Blog
About

0
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      New concepts of microbial treatment processes for the nitrogen removal: effect of protein and amino acids degradation

      , ,

      Amino Acids

      Springer Nature

      Read this article at

      ScienceOpenPublisher
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Related collections

          Most cited references 33

          • Record: found
          • Abstract: found
          • Article: not found

          A Nitrospira metagenome illuminates the physiology and evolution of globally important nitrite-oxidizing bacteria.

          Nitrospira are barely studied and mostly uncultured nitrite-oxidizing bacteria, which are, according to molecular data, among the most diverse and widespread nitrifiers in natural ecosystems and biological wastewater treatment. Here, environmental genomics was used to reconstruct the complete genome of "Candidatus Nitrospira defluvii" from an activated sludge enrichment culture. On the basis of this first-deciphered Nitrospira genome and of experimental data, we show that Ca. N. defluvii differs dramatically from other known nitrite oxidizers in the key enzyme nitrite oxidoreductase (NXR), in the composition of the respiratory chain, and in the pathway used for autotrophic carbon fixation, suggesting multiple independent evolution of chemolithoautotrophic nitrite oxidation. Adaptations of Ca. N. defluvii to substrate-limited conditions include an unusual periplasmic NXR, which is constitutively expressed, and pathways for the transport, oxidation, and assimilation of simple organic compounds that allow a mixotrophic lifestyle. The reverse tricarboxylic acid cycle as the pathway for CO2 fixation and the lack of most classical defense mechanisms against oxidative stress suggest that Nitrospira evolved from microaerophilic or even anaerobic ancestors. Unexpectedly, comparative genomic analyses indicate functionally significant lateral gene-transfer events between the genus Nitrospira and anaerobic ammonium-oxidizing planctomycetes, which share highly similar forms of NXR and other proteins reflecting that two key processes of the nitrogen cycle are evolutionarily connected.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Microbial nitrate respiration--genes, enzymes and environmental distribution.

            Nitrate is a key node in the network of the assimilatory and respiratory nitrogen pathways. As one of the 'fixed' forms of nitrogen, nitrate plays an essential role in both nature and industry. For bacteria, it is both a nitrogen source and an electron acceptor. In agriculture and wastewater treatment, nitrate respiration by microorganisms is an important issue with respect to economics, greenhouse gas emission and public health. Several microbial processes compete for nitrate: denitrification, dissimilatory nitrate reduction to ammonium and anaerobic ammonium oxidation. In this review we provide an up to date overview of the organisms, genes and enzymes involved in nitrate respiration. We also address the molecular detection of these processes in nature. We show that despite rapid progress in the experimental and genomic analyses of pure cultures, knowledge on the mechanism of nitrate reduction in natural ecosystems is still largely lacking. Copyright © 2011 Elsevier B.V. All rights reserved.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Pretreatment methods to improve sludge anaerobic degradability: a review.

              This paper presents a review of the main sludge treatment techniques used as a pretreatment to anaerobic digestion. These processes include biological (largely thermal phased anaerobic), thermal hydrolysis, mechanical (such as ultrasound, high pressure and lysis), chemical with oxidation (mainly ozonation), and alkali treatments. The first three are the most widespread. Emphasis is put on their impact on the resulting sludge properties, on the potential biogas (renewable energy) production and on their application at industrial scale. Thermal biological provides a moderate performance increase over mesophilic digestion, with moderate energetic input. Mechanical treatment methods are comparable, and provide moderate performance improvements with moderate electrical input. Thermal hydrolysis provides substantial performance increases, with a substantial consumption of thermal energy. It is likely that low impact pretreatment methods such as mechanical and thermal phased improve speed of degradation, while high impact methods such as thermal hydrolysis or oxidation improve both speed and extent of degradation. While increased nutrient release can be a substantial cost in enhanced sludge destruction, it also offers opportunities to recover nutrients from a concentrated water stream as mineral fertiliser. Copyright © 2010 Elsevier B.V. All rights reserved.
                Bookmark

                Author and article information

                Journal
                Amino Acids
                Amino Acids
                Springer Nature
                0939-4451
                1438-2199
                May 2016
                February 8 2016
                May 2016
                : 48
                : 5
                : 1123-1130
                10.1007/s00726-016-2185-4
                © 2016

                http://www.springer.com/tdm

                Comments

                Comment on this article