Data/hora: 02/06/2024 16:40:49

Biblioteca(s): 	Embrapa Florestas.	
Data corrente: 	16/09/2008	
Data da última atualização: 	16/09/2008	
Autoria: 	GÓMEZ-BRANDÓN, M.; LAZCANO, C.; LORES, M.; BAATH, E.; DOMÍNGUEZ, J.	
Título: 	Effects of earthworms on the microbial community structure and activity during vermicomposting.	
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 involves the biooxidation and stabilization of organic matter through the joint
action of earthworms and microorganisms. The rapid transformations in the physicochemical
and biochemical properties of the organic matter make vermicomposting a suitable system for
studying microbe-earthworm interactions. In this study, we focused on how three epigeic
earthworm species modified the structure and activity of the microbial community during the
vermicomposting process of three animal manures. We analyzed the phospholipid fatty acid
(PLFAs) profiles to characterize and quantify the composition of the microbial community; the
respiration rate to give an estimation of the total microbial activity; and the instantaneous growth
rates of bacteria and fungi to estimate the activity of each microbial group separately. We
performed a two-factor experiment in plastic containers (2L) with each combination of manure
(cattle, horse and rabbit) and earthworm species (Eisenia andrei, Eisenia fetida, and Perionyx
excavatus) in triplicate (n=27). We selected these species due to their suitability for use in
vermicomposting. Each animal manure (c.a. 200 g, fresh weight) was placed into the container
and inoculated with 10 earthworms. Other containers remained without earthworms and served
as controls (n=9). All the containers were maintained at 20 ºC and 90% relative humidity in a
scientific incubator and after one month, control and vermicompost samples were collected to
analyze. Since earthworm species used in this study are epigeic, with rapid gut transit times, all
the manures were completely processed at the end of the experiment (one month). Earthworm
species affected differently the total microbial activity and this effect was dependent on the type
of manure. Compared to the control, the activity of E. andrei and E. fetida decreased the
respiration rate of cattle and horse manures, whereas in the presence of P. excavatus the
respiration rate of both manures did not differ from the control. In rabbit manure, there were no
significant differences between control and vermicompost samples. Earthworm species also
affected significantly the bacterial growth rate, and this effect was dependent on the type of
manure. Compared to the control, the bacterial growth rate of cattle and horse manures was
lower in the presence of E. andrei; however, there were no significant differences between the
control and the other two species. In rabbit manure, the three species greatly reduced the bacterial
growth rate with respect to the control. In contrast to bacterial activity, earthworm species did not
affect significantly fungal growth rate. Our results provide a new insight into how earthworms
affect the microbial ecology of the substrates that they inhabit, by quantifying the activity (growth
rate) of each microbial group separately.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Florestas (CNPF)	
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