Fast DNA-analyses for surveillance of microbial communities in full-scale deammonification tanks: Potential for control and troubleshooting.

The partial nitritation/anammox process is a popular process for sidestream nitrogen removal, but the process is sensitive to disturbances and requires extensive surveillance and monitoring for optimal performance. We followed two parallel sidestream full-scale deammonification reactors treating digester centrate for a year with high time-resolution of both online sensor data and microbial community as measured by Nanopore DNA sequencing. DNA surveillance revealed system disturbances and allowed for detection of process and equipment upsets, and it facilitated remediating operational actions. Surveillance of anammox bacteria (Ca. Brocadia) revealed unexpected variations, and the composition and dynamics of the flanking community indicated causes for occasional process disturbances with poor nitrogen removal. Monitoring the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) could potentially allow reactor operation with increased dissolved oxygen (DO), yielding higher ammonia conversion while keeping NOB in control. The use of fast and frequent DNA sequencing (sampling 3-5 times a week, analysed once per week) was an important supplement, and in many cases superior, to the online sensor data for process surveillance, understanding and control.

Comparison of pre- and inter-stage aerobic treatment of wastewater sludge: Effects on biogas production and COD removal.

The aim of this study was to investigate thermophilic (55°C) aerobic digestion (TAD) as pre- and inter-stage treatment of sludge anaerobic digestion and to analyse the change in organic matter accessibility and complexity. Pre-treatment decreased methane yield (up to -70%), due to oxidation losses whereas inter-stage treatment slightly improved overall methane yield (+2.6%) and total COD removal (+5%) compared to control. Anaerobic degradability and COD removal in the second anaerobic stage significantly increased, by 13-40%. Organic matter fractionation showed that TAD led to an increase in sludge organic matter accessibility in all cases. Organic matter complexity, measured by fluorimetry, increased after TAD pre-treatment whereas it remained constant after inter-stage treatment. TAD was shown to be more efficient if applied to a more recalcitrant substrate and should thus be used as inter-stage treatment to avoid decreasing methane production.

Identification of protein components from the mature ovary of the sea urchin Evechinus chloroticus (Echinodermata: Echinoidea).

The gonads of sea urchins are a high value seafood product, with considerable research being undertaken worldwide on the development of sea urchin aquaculture. As the best prices are obtained for specific gonad attributes, research has also focused on the development of artificial diets that enhance gonad quality and quantity. Total protein has been used as a measure of gonad quality; yet no studies to date have applied proteomics technology to diet development. Here we use a MudPIT and 2-DE approach to describe the major proteins in mature ovaries of a New Zealand sea urchin Evechinus chloroticus. This tissue, which is a target seafood product, contained 138 proteins that were identified from the recently completed sea urchin genome (Strongylocentrotus purpuratus) with high confidence. The majority of these proteins had general functions, with only 12 related to ovarian reproductive function. Eighteen proteins were located on the 2-DE; four of these were directly identified from S. purpuratus protein sequences. In combination this paper shows that the genome resources of S. purpuratus can be used to identify proteins in sea urchins from different families; describes the proteome of E. chloroticus mature ovary; and, provides proteomic tools for analysis of gonads from other edible sea urchins.

Proteomic analysis of the venom of Heterometrus longimanus (Asian black scorpion).

Venoms have evolved over millions of years into potent cocktails of bioactive peptides and proteins. These compounds can be of great value to the pharmaceutical industry for numerous clinical applications. In this study, a novel proteomic - bioinformatic approach was utilised, where chromatography followed by gel electrophoresis was utilised to separate the venom peptides/proteins of Heterometrus longimanus (Asian black scorpion). Purified peptides were analysed by tandem mass spectrometry, de novo sequenced and then homology matched against known peptides in the Swiss-Prot protein database. Numerous potentially biologically active peptide matches were discovered, and a simple scoring system applied to putatively assign functions to the peptides. As a validation of this approach, the functional composition of the experimentally derived proteome is similar to that of other scorpions, and contains a potent mix of toxins, antimicrobials and ionic channel inhibitors.