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To get insight into the microbial community of an Upflow Anaerobic Sludge Blanket reactor treating paper mill wastewater, conventional microbiological methods were combined with 16S rRNA gene analyses. Particular attention was paid to microorganisms able to degrade propionate or butyrate in the presence or absence of sulphate. Serial enrichment dilutions allowed estimating the number of microorganisms per ml sludge that could use butyrate with or without sulphate (10(5)), propionate without sulphate (10(6)), or propionate and sulphate (10(8)). Quantitative RNA dotblot hybridisation indicated that Archaea were two-times more abundant in the microbial community of anaerobic sludge than Bacteria. The microbial community composition was further characterised by 16S rRNA-gene-targeted Denaturing Gradient Gel Electrophoresis (DGGE) fingerprinting, and via cloning and sequencing of dominant amplicons from the bacterial and archaeal patterns. Most of the nearly full length (approximately 1.45 kb) bacterial 16S rRNA gene sequences showed less than 97% similarity to sequences present in public databases, in contrast to the archaeal clones (approximately. 1.3 kb) that were highly similar to known sequences. While Methanosaeta was found as the most abundant genus, also Crenarchaeote-relatives were identified. The microbial community was relatively stable over a period of 3 years (samples taken in July 1999, May 200 1, March 2002 and June 2002) as indicated by the high similarity index calculated from DGGE profiles (81.9 +/- 2.7% for Bacteria and 75.1 +/- 3.1% for Archaea). 16S rRNA gene sequence analysis indicated the presence of unknown and yet uncultured microorganisms, but also showed that known sulphate-reducing bacteria and syntrophic fatty acid-oxidising microorganisms dominated the enrichments. (c) 2004 Elsevier GmbH. All rights reserved.

Bacterial community compositions from 10 pulp- and paper-mill treatment systems were compared using both traditional and molecular techniques. 16S-RFLP (Random Fragment Length Polymorphisms) analysis was used to examine the genotypic profiles of the whole bacterial community of each treatment system. Although all the communities shared approximately 60% of their DNA band pattern, as determined by computer-assisted cluster analysis, each community displayed a unique profile that was stable over time under normal operating parameters. Reverse Sample Genome Probing (RSGP) and 16S-RFLP were used to compare the culturable bacterial communities of several geographically separated pulp-mill biotreatment system communities. There was little overlap in the composition of the culturable community between mills at the genus level. Furthermore, RSGP variation was almost as high within a mill as between mills. Partial sequences of the 16S rRNA genes from culturable isolates identified Bacillus spp., Pseudomonas spp., and Xanthobacter as some of the dominant species. Finally, several 16S rRNA genes from two whole community 16S RNA gene libraries were partially sequenced and identified as similar to unknown α-, β-, and γ-Proteobacteria, Ralstonia, Alcaligenes, Nitrospira, Firmicutes, and clones representing the new Holophaga/Acidobacterium phylum. These findings suggest that although these pulp- and paper-mill biotreatment communities perform similar functions, they are populated by unique mixtures of species.Key words: biodiversity, 16S-RFLP, secondary treatment, pulp mills.

Soluble silicates, commercially known as waterglass, are among the largest volume synthetic chemicals in the world. Silicon from waterglass is rapidly transformed to the biologically active orthosilicic acid (referred to as dissolved silicate). This paper aims to assess the impact of waterglass on the aquatic environment in Western Europe. The emission to surface waters from the four most relevant application areas, household detergents, pulp and paper production, water and wastewater treatment, and soil stabilization, is estimated to be ca. 88-121 kton of SiO2 per year. This is a small fraction (

The potential of four aquatic macrophytes for treatment of wastewater in constructed wetlands was investigated in bucket mesocosms at Pan African Paper Mills (E.A) Limited. The buckets were operated as semi-continuous batch reactors with reversed vertical flow for a period of 3 months. Four treatments were applied involving two hydraulic retention times (HRT) and two wastewater concentrations. Plants appear healthier and greener in treatments at HRT5 than at HRT10. Cyperus immensus and Typha domingensis had higher biomass gain compared to the other two species. Plant nitrogen and phosphorus content, based on dry weight, was lower at the end of the experiment than at the beginning in all treatments for all species The removal efficiency achieved for COD ranged from 10 to 55% for planted buckets at HRT5 and 15 to 65% at HRT10 for similar buckets. The mean percentage COD removal in unplanted buckets was significantly lower than in planted ones. TSS removal efficiency ranged from 44-86%. Buckets planted with Typha exhibited the highest removal efficiency in all treatments. Those at HRT5 showed significantly higher removal efficiencies than those at HRT10 for all species. The results indicate that the plants are suitable for use in constructed wetlands for treatment of the wastewater provided the appropriate treatment is applied.

