Publications by authors named "Robert Seviour"

is an invasive weed species found in many countries. Methods to control the spread of this weed have been largely unsuccessful. Soil pH is the most important soil factor affecting the availability of nutrients for plant and impacting its growth.

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This review discusses critically how seasonal changes might affect the community composition and dynamics of activated sludge wastewater treatment plants (WWTP), and examines the factors thought more generally to control microbial community assembly, including the role of taxa-time relationships and stochastic and deterministic influences. The review also questions the differences in protocols used in these studies, which make any subsequent attempts at data comparisons problematic. These include bacterial DNA extraction and PCR methodologies, 16S rRNA sequencing and especially its depth, and subsequent statistical analyses of the data, which together often fail to reveal seasonal dynamic community shifts.

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Plant-growth promoting rhizobacteria (PGPR) play a vital role in soil fertility and crop production. The rhizosphere of many crop plants has been well documented by screening PGPR for their plant-growth promoting (PGP) mechanisms. However, the rhizosphere of grass species that may act as potential habitats for novel PGPR remains relatively unexplored.

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The taxonomic status of two strains, designated BEN371 and CON9, isolated from stable foams on activated sludge plants was the subject of a polyphasic study which also included the type strains of species and three authenticated strains recovered from such foams. Phylogenetic analyses of 16S rRNA gene sequences showed that these isolates formed a compact cluster suggesting a well-supported lineage together with a second branch containing the strains. A phylogenomic tree based on sequences of 92 core genes extracted from whole genome sequences of the isolates, the strains and type strains confirmed the assignment of the isolates and the strains to separate but closely associated lineages.

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This comprehensive review looks critically what is known about members of the genus Defluviicoccus, an example of a glycogen accumulating organism (GAO), in wastewater treatment plants, but found also in other habitats. It considers the operating conditions thought to affect its performance in activated sludge plants designed to remove phosphorus microbiologically, including the still controversial view that it competes with the polyphosphate accumulating bacterium Ca. Accumulibacter for readily biodegradable substrates in the anaerobic zone receiving the influent raw sewage.

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Members of the genus occur often at high abundances in activated sludge wastewater treatment plants designed to remove phosphorus, where biomass is subjected to alternating anaerobic feed/aerobic famine conditions, believed to favor the proliferation of organisms like . Accumulibacter and other phosphate-accumulating organisms (PAO), and All have a capacity to assimilate readily metabolizable substrates and store them intracellularly during the anaerobic feed stage so that under the subsequent famine aerobic stage, these can be used to synthesize polyphosphate reserves by the PAO and glycogen by Consequently, is described as a glycogen-accumulating organism or GAO. Because they share a similar anaerobic phenotype, it has been proposed that at high abundance, the PAO are out-competed for assimilable metabolites anaerobically, and hence aerobic P removal capacity is reduced.

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Akkermansia muciniphila is a Gram-negative bacterium that resides within the gut mucus layer, and plays an important role in promoting gut barrier integrity, modulating the immune response and inhibiting gut inflammation. Growth stimulation of A. muciniphila by polyphenols including epigallocatechin-3-gallate (EGCG) from difference sources is well-documented.

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Inulin is a highly effective prebiotic and an attractive alternative to antibiotic growth promoters for increasing production and maintaining health in chickens. However, how inulin elicits its effects on members of the intestinal microbiota is unknown, even though their importance for energy metabolism and the health of chickens is well documented. A combination of 16S rRNA Illumina sequencing and transcriptomic analysis was used to investigate the effects of supplementing a corn-based basal diet with 1, 2, or 4% inulin or 400 ppm bacitracin on the composition, diversity and activities of carbohydrate-metabolizing organisms (CMOs) in the cecal microbiota of broiler chickens.

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Many wastewater treatment plants around the world suffer from the operational problem of foaming. This is characterized by a persistent stable foam that forms on the aeration basin, which reduces effluent quality. The foam is often stabilized by a highly hydrophobic group of Actinobacteria known as the Mycolata.

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The rhizosphere soil microbiome (RSM) plays an important role in the nutritional metabolism of the exotic weed . However, our understanding of the composition and metabolic activity of this microbiome is limited. We used high-throughput sequencing of bacterial 16S rRNA genes and fungal internal transcribed spacer fragments in combination with transcriptome analysis to compare the composition and metabolic features of the RSMs of and the native plant species and .

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Amplicon sequence fingerprinting of communities in activated sludge systems have provided data revealing the true level of their microbial biodiversity and led to suggestions of which intrinsic and extrinsic parameters might affect the dynamics of community assemblage. Most studies have been performed in China and Denmark, and comparatively little information is available for plants in other countries. This study looked at how the communities of three plants in Victoria, Australia, treating domestic sewage changed with season.

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This study reveals that the abundance of the filament Kouleothrix (Eikelboom type 1851) correlated positively with poor settleability of activated sludge biomass in a Japanese full-scale nutrient removal wastewater treatment plant sampled over a one-year period. 16S rRNA amplicon sequence data confirmed that Kouleothrix was the dominant filament in the plant, with a relative abundance of 3.06% positively correlated with sludge volume index (SVI) (R = 0.

