Topics: Biotechnology and industrial microbiology ... - Lirias@Lessius

callousparliamentBiotechnology

Feb 12, 2013 (4 years and 8 months ago)

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T
opics:

Biotechnology and industrial microbiology

(of f
ood microbiology
)


Molecular characterization of the microflora during malting

to enhance malt quality
and processability

Justé
1
,

A., Malfliet
2
,

S.,
Lenaerts
1
, M.,
De Cooman
2
, L.,
Aerts
2
,

G., Willems
1
,

K
. A
. and
Lievens
1
,

B.


1
Laboratory for Process Microbial Ecology and Bioinspirational Management, Consortium
for Industrial Microbiology and Biotechnology (CIMB), Lessius
Mechelen,
Department of
Microbial and Molecular Systems,

KULeuven Association, 2860 Sint
-
Katelijne
-
Waver,
Belgiu
m

2
Laboratory
of Enzyme, Fermentation and Brewing Technology,

Consortium for Industrial
Microbiology and Biotechnology (CIMB),
KaHo Sint
-
Lieven
,
Department of Microbial and
Molecular Systems,

KULeuven

Association,
9000 Ghent
, Belgium.


Background

-

Optimization of malt quality in
regard to a better lautering performance

is a
critical factor in the malting and brewing industry. Since malt quality is inversely related to
the concentration of endosperm cell wall components

such as

arabinoxylans,
management of
cell wall degrading microorganisms may result in enhanced process
ing. An essential step in
microflora management

during malting

requires the understanding of the microbial
community structure as well as the population dynamics in the processing.


Objectives


The objective of this study was to characterize the microbia
l (bacterial)
communities in different industrial malting settings

and relate these
to malt quality

and
processability
.


Methods and Conclusions

-

B
oth culture dependent and culture independent molecular
techniques
we
re used to characterize the
bacterial

c
ommunities in different industrial malting
settings, generating malt of different quality. 16S ribosomal DNA
-
targeted Terminal
Restriction Fragment Length Polymorphism (T
-
RFLP) analysis, supported by
sequencing of
clone libraries, we
re used to screen and c
ompare the microbial communities at different stages
of the malting process, i.e. from barley up to kilned malt. In addition, emphasis
i
s put on the
xylanase producing microflora
. Apart from isolation and identification, the diversity of the
xylanase genes

was explored using two sets of degenerate primers amplifying xylanase genes
from the g
lycosyl hydrolase (GH) family 10 and 11.

Specific patterns associated with high
-
quality malt will be further investigated, aiming at obtaining cultures responsible for
the malt
quality. Ultimately, this study may result in the discovery of promising, process
-
borne
microorganisms which may enhance malt processability, or the malting and brewing process
in general, such as the improvement of the filtration step.

The result
s obtained in this study
will be presented
in the poster
.