Many micro-organisms are known to produce efficient toxic substances against conspecifics and closely related species. The widespread coexistence of killer (toxin producer) and sensitive (non-producer) strains is a puzzle calling for a theoretical explanation. Based on stochastic cellular automaton simulations and the corresponding semi-analytical configuration-field approximation models, we suggest that metapopulation dynamics offers a plausible rationale for the maintenance of polymorphism in killer-sensitive systems. A slight trade-off between toxin production and population growth rate is sufficient to maintain the regional coexistence of toxic and sensitive strains, if toxic killing is a local phenomenon restricted to small habitat patches and local populations regularly go extinct and are renewed via recolonizations from neighbouring patches. Pattern formation on the regional scale does not play a decisive part in this mechanism, but the local manner of interactions is essential.

Ecosystems provide a wide range of services that improve human welfare. Changes in ecosystems imply potential changes in the generation of these ecosystem services and thus changes in welfare. In the lingo of economists, these welfare changes are measured as changes in economic values--increases in welfare being benefits and decreases in welfare being costs. For instance, individuals may benefit from, and thus value, reductions in risks to endangered species. Yet values for many changes in ecosystem services are not captured in market transactions, and thus measuring these values requires nonmarket valuation methods. This paper discusses ecosystem services and values from the viewpoint of an economist, explains what is meant by the valuation of ecosystems, and provides an overview of methods for valuation of ecosystem services. An example is presented from a recent natural resource damage assessment--the Green Bay total value equivalency study. Resources in the Lower Fox River and Green Bay in Wisconsin have been injured by polychlorinated biphenyl contamination from numerous paper mills along the river over several decades. The Green Bay study examines individuals' preferences and values for reducing ecosystem risks and improving ecosystem services and how these values are related to individuals' awareness of and use of ecosystem services in the area. The study uses methods from nonmarket valuation to scale potential restoration projects.

The aim of this research was to study the influence of lignin content and composting temperature on the biodegradation of lignin-containing pulp and paper products in a controlled composting test (European standard prEN 14046). Lignin reduced the biodegradation of the samples, and there was a linear correlation between the lignin content and the biodegradation of pulp and paper products at 58 degrees C. The influence of incubation temperature (35, 50 and 58 degrees C) on biodegradation was studied using bleached kraft paper containing 0.2 wt% lignin and mechanical pulp (stone-ground wood) containing 24-27 wt% lignin. Mechanical pulp biodegraded better at lower temperatures, while kraft paper biodegraded well at all three temperatures. Microbial activity was evaluated by measuring CO(2) evolution and the change in ATP content, and fungal biomass by measuring the ergosterol content during the composting experiments. Kraft paper strongly increased microbial activity during the controlled composting test, but the activity returned to the background level at the end of the composting test. The proportion of sample carbon converted to microbial biomass carbon was considerably higher at lower incubation temperatures. Changes in microbial community structure during biodegradation of mechanical pulp and kraft paper at 50 degrees C were studied by the PCR-based technique denaturing gradient gel electrophoresis. Changes in the microbial community were observed during the intensive degradation phase of kraft paper.

International audience; The agronomic and pulping performance of transgenic trees with altered lignin has been evaluated in duplicated, long-term field trials. Poplars expressing cinnamyl alcohol dehydrogenase (CAD) or caffeate/5-hydroxy-ferulate O-methyltransferase (COMT) antisense transgenes were grown for four years at two sites, in France and England. The trees remained healthy throughout the trial. Growth indicators and interactions with insects were normal. No changes in soil microbial communities were detected beneath the transgenic trees. The expected modifications to lignin were maintained in the transgenics over four years, at both sites. Kraft pulping of tree trunks showed that the reduced-CAD lines had improved characteristics, allowing easier delignification, using smaller amounts of chemicals, while yielding more high-quality pulp. This work highlights the potential of engineering wood quality for more environmentally benign papermaking without interfering with tree growth or fitness.