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We report the complete genome sequence of strain YV1, which was isolated from a wastewater treatment plant in Australia. The YV1 genome comprises a 2,615,801-bp chromosome and four plasmids. strain YV1 displays the distinctive morphology of Eikelboom morphotype 1863.

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It is now clear that several of the filamentous bacteria in activated sludge wastewater treatment plants globally, are members of the phylum They appear to be more commonly found in treatment plants designed to remove nitrogen (N) and phosphorus (P), most of which operate at long sludge ages and expose the biomass to anaerobic conditions. The seem to play an important beneficial role in providing the filamentous scaffolding around which flocs are formed, to feed on the debris from lysed bacterial cells, to ferment carbohydrates and to degrade other complex polymeric organic compounds to low molecular weight substrates to support their growth and that of other bacterial populations. A few commonly extend beyond the floc surface, while others can align in bundles, which may facilitate interfloc bridging and hence generate a bulking sludge.

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Inulin, a prebiotic, is an attractive alternative to antibiotic growth promoters in chickens. Dietary supplementation with inulin can improve growth performance, carcass yield, immune system activity, and serum biochemical parameters in chickens. A few studies investigated the impact of dietary inulin supplementation on chicken intestinal microbiota.

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Bacteriophages (phages) are biological entities that have attracted a great deal of attention in recent years. They have been reported as the most abundant biological entities on the planet and their ability to impact the composition of bacterial communities is of great interest. In this review, we aim to explore where phages exist in natural and artificial environments and how they impact communities.

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Lysozyme is known to eliminate intestinal pathogens in poultry and improve their growth performance. However, whether it can replace antibiotic growth promoters without the associated risk of the emergence of antibiotic-resistant bacterial strains is not known, and the effects of lysozyme supplementation on the composition, biodiversity, and function of the chicken gut microbiota remain unclear. Here, we used the 16S rRNA gene and ITS fragment Illumina sequencing combined with transcriptomic analysis to address this issue.

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Pu-erh tea is attracting increased attention worldwide because of its unique flavor and health effects, but its impact on the composition and function of the gut microbiota remains unclear. The aim of this study was to investigate the effects of aqueous extracts of fermented (ripe) and non-fermented (raw) Pu-erh teas on the composition and function of the intestinal microbiota of rats with diet-induced obesity. We conducted a comparative metagenomic and meta-proteomic investigation of the microbial communities in cecal samples taken from obese rats treated with or without extracts of raw or ripe Pu-erh teas.

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We describe here the isolation and characterization of the bacteriophage, NTR1 from activated sludge. This phage is lytic for Nocardia transvalensis, Nocardia brasiliensis and Nocardia farcinica. NTR1 phage has a genome sequence of 65,275 bp in length, and its closest match is to the Skermania piniformis phage SPI1 sharing over 36% of its genome.

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Previous studies have shown that enhanced biological phosphorus removal (EBPR) performance under continuous aerobic conditions always eventually deteriorates; however, the speed at which this happens depends on the carbon source supplied. The published data suggest that propionate is a better carbon source than acetate is for maintaining operational stability, although it is not clear why. A lab-scale sequencing batch reactor was run initially under conventional anaerobic/aerobic conditions with either acetate or propionate as the carbon source.

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The dominant filamentous bacteria associated with bulking incidents in Japanese activated sludge plants with nutrient removal were identified and their quantitative correlations with sludge settleability were assessed, with the aim of controlling bulking incidents by specifically suppressing bacterial growth. Fluorescence in situ hybridization (FISH) analyses using existing oligonucleotide FISH probes indicated that the presence of Eikelboom type 1851 filamentous bacteria belonging to the phylum Chloroflexi is correlated with biomass settleability in the municipal wastewater treatment plants examined. Real-time quantitative PCR (qPCR) assays developed in this study also showed a linear correlation between type 1851 filament members and sludge settleability, with the exception of some winter samples.

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Little is known about the prevalence, functionality and ecological roles of temperate phages for members of the mycolic acid producing bacteria, the Mycolata. While many lytic phages infective for these organisms have been isolated, and assessed for their suitability for use as biological control agents of activated sludge foaming, no studies have investigated how temperate phages might be induced for this purpose. Bioinformatic analysis using the PHAge Search Tool (PHAST) on Mycolata whole genome sequence data in GenBank for members of the genera Gordonia, Mycobacterium, Nocardia, Rhodococcus, and Tsukamurella revealed 83% contained putative prophage DNA sequences.

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We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA.

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Aims: To isolate and characterise phage which could lyse P. acnes and to formulate the phage into a delivery form for potential application in topical treatment of acne infection.

Methods And Results: Using standard phage isolation techniques, ten phage capable of lysing P.

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Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking episodes. Members of the uncultured B45 phylotype, which is embraced within the phylum Chloroflexi, were recently shown to exhibit this morphology.

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