Print Email Facebook Twitter Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor Title Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor Author Bagchi, Samik (King Abdullah University of Science and Technology) Lamendella, Regina (Juniata College) Strutt, Steven (University of California) van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology) Saikaly, Pascal E. (King Abdullah University of Science and Technology) Date 2016-06-20 Abstract Granules enriched with anammox bacteria are essential in enhancing the treatment of ammonia-rich wastewater, but little is known about how anammox bacteria grow and multiply inside granules. Here, we combined metatranscriptomics, quantitative PCR and 16S rRNA gene sequencing to study the changes in community composition, metabolic gene content and gene expression in a granular anammox reactor with the objective of understanding the molecular mechanism of anammox growth and multiplication that led to formation of large granules. Size distribution analysis revealed the spatial distribution of granules in which large granules having higher abundance of anammox bacteria (genus Brocadia) dominated the bottom biomass. Metatranscriptomics analysis detected all the essential transcripts for anammox metabolism. During the later stage of reactor operation, higher expression of ammonia and nitrite transport proteins and key metabolic enzymes mainly in the bottom large granules facilitated anammox bacteria activity. The high activity resulted in higher growth and multiplication of anammox bacteria and expanded the size of the granules. This conceptual model for large granule formation proposed here may assist in the future design of anammox processes for mainstream wastewater treatment. Subject Microbial ecologyWater microbiology To reference this document use: http://resolver.tudelft.nl/uuid:ed48b6c4-f48f-49e4-b6e8-0bc5447527a3 DOI https://doi.org/10.1038/srep28327 ISSN 2045-2322 Source Scientific Reports, 6 Part of collection Institutional Repository Document type journal article Rights © 2016 Samik Bagchi, Regina Lamendella, Steven Strutt, Mark C.M. van Loosdrecht, Pascal E. Saikaly Files PDF srep28327.pdf 1.14 MB Close viewer /islandora/object/uuid:ed48b6c4-f48f-49e4-b6e8-0bc5447527a3/datastream/OBJ/view