Aerobic granular sludge phosphate removal using glucose.

Enhanced biological phosphate removal and aerobic sludge granulation are commonly studied with fatty acids as substrate. Fermentative substrates such as glucose have received limited attention. In this work, glucose conversion by aerobic granular sludge and its impact on phosphate removal was studied.

Metaproteomics, metagenomics and 16S rRNA sequencing provide different perspectives on the aerobic granular sludge microbiome.

The tremendous progress in sequencing technologies has made DNA sequencing routine for microbiome studies. Additionally, advances in mass spectrometric techniques have extended conventional proteomics into the field of microbial ecology. However, systematic studies that provide a better understanding of the complementary nature of these 'omics' approaches, particularly for complex environments such as wastewater treatment sludge, are urgently needed.

Glycerol conversion by aerobic granular sludge.

Glycerol is abundantly present in wastewater from industries such as biodiesel production facilities. Glycerol is also a potential carbon source for microbes that are involved in wastewater nutrient removal processes. The conversion of glycerol in biological phosphorus removal of aerobic granular sludge processes has not been explored to date.

Ecology of Methanonatronarchaeia.

Methanonatronarchaeia represents a deep-branching phylogenetic lineage of extremely halo(alkali)philic and moderately thermophilic methyl-reducing methanogens belonging to the phylum Halobacteriota. It includes two genera, the alkaliphilic Methanonatronarchaeum and the neutrophilic Ca. Methanohalarchaeum.

Database-independent de novo metaproteomics of complex microbial communities.

Metaproteomics has emerged as one of the most promising approaches for determining the composition and metabolic functions of complete microbial communities. Conventional metaproteomics approaches rely on the construction of protein sequence databases and efficient peptide-spectrum-matching algorithms, an approach that is intrinsically biased towards the content of the constructed sequence database. Here, we introduce a highly efficient, database-independent de novo metaproteomics approach and systematically evaluate its quantitative performance using synthetic and natural microbial communities comprising dozens of taxonomic families.

Revealing the Metabolic Flexibility of " Accumulibacter phosphatis" through Redox Cofactor Analysis and Metabolic Network Modeling.

Environmental fluctuations in the availability of nutrients lead to intricate metabolic strategies. " Accumulibacter phosphatis," a polyphosphate-accumulating organism (PAO) responsible for enhanced biological phosphorus removal (EBPR) from wastewater treatment systems, is prevalent in aerobic/anaerobic environments. While the overall metabolic traits of these bacteria are well described, the nonavailability of isolates has led to controversial conclusions on the metabolic pathways used.

Anticipating Xenogenic Pollution at the Source: Impact of Sterilizations on DNA Release From Microbial Cultures.

The dissemination of DNA and xenogenic elements across waterways is under scientific and public spotlight due to new gene-editing tools, such as do-it-yourself (DIY) CRISPR-Cas kits deployable at kitchen table. Over decades, prevention of spread of genetically modified organisms (GMOs), antimicrobial resistances (AMR), and pathogens from transgenic systems has focused on microbial inactivation. However, sterilization methods have not been assessed for DNA release and integrity.

Exploring Biodiversity and Arsenic Metabolism of Microbiota Inhabiting Arsenic-Rich Groundwaters in Northern Italy.

Arsenic contamination of groundwater aquifers is an issue of global concern. Among the affected sites, in several Italian groundwater aquifers arsenic levels above the WHO limits for drinking water are present, with consequent issues of public concern. In this study, for the first time, the role of microbial communities in metalloid cycling in groundwater samples from Northern Italy lying on Pleistocene sediments deriving from Alps mountains has been investigated combining environmental genomics and cultivation approaches.

Coexistence of sulfate reducers with the other oil bacterial groups in Diyarbakır oil fields.

The existence of sulfate-reducing bacteria (SRB) is a major concern in oil industry due to the detrimental effects of SRB in oil technology. SRB are co-habited with diverse microbial populations in oil fields. The presence of other bacterial groups in oil fields may alter SRB activity in different ways.

