9.1.2
Artículos completos publicados en revistas
científicas
| 1 |
LeBlanc, J.G., MATAR, C, VALDEZ, JC,
LEBLANC, J, PERDIGON, G Immunomodulating effects of
peptidic fractions issued from milk fermented with
Lactobacillus helveticus. Journal of Dairy Science. ,
v.85, n.11, p.2733 - 2742, 2002.
| Palabras
clave: fermented milk, bioactive peptides, lactic acid
bacteria, immunomodulation |
Referencias
adicionales: Estados Unidos/Inglés. Medio de
divulgación: Impreso; ISSN/ISBN: 00220302.
ABSTRACT
The effect of peptides released during the fermentation
of milk on the humoral immune system and on fibrosarcoma
growth was studied. Lactobacillus helveticus was able to
release peptidic compounds during milk fermentation due
to its high proteolytic activity, as was shown by the
degree of proteolysis and size-exclusion HPLC elution
profiles. Three fractions of these compounds were
separated and fed to mice during different periods (2,
5, and 7 d). The humoral immune response was assessed by
following the number of IgA-secreting cells, and the
antitumor activity was monitored by studying the
regression of subcutaneously implanted fibrosarcomas.
Feeding during 2 and 7 d with the medium-sized fraction
(Fraction II) significantly increased the IgA-producing
cells in the intestines, whereas feeding with the large
compound fraction (Fraction I) during 5 d and the small
compound fraction (Fraction III) during all three
feeding periods provided similar increases. A double
dose of Fraction II showed the highest IgAproducing cell
count. The increase by Fraction III was shown to be
caused by the presence of L-Tryptophan. Fraction II
significantly decreased the size of fibrosarcoma when
previously fed during 7 d, and feeding with Fraction I
during 5 d decreased significantly its size after 35 d
of growth. Although the mechanisms by which lactic acid
bacteria enhance the immune system are not clear, this
study clearly shows that bioactive compounds released in
fermented milks contribute to the immunoenhancing and
antitumor properties of these products. The release of
bioactive peptides by lactic acid bacteria can have
important implications on the modulation of the cellular
immune response.
| |
| 2 |
LeBlanc, J.G., GARRO, M, SAVOY DE
GIORI, G, FONT DE VALDEZ, G A Novel Functional
Soy-Based Food Fermented by Lactic Acid Bacteria. Effect of
Heat Treatment. Journal of Food Science. , v.69, n.8,
p.M246 - M250, 2004.
| Palabras
clave: soymilk, lactic acid bacteria, fermentation,
functional food, immune-modulation
|
Referencias
adicionales: Estados Unidos/Inglés. Medio de
divulgación: Impreso; ISSN/ISBN: 00221147.
ABSTRACT
The development of a novel fermented soymilk product
using selected lactic acid bacteria was performed. The
immunomodulatory properties of strains able to grow in
soymilk were evaluated in a murine model using inbred
BALB/c mice. Lactobacillus acidophilus CRL 43 and CRL
1064 and Lactobacillus paracasei CRL 75 and CRL 208 were
all able to significantly increase the phagocytic index
(41 +/- 4) compared with the control group (16 +/- 3)
when given individually. These strains were then used in
the elaboration of multicultured fermented soymilks that
were able to stimulate an innate immune response
(peritoneal macrophage activation). However, these novel
fermented products sometimes caused undesired secondary
effects such as microbial translocation and animal
weight loss. When the same fermented products were
subjected to heat treatment, they were still able to
stimulate the innate immune response without causing
secondary effects. These results clearly show that it is
not always necessary for lactic acid bacteria to be
alive to exert a beneficial physiological effect. This
study could thus be used as a model in the design and
future evaluation of novel fermented vegetable
products.
| |
| 3 |
LeBlanc, J.G., GARRO, M, SAVOY DE
GIORI, G Effect of pH on Lactobacillus fermentum
growth, raffinose removal, alpha-galactosidase activity and
fermentation products. Applied Microbiology and
Biotechnology. , v.65, n.1, p.119 - 123, 2004.
Referencias
adicionales: Gran Bretaña/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 01757598.
ABSTRACT In this study,
the behaviour of Lactobacillus fermentum CRL 722 and CRL
251 were evaluated under different pH conditions (pH
6.0, 5.5, 5.0, 4.5) and without pH control. Growth was
similar under all conditions assayed except at pH 4.5.
