Microbial characteristics of nitrifiers, denitrifiers and anammox bacteria on different support media to treat space mission wastewater.

Biomass attachment and growth are important factors for the startup and stability of fixed-film biological reactors being proposed to recycle wastewater for potable water use in manned space activity. Eight different biofilm support media commonly used in wastewater treatment plants, aquaculture, and aquariums were compared for their relative ability to support attachment and growth of nitrifiers, denitrifiers, and anaerobic ammonia oxidizing (anammox) bacteria biomass. Accumulated total biomass was determined by comparing dry weight of each media before and after culturing of biomass. Fluorescence In-Situ Hybridization (FISH) analysis was used to quantify the proportion and relative activity of each organism group on each media. Measurements of dry biomass normalized to several media properties showed polyether polyurethane foam to have the highest extent of specific biomass attachment and colonization. Six of the eight media were able to sustain a population of anammox bacteria that was more abundant than the other cohorts.

Bacteriophages in wastewater treatment: can they be an approach to optimize biological treatment processes?

In this paper, we explore the applications of bacteriophages and the advantages of using these viruses to control undesirable organisms in wastewater treatment plants. Based on this, this paper reviewed the literature on the subject by performing a bibliometric and scientometric analysis of articles published in peer-reviewed journals through 2021. We obtained 806 publications, of which 40% were published in the last 5 years, demonstrating an increase in interest in the subject. These articles analyzed, bacteriophages in treatment plants were strongly linked to bacteria such as Escherichia coli and related to disinfection, inactivation, sewage, and wastewater, in addition, biocontrol studies have gained prominence in recent years, particularly due to the resistance of microorganisms to antibiotics. Studies have shown that bacteriophages have great potential for application in treatment systems to control unwanted processes and act as valuable economic and environmental tools to improve the efficiency of various treatment technologies. Although these viruses have already been studied in various applications to optimize treatment plant processes, technology transfer remains a challenge due to the limitations of the technique-such as physicochemical factors related to the environment-and the complexity of biological systems. The research focusing on application strategies in conjunction with molecular biology techniques can expand this study area, enabling the discovery of new bacteriophages.

Key enzymes involved in anammox-based processes for wastewater treatment: An applied overview.

The anaerobic ammonium oxidation (anammox) process has attracted significant attention as an economic, robustness, and sustainable method for the treatment of nitrogen (N)-rich wastewater. Anammox bacteria (AnAOB) coexist with other microorganisms, and particularly with ammonia-oxidizing bacteria (AOB) and/or heterotrophic bacteria (HB), in symbiosis in favor of the substrate requirement (ammonium and nitrite) of the AnAOB being supplied by these other organisms. The dynamics of these microbial communities have a significant effect on the N-removal performance, but the corresponding metabolic pathways are still not fully understood. These processes involve many common metabolites that may act as key factors to control the symbiotic interactions between these organisms, to maximize N-removal efficiency from wastewater. Therefore, this work overviews the current state of knowledge about the metabolism of these microorganisms including key enzymes and intermediate metabolites and summarizes already reported experiences based on the employment of certain metabolites for the improvement of N-removal using anammox-based processes. PRACTITIONER POINTS: Approaches knowledge about the biochemistry and metabolic pathways involved in anammox-based processes. Some molecular tools can be used to determine enzymatic activity, serving as an optimization in nitrogen removal processes. Enzymatic evaluation allied to the physical-chemical and biomolecular analysis of the nitrogen removal processes expands the application in different effluents.