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World Journal of Microbiology and Biotechnology (2018) 34:84
https://doi.org/10.1007/s11274-018-2468-x
ORIGINAL PAPER
Endoglucanase activity in Neoteredo reynei (Bivalvia, Teredinidae)
digestive organs and its content
Daniela Toma de Moraes Akamine
1
· Daniel de Almeida Cozendey da Silva
1
· Gabriela de Lima Câmara
1
·
Thayane Vieira Carvalho
1
· Michel Brienzo
2
Received: 27 May 2017 / Accepted: 31 May 2018 / Published online: 1 June 2018
© Springer Science+Business Media B.V., part of Springer Nature 2018
Abstract
Cellulolytic enzymes have been studied in several organisms, such as insects, molluscs and other organisms, which can
have enzymes endogenously produced or by symbiotic microorganisms. These enzymes are responsible for breaking down
the cellulosic material upon which these organisms feed, probably with the aim of assimilating the sugars and nutrients.
As Teredinidae bivalves grown in mangrove trees, this study aimed to measure endo-β-1,4-glucanase activity in different
organs and its content. Endo-β-1,4-glucanase activity was detected in different organs of the Teredinidae bivalves, includ-
ing gills and digestive organs tissues and its content. Moreover, organisms such as teredinids grow up inside wood and this
process could perhaps be related to creating growth space. All the endoglucanase extracts, from organs tissues and contents,
showed maximum activity at 40 °C. The maximum activity was observed at pH 5.5 for all the extracts, except for intestine
tissue, which maximum was at pH 6. Moreover, some of the extracts showed a different profile of the activity as a pH influ-
ence, suggesting different distribution of enzymes over the digestive system of the teredinids. The results suggested that the
endo-β-1,4-glucanase from Teredinidae could be applied in process that requires low temperature, such as, simultaneous
saccharification and fermentation, since it presents lower optimum temperature in comparison to enzymes from terrestrial
microorganisms.
Keywords Teredinidae · Cellulases · Wood digestion · Endo-β-1,4-glucanase · Optimum activity
Introduction
The Teredinidae family is a specialized bivalve, which bore
and digest the wood to live inside trunks. Most of them are
marine tropical molluscs found around the world, mainly
in shallow environments. The digestion of wood in the
shipworms, as they are commonly known, begins when the
shell scrapes the wood, generating small particles that go
into the mouth, pass through the esophagus and reach the
stomach. In some teredinid species, there is only one part
of the stomach, which is circular (Lopes et al. 2000). In
others, the stomach is divided into three parts, one circular
and other two elongated (Lopes and Narchi 1998). In the
stomach, wood particles receive the enzymes from the diges-
tive glands, whose ducts deflate into these organs. From the
stomach, the material (wood particles) goes to the appendix,
and it can stay there for a long time. From the appendix, it
returns to the stomach and is conducted to the intestine. The
material passes throughout the intestine length and flows
into the anal canal. In some species, such as the Neoteredo
reynei, the anal canal is closed by a valve and the wood
particles remain in this organ for a long time while they go
through the whole length of the organ. Finally, the material
is ejected as feces, through an exhalant siphon, into the envi-
ronment. A detailed illustrated anatomy of the N. reynei has
been published elsewhere (Lopes et al. 2000). The material
would be digested during its journey across the digestive
system, however the digestion of wood in the appendix and
anal canal was not found in some organisms, such as N.
reynei (Lopes et al. 2000).
* Michel Brienzo
michel.brienzo@unesp.br
1
Laboratory of Biotechnology (Labio), Metrology Applied
to Life Science Division - National Institute of Metrology,
Quality and Technology (Inmetro), Duque de Caxias, RJ,
Brazil
2
Bioenergy Research Institute (IPBEN), Universidade
Estadual Paulista (UNESP), Rio Claro, SP, Brazil
@Phil_Robichaud
@deepthiw
@JoseServera