Effects of dietary arabinoxylan-oligosaccharides (AXOS) and endogenous probiotics on the growth performance, non-specific immunity and gut microbiota of juvenile Siberian sturgeon (Acipenser baerii).

We investigated the effects of administration of putative endogenous probiotics Lactococcus lactis spp. lactis or Bacillus circulans, alone and in combination with arabinoxylan-oligosaccharides (AXOS), a new class of candidate prebiotics, in juvenile Siberian sturgeon (Acipenser baerii). Eight experimental diets were tested: basal diet (Diet 1), basal diet supplemented with 2% AXOS (Diet 2), or L.

Prebiotic effects of arabinoxylan oligosaccharides on juvenile Siberian sturgeon (Acipenser baerii) with emphasis on the modulation of the gut microbiota using 454 pyrosequencing.

The potential of a novel class of prebiotics, arabinoxylan oligosaccharides (AXOS), was investigated on growth performance and gut microbiota of juvenile Acipenser baerii. Two independent feeding trials of 10 or 12 weeks were performed with basal diets supplemented with 2% or 4% AXOS-32-0.30 (trial 1) and 2% AXOS-32-0.

Effects of arabinoxylan-oligosaccharides (AXOS) on juvenile Siberian sturgeon (Acipenser baerii) performance, immune responses and gastrointestinal microbial community.

Arabinoxylan-oligosaccharides (AXOS) are a newly discovered class of candidate prebiotics that exert different properties depending on their structure. In this study the effects of two different structures of AXOS, namely AXOS-32-0.30 (average degree of polymerization: 32, average degree of substitution: 0.

A zone-specific fish-based biotic index as a management tool for the Zeeschelde estuary (Belgium).

Fish-based indices monitor changes in surface waters and are a valuable aid in communication by summarising complex information about the environment (Harrison and Whitfield, 2004). A zone-specific fish-based multimetric estuarine index of biotic integrity (Z-EBI) was developed based on a 13 year time series of fish surveys from the Zeeschelde estuary (Belgium). Sites were pre-classified using indicators of anthropogenic impact.

Tolerance of arabinoxylan-oligosaccharides and their prebiotic activity in healthy subjects: a randomised, placebo-controlled cross-over study.

The tolerance and prebiotic effect following oral intake by healthy human subjects of arabinoxylan-oligosaccharides (AXOS), produced by partial enzymic hydrolysis of the wheat fibre arabinoxlyan, were studied. A total of twenty healthy subjects participated in the present randomised, placebo-controlled cross-over study. They consumed 10 g AXOS or placebo per d each for 3 weeks with a 4-week wash-out period in between.

Evaluation of process parameters of ultrasonic treatment of bacterial suspensions in a pilot scale water disinfection system.

In this study, several process parameters that may contribute to the efficiency of ultrasound disinfection are examined on a pilot scale water disinfection system that mimics realistic circumstances as encountered in an industrial environment. The main parameters of sonication are: (i) power; (ii) duration of treatment; (iii) volume of the treated sample. The specific energy (E(s)) is an indicator of the intensity of the ultrasound treatment because it incorporates the transferred power, the duration of sonication and the treated volume.

Evaluation of power ultrasound for disinfection of both Legionella pneumophila and its environmental host Acanthamoeba castellanii.

The objectives of this study were to (1) examine the effect of power ultrasound on the viability of both Legionella pneumophila and Acanthamoeba castellanii trophozoites and cysts, (2) investigate if intracellular Legionella replication in trophozoites positively affects bacterial resistance to ultrasound and (3) study if Legionella renders viable but non-culturable (VBNC) due to ultrasound treatments. Using laboratory scale experiments, microorganisms were exposed for various time periods to power ultrasound at a frequency of 36 kHz and an ultrasound power setting of 50 and 100%. Due to a fast destruction, trophozoite hosts were not able to protect intracellular Legionella from eradication by ultrasound, in contrast to cysts.

Estuarine recruitment of a marine goby reconstructed with an isotopic clock.

Information on movement patterns of marine fishes between estuarine populations and stocks at sea is fundamental to understanding their population dynamics, life history tactics and behavior. Furthermore, understanding estuarine habitat use by marine fishes is crucial for their effective conservation and integrated estuarine management. Although large numbers of young marine fish make use of temperate estuaries in highly predictable abundance patterns, very little is known about how estuarine populations interact with the populations at sea.

Correcting the short-term effect of food deprivation in a damselfly: mechanisms and costs.

1. Mass at emergence is a life-history trait strongly linked to adult fitness. Therefore, when faced with transient food shortage in the larval stage, mass-correcting mechanisms are common.

Ecological relevance and sensitivity depending on the exposure time for two biomarkers.

Biomarkers are widely used to assess pesticide stress, but their ecological relevance and exposure time dependent sensitivity is still heavily debated. We studied both aspects in larvae of the damselfly Coenagrion puella, comparing the impact of low doses of atrazine, carbaryl, and endosulfan on two key biomarkers (acetylcholinesterase [AChE] activity and fluctuating asymmetry [FA]) and their relationship with life history traits (mortality, development time, growth rate, and body size). Larvae exposed to the pesticides had, in general, longer development times.

Sublethal pesticide concentrations and predation jointly shape life history: behavioral and physiological mechanisms.

Despite their relevance for risk assessment, the interactive effects of pesticide and predation cues are poorly understood because the underlying behavioral and physiological mechanisms are largely unknown. To explore these mechanisms, we reared larvae of the damselfly Coenagrion puella at three different predation risk levels and a range of environmentally realistic concentrations of three pesticides used worldwide (atrazine, carbaryl, and endosulfan). We compared key development responses (growth rate, developmental time, and final size) against food ingestion, assimilation, and conversion efficiency, and acetylcholinesterase (AChE) activity.