Effect of Lactate on the Microbial Community and Process Performance of an EBPR System.

Accumulibacter phosphatis is in general presented as the dominant organism responsible for the biological removal of phosphorus in activated sludge wastewater treatment plants. Lab-scale enhanced biological phosphorus removal (EBPR) studies, usually use acetate as carbon source. However, the complexity of the carbon sources present in wastewater could allow other potential poly-phosphate accumulating organism (PAOs), such as putative fermentative PAOs (e.

Methanonatronarchaeum thermophilum gen. nov., sp. nov. and 'Candidatus Methanohalarchaeum thermophilum', extremely halo(natrono)philic methyl-reducing methanogens from hypersaline lakes comprising a new euryarchaeal class Methanonatronarchaeia classis nov.

Methanogenic enrichments from hypersaline lakes at moderate thermophilic conditions have resulted in the cultivation of an unknown deep lineage of euryarchaeota related to the class Halobacteria. Eleven soda lake isolates and three salt lake enrichment cultures were methyl-reducing methanogens that utilize C1 methylated compounds as electron acceptors and H2 or formate as electron donors, but they were unable to grow on either substrates alone or to form methane from acetate. They are extreme halophiles, growing optimally at 4 M total Na and the first representatives of methanogens employing the 'salt-in' osmoprotective mechanism.

Discovery of extremely halophilic, methyl-reducing euryarchaea provides insights into the evolutionary origin of methanogenesis.

Methanogenic archaea are major players in the global carbon cycle and in the biotechnology of anaerobic digestion. The phylum Euryarchaeota includes diverse groups of methanogens that are interspersed with non-methanogenic lineages. So far, methanogens inhabiting hypersaline environments have been identified only within the order Methanosarcinales.

Effects of electron acceptors on sulphate reduction activity in activated sludge processes.

The concentration of sulphate present in wastewater can vary from 10 to 500 mg SO/L. During anaerobic conditions, sulphate is reduced to sulphide by sulphate-reducing bacteria (SRB). Sulphide generation is undesired in wastewater treatment plants (WWTPs).

Metabolic Response of " Accumulibacter Phosphatis" Clade II C to Changes in Influent P/C Ratio.

The objective of this study was to investigate the ability of a culture highly enriched with the polyphosphate-accumulating organism, " Accumulibacter phosphatis" clade IIC, to adjust their metabolism to different phosphate availabilities. For this purpose the biomass was cultivated in a sequencing batch reactor with acetate and exposed to different phosphate/carbon influent ratios during six experimental phases. Activity tests were conducted to determine the anaerobic kinetic and stoichiometric parameters as well as the composition of the microbial community.

Denitrification of nitrate and nitrite by 'Candidatus Accumulibacter phosphatis' clade IC.

Phosphate accumulating organisms (PAO) are assumed to use nitrate as external electron acceptor, allowing an efficient integration of simultaneous nitrogen and phosphate removal with minimal organic carbon (COD) requirements. However, contradicting findings appear in literature regarding the denitrification capacities of PAO due to the lack of clade specific highly enriched PAO cultures. Whereas some studies suggest that only PAO clade I may be capable of using nitrate as external electron acceptor for anoxic P-uptake, other studies indicate that PAO clade II may be responsible for anoxic P-removal.

Syntrophic associations from hypersaline soda lakes converting organic acids and alcohols to methane at extremely haloalkaline conditions.

Until now anaerobic oxidation of VFA at high salt-pH has been demonstrated only at sulfate-reducing conditions. Here, we present results of a microbiological investigation of anaerobic conversion of organic acids and alcohols at methanogenic conditions by syntrophic associations enriched from hypersaline soda lakes in Central Asia. Sediment incubation experiments showed active, albeit very slow, methane formation from acetate, propionate, butyrate and C2 C4 alcohols at pH 10 and various levels of salinity.

