Lisis de paredes celulares de hongos filamentosos : producción de protoplastos

Tesis Univ. Complutense de Madrid, 1981.Fac. de Ciencias BiológicasTRUEProQuestpu

Paper mill effluent decolorization by fifty Streptomyces strains.

Fifty actinomycete strains isolated from lignocellulosic substrates were examined for the ability to remove the color from a paper mill effluent obtained after semichemical alkaline pulping of wheat straw. Streptomyces sp. strains UAH 15, UAH 23, UAH 30, and UAH 51 were selected for their ability to decolorize the effluent in a liquid medium containing 1% (wt/vol) glycerol, 0.2% (wt/vol) ammonium sulfate, and 80% (vol/vol) effluent. The highest levels of decolorization achieved after the strains grew were 60 to 65%. Strains UAH 30 and UAH 51 were selected for further study because of their different patterns of effluent decolorization during growth. Fractionation of the decolorized effluent by gel permeation chromatography demonstrated that there were reductions in the levels of absorbance of the high- and medium- molecular-weight compounds. These fractions were mainly responsible for the color of the effluent, while the last fractions, the low-molecular-weight compounds, could have been responsible for the residual color of the decolorized effluent. Thin-layer chromatography revealed significant differences among the patterns of bands corresponding to the acidified supernatants obtained after precipitation of alkali-lignin from the effluent samples decolorized by different Streptomyces strains

Análisis de indicadores microbiológicos en suelos de Tenerife afectados por incendios

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Estudio de la diversidad microbiana en suelos de vertederos de residuos sólidos urbanos

12 pági as, 6 tablas estadísticas y 3 figuras.En España, una de las prácticas más habitu ales para la eliminación de los residuos generados como consecuencia de la actividad doméstica y comercial de ciudades y pueblos, ha sido y sigue siendo, su almace namiento en vertederos de residuos sólidos urbanos (VRSU). Entre los desechos que se acumulan en los mismos figuran, tanto residuos domésticos (basuras, muebles, electrodomésticos . .. ), como residuos industriales (metales, disolventes, pinturas... ), que dan lugar a la acumulación, tanto en el suelo, como en las aguas subterráneas, de compuestos nitro-aromáticos, hidrocarburos policíclicos aromáticos, pesticidas y metales pesados, entre otros. Estos compuestos, aunque se encuentran en bajas concentraciones, prod ucen graves efectos biológicos, dado que muchos de ellos son tóxicos y/o cancerígenos (Baun et al., 2000). Además , debido a los procesos químicos y biológicos que tienen lugar en los vertederos, aparecen compuestos orgánicos e inorgánicos solubles, que, dependiendo de la composición y de las características del suelo, pueden originar cambios muy drásticos en la geoquímica y microbiología del vertedero (Roling et al., 200 1; Sastre et al., 2003) . Existe, pues, una gran preocupación por parte de la opinión pública y de los investigadores sobre el impacto ambiental que estos vertederos ejercen sobre el suelo, y en este sentido, muchos grupos de investigación, tanto a nivel nacional, como internacional, están tratando de encontrar nuevas estrategias para descontaminar los emplazamientos donde estos se situan.CTM 2008-04827/TECNOPeer reviewe

Indicadores microbiológicos de suelos de Andalucía afectados por incendios

2 pages. Póster presentado en la Session: Soil Biology and Microbiology. en la Session 4: Chemical and biological changes in soils affected by wildfires, del citado congreso celebrado en Sevilla y Cortegana (Huelva) del 4-6 de noviembre, 2009.Proyecto CGL 2006-12730-C03-02 (CICYT).Peer reviewe

Analysis of chemical changes in Picea abies wood decayed by different Streptomyces strains showing evidence for biopulping procedures

10 pages, 1 figure, 2 tables, 24 references.The present study is focused on analysing the suitability of different Streptomyces strains for biomechanical pulping purposes using spruce wood (Picea abies) as substrate. After 2 weeks of incubation, no apparent variations in lignin Klason content of treated woods were detected compared with the control. However, the increase in acid-soluble lignin fraction pointed out chemical alterations in lignin moiety. Through Py-GC/MS analysis enrichment in cellulose and lignin molecule modifications were detected in treated woods. The increase in the relative abundance of the most G-type phenol units with a higher oxidation degree suggests that some oxidation occurred in the lignin C3-alkyl chain. In addition, the decrease in the phenylmethane? phenylethane/phenylpropane(phC1? phC2/phC3) ratio would indicate the ability of Streptomyces strains to breakdown the C3-alkyl chain linkages once carbons had been oxidized. From this study it could be concluded that the assayed strains are able to produce a delignification of spruce wood which may improve mechanical pulping processes.This work was supported by the Spanish CICYT Project CTQ2004-03441/PPQ.Peer reviewe