These microorganisms were able to eliminate raffinose, a
nondigestible alpha-oligosaccharide (NDO) found in soy
products, showing a consumption rate of 0.25 g l.1 h.1
(pH 6.0¿5.0). The removal of raffinose was due to the
high alpha-galactosidase (alpha-gal) activities of these
lactic acid bacteria, which was highest at pH 5.5 (5.0
U/ml). The yield of organic acids produced during
raffinose consumption was also highest at this pH. The
results of this study will allow selection of the
optimum growth conditions of L. fermentum with elevated
levels of alpha-gal to be used in the reduction of NDO
in soy products when used as starter cultures.
| |
| 4 |
LeBlanc, J.G., GARRO, M, SILVESTRONI,
A, CONNES, C, PIARD, JC, SESMA, F, SAVOY DE GIORI,
G Reduction of a-Galactooligosaccharides in
Soyamilk by Lactobacillus fermentum CRL 722: In vitro and in
vivo evaluation of fermented soyamilk. Journal of Applied
Microbiology. , v.97, n.4, p.876 - 881, 2004.
| Palabras
clave: alpha-galactosidase, alpha-GOS, flatulence,
lactic acid bacteria, soyamilk
|
Referencias
adicionales: Estados Unidos/Inglés. Medio de
divulgación: Impreso; ISSN/ISBN: 13645072.
ABSTRACT
Aims: Consumption of soya-derived products has been
hampered by the presence of
alpha-galactooligosaccharides (alpha-GOS) because
mammals lack pancreatic alpha-galactosidase (alpha-Gal)
which is necessary for their hydrolysis. These sugars
thus reach the large intestine causing gastrointestinal
disorders in sensitive individuals. The use of lactic
acid bacteria (LAB) expressing alpha-Gal is a promising
solution for the degradation of alpha-GOS in soyamilk.
Methods and Results: The capacity of the LAB
Lactobacillus fermentum CRL 722 to properly degrade
alpha-GOS was studied in vitro using controlled
fermentation conditions and in vivo using a rat model.
Lactobacillus fermentum CRL 722 was able to grow on
commercial soyamilk and completely eliminated stachyose
and raffinose during fermentation because of its high
alpha-Gal activity. Rats fed soyamilk fermented by this
LAB had smaller caecums compared with rats fed
unfermented soyamilk. Conclusions: Soyamilk fermentation
by Lact. fermentum CRL 722 results in the reduction of
alpha-GOS concentrations in soyamilk, thus eliminating
possible undesirable physiological effects normally
associated with its consumption. Significance and Impact
of the Study: Fermentation with Lact. fermentum CRL 722
could prevent gastrointestinal disorders in sensitive
individuals normally associated with the consumption of
soya-based products. This LAB could thus be used in the
elaboration of novel fermented vegetable products which
better suit the digestive capacities of
consumers.
| |
| 5 |
LeBlanc, J.G., SILVESTRONI, A, CONNES, C, PIARD, J.-C,
SESMA, F, SAVOY DE GIORI, G Reduction of
non-digestible oligosaccharides in soymilk using engineered
lactic acid bacteria.. Genetics and molecular research.
, v.3, n.3, p.432 - 440, 2004.
| Palabras
clave: alpha-galactosidase, genetically modified
microorganisms, lactic acid bacteria,
alpha-galactosides, soy |
Referencias
adicionales: Brasil/Inglés. Medio de divulgación:
Internet; ISSN/ISBN: 16765680.
ABSTRACT Human
consumption of soy-derived products has been limited by
the presence of non-digestible oligosaccharides (NDO),
such as the alpha-galactooligosaccharides raffinose and
stachyose. Most mammals, including man, lack pancreatic
alpha-galactosidase (alpha-Gal), which is necessary for
the hydrolysis of these sugars. However, such NDO can be
fermented by gas-producing microorganisms present in the
cecum and large intestine, which in turn can induce
flatulence and other gastrointestinal disorders in
sensitive individuals.The use of microorganisms
expressing alpha-Gal is a promising solution to the
elimination of NDO before they reach the large
intestine. In the present study, lactic acid bacteria
engineered to degrade NDO have been constructed and are
being used as a tool to evaluate this solution. The
alpha-Gal structural genes from Lactobacillus plantarum
ATCC8014 (previously characterized in our laboratory)
and from guar have been cloned and expressed in
Lactococcus lactis. The gene products were directed to
different bacterial compartments to optimize their
possible applications. The á-Gal-producing strains are
being evaluated for their efficiency in degrading
raffinose and stachyose: i) in soymilk fermentation when
used as starters and ii) in situ in the upper
gastrointestinal tract when administered to animals
orally, as probiotic preparations. The expected outcomes
and possible complications of this project are
discussed.
| |
| 6 |
CONNES, C, SILVESTRONI, A, LeBlanc, J.G., JUILLARD, V,
SAVOY DE GIORI, G, SESMA, F, PIARD, JC Towards
probiotic lactic acid bacteria strains to remove
raffinose-type sugars present in soy-derived products.
