with glucose as sole carbon source. Four bacterial morphotypes identified as Bacillus megaterium (2), B. mycoides (1) and Gordonia sp. (1) showed potential to produce PHAs. However, the PhaC gene was detected in B. megaterium. Chromatographic analysis showed polyhydroxybutirate (PHB) to be the main component in the PHAs produced by B. megaterium with levels between 63.8 mg/g and 95.3 mg/g in the fermentation test. The isolated bacteria have potential to produce PHAs, generating added value to the Agro-industrial waste, as in the fique industry, and reducing its contamination impact.
Subject(s)
Bacteria , Polyhydroxyalkanoates , Biopolymers , Plastics , SoilABSTRACT
Effect of the dry leaves powder water suspension of the plant Furcraea selloa marginata, belonging to family Agavaceae and Bacillus thuringiensis kurstaki (Dipel-2x) was evaluated against non-infected and Schistosoma mansoni-infected Biomphalaria alexandrina snails as well as their efficacy against the free larval stages of S. mansoni. The obtained results indicated that the LC50 and LC90 values after 24 hrs exposure were 53.66 & 84.35 ppm for F. selloa marginata and 392.3 & 483.64 ppm for B. thuringiensis kurstaki against adult B. alexandrina snails, respectively. The plant F. selloa marginata and B. thuringiensis kurstaki have a larvicidal activity against S. mansoni larvae (miracidia and cercariae), the plant F. selloa marginata was more toxic against larvae than B. thuringiensis kurstaki, the miracidia were more sensitive towards the toxic action of the tested agents than cercariae and the mortality percent of miracidia and cercariae is directly proportional to the time and the tested concentrations. The results revealed that the tested sub-lethal concentrations (LCo, LC10 and LC25) reduced the survival, growth rates and egg laying capacity of both non-infected and S. mansoni-infected snails during 12 weeks of exposure in comparison with their control group. The hatchability percent of B. alexandrina eggs of one, three and six days old exposed to LCo, LC10, LC25, LC50 & LC90 concentrations of F. selloa marginata and B. thuringinesis kurstaki, significantly decreased by increasing their age and the tested concentrations. Exposing B. alexandrina snails to sub-lethal concentrations of the tested agents for 24 hours either pre-, during or post exposure of snails to S. mansoni miracidia caused a marked reduction in the infection rate and decreased the mean total number of shedding cercariae/snail. Also, elongated their prepatent period (cercarial incubation period) and shortened the duration of cercarial shedding in comparison with their control group. Under semi-field conditions the more time of exposure to the concentration (LC90= 84.35 ppm) of the plant F. selloa marginata the more mortality among snails. The mortality rates of the snails were 0%, 2%, 18% and 30% at 3, 6, 12 and 24 hrs post exposure, respectively.