Levures des eaux saumatres de Lagrange-Fouquet

The briny waters of Lagrange-Fouquet contain a wide variety of yeasts. The more common ones are Cryptococcus laurentii, Cryptococcus albidus, Sporobolomyces pararoseus and Sporobolomyces roseus.These yeasts stem from the phyllosphere of the surrounding vegetation, and constitute a population which is characteristic of the natural zones.

     

Etude de la reproduction du gardon (Rutilus rutilus) et des effets d'une élévation provoquée de la température en Meuse sur cette reproduction

The thermal pollution of the Tihange Nuclear Power Plant increases the temperature (± 3 °C) of the river Meuse and has precise effects on the reproductive cycle of the roach (Rutilus rutilus) downstream: well-defined, ovarial development, acceleration of maturation, and earlier laying of eggs (3 weeks). The volume of the different testicular cell types appears to be more important in males downstream. Spermatozoa are retained for a longer period in both populations (upstream and downstream) as a result of diminished spawning-grounds along the river.

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Etude de la reproduction du gardon (Rutilus rutilus) et des effets d'une élévation provoquée de la température en Meuse sur cette reproduction

     

Bacterial community shift revealed Chromatiaceae and Alcaligenaceae as potential bioindicators in the receiving river due to palm oil mill effluent final discharge

A thorough outlook on the effect of palm oil mill effluent (POME) final discharge towards bacterial community dynamics in the receiving river is provided in this study by using a high-throughput MiSeq. The shift of bacterial composition could be used to determine the potential bacterial indicators to indicate contamination caused by POME. This study showed that the POME final discharge did not only alter the natural physicochemical properties of the river water but also caused the reduction of bacterial diversity in the receiving river. The Chromatiaceae and Alcaligenaceae which were not detected in the upstream but were detected in the downstream part of the river are proposed as the indicator bacteria to indicate the river water contamination caused by POME final discharge. The emergence of either one or both bacteria in the downstream part of the river were shown to be carried over by the effluent. Therefore, an accurate pollution monitoring approach using bacterial indicator is expected to complement the conventional POME pollution assessment method which is currently dependent on the physicochemical properties of the final discharge. This is the first study that reported on the potential indicator bacteria for the assessment of river water contamination caused by POME final discharge.     

Impact of habitat fragmentation on genetic population structure of roach, Rutilus rutilus, in a riparian ecosystem

During the last 200 years, the riparianecosystem along major rivers has been reducedto a few scattered remnants. Important elementsof the riparian ecosystem are water bodieswhich were originally connected to the mainriver channel by annual floodings. Due to riverregulations many of these remnants are nowvirtually isolated. In an allozyme analysisusing roach, Rutilus rutilus, as a studyspecies we demonstrate that the geneticdiversity (number of alleles per locus,expected heterozygosity) of populations livingwithin floodplain water bodies is not severelyimpoverished compared to the genetic diversitywithin the main river channel. However, wefound slight differences in the allelefrequencies of flood plain water bodies and themain river channel. Nevertheless, fishpopulations in floodplain water bodies mayserve as reservoirs of autochthonous geneticmaterial for restoration of fish populations inthe main river channel after populationextinction due to catastrophic accidents (e.g.industrial pollution).     

Disentangling the effects of acidic air pollution,atmospheric CO2, and climate change on recent growth of red spruce trees in the Central Appalachian Mountains