454-Pyrosequencing Analysis of Bacterial Communities from Autotrophic Nitrogen Removal Bioreactors Utilizing Universal Primers: Effect of Annealing Temperature.

Identification of anaerobic ammonium oxidizing (anammox) bacteria by molecular tools aimed at the evaluation of bacterial diversity in autotrophic nitrogen removal systems is limited by the difficulty to design universal primers for the Bacteria domain able to amplify the anammox 16S rRNA genes. A metagenomic analysis (pyrosequencing) of total bacterial diversity including anammox population in five autotrophic nitrogen removal technologies, two bench-scale models (MBR and Low Temperature CANON) and three full-scale bioreactors (anammox, CANON, and DEMON), was successfully carried out by optimization of primer selection and PCR conditions (annealing temperature). The universal primer 530F was identified as the best candidate for total bacteria and anammox bacteria diversity coverage.

Comparison of bacterial diversity in full scale anammox bioreactors operated under different conditions.

Bacterial community structure of full-scale anammox bioreactor is still mainly unknown. It has never been analyzed whether different anammox bioreactor configurations might result in the development of different bacterial community structures among these systems. In this work, the bacterial community structure of six full-scale autotrophic nitrogen removal bioreactors located in The Netherlands and China operating under three different technologies and with different influent wastewater characteristics was studied by the means of pyrotag sequencing evaluation of the bacterial assemblage yielded a great diversity in all systems.

Methanosalsum natronophilum sp. nov., and Methanocalculus alkaliphilus sp. nov., haloalkaliphilic methanogens from hypersaline soda lakes.

Two groups of haloalkaliphilic methanogenic archaea were dominating in enrichments from hypersaline soda lake sediments at pH 10. At moderate salt concentrations with formate or H2 as electron donor, methanogens belonging to the genus Methanocalculus were enriched, while at high salt concentrations with methylated substrates, a group related to Methanosalsum zhilinae was dominating. For both groups, several pure cultures were obtained including the type strains AMF2T for the Methanocalculus group and AME2T for the Methanosalsum group.

Digester performance and microbial community changes in thermophilic and mesophilic sequencing batch reactors fed with the fine sieved fraction of municipal sewage.

This study investigates the start-up and operation of bench-scale mesophilic (35 °C) and thermophilic (55 °C) anaerobic sequencing batch reactor (SBR) digesters treating the fine sieved fraction (FSF) from raw municipal sewage. FSF was sequestered from raw municipal wastewater, in the Netherlands, using a rotating belt filter equipped with a 350 micron mesh. For the given wastewater, the major component of FSF was toilet paper, which is estimated to be 10-14 kg per year per average person in the western European countries.

Enrichment of DNRA bacteria in a continuous culture.

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are competing microbial nitrate-reduction processes. The occurrence of DNRA has been shown to be effected qualitatively by various parameters in the environment. A more quantitative understanding can be obtained using enrichment cultures in a laboratory reactor, yet no successful DNRA enrichment culture has been described.

Methanogenesis at extremely haloalkaline conditions in the soda lakes of Kulunda Steppe (Altai, Russia).

Microbial methanogenesis at extreme conditions of saline alkaline soda lakes has, so far, been poorly investigated. Despite the obvious domination of sulfidogenesis as the therminal anaerobic process in the hypersaline soda lakes of Kulunda Steppe (Altai, southwestern Siberia), high concentrations of methane were detected in the anaerobic sediments. Potential activity measurements with different substrates gave results significantly deviating from what is commonly found in hypersaline habitats with neutral pH.

Absolute quantification of individual biomass concentrations in a methanogenic coculture.

Identification of individual biomass concentrations is a crucial step towards an improved understanding of anaerobic digestion processes and mixed microbial conversions in general. The knowledge of individual biomass concentrations allows for the calculation of biomass specific conversion rates which form the basis of anaerobic digestion models. Only few attempts addressed the absolute quantification of individual biomass concentrations in methanogenic microbial ecosystems which has so far impaired the calculation of biomass specific conversion rates and thus model validation.