Pulp and paper secondary waste-treatment systems in Brazil, Canada, New Zealand, and the U.S.A. contained dynamic cyanobacterial communities, some of which exceeded heterotrophic bacterial biomass. No other viable photoautotrophic populations were detected in the ponds. Regardless of geographical location, Oscillatoriales including Phormidium, Geitlerinema, and Pseudanabaena were the dominant taxa. As well, Chroococcus (Chroococcales) was an important genus in Brazil and New Zealand. The possible impact of cyanobacteria on waste-treatment efficiency deserves further study given their large biomass and diverse metabolic characteristics.Key words: cyanobacteria, blue-green algae, heterotrophic bacteria, community structure, pulp and paper secondary waste treatment.

Xylan is the main carbohydrate found in the hemicellulosic fraction of plant tissues and accounts for one third of all renewable organic carbon available on earth. Xylanase, the major component of an enzymatic consortium, acts in nature by depolymerizing xylan molecules into monomeric pentosan units that are used by bacterial and fungal populations as a primary carbon source. Xylanase producers have been isolated from all ecological niches where plant material is deposited, and microorganisms often contain multiple loci encoding overlapping xylanolytic functions. The numerical excess of genes and the extensive sharing of structural features within beta-glycanase families suggests that extensive gene duplication and conversion events have occurred during xylanase evolution. Hydrolysis of beta-glycosidic linkages is sponsored by a general acid catalytic reaction common to all glycanases, whereas substrate recognition is specified by subsites that interact with adjacent glycosyl units. Under natural conditions xylanases are inducible by the products of their own action and subject to carbon catabolite repression. Bleaching paper pulps with xylanases is the first successful commercial application for these enzymes. The recovery of cellulosic textile fibers is the next logical application and bioconversion of biomass into fuels and chemicals, remains the ultimate target. Recent developments have shown that metabolic pathways can be transferred from one organism to another and proteins can be modified to gain conformational stability, suggesting that naturally occurring systems can be custom engineered to the situation in the fermentation tank. Thus, biotechnologies developed to transform biomass into marketable products that gradually substitute materials derived from non-renewable resources are becoming commercially worthwhile.

The effect of 22 technological waste water samples and of some standards was tested on bacteria, fungi, chlorococcal algae, flagellata, plant cells, cells of Tubifex tubifex, hamster cells V79 and the fish Lebistes reticulatus. Of these 22 samples, some inhibition of cell life processes was displayed by the black liquor formed in the production of paper pulp and viscose pulp, by the waste solution produced during the preparation of bleaching agents for paper pulp and viscose pulp, and by the residual liquor after hypochlorite treatment of paper pulp.

A regional-scale watershed assessment using the relative risk model has now been performed on each of the watersheds that are part of the Long-Term Receiving Waters Study (LTRWS) to generate patterns of risk at each study site. The watersheds assessed included the lower McKenzie and mid-Willamette rivers in Oregon, USA; Codorus Creek in Pennsylvania, USA; and the Leaf River in Mississippi, USA. In each case, the goal was to put the LTRWS into a watershed and regional context, including multiple sources, stressors, habitats, and assessment endpoints. In each instance, the relative risk model provided measures of relative risk and testable hypotheses about patterns within the watersheds. There were similarities among the 3 risk studies. First, land use within the watershed was the most important driver of risk in each instance, even compared with point sources. Second, the list of endpoints was similar for each risk assessment. Water quality was held as important, along with populations critical to recreation or commercial use. At each site, data from the LTRWS and other sources could be used to support the risk patterns predicted from the risk assessment process. However, the sampling design of the LTRWS prevented the confirmation of specific cause-effect relationships. A fundamental conclusion is that risk assessment, using an adaptation of the relative risk model, should be performed as an integral part of any watershed assessment and management effort. These initial watershed risk assessments have led to similar assessments across the world.

Habitat spatial structure has a profound influence on bacterial life, yet there currently are no low‐cost equipment‐free laboratory techniques to reproduce the intricate structure of natural bacterial habitats. Here, we demonstrate the use of paper scaffolds to create landscapes spatially structured at the scales relevant to bacterial ecology. In paper scaffolds, planktonic bacteria migrate through liquid‐filled pores, while the paper’s cellulose fibres serve as anchor points for sessile colonies (biofilms). Using this novel approach, we explore bacterial colonisation dynamics in different landscape topographies and characterise the community composition of Escherichia coli strains undergoing centimetre‐scale range expansions in habitats structured at the micrometre scale. The bacteria‐in‐paper platform enables quantitative assessment of bacterial community dynamics in complex environments using everyday materials.