Hydrolysis of lignocellulosic material to sugars as feedstock for growing microorganisms

Los materiales lignocelulósicos son potenciales precursores de recursos bioenergéticos, por lo que sería interesante desarrollar tecnologías capaces de capturar su energía y utilizarla en el sector del transporte como combustibles. El azúcar contenido en los materiales lignocelulósicos puede ser liberado por medio de la hidrólisis y usado después por microorganismos. El objetivo del proyecto es encontrar un método de separación de la celulosa y la biomasa de chopo en monómeros de glucosa por medio de la hidrólisis. Para ello se han estudiado tres métodos de hidrólisis: la mecano-catálisis, utilizando diferentes tipos de molinos y caolinita como catalizador, la hidrólisis con líquidos iónicos, estudiando la viabilidad de los reactivos [C4mim+][I-] y [C4mim+][PF6-], y la hidrólisis ácida, usando HCl en concentraciones y temperaturas distintas para optimizar el proceso. En todos los casos se ha llevado a cabo un pretratamiento y se ha aplicado el método de TLC como verificación del proceso. Los tres métodos se han comparado y se ha desarrollado un método de correlación entre la mancha de TLC y la concentración del producto.

Gene discovery in the wood-forming tissues of poplar: Analysis of 5,692 expressed sequence tags

A rapidly growing area of genome research is the generation of expressed sequence tags (ESTs) in which large numbers of randomly selected cDNA clones are partially sequenced. The collection of ESTs reflects the level and complexity of gene expression in the sampled tissue. To date, the majority of plant ESTs are from nonwoody plants such as Arabidopsis, Brassica, maize, and rice. Here, we present a large-scale production of ESTs from the wood-forming tissues of two poplars, Populus tremula L. × tremuloides Michx. and Populus trichocarpa ‘Trichobel.’ The 5,692 ESTs analyzed represented a total of 3,719 unique transcripts for the two cDNA libraries. Putative functions could be assigned to 2,245 of these transcripts that corresponded to 820 protein functions. Of specific interest to forest biotechnology are the 4% of ESTs involved in various processes of cell wall formation, such as lignin and cellulose synthesis, 5% similar to developmental regulators and members of known signal transduction pathways, and 2% involved in hormone biosynthesis. An additional 12% of the ESTs showed no significant similarity to any other DNA or protein sequences in existing databases. The absence of these sequences from public databases may indicate a specific role for these proteins in wood formation. The cDNA libraries and the accompanying database are valuable resources for forest research directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.

Suppression of O-Methyltransferase Gene by Homologous Sense Transgene in Quaking Aspen Causes Red-Brown Wood Phenotypes1

Homologous sense suppression of a gene encoding lignin pathway caffeic acid O-methyltransferase (CAOMT) in the xylem of quaking aspen (Populus tremuloides Michx.) resulted in transgenic plants exhibiting novel phenotypes with either mottled or complete red-brown coloration in their woody stems. These phenotypes appeared in all independent transgenic lines regenerated with a sense CAOMT construct but were absent from all plants produced with antisense CAOMT. The CAOMT sense transgene expression was undetectable, and the endogenous CAOMT transcript levels and enzyme activity were reduced in the xylem of some transgenic lines. In contrast, the sense transgene conferred overexpression of CAOMT and significant CAOMT activity in all of the transgenic plants' leaves and sclerenchyma, where normally the expression of the endogenous CAOMT gene is negligible. Thus, our results support the notion that the occurrence of sense cosuppression depends on the degree of sequence homology and endogene expression. Furthermore, the suppression of CAOMT in the xylem resulted in the incorporation of a higher amount of coniferyl aldehyde residues into the lignin in the wood of the sense plants. Characterization of the lignins isolated from these transgenic plants revealed that a high amount of coniferyl aldehyde is the origin of the red-brown coloration—a phenotype correlated with CAOMT-deficient maize (Zea mays L.) brown-midrib mutants.

Prediction of blackwood wood and pulp quality parameters using NIR-PLS-R spectral modelling : wavenumber ranges and smoothing points

Só está disponível o resumo.

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1895

Time factors of differentially preserved wood in two calcitic concretions in Pennsylvanian black shale from Indiana / Bertram G. Woodland -- and Catherine K. Richardson --.

v.33:no.10(1975)

Benjamin Wood, AB, 1797

This folder contains an original (20.5 x 12 in.), a typewritten copy (14.75 x 8.5 in.), and a photostat copy (21.5 x 13.75 in.) of the diploma of Benjamin Wood.

Certificate of the sale of Cyrus' freight of wood, 1793 September 9

Accounting records related to the wood brought by the sloop between May and September 1793 on three slips of paper bound with thread. The last page contains a certification signed by William Winthrop on September 9, 1793 of the sale of wood in Charlestown.

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1899

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1896-1897

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1893

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1898

Biological lectures delivered at the Marine Biological Laboratory of Wood's Holl [sic].

1894