In the 45 years after legislation of the Clean Air Act, there has been tremendous progress in reducing acidic air pollutants in the eastern United States, yet limited evidence exists that cleaner air has improved forest health. Here, we investigate the influence of recent environmental changes on the growth and physiology of red spruce (Picea rubens Sarg.) trees, a key indicator species of forest health, spanning three locations along a 100 km transect in the Central Appalachian Mountains. We incorporated a multiproxy approach using 75‐year tree ring chronologies of basal tree growth, carbon isotope discrimination (?¹³C, a proxy for leaf gas exchange), and δ¹⁵N (a proxy for ecosystem N status) to examine tree and ecosystem level responses to environmental change. Results reveal the two most important factors driving increased tree growth since ca. 1989 are reductions in acidic sulfur pollution and increases in atmospheric CO₂, while reductions in pollutant emissions of NO_x and warmer springs played smaller, but significant roles. Tree ring ?¹³C signatures increased significantly since 1989, concurrently with significant declines in tree ring δ¹⁵N signatures. These isotope chronologies provide strong evidence that simultaneous changes in C and N cycling, including greater photosynthesis and stomatal conductance of trees and increases in ecosystem N retention, were related to recent increases in red spruce tree growth and are consequential to ecosystem recovery from acidic pollution. Intrinsic water use efficiency (iWUE) of the red spruce trees increased by ~51% across the 75‐year chronology, and was driven by changes in atmospheric CO₂ and acid pollution, but iWUE was not linked to recent increases in tree growth. This study documents the complex environmental interactions that have contributed to the recovery of red spruce forest ecosystems from pervasive acidic air pollution beginning in 1989, about 15 years after acidic pollutants started to decline in the United States.     

Molecular identification of fecal pollution sources in water supplies by host-specific fecal DNA markers and Terminal Restriction Fragment Length Polymorphism profiles of 16S rRNA gene

Specific fecal DNA markers were investigated for major pollution sources, cow, human, and pig, and occurrence of the identified markers was analyzed in river waters using Terminal Restriction Fragment Length Polymorphism (T-RFLP) techniques and sequencing of 16S rDNA of Bacteroides-Prevotella. The unique and specific DNA markers for cow and human were identified as a 222 bp and 60 bp peak in HaeIII T-RFLP profiles, respectively, and the pig-specific marker was not identified but the unique T-RFLP profile of pig could be used as a substitution. Human-specific marker was detected in most of the river waters tested (92.1%) and T-RFLP profiles of river waters were shown to be similar to those of human feces. Cluster analysis of T-RFLP data showed that the fecal sources were multiple (human plus cow and human plus dairy cow) in most of the river waters. The phylogenetic analysis for the clones recovered from the fecal and water samples showed that the clones from cow formed a discreet cluster from those of other sources. The other clones from human, pig, and river water formed two groups all together. The results of this study could be used to identify and control the fecal pollution source in the bodies of water in Korea.     

Survival of Helicobacter pylori in well water

The mortality of a clinical Helicobacter pylori strain was assessed by inoculating it in untreated well water, filtered well water, and autoclaved well water. Two different temperatures (5 and 25 °C) were used during the experimental period. Because Escherichia coli is commonly used as indicator of faecal pollution of water, we compared the survival of H. pylori using E. coli as indicator of its persistence. H. pylori was not culturable 48 h after inoculation, whereas the population of E. coli, monitored at the same temperature, decreased slowly, especially in filtered water. In untreated water, both H. pylori and E. coli survived less well than in filtered and autoclaved water. In general the survival of H. pylori and E. coli was better in filtered water than in autoclaved water and the ability of H. pylori to survive several days in water at 5 °C is reported, supporting the observation that H. pylori survives better at 5 °C than at higher temperature. This suggests a possible faecal–oral transmission of H. pylori in the presence of a contaminated water.     

Significance and suitability of <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> vs. fecal coliforms in assessing microbiological water quality

We examined the significance and suitability of Aeromonas hydrophila versus fecal coliforms in assessing microbiological water quality. For this, we used the membrane filtration method to simultaneously estimate the abundance level of A. hydrophila and fecal coliforms in waters from the Mfoundi river watershed at Yaoundé, and compared how fluctuations in A. hydrophila abundance matched those observed with fecal coliforms index as an indicator of water quality in the system under study. Our results revealed that waters were not safe according to the standards for water quality established by the Word Health Organization (WHO). They also indicated the prevalence of A. hydrophila as compared to fecal coliforms, and suggested that water from the Mfoundi River and its tributaries could be classified as hypereutrophic based on the density of Aeromonas. Moreover, the spatial distribution of fecal coliforms and A. hydrophila exhibited similar trends within the different water bodies investigated, suggesting that A. hydrophila can be used as indicator of water quality in highly polluted waters. We concluded that waters from the Mfoundi River watershed at Yaoundé represent a great potential risk of infection for users, and foresee that the next challenge will be to determine, among other factors, the physico-chemical factors influencing the observed spatial distribution.     