Lait. , v.84, n.1-2, p.207 - 214, 2004.
| Palabras
clave: lactic acid bacteria, probiotic, soy product,
a-galactoside digestion |
Referencias
adicionales: Francia/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 00237302.
ABSTRACT Lactic acid
bacteria (LAB), that are widely used in food
fermentations and that may survive in the
gastrointestinal tract of consumers, are potent
candidates as vehicles for delivery of biologically
active proteins. To evaluate this potential of LAB, we
focus on the degradation of alpha-galactosides of soy.
These sugars, which are not degraded by the pancreatic
enzymes of humans, are metabolized by gas-producing
bacteria of the large intestine, thus creating
intestinal disorders such as flatulence in sensitive
individuals. In this study, we aim to demonstrate that
á-galactosidase (alpha-Gal) expressing LAB can
efficiently degrade alpha-galactosides: (i) in soy milk
fermentation when they are used as starters; and (ii) in
the small intestine when they are administered orally to
animals as probiotic preparations. To reach these goals,
we characterized the alpha-Gal structural gene of
Lactobacillus plantarum ATCC8014. This gene, as well as
the structural gene for the alpha-Gal from guar were
expressed in Lactococcus lactis so that the enzymes are
located in various bacterial compartments. This allows
us to take into account the environmental constraints
which are specific to each application. Active
alpha-Gals could be produced in L. lactis and resulting
strains will be evaluated both in soy milk fermentations
and in oral administrations in animals. The expected
outcomes of this study are discussed.
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| 7 |
LeBlanc, J.G., BURGESS, C, SESMA, F, SAVOY DE GIORI, G,
VAN SINDEREN, D Ingestion of Milk Fermented by
Genetically Modified Lactococcus lactis Improves the
Riboflavin Status of Deficient Rats. Journal of Dairy
Science. , v.88, n.10, p.3435 - 3442, 2005.
| Palabras
clave: riboflavin, lactic acid bacteria, fermented milk,
genetically modified microorganism
|
Referencias
adicionales: Estados Unidos/Inglés. Medio de
divulgación: Impreso; ISSN/ISBN: 00220302.
ABSTRACT
Riboflavin deficiency is common in many parts of the
world, particularly in developing countries. The use of
riboflavin-producing strains in the production of dairy
products such as fermented milks, yogurts, and cheeses
is feasible and economically attractive because it would
decrease the costs involved during conventional vitamin
fortification and satisfy consumer demands for healthier
foods. The present study was conducted to assess in a
rat bioassay the response of administration of milk
fermented by modified Lactococcus lactis on the
riboflavin status of deficient rats. Rats were fed a
riboflavin-deficient diet during 21 d after which this
same diet was supplemented with milk fermented by
Lactoccus lactis pNZGBAH, a strain that overproduces
riboflavin during fermentation. The novel fermented
product, with increased levels of riboflavin, was able
to eliminate most physiological manifestations of
ariboflavinosis, such as stunted growth, elevated
erythrocyte glutathione reductase activation coefficient
values and hepatomegaly, that were observed using a
riboflavin depletion-repletion model, whereas a product
fermented with a nonriboflavin-producing strain did not
show similar results. A safety assessment of this
modified strain was performed by feeding rodents with
the modified strain daily for 4 wk. This strain caused
no detectable secondary effects. These results pave the
way for analyzing the effect of similar
riboflavin-overproducing lactic acid bacteria in human
trials. The regular consumption of products with
increased levels of riboflavin could help prevent
deficiencies of this essential vitamin.
| |
| 8 |
LeBlanc, J.G., PIARD, JC, SESMA, F, SAVOY DE GIORI,
G Lactobacillus fermentum CRL 722 is able to
deliver active alpha-Galactosidase activity in the small
intestine of rats. Fems Microbiology Letters. , v.248,
n.2, p.177 - 182, 2005.
| Palabras
clave: a-galactosidase, lactic acid bacteria, soymilk,
a-GOS, flatulence, gut |
Referencias
adicionales: Gran Bretaña/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03781097.