Replication of Legionella pneumophila in floating biofilms.

Biofilms are a major source of human pathogenic Legionella pneumophila in aquatic systems. In this study, we investigated the capacity of L. pneumophila to colonize floating biofilms and the impact of Acanthamoeba castellanii on the replication of biofilm-associated Legionella.

Replication of Legionella pneumophila in biofilms of water distribution pipes.

Biofilms similar to those present in water distribution pipes of anthropogenic aquatic systems were simulated in a rotating annular reactor using a non-Legionella community consisting of Aeromonas hydrophila, Escherichia coli, Flavobacterium breve and Pseudomonas aeruginosa. The impact of this community and Acanthamoeba castellanii on the replication of Legionella pneumophila was investigated. Despite the presence of 10(7) non-Legionella bacteria, culture and real-time polymerase chain reaction (PCR) results clearly showed that biofilm-associated Legionella bacteria only increased after intracellular replication in A.

Detection of Legionella spp. and some of their amoeba hosts in floating biofilms from anthropogenic and natural aquatic environments.

Floating biofilms develop at the water-air interface and harbor numerous microorganisms, some of which are human pathogens like Legionella pneumophila. The presence of Legionella spp. and especially L.

Survey for the presence of specific free-living amoebae in cooling waters from Belgian power plants.

Free-living amoebae (FLA) are distributed ubiquitously in aquatic environments with increasing importance in hygienic, medical and ecological relationships to man. In this study, water samples from Belgian industrial cooling circuits were quantitatively surveyed for the presence of FLA. Isolated, thermotolerant amoebae were identified morphologically as well as using the following molecular methods: enzyme-linked immunosorbent assay and isoenzyme electrophoresis and PCR.

Quantitative detection and differentiation of free-living amoeba species using SYBR green-based real-time PCR melting curve analysis.

Real-time polymerase chain reaction melting curve analysis (MCA) allows differentiation of several free-living amoebae species. Distinctive characteristics were found for Naegleria fowleri, N. lovaniensis, N.

A duplex real-time PCR assay for the quantitative detection of Naegleria fowleri in water samples.

A fast and accurate duplex real-time PCR (qPCR) was developed to detect and quantify the human pathogenic amoeba Naegleria fowleri in water samples. In this study, primers and probe based on the Mp2Cl5 gene were designed to amplify and quantify N. fowleri DNA in a single duplex reaction.

Long-term exposure to environmentally relevant doses of methyl-tert-butyl ether causes significant reproductive dysfunction in the zebrafish (Danio rerio).

Methyl-tert-butyl ether (MTBE), an anthropogenic chemical used as a gasoline additive, is being detected at an increasing frequency in the environment. The acute lethal concentration that kills 50% of the fish test population and the chronic effects of exposure to MTBE were investigated in the zebrafish (Danio rerio). Chronic exposure over three weeks to effective MTBE conceritrations as low as 0.

Detection of legionella in various sample types using whole-cell fluorescent in situ hybridization.

The human pathogenic Legionella bacteria are found ubiquitously in natural and human-made aquatic environments as residents in biofilms, where close interactions with other microorganisms like protozoa are possible. Nosocomial legionellosis already has been linked frequently to Legionella-contaminated artificial water supplies. For this reason, a rapid and accurate detection and quantification of these bacteria in environmental and clinical samples, combined with more information about their behavior in complex microbial communities and diverse ecosystems, is of importance.

Development and evaluation of a Taqman duplex real-time PCR quantification method for reliable enumeration of Legionella pneumophila in water samples.

This study describes the development and evaluation of a specific Legionella pneumophila Taqman duplex real-time PCR (qPCR) for fast and reliable quantification of this human pathogen in suspected man-made water systems. The qPCR assay was 100% specific for all L. pneumophila serogroups 1-15 with a sensitivity of 60 genome units/l and an amplification efficiency of 98%.

The impact of electrochemical disinfection on Escherichia coli and Legionella pneumophila in tap water.

In order to reduce the risks of Legionnaires' disease, caused by the bacterium Legionella pneumophila, disinfection of tap water systems contaminated with this bacterium is a necessity. This study investigates if electrochemical disinfection is able to eliminate such contamination. Hereto, water spiked with bacteria (10(4)CFU Escherichia coli or L.

Detection and quantification of Legionella pneumophila in water samples using competitive PCR.

The presence of high levels of Legionella pneumophila in man-made aquatic systems correlates with the incidence of nosocomial Legionnaires' disease. This requires a rapid, reliable, and sensitive quantification of L. pneumophila concentrations in suspected water systems.

Effect of short-term exposure to methyl-tert-butyl ether and tert-butyl alcohol on the hatch rate and development of the African catfish, Clarias gariepinus.

Methyl tert-butyl ether (MTBE), a synthetic chemical used as a fuel additive, has been detected more frequently in the environment than previously. In this study, we examine the effects of MTBE (up to 100 mg/L) and its primary metabolite tertbutyl alcohol (TBA) (up to 1,400 mg/L) on the hatch rate and larval development of the African catfish Clarias gariepinus. Exposure to higher MTBE concentrations resulted in deformed eyes, mouthparts, and spinal cord and in increased larval mortality.

Mucosal response in African catfish after administration of Vibrio anguillarum O2 antigens via different routes.

The aim of this study was to investigate the possibility of mucosal vaccination in African catfish (Clarias gariepinus) with Vibrio anguillarum O2 bacterins. The antigen was administered via different routes: anal intubation, oral administration, intraperitoneal injection and immersion. To monitor the antigen uptake, a competitive ELISA was used.