Zur Kenntnis der OscillatoriaceePseudanabaena galeata (Cyanophyta)

If exsiccated trichomes ofPseudanabaena galeata are immersed in water, striking changes occur as a consequence of lysis and maceration. The locomotion of living trichomes differs from that inOscillatoriaceae. This and other differences make it doubtful, whetherPs. galeata belongs to theOscillatoriaceae; at any rate it occupies an aberrant position.

     

Application of PFGE to source tracking of faecal pollution in coastal recreation area: a case study in Aoshima Beach, Japan

Aims: The development of a microbial source tracking (MST) method is strongly desired to ensure public health and bacteriological safety in coastal recreation areas. We try to specify the source of faecal pollution by applying pulsed‐field gel electrophoresis (PFGE) to the study of the aquatic environment on Aoshima Beach, Japan. Methods and Results: Enterococcus faecium, an enterococcus, was used as a faecal indicator bacterium in this study. Enterococcus faecium strains were isolated and identified from each water sample collected from Aoshima Beach and five rivers (Oyodo, Kiyotake, Kaeda, Chifuku and Tsukunami Rivers) that might be potential sources of faecal pollution. Enterococcus faecium strains collected from water samples were analysed using PFGE. The similarities of all the PFGE types of the Ent. faecium strains were compared using dendrogram analysis. The PFGE types of the strains isolated from Aoshima Beach showed a high similarity to those of the strains isolated from the Oyodo River at a 0·9 similarity level. It was suggested that the Oyodo River is the source of faecal pollution on Aoshima Beach. Conclusions: The PFGE analysis using enterococci is a potential tool for the MST of faecal indicator bacteria that can be applied to the study of the coastal environment. Significance and Impact of the Study: This is one of the studies that PFGE was applied to the coastal environment. The approach using PFGE could estimate the river that is source of faecal pollution in Aoshima Beach. By applying PFGE as a tool of MST method, detailed information of faecal pollution in coastal area can be provided.     

Morphological and ecological similarities: wood-boring beetles associated with novel xylose-fermenting yeasts, Spathaspora passalidarum gen. sp. nov. and Candida jeffriesii sp. nov.

Ascomycete yeasts that both ferment and assimilate xylose were reported previously as associates of insects living in woody substrates. Most notable have been reports of Pichia stipitis-like yeasts that are widely associated with the wood-boring beetle, Odontotaenius disjunctus (Coleoptera: Passalidae), in the eastern United States. Our continuing investigation of insect gut yeasts has lead to the discovery of two new xylose-fermenting yeasts that phylogenetic analysis places as sister taxa. The beetle hosts, O. disjunctus and Phrenapates bennetti (Coleoptera: Tenebrionidae), are similar in habitat and appearance, and the presence of similar gut yeasts is an additional common feature between them. Here we describe the new yeast genus Spathaspora, the type species S. passalidarum, and its sister taxon Candida jeffriesii and discuss their natural history, including a comparison with Pichia stipitis, another member of a guild of xylose-fermenting yeasts with similar metabolic traits. In addition a morphologically distinct yeast ascospore type is described for Spathaspora.     

Blaue,rote und gelbgrüne männlichePinus-Blüten

Differences in colours of male strobili, originally encountered in races ofPinus mugo, are found among other pine species too: Species of subsect.Cembrae flower bright red, whereas in subsect.Cembroides yellowgreen is dominant. Recently, blue and grey-blue male flowers have been discovered inP. engelmannii from Mexico,P. palustris, P. elliotti andP. densa from Florida. These flower colour differences apparently reflect some species relationships.

     

Are the characeae able to indicate the origin of groundwater in former river channels?

