Whole proteome analyses on Ruminiclostridium cellulolyticum show a modulation of the cellulolysis machinery in response to cellulosic materials with subtle differences in chemical and structural properties

Lignocellulosic materials from municipal solid waste emerge as attractive resources for anaerobic digestion biorefinery. To increase the knowledge required for establishing efficient bioprocesses, dynamics of batch fermentation by the cellulolytic bacterium Ruminiclostridium cellulolyticum were compared using three cellulosic materials, paper handkerchief, cotton discs and Whatman filter paper. Fermentation of paper handkerchief occurred the fastest and resulted in a specific metabolic profile: it resulted in the lowest acetate-to-lactate and acetate-to-ethanol ratios. By shotgun proteomic analyses of paper handkerchief and Whatman paper incubations, 151 proteins with significantly different levels were detected, including 20 of the 65 cellulosomal components, 8 non-cellulosomal CAZymes and 44 distinct extracytoplasmic proteins. Consistent with the specific metabolic profile observed, many enzymes from the central carbon catabolic pathways had higher levels in paper handkerchief incubations. Among the quantified CAZymes and cellulosomal components, 10 endoglucanases mainly from the GH9 families and 7 other cellulosomal subunits had lower levels in paper handkerchief incubations. An in-depth characterization of the materials used showed that the lower levels of endoglucanases in paper handkerchief incubations could hypothetically result from its lower crystallinity index (50%) and degree of polymerization (970). By contrast, the higher hemicellulose rate in paper handkerchief (13.87%) did not result in the enhanced expression of enzyme with xylanase as primary activity, including enzymes from the xyl-doc cluster. It suggests the absence, in this material, of molecular structures that specifically lead to xylanase induction. The integrated approach developed in this work shows that subtle differences among cellulosic materials regarding chemical and structural characteristics have significant effects on expressed bacterial functions, in particular the cellulolysis machinery, resulting in different metabolic patterns and degradation dynamics.This work was supported by a grant [R2DS 2010-08] from Conseil Regional d'Ile-de-France through DIM R2DS programs (http://www.r2ds-ile-de-france.com/). Irstea (www.irstea.fr/) contributed to the funding of a PhD grant for the first author. The funders provided support in the form of salaries for author [NB], funding for consumables and laboratory equipment, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Omics Services provided support in the form of salaries for authors [VS, MD], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors [NB, VS, MD] are articulated in the 'author contributions' section.info:eu-repo/semantics/publishedVersio

Drainage par injection à l’aide des forages absorbants. (Périmètre d’irrigation de la plaine des Doukkalas, Maroc)

Injection drainage by means of absorption wells. — Doukkalas Plain irrigation area (Morocco). The problem was to dispose of surplus runoff from an irrigation area covering roughly 1,000 hectares. Geological prospections, boreholes and tests were carried out in order to ascertain the possibility of draining the water off into absorption wells. The results of water absorption tests carried out in Pliocene sandstone were interpreted, and the point permeability rates and transmitting capacities were calculated. The final stage was a transition from the reconnaissance work to the construction of the final structures, the operation and layout of which are described in this report.Problème de l'évacuation des eaux de colature d'un casier d'irrigation de 1 000 hectares environ. Etudes géologiques, campagne de sondages de reconnaissance et essais destinés à déterminer la possibilité d'évacuer ces eaux à l'aide de forages absorbants. Interprétation d'essais d'absorption d'eau réalisée dans un grès Pliocène et calcul des perméabilités et transmissivités ponctuelles. Passage du stade reconnaissance aux ouvrages définitifs. Disposition et comportement de ces derniers.Ambroggi R., Moullard L., Hazan R., Sabarly F. Drainage par injection à l’aide des forages absorbants. (Périmètre d’irrigation de la plaine des Doukkalas, Maroc). In: L'hydraulique souterraine. Compte rendu des sixièmes journées de l'hydraulique, Nancy, 28-30 juin 1960. Tome 1, 1961