ABSTRACT
Alpha-galactooligosaccharides (alpha-GOS) found in
legumes such as soybeans can cause gastrointestinal
disorders since mammals lack alpha-galactosidase
(alpha-Gal) in the small intestine which is necessary
for their hydrolysis. Lactobacillus fermentum CRL 722 is
a lactic acid bacterium (LAB) capable of degrading
alpha-GOS due to its elevated alpha-Gal activity. When
conventional rats were fed live L. fermentum CRL 722 or
cell-free extracts of this strain, a short-lived
alpha-Gal activity was detected in the upper
gastrointestinal tract. The safety of this LAB was also
assessed. L. fermentum CRL 722 could thus be used as a
vehicle to safely confer alpha-Gal in the small
intestine of monogastric animal.
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| 9 |
LeBlanc, J.G., BURGESS, C, SESMA, F,
SAVOY DE GIORI, G, VAN SINDEREN, D Riboflavin
overproducing Lactococcus lactis strains are capable of
improving the riboflavin status in deficient rats. .
British Journal of Nutrition. WALLINGFORD: , v.94, n.2,
p.262 - 267, 2005.
| Palabras
clave: riboflavin, lactic acid bacteria,
ariboflavinosis, genetically modified
microorganism |
Referencias
adicionales: Gran Bretaña/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 00071145.
ABSTRACT Lactococcus
lactis is a commonly used starter strain that can be
converted from a vitamin B2 consumer into a vitamin B2
'factory' by over-expressing its riboflavin biosynthesis
genes. The present study was conducted to assess in a
rat bioassay the response of riboflavin produced by GM
or native lactic acid bacteria (LAB). The
riboflavin-producing strains were able to eliminate most
physiological manifestations of ariboflavinosis such as
stunted growth, elevated erythrocyte glutathione
reductase activation coefficient values and
hepatomegalia that were observed using a riboflavin
depletion-repletion model. Riboflavin status and growth
rates were greatly improved when the depleted rats were
fed with cultures of L. lactis that overproduced this
vitamin whereas the native strain did not show the same
effect. The present study is the first animal trial with
food containing living bacteria that were engineered to
overproduce riboflavin. These results pave the way for
analysing the effect of similar riboflavin-overproducing
LAB in human trials.
| |
| 10 |
LeBlanc, J.G., RUTTEN, GER, BRUINENBERG, PAUL, SESMA,
FERNANDO, SAVOY DE GIORI, GRACIELA, SMID, EDDY A
novel dairy product fermented with Propionibacterium
freudenreichii improves the riboflavin status of deficient
rats. Nutrition. , v.22, p.645 - 651, 2006.
| Palabras
clave: Riboflavin, Propionibacterium freudenreichii,
Yogurt, Lactic acid bacteria, Fermented milk
|
Referencias
adicionales: Estados Unidos/Inglés. Medio de
divulgación: Impreso; ISSN/ISBN: 08999007.
ABSTRACT
Objective: Riboflavin deficiency is common in many parts
of the world, particularly in developing countries. The
use of riboflavin-producing strains in the production of
dairy products such as fermented milk, yogurt, and
cheese is feasible and economically attractive because
it would decrease the costs involved during conventional
vitamin fortification and satisfy consumer demands for
healthier foods. The present study in a rat bioassay
assessed the response of administration of yogurt
containing a riboflavin-producing strain of
Propionibacterium freudenreichii on the riboflavin
status of deficient rats. Methods: Propionibacterium
freudenreichii NIZO B2336 is a spontaneous
roseoflavin-resistant mutant derived from P.
freudenreichii B374 that produces larger amounts of
riboflavin than the parental stain. Rats were fed a
riboflavin-deficient diet for 21 d (depletion period),
after which this same diet was supplemented with
conventional yogurt, yogurt containing the
riboflavin-producing strain (B2336), or the parental
non-producing strain (B374) and fed to animals for 28 d
(repletion period). As controls, rats were fed the same
diet with different concentrations of commercial
riboflavin. Results: The novel fermented product
containing P. freudenreichii B2336, with increased
levels of riboflavin, eliminated most physiologic
manifestations of ariboflavinosis such as stunted
growth, high erythrocyte glutathione reductase
activation coefficient values, and hepatomegaly that
were observed when using a riboflavin
depletion-repletion model, whereas the product fermented
with the non¿riboflavin-producing strain did not show
this beneficial effect. Conclusions: Consumption of such
products with increased levels of riboflavin on a
regular basis may help prevent deficiencies of this
essential vitamin.