The macroscopic algae Characeae are usually assumed to occur in waterbodies supplied by groundwater with low phosphate content, but the indicative value of the species is seldom defined in bibliography. Former braided channels of the Rhône river are supplied with groundwater originating from the main channel (seepage) or from hillslope aquifer. The aim of the present paper was to determine if it possible to use the Characeae as indicators of physicochemical characteristies of water in order to assess the origin of groundwater supplying former river channels. Four former braided channels of the Rhône River colonized by Characeae were investigated, and the physico-chemical characteristics of i) the channels, ii) the groundwater and iii) the river were measured over a period of several months. Species are arranged along a gradient of conductivity, alkalinity, ammonium and phosphate content of the water. Charophyte species can indicate the origin of groundwater, either seepage or hillslope nutrient-poor aquifer, and integrate both the average value of the chemical parameter, and their variations. C. hispida occurs in a nutrient-poor channel mainly supplied by highly calcareous groundwater coming from hillslope aquifer. Chara major has requirements close to those of C. hispida, but is more tolerant to periodic inputs of nutrients. C. vulgaris and N. syncarpa both tolerate mesotrophic waters originating from both hillslope aquifer and seepage, and C. globularis is associated to a channel mainly supplied by mesotrophic to eutrophic river seepage.     

A bacteriophytochrome regulates the synthesis of LH4 complexesin <Emphasis Type="Italic">Rhodopseudomonas palustris</Emphasis>

The non-sulphur purple bacterium Rhodopseudomonas palustris contains five pucAB genes for peripheral light-harvesting complexes. Bacteria grown under high-light conditions absorb at 800 and 850 nm but in low-light the 850 nm peak is almost absent and LH2 complexes are replaced by LH4. The genome contains six bacteriophytochromes (Bph). Bphs sense light in the red/far-red through a reversible Pr to Pfr transformation that controls gene expression. Bph3 (RPA1537) controls the expression of a cluster of photosynthetic genes, however most of the peripheral light harvesting complex genes are outside of this region. The pucAB-d genes encode LH4 peptides and are near two Bphs (RPA3015, RPA3016). We have characterised three Bphs and show that Bph4 RPA3015 and Bph3 RPA1537 have different dark stable states. It is known that Bph3 is active in its red absorbing Pr form and suggests a working hypothesis that Bph4 is active in the Pfr state. We show that LH4 expression can be induced with red light at the Pr absorption maximum (708 nm) of Bph4. The property of light transmission of water maybe an important factor in understanding this adaptation. Bph4 can sense the reduction in light intensity indirectly through an increase in ratio of transmitted red/far-red light. The red right activated Bph4 regulates the synthesis of LH4 which concentrates bacteriochlorophyll a pigment absorption at 800 nm to exploit a recovery in water light transmission in this region.     

Das Rhizoid vonUlothrix zonata (Chlorophyceae)

Ulothrix zonata was studied under natural conditions in situ on slides exposed in a river. On them specimens grow in all stages of development. Older filaments are fixed on the substrate not only by the pointed basal cell but mainly by a branched, horizontally expanded rhizoid produced by this cell. The rhizoid grows in correlation with the growth of the filament as a whole. In addition to the basal cell the following cells of the lower portions of the filament are incapable of division and reproduction. Through these cells the upper fully vital cell grows downwards in older stages.

     

Ducellieria chodati — Alge oder Pilz?

Ducellieria chodati Teiling is an organism rarely mentioned from plankton samples. Its propagation was unknown, and all earlier authors have failed to see that it is a colourless organism. Because of its structure and some chemical reactions,Ducellieria was thought to be a member of theXanthophyceae. Many living coenobia ofD. chodati from several Austrian lakes and some steps of their reproduction have been studied: Zoospores with two unequal flagella are released. After a mobile phase they settle on coniferous pollen grains drifting in water. Inside the pollen grain, a tube or flask is developed from which zoospores are released again after one or two days. These aggregate to form newDucellieria coenobia. These observations suggest thatDucellieria chodati belongs to thePhycomycetes, perhaps to theSaprolegniales.