Effect of wildfires on the genetic microbial diversity in Canary Island forest soils

3 páginas, 1 figura, 7 referencias.Wildfires produce several ecological and environmental impacts on the physical and chemical soil characteristics, as well as on the properties and dynamics of soil microbial populations. Microorganisms are good indicators of ecosystem function and sustainability and therefore the studies about the impact of fire on microbial communities is relevant to understand the role of fire in ecosystem functioning. Although several authors have provided data about total microbial biomass and activity in soils affected by fires, there is little information about the composition and evolution of soil microbial populations after the passage of fire. In this work the effect of wildfires on the genetic diversity of microbial populations in soils from the island of Tenerife (Canary Islands, Spain) is studied. The final objective was to get information about the recovery of soil functionality after wildfires.This work has been supported by CICYT projects CGL 2006-12730-C03-02 and CTQ2009-10447/PPQ.Peer reviewe

Influence of xenobiotic contaminants on landfill soil microbial activity and diversity

6 páginas, 3 figuras y 3 tablasLandfills are often the final recipient of a range of environmentally important contaminants such as hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). In this study the influence of these contaminants on microbial activity and diversity was assessed in a municipal solid waste (MSW) landfill placed in Torrejón de Ardoz (Madrid, Spain). Soil samples were collected from four selected areas (T2, T2B, T8 and T9) in which the amount of total hydrocarbons, PAHs and PCBs were measured. Soil biomass, substrate induced respiration (SIR) and physiological profiles of soil samples were also determined and used as indicators of total microbial activity. Highest concentration of total hydrocarbons was detected in T2 and T9 samples, with both PCBs and benzopyrene being detected in T9 sample. Results corresponding to microbial estimation (viable bacteria and fungi, and SIR) and microbiological enzyme activities showed that highest values corresponded to areas with the lowest concentration of hydrocarbons (T2B and T8). It is noticeable that in such areas was detected the lowest concentration of the pollutants PAHs and PCBs. A negative significant correlation between soil hydrocarbons concentration and SIR, total bacteria and fungi counts and most of the enzyme activities determined was established. DGGE analysis was also carried out to determine the microbial communities’ structure in the soil samples, establishing different profiles of Bacteria and Archaea communities in each analysed area. Through the statistical analysis a significant negative correlation was only found for Bacteria domain when Shannon index and hydrocarbon concentration were correlated. In addition, a bacterial 16S rRNA gene based clone library was prepared from each soil. From the clones analysed in the samples, the majority corresponded to Proteobacteria, followed by Acidobacteria and Actinobacteria. It is important to remark that the most polluted sample (T9) showed the lowest microbial diversity only formed by six phyla being Proteobacteria and Acidobacteria the most representative.This work has been supported by the Comunidad de Madrid EIADES project (S-0505/AMB/0296) and the CICYT project (CGL2006-12730-C03-02).Peer reviewe

Biotechnological enhancement of coffee pulp residues by solid-state fermentation with Streptomyces. Py-GC/MS analysis

The ability of three Streptomyces strains to upgrade the nutritional value of coffee pulp residues from Nicaragua in solid-state fermentation (SSF) conditions was analyzed by Py-GC/MS. The presence in these residues of compounds such as polyphenols, tannins, chlorogenic acids and caffeine prevents their utilization as domestic fodder. The characteristic pyrolysis products derived from polyphenols and polysaccharides were identified both in control and treated coffee pulp being remarkable the decrease achieved in the total polyphenols derived compounds after the growth of the strains. The analysis of these compounds demonstrated that both monomethoxy- and dimethoxy-phenols were degraded. In addition, an increase in the microbial treated coffee pulp of protein content was detected by Kjeldahl method. In summary, changes evidenced in coffee pulp treated by Streptomyces through the application of analytical pyrolysis reveal the biotechnological interest of these bacteria to upgrade a usefulness and pollutant residue to be used for feeding purposes. © 2007 Elsevier B.V. All rights reserved.Peer Reviewe