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| 11 |
CARRERA SILVA, ANTONIO, LeBlanc, J.G., SILVESTRONI,
AURELIO, PIARD, JEAN-CHRISTOPHE, SAVOY DE GIORI, GRACIELA,
SESMA, FERNANDO A thermostable alpha-Galactosidase
from Lactobacillus fermentum CRL722 genetic characterization
and main properties. Current Microbiology. , 2006.
| Palabras
clave: biotechnology, Lactobacillus, microbial enzymes,
microbiology, food microbiology, lactic acid
bacteria |
Referencias
adicionales: Alemania/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03438651.
ABSTRACT The
alpha-Galactosidase (alpha-Gal) enzyme, which is encoded
by the melA gene, hydrolyzes alpha-1,6 galactoside
linkages found in sugars such as raffinose and
stachyose. These alpha-galacto-oligosaccharides
(alpha-GOS), which are found in large quantities in
vegetables such as soy, can cause gastrointestinal
disorders in sensitive individuals since monogastric
animals (including humans) do not posses alpha-Gal in
the gut. The use of microbial alpha-Gal is a promising
alternative to eliminate alpha-GOS in soy derived
products. Using degenerate primers, the melA gene from
Lactobacillus (L.) fermentum CRL722 was identified. The
complete genomic sequence of melA (2,223 bp) and of the
genes flanking melA were obtained using a combination of
PCR based techniques, showing strong similarities with
the alpha-Gal gene of thermophilic microorganisms. The
alpha-Gal gene from L. fermentum CRL722 was cloned and
the protein purified from cell-free extracts of the
native and recombinant strains using various techniques
(ion exchange chromatography, salt precipitation,
SDS-PAGE and ultra-filtration); Its main biochemical
properties were determined. The enzyme was active at
moderately high temperatures (55ºC) and stable at wide
ranges of temperatures and pH. The thermostable
alpha-Gal from L. fermentum CRL722 could thus be used
for technological applications such as the removal of
alpha-GOS found in soy products. The complete melA gene
could also be inserted in other microorganisms which can
survive in the harsh conditions of the gut in order to
degrade alpha-GOS in situ. Both strategies would improve
the overall acceptability of soy-derived products by
improving their nutritional value.
| |
9.1.3 Artículos resumidos publicados en
revistas científicas
| 1 |
LeBlanc, J.G., SESMA, F, SAVOY DE GIORI,
G Characterization of a-Galactosidase and
Identification of melA gene of Lactobacillus fermentum CRL
722. Biocell. , v.27, p.121 - 121, 2003.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT The use of
microbial alpha-galactosidase (alpha-gal), which
hidrolizes alpha-1,6 galactoside links is a promissing
alternative to eliminate alpha-galactooligosaccharides
(alpha-GOS) in soy derived products. These often pass
through the small intestine (SI) and reach the large
intestine where they are fermented, producing gases that
can cause physiological problems in sensitive
individuals. The goal of this study was the
characterization of a-gal and the identification of the
structural gene (melA) of L. fermentum CRL722. alpha-gal
activity was determined in cell free extract of CRL722
and its kinetic parameters were studied (pH and
temperature). melA was identified by PCR using
degenerate primers and used as a probe in Southern
hibridazation were a 2.8kbp band was identified. a-gal
shows high activity between 30 & 50ºC and between pH
4.5 & 6.0. A 550bp fragment was amplified and showed
strong identity (91%) with other melA.This gene will be
introduced in lactic acid bacteria that colonize the SI
in order to create a probiotic strain capable of
eliminating alpha-GOS in vivo.
