Data/hora: 12/06/2024 09:30:29

Biblioteca(s): 	Embrapa Florestas.	
Data corrente: 	15/09/2008	
Data da última atualização: 	15/09/2008	
Autoria: 	GÓMEZ-BRANDÓN, M.; AIRA, M.; LAZCANO, C.; LORES, M.; DOMÍNGUEZ, J.	
Título: 	Effects of earthworms on the structure and physiological capabilities of the microbial community during vermicomposting of pig manure.	
Ano de publicação: 	2008	
Fonte/Imprenta: 	In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.	
Idioma: 	Inglês	
Conteúdo: 	Vermicomposting is the biooxidation and stabilization of organic matter involving the joint action
of earthworms and microorganisms. Although earthworms are the main drivers of the process,
the composition and activity of the microbial populations are responsible for the biochemical
degradation of the organic matter, largely determining the turnover processes. Therefore, the
characterization of microorganisms would clearly improve the understanding and development
of this process. In this study, we focused on how earthworms modified the structure and activity
of the microbial community during the vermicomposting of pig manure. We also determined if
these modifications affect the functional diversity of microbial populations through the communitylevel
physiological profiles. We analyzed the phospholipid fatty acid (PLFAs) profiles to
characterize and quantify the composition of the microbial community; the microbial biomass
carbon and the respiration rate to give an estimation of the total microbial biomass and its
activity, respectively; and the substrate utilization patterns (Biolog Ecoplate) to determine the
functional diversity of the microbial community. We set up a batch of six vermireactors, three
without earthworms (control) and three containing 500 mature specimens of Eisenia fetida each.
Vermireactors were initially composed of one module containing vermicompost, in which
earthworms were placed, and another module containing a layer of fresh pig slurry (1.5 kg fresh
weight). New modules containing the same amount of fresh pig slurry were added when required;
this procedure allowed us to date the addition of each module within vermireactors. At the end
of the experiment, the vermireactors comprised 12 modules with an increasing gradient of age,
resembling a soil profile, from upper to lower layers as follows: 2, 4, 7, 8, 11, 18, 21, 25, 27, 29,
33 and 36 weeks. Total microbial biomass and its activity were clearly enhanced in vermireactors
with earthworms, and in particular in the upper layers, which contain the highest density of
earthworms. Fungal biomass, estimated by the ergosterol content, was also stimulated in
vermireactors with earthworms and the highest biomass was observed in the upper layers.
Using PLFAs as biomarkers, we found that Gram-positive and ?negative bacteria were greatly
higher in vermireactors without earthworms, and in particular in the upper layers. In both types of
vermireactors, the abundance of bacteria was lower than in the initial pig slurry. Fungi were also
reduced depending on the age of the layers in the vermireactors both with and without earthworms,
but they were not affected by the presence of earthworms. Cluster analysis of the data from
Biolog Ecoplate revealed that the presence of earthworms and the age of layers modified the
functional diversity of the microbial community of pig slurry.Our results provide a better knowledge
of the modifications in the microbial community structure in a vermicomposting system, as well
as permitted us to determine the ability of the different approaches to describe these changes	
Categoria do assunto: 	--	
Registro original: 	Embrapa Florestas (CNPF)	
Exemplares: 	CNPF - (43550-1) - UPE - PL - -- - CD0305 -  -  - DIS