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There is great potential to understand the functional diversity of microorganisms that are involved in waste water treatment through metagenomic analyses. This study presents the first metagenomic comparison of taxonomic and functional profiles of the microbial communities occurring in different aggregates from anaerobic ammonium-oxidizing (anammox) bioreactors. The anammox bacterial communities in both biofilm and granule sludge samples showed relatively high abundance and diversity compared with floccular sludge. Four of the five known genera of anammox bacteria were detected in the three cultures except Candidatus Jettenia, which was absent in the granules. C andidatus Kuenenia comprised the major population of anammox bacteria in these three sludges, independent of their growth morphologies. The genome assembled for the C andidatus Kuenenia in the granule was very similar to the published reference genome of C andidatus K. stuttgartiensis. Genes involved in the metabolism of the anammox process were highly detected in the biofilm and granule sludges. In particular, the abundance of hydrazine synthase gene ( hzs) in the biofilm was around 486 times more pronounced than that in the granules. The knowledge gained in this study highlights an important role of sludge aggregate in affecting community structure and metabolic potential of anammox systems. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) accounting protocols have addressed emissions from wastewater conveyance and treatment using a variety of simplifying methodologies. While these methodologies vary to some degree by protocol, within each protocol they provide consistent tools for organizational entities of varying size and scope to report and verify GHG emissions. Much of the science supporting these methodologies is either limited or the protocols have failed to keep abreast of developing GHG research. This state-of-the-art review summarizes the sources of direct GHG emissions (both those covered and not covered in current protocols) from wastewater handling; provides a review of the wastewater-related methodologies in a select group of popular protocols; and discusses where research has out-paced protocol methodologies and other areas where the supporting science is relatively weak and warrants further exploration. [ABSTRACT FROM AUTHOR]

A Xanthomonas sp. was isolated from the sludge on the drain outlet of a pharmaceutical factory. Then, the bacterium and carbon nanotubes (CNTs) were co-attached to an oxygen electrode for rapid analysis of biochemical oxygen demand (BOD). The response current was linear with BOD values in the range 10 to 300 mg/L for standard BOD solution with a response time of 35 seconds (R = 0.9994) and 20 to 580 mg/L for pharmaceutical wastewater with a response time ≤200 seconds (R 0.9985), which means that this modified electrode might be used for online SOD analysis of pharmaceutical wastewater. Further studies revealed that the modified electrode can be used for BOD measurement in a high-salt condition. Also, the bacterium/CNTs biofilm can maintain its activity and good performance, even after being sealed and stored at 4°C for 50 days. [ABSTRACT FROM AUTHOR]

In enhanced biological phosphorus removal (EBPR) systems, polyphosphate-accumulating organisms (PAOs) are primarily responsible for removing phosphate from wastewater. Propionate is an abundant carbon substrate in many EBPR plants and has been suggested to provide PAOs an advantage over their carbon competitors--the glycogen-accumulating organisms (GAOs). The aerobic metabolism of PAOs enriched with a propionate carbon source is studied in this paper. A metabolic model is proposed and experimentally validated to characterize the aerobic biochemical transformations by PAOs. The model predicts very well the experimental data obtained from the enriched PAO culture through solid-, liquid-, and gas-phase analyses. This model may be combined with previously formulated metabolic models to better describe the biochemical activity of PAOs with acetate and propionate as the primary carbon sources. Furthermore, it can also facilitate the study of the effect of different carbon sources on PAO-GAO competition. Water Environ. [ABSTRACT FROM AUTHOR]

Two laboratory-scale sequencing batch reactors (SBRs) were operated for enhanced biological phosphorus removal (EBPR) in alternating anaerobic–aerobic or alternating anaerobic–anoxic modes, respectively. Polyphosphate-accumulating organisms (PAOs) were enriched in the anaerobic–aerobic SBR and denitrifying PAOs (DPAOs) were enriched in the anaerobic–aerobic SBR. Fluorescence in situ hybridization (FISH) demonstrated that the well-known PAO, “Candidatus Accumulibacter phosphatis” was abundant in both SBRs, and post-FISH chemical staining with 4,6-diamidino-2-phenylindol (DAPI) confirmed that they accumulated polyphosphate. When the anaerobic–anoxic SBR enriched for DPAOs was converted to anaerobic–aerobic operation, aerobic uptake of phosphorus by the resident microbial community occurred immediately. However, when the anaerobic–aerobic SBR enriched for PAOs was exposed to one cycle with anoxic rather than aerobic conditions, a 5-h lag period elapsed before phosphorus uptake proceeded. This anoxic phosphorus-uptake lag phase was not observed in the subsequent anaerobic–aerobic cycle. These results demonstrate that the PAOs that dominated the anaerobic–aerobic SBR biomass were the same organisms as the DPAOs enriched under anaerobic–anoxic conditions. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 140–148, 2003. [ABSTRACT FROM AUTHOR]