Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis

Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems.

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Microbial Community Composition Affects Soil Fungistasis

Applied and Environmental Microbiology ◽

10.1128/aem.69.2.835-844.2003 ◽

2003 ◽

Vol 69 (2) ◽

pp. 835-844 ◽

Cited By ~ 99

Author(s):

Wietse de Boer ◽

Patrick Verheggen ◽

Paulien J. A. Klein Gunnewiek ◽

George A. Kowalchuk ◽

Johannes A. van Veen

Keyword(s):

Microbial Community ◽

Community Composition ◽

Bacterial Community Composition ◽

Microbial Community Composition ◽

Fusarium Culmorum ◽

Community Analysis ◽

Microbial Community Analysis ◽

Carbon Limitation ◽

Soil Fungistasis

ABSTRACT Most soils inhibit fungal germination and growth to a certain extent, a phenomenon known as soil fungistasis. Previous observations have implicated microorganisms as the causal agents of fungistasis, with their action mediated either by available carbon limitation (nutrient deprivation hypothesis) or production of antifungal compounds (antibiosis hypothesis). To obtain evidence for either of these hypotheses, we measured soil respiration and microbial numbers (as indicators of nutrient stress) and bacterial community composition (as an indicator of potential differences in the composition of antifungal components) during the development of fungistasis. This was done for two fungistatic dune soils in which fungistasis was initially fully or partly relieved by partial sterilization treatment or nutrient addition. Fungistasis development was measured as restriction of the ability of the fungi Chaetomium globosum, Fusarium culmorum, Fusarium oxysporum, and Trichoderma harzianum to colonize soils. Fungistasis did not always reappear after soil treatments despite intense competition for carbon, suggesting that microbial community composition is important in the development of fungistasis. Both microbial community analysis and in vitro antagonism tests indicated that the presence of pseudomonads might be essential for the development of fungistasis. Overall, the results lend support to the antibiosis hypothesis.

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Rapid Method for Coextraction of DNA and RNA from Natural Environments for Analysis of Ribosomal DNA- and rRNA-Based Microbial Community Composition

Applied and Environmental Microbiology ◽

10.1128/aem.66.12.5488-5491.2000 ◽

2000 ◽

Vol 66 (12) ◽

pp. 5488-5491 ◽

Cited By ~ 1051

Author(s):

Robert I. Griffiths ◽

Andrew S. Whiteley ◽

Anthony G. O'Donnell ◽

Mark J. Bailey

Keyword(s):

Microbial Community ◽

Ribosomal Dna ◽

Denaturing Gradient Gel Electrophoresis ◽

Microbial Community Composition ◽

Pcr Amplification ◽

Community Analysis ◽

Microbial Community Analysis ◽

Natural Environments ◽

Dna And Rna ◽

Gradient Gel Electrophoresis

ABSTRACT A rapid protocol for the extraction of total nucleic acids from environmental samples is described. The method facilitates concomitant assessment of microbial 16S rRNA diversity by PCR and reverse transcription-PCR amplification from a single extraction. Denaturing gradient gel electrophoresis microbial community analysis differentiated the active component (rRNA derived) from the total bacterial diversity (ribosomal DNA derived) down the horizons of an established grassland soil.

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Effect of Start-Up Strategies and Electrode Materials on Carbon Dioxide Reduction on Biocathodes

Applied and Environmental Microbiology ◽

10.1128/aem.02242-17 ◽

2017 ◽

Vol 84 (4) ◽

Cited By ~ 7

Author(s):

Soroush Saheb-Alam ◽

Abhijeet Singh ◽

Malte Hermansson ◽

Frank Persson ◽

Anna Schnürer ◽

...

Keyword(s):

Microbial Community ◽

Electrode Materials ◽

Microbial Community Composition ◽

Community Analysis ◽

Microbial Community Analysis ◽

Cathodic Current ◽

Content Type ◽

Term Operation ◽

Start Up

ABSTRACT The enrichment of CO 2 -reducing microbial biocathodes is challenging. Previous research has shown that a promising approach could be to first enrich bioanodes and then lower the potential so the electrodes are converted into biocathodes. However, the effect of such a transition on the microbial community on the electrode has not been studied. The goal of this study was thus to compare the start-up of biocathodes from preenriched anodes with direct start-up from bare electrodes and to investigate changes in microbial community composition. The effect of three electrode materials on the long-term performance of the biocathodes was also investigated. In this study, preenrichment of acetate-oxidizing bioanodes did not facilitate the start-up of biocathodes. It took about 170 days for the preenriched electrodes to generate substantial cathodic current, compared to 83 days for the bare electrodes. Graphite foil and carbon felt cathodes produced higher current at the beginning of the experiment than did graphite rods. However, all electrodes produced similar current densities at the end of the over 1-year-long study (2.5 A/m 2 ). Methane was the only product detected during operation of the biocathodes. Acetate was the only product detected after inhibition of the methanogens. Microbial community analysis showed that Geobacter sp. dominated the bioanodes. On the biocathodes, the Geobacter sp. was succeeded by Methanobacterium spp., which made up more than 80% of the population. After inhibition of the methanogens, Acetobacterium sp. became dominant on the electrodes (40% relative abundance). The results suggested that bioelectrochemically generated H 2 acted as an electron donor for CO 2 reduction. IMPORTANCE In microbial electrochemical systems, living microorganisms function as catalysts for reactions on the anode and/or the cathode. There is a variety of potential applications, ranging from wastewater treatment and biogas generation to production of chemicals. Systems with biocathodes could be used to reduce CO 2 to methane, acetate, or other high-value chemicals. The technique can be used to convert solar energy to chemicals. However, enriching biocathodes that are capable of CO 2 reduction is more difficult and less studied than enriching bioanodes. The effect of different start-up strategies and electrode materials on the microbial communities that are enriched on biocathodes has not been studied. The purpose of this study was to investigate two different start-up strategies and three different electrode materials for start-up and long-term operation of biocathodes capable of reducing CO 2 to valuable biochemicals.

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