     

Macrophytic primary production and nutrient concentrations in a deltaic floodplain marsh of the Lower Paraná River

Biomass changes across an annual cycle were followed at two sampling sites in the floodplain marsh of the Lower Paraná River: close to the river-shore and 800 m inside the floodplain marsh, both dominated by Scirpus californicus and Cyperus giganteus. Tidal influence determines a daily exchange of water between the river and the floodplain marsh.Estimated net primary production was higher in the river (2820 against 1770 g m^–2). Contents of nitrogen and phosphorus in plant tissue decreased from the river to the floodplain (0.62 to 0.45% N and 0.18 to 0.14% P). In spite of the important water exchange between the river and the floodplain, a decrease in nitrate, oxygen and suspended matter, and an increase in soluble reactive phosphorus in the water were observed from the river towards the floodplain marsh.A primary production gradient exists from the river to the inner floodplain marsh, where production is nitrogen-limited, sustained mainly on nutrients supplied by the river. Floodplain marshes are nitrate sinks, probably through denitrification losses and macrophyte uptake.     

Ecology of yeasts in polluted water

The general size and composition of the extant yeast populations in 13 polluted freshwater habitats were surveyed. Subsequently the yeast populations in three of the 13 locations were quantitatively determined and compared. The three locations had (A) low pollution levels, (B) heavy industrial waste pollution, and (C) heavy domestic waste pollution.The yeast population at location A was dominated byRhodotorula andCryptococcus isolates. At station BRhodotorula andCandida were predominant.Candida isolates were in the majority at location C andRhodotorula strains were second in frequency, but were much lower in proportion of the population than at the other two habitats.These polluted waters in general had large yeast populations, ranging as high as 27,000 yeasts per 100 ml, and averaging approximately 3000 yeasts per 100 ml.The presence of human wastes was especially associated with large increases in the proportion ofCandida yeasts in the environment. The genusRhodotorula was consistently present at all locations, but the genusCryptococcus was a major component of the yeast population only in non-polluted or lightly polluted fresh water.We appreciate the assistance of the Calumet Area Surveillance Program, Federal Water Pollution Control Administration, Chicago, in the collection of water samples. This investigation was supported by U.S. Public Health Service Research Grant No. AI 04642 from the National Institute of Allergy and Infectious Diseases.     

Assessing the value of secondary forest for amphibians: <Emphasis Type="Italic">Eleutherodactylus</Emphasis> frogs in a gradient of forest alteration

Secondary forests constitute a growing portion of forested areas worldwide. They might have a substantial role for the conservation of biodiversity in tropical areas, but there is little information on their potential to support forest species and the recovery of faunal communities. We studied two forest frogs (Eleutherodactylus diastema and E. fitzingeri) in an area of Costa Rica composed of a mosaic of primary forest, young secondary forest and pasture, and we compared the density of calling males in areas with different forest alteration. Autoregressive models were used to compensate for potentially undesired effects of spatial autocorrelation and pseudoreplication. Both species were most abundant in riparian, primary forest. However, E. fitzingeri was also abundant in riparian secondary forests, and its density far from the river was similar in primary and secondary forest, suggesting that river proximity can influence the recovery of secondary forest for amphibians. Conversely, the density of E. diastema was similar in secondary forest and pasture, stressing interspecific differences for recovery rate. These frogs have a keystone role in nutrient cycling and food webs, and their prompt recovery might represent an important step for the functional recovery of forests. Nevertheless, the strong interspecific differences stress the complexity of these processes.     

Reduction of phenolics content and COD in olive oil mill wastewaters by indigenous yeasts and fungi

Olive oil mill wastewaters (OOMW) cause a recurrent environmental pollution problem. The large concentration of phenolic compounds in the organic fraction of OOMW is principally responsible for the phytotoxicity and microbial growth inhibitory effects of the effluent. Candida boidinii, Geotrichum candidum, a Penicillium sp. and Aspergillus niger HA37 were isolated from OOMW. When cultivated directly on an undiluted OOMW-based medium containing 82 g l⁻¹ COD, these strains removed only 4–8% of chemical oxygen demand (COD) and phenolics. In contrast, reduction values attaining respectively 40–73% for phenolics and 45–78% for COD removal in the undiluted OOMW-based medium were obtained when using the strains gradually acclimated to high concentration of OOMW by successive stepwise transfer from media containing COD of 20.5 up to 82 g l⁻¹. Possibly, a sufficient production level of degradation and/or detoxification enzymes has to be attained to overcome the toxic effects of the phenolic fraction of concentrated OOMW. The present investigation calls attention to the necessity of acclimation for certain fungal and yeasts strains potentially useful for treating highly polluted effluents.