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| 2 |
SILVESTRONI, A, CONNES, C, LeBlanc, J.G., PIARD, JC,
SESMA, F, SAVOY DE GIORI, G Galactosides metabolism
of L. plantarum, Genes and their function: Regulation is the
key. Biocell. , v.27, n.Supl, p.48 - 48, 2003.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT In this study
we present evidence that Lactobacillus plantarum has
sugar metabolism functional genes but fail to metabolize
these carbohydrates probably because they lack a crucial
step of their metabolic pathway. In L. plantarum
ATCC8014, a 7.5 Kb gene cluster involved in galactosides
metabolism was identified and sequenced. Their relevant
genes, an alpha¿galactosidase (melA) and
alpha-galactosides permease (rafP) were cloned and
expressed in heterologous hosts showing enzymatic
activity and lactose transport, not present in the
native strain. Using the cloned genes, the alpha-Gal
activity was evidenced in different E. coli strains and
Lactococcus lactis, while functional lactose transport
was demonstrated in E. coli. The metabolic capacity of
two L. plantarum strains were compared as was the
complete genome region encoding the melA and rafP genes
at the nucleotide and amino-acid level. Only one of
these strains was able to grow on melibiose and lactose.
However, sequence comparison showed no relevant
differences, suggesting that regulatory genes could be
responsible for these divergent results. This comparison
provides another good example that genes ¿are live and
are functional¿ only in a specific genetic
environment.
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| 3 |
LeBlanc, J.G., SYBESMA, W, SESMA, F, HUGENHOLTZ, J, SAVOY
DE GIORI, G Bioavailability of Folates Produced by
Engineered Lactic Acid Bacteria. Biocell. , v.28, n.1,
p.47 - 47, 2004.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT Folic acid
participates in numerous metabolic reactions and its
deficiency can cause physiological manifestations such
as anemia, abortions and neurological diseases. Wistar
rats were used to assess the bioavailability of folates
produced by and accumulated in living lactic acid
bacteria. Folic acid deficient Wistar rats were fed live
L. lactis NZ9000 genetically engineered to produce
folates intracellularly with short glutamyl tails, long
polyglutamyl tails or with a mixture of both in a
depletion - repletion model. After completion of the
repletion phase, folate levels were determined in liver,
spleen, kidney, serum, plasma and erythrocytes. Growth
was also followed during the depletion and repletion
phases. The accumulation of folates in various organs
and the reversion of megaloblastic anemia showed that
the genetically modified bacteria were able to counter
folate deficiency. Also, the glutamyl tail length did
not affect the bioavailability of folates and no
secondary effects were observed. The results are
promising for further research aimed at the
commercialization of fermented foods with increased
folate levels.
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| 4 |
CARRERA SILVA, A, LeBlanc, J.G., SILVESTRONI,
A Genetic Characterization of melA in Lactbacillus
fermentum CRL722. Biocell. , v.28, p.58 - 58, 2004.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT The use of
microbial a-galactosidasa (alpha-Gal), which hidrolyzes
alpha-1,6 galactoside links is a promising alternative
to eliminate non-digestible
alpha-galacto-oligosaccharides (alphaGOS) found in
vegetable products such as soy. These alpha-GOS can
cause gastrointestinal disorder in sensitive
individuals. The objective of this study was to
characterize the melA gene which codes for alpha-Gal in
Lactobacillus fermentum CRL722. A fragment of the melA
gene from L. fermentum CRL722, previously identified by
PCR, was cloned and sequenced. This same fragment was
used as a marker in DNA hybridation studies (Southern)
to select appropriate genomic fragments used in the
creation of genomic libraries. The identification of
recombinant clones was performed using colony
hybridation techniques. Positive clones will be used in
the goal of identifying the complete genomic sequence of
the melA gene. The complete gene will then be amplified
and inserted in probiotic microoganisms which would then
be able to degrade alpha-GOS in situ.
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| 5 |
LeBlanc, J.G., SESMA, F, SAVOY DE GIORI,
G Nutraceutical Production by Lactic Acid Bacteria:
Evaluation of Riboflavin, Folates and a-Galactosidase.
Biocell. , v.29, n.Suppl, p.62 - 62, 2005.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT The
consumption of functional foods containing
nutraceuticals should be encouraged since these foods
provide more than simple nutrition; they supply
additional physiological benefit to the consumer. Lactic
acid bacteria (LAB) are ideal candidates for the
production of these beneficial compounds because of
their history of safe use in the food industry. Native
and engineered LAB were studied because of their
capacity to produce B vitamins (folates and riboflavin)
and the enzyme a-galactosidase (alpha-Gal). Using animal
models, Lactococcus lactis was shown to be able to
reverse megaloblastic anemia, increase biological levels
of folates and riboflavin in blood and organs, and
eliminate most physiological manifestations associated
with deficiencies of these vitamins. Lactobacillus
fermentum CRL 722, a high alpha-Gal producing strain,
was used to reduce the non-digestible sugars (alpha-GOS)
found in legumes such as soybeans. This strain was
capable of eliminating the flatulence associated with
these alpha-GOS. These results should open the door to
many applications in the development of both new food
products with enhanced nutritional value and probiotic
preparations with well-demonstrated in vivo
activity.
