Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis

The purpose of this study was to investigate the deoxycholic acid (DCA) reduction by Bifidobacterium pseudocatenulatum G4 at in vitro conditions with the emphasis of its bile salt deconjugation ability and antagonistic activity against 7α-dehydroxylating bacteria. B. pseudocatenulatum G4 showed anta...

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Main Author: Rasti, Babak
Format: Thesis
Language:English
English
Published: 2009
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/5736/
http://psasir.upm.edu.my/id/eprint/5736/1/FSTM_2009_6_abstract.pdf
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author Rasti, Babak
author_facet Rasti, Babak
author_sort Rasti, Babak
building UPM Institutional Repository
collection Online Access
description The purpose of this study was to investigate the deoxycholic acid (DCA) reduction by Bifidobacterium pseudocatenulatum G4 at in vitro conditions with the emphasis of its bile salt deconjugation ability and antagonistic activity against 7α-dehydroxylating bacteria. B. pseudocatenulatum G4 showed antagonistic activity against Clostridium scindens and C. hiranonis at colonic pH (5.7, 6.2 and 6.8), with highest activity (4mm inhibition zone) at pH 5.7 against C. hiranonis. Growth rates of B. pseudocatenulatum G4 (time required for the initial absorbance at zero time to increase by 0.3 units), decreased in the presence of 2.0% oxgall compared to absence of oxgall. Effect of B. pseudocatenulatum G4 on pH reduction was measured; B. pseudocatenulatum G4 reduced pH from 6.8 to 3.9 in TPY broth supplemented with 0.1% and pH 3.74 in TPY broth without oxgall (control), compared to pH 5.28 in TPY broth supplemented with 2.0% oxgall. This results showed oxgall exert inhibitory effect on pH reduction by B. pseudocatenulatum G4. Bile salt hydrolase (BSH) activity, which is the measurement of enzyme activity responsible for bile salt deconjugation, was quantified by high pressure liquid chromatography (HPLC) assay. B. pseudocatenulatum G4 gave deconjugation rate (disappearance of conjugated bile acid) in TPY broth supplemented with 0.25 mM (the highest concentration in colon) and 5.0 mM (the highest concentration in small intestine) of all 6 different conjugated bile acids (TCA, GCA, TCDCA, GCDCA, TDCA, and GDCA). Generally B. pseudocatenulatum G4 deconjugated glycoconjugated bile acids in higher amount compare to tauroconjugates. The percentage of deconjugation activity was higher in TPY medium supplemented with 0.25mM bile acids compared to TPY broth with 5.0mM bile acids. On other hand, pH 6.2 was observed as the optimum pH for BSH activity. Full factorial statistical design was used to evaluate the effects of three factors (pH, B. pseudocatenulatum G4 concentrations and Clostridiums) with different levels and interactions between them, on DCA production. Statistical analysis for results of the in vitro experiment showed that total DCA concentration produced by C. scindens and C. hiranonis in the presence of B. pseudocatenulatum G4 and low pH, were lower than the control group with highest pH and in the absence of B. pseudocatenulatum G4.
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spelling upm-57362013-05-27T07:24:47Z http://psasir.upm.edu.my/id/eprint/5736/ Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis Rasti, Babak The purpose of this study was to investigate the deoxycholic acid (DCA) reduction by Bifidobacterium pseudocatenulatum G4 at in vitro conditions with the emphasis of its bile salt deconjugation ability and antagonistic activity against 7α-dehydroxylating bacteria. B. pseudocatenulatum G4 showed antagonistic activity against Clostridium scindens and C. hiranonis at colonic pH (5.7, 6.2 and 6.8), with highest activity (4mm inhibition zone) at pH 5.7 against C. hiranonis. Growth rates of B. pseudocatenulatum G4 (time required for the initial absorbance at zero time to increase by 0.3 units), decreased in the presence of 2.0% oxgall compared to absence of oxgall. Effect of B. pseudocatenulatum G4 on pH reduction was measured; B. pseudocatenulatum G4 reduced pH from 6.8 to 3.9 in TPY broth supplemented with 0.1% and pH 3.74 in TPY broth without oxgall (control), compared to pH 5.28 in TPY broth supplemented with 2.0% oxgall. This results showed oxgall exert inhibitory effect on pH reduction by B. pseudocatenulatum G4. Bile salt hydrolase (BSH) activity, which is the measurement of enzyme activity responsible for bile salt deconjugation, was quantified by high pressure liquid chromatography (HPLC) assay. B. pseudocatenulatum G4 gave deconjugation rate (disappearance of conjugated bile acid) in TPY broth supplemented with 0.25 mM (the highest concentration in colon) and 5.0 mM (the highest concentration in small intestine) of all 6 different conjugated bile acids (TCA, GCA, TCDCA, GCDCA, TDCA, and GDCA). Generally B. pseudocatenulatum G4 deconjugated glycoconjugated bile acids in higher amount compare to tauroconjugates. The percentage of deconjugation activity was higher in TPY medium supplemented with 0.25mM bile acids compared to TPY broth with 5.0mM bile acids. On other hand, pH 6.2 was observed as the optimum pH for BSH activity. Full factorial statistical design was used to evaluate the effects of three factors (pH, B. pseudocatenulatum G4 concentrations and Clostridiums) with different levels and interactions between them, on DCA production. Statistical analysis for results of the in vitro experiment showed that total DCA concentration produced by C. scindens and C. hiranonis in the presence of B. pseudocatenulatum G4 and low pH, were lower than the control group with highest pH and in the absence of B. pseudocatenulatum G4. 2009 Thesis NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/5736/1/FSTM_2009_6_abstract.pdf Rasti, Babak (2009) Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis. Masters thesis, Universiti Putra Malaysia. Bifidobacterium - Clostridium - Case studies English
spellingShingle Bifidobacterium - Clostridium - Case studies
Rasti, Babak
Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title_full Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title_fullStr Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title_full_unstemmed Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title_short Effects of Bifidobacterium Pseudocatenulatum G4 on Clostridium Scindens and Clostridium Hiranonis
title_sort effects of bifidobacterium pseudocatenulatum g4 on clostridium scindens and clostridium hiranonis
topic Bifidobacterium - Clostridium - Case studies
url http://psasir.upm.edu.my/id/eprint/5736/
http://psasir.upm.edu.my/id/eprint/5736/1/FSTM_2009_6_abstract.pdf