Insight into the rapid biogranulation for suspended single-cell microalgae harvesting in wastewater treatment systems: Focus on the role of extracellular polymeric substances

2019 ◽

Vol 374 (1786) ◽

pp. 20190083 ◽

Cited By ~ 5

Author(s):

Marta Sebastián ◽

Josep M. Gasol

Keyword(s):

Single Cell ◽

Metabolic Activity ◽

Cell Activity ◽

Level Of Activity ◽

Single Cell Activity ◽

Recent Developments ◽

Insight Into ◽

Do So

Recent developments in community and single-cell genomic approaches have provided an unprecedented amount of information on the ecology of microbes in the aquatic environment. However, linkages between each specific microbe's identity and their in situ level of activity (be it growth, division or just metabolic activity) are much more scarce. The ultimate goal of marine microbial ecology is to understand how the environment determines the types of different microbes in nature, their function, morphology and cell-to-cell interactions and to do so we should gather three levels of information, the genomic (including identity), the functional (activity or growth), and the morphological, and for as many individual cells as possible. We present a brief overview of methodologies applied to address single-cell activity in marine prokaryotes, together with a discussion of the difficulties in identifying and categorizing activity and growth. We then provide and discuss some examples showing how visualization has been pivotal for challenging established paradigms and for understanding the role of microbes in the environment, unveiling processes and interactions that otherwise would have been overlooked. We conclude by stating that more effort should be directed towards integrating visualization in future approaches if we want to gain a comprehensive insight into how microbes contribute to the functioning of ecosystems. This article is part of a discussion meeting issue ‘Single cell ecology’.

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Involvement of Crawling and Attached Ciliates in the Aggregation of Particles in Wastewater Treatment Plants

Air Soil and Water Research ◽

10.4137/aswr.s752 ◽

2008 ◽

Vol 1 ◽

pp. ASWR.S752 ◽

Cited By ~ 4

Author(s):

Lucía Arregui ◽

María Linares ◽

Blanca Pέrez-Uz ◽

Almudena Guinea ◽

Susana Serrano

Keyword(s):

Wastewater Treatment ◽

Extracellular Polymeric Substances ◽

Wastewater Treatment Plants ◽

Biological Activities ◽

Feeding Strategies ◽

Complex Matrix ◽

Active Secretion ◽

Latex Beads ◽

The Matrix

The biological community in activated sludge wastewater plants is organized within this ecosystem as bioaggregates or flocs, in which the biotic component is embedded in a complex matrix comprised of extracellular polymeric substances mainly of microbial origin. The aim of this work is to study the role of different floc-associated ciliates commonly reported in wastewater treatment plants-crawling Euplotes and sessile Vorticella- in the formation of aggregates. Flocs, in experiments with ciliates and latex beads, showed more compactation and cohesion among particles than those in the absence of ciliates. Ciliates have been shown to contribute to floc formation through different mechanisms such as the active secretion of polymeric substances (extrusomes), their biological activities (movement and feeding strategies), or the cysts formation capacity of some species. Staining with lectins coupled to fluorescein showed that carbohydrate of the matrix contained glucose, manose, N-acetyl-glucosamine and galactose. Protein fraction revealed over the latex beads surfaces could probably be of bacterial origin, but nucleic acids represented an important fraction of the extracellular polymeric substances of ciliate origin.

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