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| 6 |
LeBlanc, J.G., SESMA, F, SAVOY DE GIORI,
G Production of a-Galactosidase in the Small
Intestine by Lb. fermentum CRL 722. Biocell. , v.29,
p.107 - 107, 2005.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT The use of
microbial alpha-galactosidase (alphaa-Gal), which
hydrolyzes alpha-1,6 galactoside links is a promissing
alternative to eliminate a-galactooligosaccharides
(alpha-GOS) in soy derived products. These often pass
through the small intestine (SI) and reach the large
intestine where they are fermented, producing gases that
can cause physiological problems in sensitive
individuals. The goal of this study was the evaluate de
capacity of Lb. fermentum CRL722 to produce alpha-Gal in
the SI. Rats were fed cell free extracts or live cells
of CRL722 and the a-Gal activity was determined in
different compartments of the SI (duodenum, jejunum, and
ileum). A short lived alpha-Gal activity was detected in
the small intestine. The short duration and variability
in the detected alpha-Gal was determined to be the
result of hostile components found in these intestinal
compartments. This short lived alpha-Gal activity might
be able to prevent certain gastrointestinal disorders
associated to soy product consumption. The evaluation of
the gas reduction capacity of Lb. fermentum CRL722 in
rats fed soymilk is currently underway.
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| 7 |
LeBlanc, J.G., CARRERA SILVA, A, SESMA, F, SAVOY DE GIORI,
G Biochemical Charaterization of a Recombinant
a-Galactosidase from Lactobacillus fermentum CRL 722.
Biocell. , v.30, p.172 - 172, 2006.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT The use of
microbial alpha-galactosidase (alpha-Gal) which
hydrolyzes alpha-1,6 galactoside links is a promising
alternative to eliminate alpha-galactooligosaccharides
(alpha-GOS) found in soy-derived products. These sugars
often pass through the small intestine and reach the
large intestine where they are fermented by the
intestinal microbiota, producing gases that can cause
physiological problems in sensitive individuals. The
goal of this study was to characterize the alpha-Gal of
Lb. fermentum CRL722 produced by E.coli. The alpha-Gal
gene was amplified using degenerate primers, sequenced
and cloned into E. coli. The recombinant enzyme was
purified and compared to the a-Gal from the original
strain (CRL722), both being active in a wide range of pH
and temperatures and in the presence of various ions.
The complete gene will now be amplified and inserted in
probiotic microorganisms which would then be able to
degrade alpha-GOS in situ in the gastrointestinal tract
or use to produce novel fermented foods.
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| 8 |
VALDEZ, JC, LeBlanc, J.G., AJMAT, C, ABBAS, L, FIAD, L,
LORENTE, C, VALVERDE, M, HARO, MI Purification of
Nuclear RNP For Clinical And Diagnostic Application in a
Autoimmune Experimental Model. Biocell. , v.30, n.1,
p.205 - 205, 2006.
Referencias
adicionales: Argentina/Inglés. Medio de divulgación:
Impreso; ISSN/ISBN: 03279545.
ABSTRACT Mixed
connective tissue disease (MCTD) is an autoimmune
disorder associated with anti-ribonuclearprotein
(U1-snRNP) antibodies. The aim of this study was to
obtain RNP to induce an experimental model (in mice) and
for use in ELISA assays. Materials and methods:
Purification of RNP: Blobel and Potter's methods was
used for the collection of the nuclei of rat liver. The
RNP was purified by ultracentrifugation and by
fractionated precipitation. The molecular weight of the
isolated protein was determined by SDS-PAGE. ELISA
assays: 96 well plates were sensitized with 1 g RNP in
100 l per well. We used MCTD patients' sera as positive
controls and normal individuals' sera as negative
controls. Sera of all induced animals were tested.
Results and conclusions: the molecular weight of
purified RNP was compatible with one fraction of U-1
snRNP (45 kDa) and was reactive with the MCTD patients'
sera. Most animals inoculated with the RNP antigen were
highly reactive, others only somewhat. Non-inoculated
mice were all negative.
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