Changes in the microbial communities during co-composting of digestates.
Anaerobic digestion is a waste treatment method which is of increasing interest worldwide. At the end of the process, a digestate remains, which can gain added value by being composted. A study was conducted in order to investigate microbial community dynamics during the composting process of a mixture of anaerobic digestate (derived from the anaerobic digestion of municipal food waste), green wastes and a screened compost (green waste/kitchen waste compost), using the COMPOCHIP microarray. The composting process showed a typical temperature development, and the highest degradation rates occurred during the first 14 days of composting, as seen from the elevated CO2 content in the exhaust air. With an exception of elevated nitrite and nitrate levels in the day 34 samples, physical-chemical parameters for all compost samples collected during the 63 day process indicated typical composting conditions. The microbial communities changed over the 63 days of composting. According to principal component analysis of the COMPOCHIP microarray results, compost samples from the start of the experiment were found to cluster most closely with the digestate and screened compost samples. The green waste samples were found to group separately. All starting materials investigated were found to yield fewer and lower signals when compared to the samples collected during the composting experiment.
University of Innsbruck, Institute of Microbiology, Technikerstraße 25, 6020 Innsbruck, Austria. Electronic address: ingrid.whittle@uibk.ac.at.
Ingrid H
IH
Franke-Whittle
Scuola Agraria del Parco di Monza,Viale Cavriga 3, 20900 Monza, Italy. Electronic address: a.confalonieri@monzaflora.it.
Alberto
A
Confalonieri
University of Innsbruck, Institute of Microbiology, Technikerstraße 25, 6020 Innsbruck, Austria.
Heribert
H
Insam
Hamburg University of Technology, Bioconversion and Emission Control Group, Eissendorfer Str. 42, 21073 Hamburg, Germany. Electronic address: Mirko.Schlegelmilch@tig-group.com.
Mirko
M
Schlegelmilch
Hamburg University of Technology, Bioconversion and Emission Control Group, Eissendorfer Str. 42, 21073 Hamburg, Germany. Electronic address: i.koerner@tuhh.de.
Ina
I
Körner
D001419:Bacteria / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012037:Refuse Disposal; D012988:Soil Microbiology; D062611:Solid Waste / Q000032:analysis*; D013997:Time Factors
D004269:DNA, Bacterial; D062611:Solid Waste
Anaerobic digestion; COMPOCHIP; Composting; Microarray; Nitrogen compounds